Around 5.4 million years ago, two rivers flowed across present-day Turkey and Syria and into the Mediterranean Sea — and eventually, they would merge to form the Euphrates River, new research suggests. The merged river would play a pivotal role in the development of early human civilizations in the Fertile Crescent.

Scientists revealed that the Paleo-Karasu and Paleo-Murat rivers discharged into the Mediterranean Sea until 5.33 million years ago, and tectonic shifts altered their paths around 3.6 million years ago, after a period when both rivers emptied onshore. The Paleo-Murat River changed course first, and the Paleo-Karasu River was rerouted 800,000 years later. Both waterways combined to flow southeast into the Persian Gulf by roughly 1.6 million years ago, according to the new study.

"The modern landscape onshore, along with buried sediments offshore, still preserves clear signs of the ancient Euphrates River," said study first author Andrew Madof, a senior geologist at the oil and gas corporation Chevron. "If the Palaeo-Murat and Palaeo-Karasu rivers had not switched course and merged when they did, it is unclear whether the Fertile Crescent would have formed in the way it did," he told Live Science in an email.

Often referred to as the "cradle of civilization," the Fertile Crescent is a boomerang-shaped region in Western Asia that stretches from present-day Egypt to southeastern Iraq. Its eastern branch, known as Mesopotamia, contains the Tigris and Euphrates rivers. These two rivers created an oasis of fertile soil in an otherwise arid region, which helped ancient civilizations such as the Sumerians and Assyrians flourish some 6,000 years ago.

Despite the Euphrates playing a central role in the success of these early civilizations, the origins of the 1,900-mile-long (3,000 kilometers) river have until now remained enigmatic. Some researchers previously proposed that the Euphrates evolved from a single river that flowed into the Mediterranean Sea or into ancient lakes in what is now Turkey, while others suggested it evolved from a river ending somewhere on the Arabian Peninsula.

But in the new study, published Monday (June 1) in the journal Nature Geoscience, Madof and his colleagues showed that the Euphrates was born from the marriage of two rivers, rather than from a single waterway.

The researchers used seismic data, maps of the land surface, and satellite data to reconstruct the Euphrates' geological history. They identified 5 million to 6 million-year-old river deposits buried off the coast of Lebanon and compared them to previously documented river deposits of a similar age off the coast of Turkey. These deposits revealed two ancient waterways: the Paleo-Karasu and Paleo-Murat.

These rivers flowed into the Mediterranean Sea during the Messinian salinity crisis, a period of about 700,000 years when tectonic processes caused most of the sea to dry up. The Mediterranean refilled 5.33 million years ago, submerging the grooves and sediments that the two rivers left on the seabed. It was those remnants that the new study uncovered.

"A useful way to think about this is that we were tracing the buried 'footprints' of the ancient Euphrates offshore and connecting them to where those footprints reappear on land," Madof said.

Tectonic shifts involving mountain-building episodes, faulting processes and earthquakes moved the Paleo-Karasu and the Paleo-Murat around 3.6 million years ago, so the researchers had to piece together the clues on land.

"Where these ancient river channels crossed faults, the landscape behaved like a conveyor belt that had shifted sideways," Madof said. "By measuring how much the river was offset and how fast the fault moves, we could estimate when this motion occurred."

The team also modeled sediment transport in the Paleo-Karasu and Paleo-Murat rivers to estimate the rivers' size and the extent of their drainage areas. The team found that the Paleo-Karasu was larger than the modern Nile River before it merged with the Paleo-Murat to form the modern Euphrates 1.6 million years ago.

Some stretches of the Paleo-Karasu and Paleo-Murat rivers changed very little, while others were completely rerouted. The position of these rivers likely influenced the routes mammals took when they migrated out of Africa and through the Levant by determining water availability, Madof said.

Understanding how the Euphrates formed helps us to better understand "how large-scale changes in water distribution can reshape landscapes and influence the conditions needed to support life," he noted.

Editor's Note: This story was updated on June 3 at 11:53 a.m. ET to update Andrew Madof's title, correct the date when the Paleo-Karasu and Paleo-Murat rivers stopped flowing into the Mediterranean Sea, and clarify that only the Paleo-Karasu River was bigger than the modern Nile River.

When Earth first formed around 4.5 billion years ago, it was a ball of molten rock. Over time, heavier elements, like iron and nickel, sank to the planet's center, forming the Earth's early core.

Today, Earth's core remains an incredibly hot and dense sphere deep inside our planet. It consists of a liquid outer core, which starts at around 1,800 miles (2,900 kilometers) below Earth's surface and extends for 1,400 miles (2,200 kilometers). There is also a solid inner core, which begins at around 3,200 miles (5,150 km) below ground, with a radius of roughly 758 miles (1,220 km).

But just how hot is Earth's core? And how did scientists figure it out, if they can't go that deep underground?

Thanks to a combination of techniques, scientists have estimated that the temperature of the Earth's core is about as hot as the surface of the sun: It reaches around 9,000 to just over 10,000 degrees Fahrenheit (roughly 5,000 to over 5,500 degrees Celsius). This temperature comes from the boundary between the inner and outer core, which is thought to be the hottest part of the core.

However, this temperature was not measured directly. Instead, it is inferred via experiments and theories that scientists have of the composition of the core.

Earth's center is composed primarily of iron, roughly 85%, alloyed with nickel and other lighter elements; this material is in liquid form in the outer core and solid in the inner core. Scientists deduced these properties from a mix of laboratory measurements of iron alloys at high pressures, analyzing the composition of meteorites, and understanding how seismic waves bend or disappear as they travel through the planet's interior.

Because Earth's outer core is made mostly of liquid iron, temperatures in this region must be higher than iron's melting temperature. At the planet's surface, the melting point of pure iron is 2,800 F (1,538 C). But this number doesn't take into account the "enormous pressures" of the deep interior, Quentin Williams, a mineral physicist at the University of California, Santa Cruz, told Live Science. Increasing pressures boost the melting point of iron and most other substances, which explains why the inner core is very hot, but remains solid due to its high pressure.

To determine the melting temperature of iron at astronomical pressures, scientists have conducted a number of experiments to simulate this environment. Some studies have squeezed a piece of iron between two sharpened diamonds (called diamond anvil cells) to generate high pressures while a laser heated the iron to high temperatures. Others have hit pieces of iron with high-velocity projectiles or shock-creating rays to simulate crushing pressures. The results from those experiments were then plotted and extrapolated to the pressures at the boundary of the inner and outer core, which led to the estimates ranging from around 9,000 to just over 10,000 F.

"To some extent, what we know about the Earth['s] core is all an educated guess," Shichun Huang, a geology professor at Sun Yat-sen University in China, told Live Science. Many mechanisms, such as how the solid inner core crystalizes into a solid, are still a mystery.

Hot from the beginning

All of this heat hints at our planet's unique history. When Earth formed, all sorts of material got pulled together, including the iron that makes up the core. That "gravitational potential was converted to heat," Huang said.

Further, scientists think that some time during that formation, a Mars-size object hit our protoplanet and that this force deposited a lot of heat into the interior. Some scientists think that radioactive elements, like potassium, uranium and thorium, also contribute to the planet’s internal heat, although whether these elements are actually present in the deep Earth is debated, Huang said.

A hot core also contributes to Earth's ability to host life. In contrast to other planets, Earth's interior has held onto much of its original, primordial heat.

"We're not really good at planet cooling," Williams said, meaning that Earth has held onto much heat from its original formation, unlike other rocky planets in our solar system. As a result, our planet has properties like plate tectonics, which moves pieces of the Earth's surface, bringing up nutrients and creating diverse habitats for life to evolve and thrive. The iron core that is part liquid also generates Earth's magnetic field, which protects the planet and life on it from dangerous solar winds.

"If you care about life, you should care about the inside of the Earth," Huang said. A blazing hot core in the center of our planet is what allows all of us to survive where we are today.

What is Earth made of? Find out with our inside Earth quiz!

​​Antarctica, which is nearly four times the size of the United States, is almost entirely covered by a miles-thick layer of ice.

But the South Pole hasn't always been frozen. So when was the last time Antarctica was ice-free?

This ice cap formed relatively recently in geological terms, experts told Live Science. "I think most people would say 34 million years ago was when the ice sheet first formed in Antarctica," said Eric Wolff, a paleoclimatologist at the University of Cambridge. "[Previously] most of it would have been like northern Canada today — tundra and coniferous forest."

Global temperatures are a key factor influencing the extent of ice coverage. Around 50 million years ago, the world was about 25 degrees Fahrenheit (14 degrees Celsius) warmer than it is today, but temperatures steadily decreased over the following 16 million years. By 34 million years ago — a time period known as the Eocene-Oligocene boundary — the climate was 14.4 F (8 C) warmer than it is today.

But what triggered this temperature drop, and was that all it took for the ice sheets to form?

Related: Which is colder: The North or South Pole?

"There are two factors, and probably both were in play," Wolff told Live Science. "One of them is a change in the carbon dioxide concentration of the atmosphere, and the other is the movements of the continents and, in particular, the opening up of the Drake Passage," the strait between South America and Antarctica that connects the South Atlantic with the South Pacific.

The more carbon dioxide that's in the atmosphere, the more heat is trapped and the warmer the planet is.

From about 60 million to 50 million years ago, the carbon dioxide concentration in Earth's atmosphere was really high — somewhere around 1,000 to 2,000 parts per million, or between 2.5 to 5 times today's levels, said Tina van de Flierdt, a geochemist at Imperial College London.

"But we know that the CO2 in the atmosphere came down across that Eocene-Oligocene boundary," she told Live Science. This decrease in atmospheric CO2 would have been accompanied by a cooling of the global climate, she added, probably tipping Earth over a threshold and allowing ice sheets to form.

However, there was also likely localized cooling on the Antarctic continent due to plate tectonics, Wolff said. Around this time, South America and Antarctica finally separated, opening up what's now the Drake Passage.

"This led to what we call a circumpolar current — water going right around Antarctica in a circle," Wolff said. "This isolates Antarctica from the rest of the world and makes it much harder for warm air masses to get across the Southern Ocean and, therefore, makes Antarctica colder."

Plate tectonics also directly influenced carbon dioxide levels, he added. Rock weathering and volcanic activity are both part of the carbon cycle, so over thousands of years, geological processes can shift the balance of gases in the atmosphere.

Although some uncertainty remains, researchers are fairly confident about this transition 34 million years ago thanks to the chemical signatures in rock sediments. Oxygen atoms exist in two forms: oxygen-16 (common oxygen) and oxygen-18 (heavy oxygen). Continental ice contains a higher proportion of the lighter oxygen-16, meaning the oceans — and, therefore, the shells of small sea creatures — contain a higher percentage of oxygen-18 when ice sheets are bigger.

"By looking at the oxygen isotopes in the carbonate shells of small sea creatures in ocean sediments, you see a jump around 34 million years ago, which people take as being because the [lighter] oxygen isotope is going onto the continent of Antarctica," Wolff explained.

As for whether Antarctica could ever be ice-free again, "It's definitely possible, van de Flierdt said. "Planet Earth has done it before. Planet Earth could do it again." While it's unlikely that human activity will lead to the complete melting of the ice sheet, it's important we do everything possible to limit the loss of ice from the Antarctic now, she added. "It's in our hands to avoid the worst-case scenario," van de Flierdt said.

Editor's note: This story was originally published on Sept. 8, 2024.

Planets go through different life stages: They form, evolve and eventually meet an end. But the timelines for these processes differ widely between Earth-like planets and worlds that orbit less-powerful stars.

So, how long do most planets last?

First, it's important to understand the life cycles of planets.

"Planets start off as microscopic dust grains in disks orbiting young stars, and eventually grow by a huge amount through a series of collisions," Sean Raymond, an astrophysicist at the University of Bordeaux in France, told Live Science in an email.

Gas giants, like Jupiter and Saturn, start off as massive rocky and icy cores, and then capture gas from the disk to become giants. Rocky planets like Earth undergo a late phase of giant collisions with other growing planets and smaller objects after the gas disk from the sun had dissipated, Raymond said. However, there is still some debate among scientists about the order in which planets formed.

Defining the "end" of a planet, however, is more complicated. "You could say a planet lasts until it's destroyed," Matthew Reinhold, a planetary scientist at Stanford University, told Live Science. Or, you could define a planet's ending to be when it no longer operates under the same conditions. "You could say, 'This was a world that had these conditions at some point, but now it has changed and has these very different conditions," Reinhold said. "Because I prefer those previous conditions; I consider this planet as having ended.'"

Let's take Earth as an example. Like many others, our planet's lifespan is tied to the evolution of the sun. The sun currently creates heat and light through nuclear fusion at its core — a process in which hydrogen transforms into helium. In about 5 billion years, the sun will run out of hydrogen, at which point it will expand into a red giant and eventually collapse into itself.

"Our Earth will 'die' in multiple ways," Raymond said. "First, the slowly-brightening Sun will make conditions on the Earth unlivable by vaporizing the oceans. Then, Earth may be swallowed by the Sun when it becomes a red giant. Finally, Earth (if it's still around) will be tossed into interstellar space."

According to these calculations, Earth's total lifespan will be about 9.5 billion years.

Earth probably won't live as long as most planets, he noted. That's because, unlike the sun, which is a yellow dwarf star, most stars are red dwarfs that are smaller and cooler than our sun, and they burn fuel much more slowly. "They can last for trillions of years," Reinhold said.

In that case, it might not be the death of the star, but rather an internal process that leads to these planets' demise.

In his work, Reinhold has modeled what might happen to a hypothetical habitable planet orbiting a red dwarf star. Active geology, such as plate tectonics, is considered crucial for habitability because it allows nutrients to move between the planet's mantle and surface and drives the carbon-silicate cycle.

"We want a planet that can stabilize its climate," Reinhold said, and the carbon-silicate cycle is Earth's natural thermostat.

Reinhold found that mantle convection will last somewhere between 30 billion and 90 billion years, while mantle melting might last somewhere between 16 billion and 23 billion years. Although these number ranges are too large to be meaningful, Reinhold said, they suggest that any Earth-like planets orbiting a red dwarf will die of an internal process long before their stars get close to the ends of their lives. And even on the shortest timelines, most rocky planets orbiting red dwarfs will maintain their conditions for billions of years.

Bigger stars have much shorter lifespans, because they use up their nuclear fuel more quickly. So the fate of an inner planet orbiting an A-type white star, for instance, would be tied up to the star's lifespan of 100 million to 1 billion years.

It's also possible for gas giants to lose their atmospheres due to the intense light from their star, Reinhold said, becoming rocky planets. This process depends on how close a planet is to its star, how much energetic radiation the star emits, and how strong a planet's gravity is. "The stronger their gravity, the better they are at holding onto their atmospheres, and the more radiation they get from their star, the more intense the stripping power," Reinhold explained. Depending on those factors, this can take anywhere from millions to billions of years.

The end of the universe

Even when a planet's conditions change over time, the rock itself still exists. But over large timescales, there are different possibilities for its fate as the probability of rare events increases. It may collide with another planet, or be kicked out of its orbit.

"In all of this mayhem over quadrillions of years, the planets that have been kicked away from their stars will be kicked out of the galaxy to wander for eternity in the void," Reinhold said. "What actually seals [its] fate really comes down to the nature of the end of the universe," said Reinhold.

Solar system quiz: How well do you know our cosmic neighborhood?

Tectonic processes and the "ghosts" of past ice sheets are contorting, lifting and pulling Greenland in different directions, new research reveals.

Greenland sits on the North American tectonic plate, which has dragged the island northwest by 0.9 inches (23 millimeters) per year over the past two decades. Researchers have been monitoring this drift for some time, but a new study analyzing satellite data has found that there is far more to the movement and to other deformations than just plate tectonics.

"We get this complicated pattern with twisting, pressure, and tension," said study lead author Danjal Longfors Berg, a postdoctoral researcher specializing in geodesy and Earth observation at the Technical University of Denmark. "The Greenlandic map will slowly lose its accuracy if not updated," he told Live Science in an email.

Berg and his colleagues analyzed data from 58 Global Network Satellite System (GNSS) stations in Greenland that record the island's horizontal and vertical movements, and nearly 2,900 GNSS stations around the North American plate. The researchers entered these data into a model, and when they removed the effect on Greenland of the North American plate, the researchers were left with bedrock deformations — areas where Earth's crust has been stretched or crumpled — that didn't match previous modeling.

In most regions, the movement of landmasses is overwhelmingly controlled by tectonic processes. But Greenland is different, because the island is covered by a giant ice sheet and has a tumultuous glacial past, according to the study, published Aug. 28 in the Journal of Geophysical Research: Solid Earth.

Ice sheets pile enormous weight onto Earth's crust, pressing it down into the mantle — the layer of the planet that sits beneath the crust. The material displaced in the mantle by the sinking crust is pushed out to the sides, creating what is known as a peripheral forebulge, Berg said.

When an ice sheet retreats, the mantle does not return to its original shape immediately. Due to the mantle's gooey consistency, it takes thousands of years for material to flow back into the dent created by the loaded crust. In other words, the mantle "has a very long memory," Berg said.

The mantle beneath and around Greenland is still adjusting to changes in ice cover since the peak of the last ice age about 20,000 years ago, which explains why data show the island deforming. Specifically, it appears that Greenland is reacting to the retreat of the Laurentide Ice Sheet, which covered large swathes of North America until about 8,000 years ago.

The Laurentide Ice Sheet created a peripheral forebulge beneath parts of Greenland. This forebulge is gradually flattening, pulling areas of southern Greenland downward and towards Canada, Berg said. Researchers already knew this, he said, but the new results reveal that the rate of deformation is higher than most modeling suggests.

The Greenland Ice Sheet also plays a role in the island's twisting motions. Meltwater from the ice sheet has contributed 13.5 feet (4.1 meters) of the 430 feet (130 m) of sea level rise recorded over the past 20,000 years, Berg said. That means Greenland has lost an incredible amount of ice, which in turn has triggered a response in the mantle that is separate from the effect of the Laurentide Ice Sheet, he said.

Melting of the Greenland Ice Sheet has accelerated in recent years due to climate change. Past and present-day declines in ice mass over Greenland have had the same general effect on the island, pushing the bedrock outward and up, Berg said.

The results offer the most detailed picture of Greenland's movements to date, particularly of how the island is scrunching up in some places, according to a statement. The findings are important because they provide new insights into how polar regions may react to climate change and thereby skew the maps we use for navigation and surveys, Berg said.

"Together with other type[s] of satellite observations it can give new information about the past ice sheets and the structure of the Earth," he added.

Fragments of the hellish, lava-covered "proto-planet" that existed before Earth 4.5 billion years ago have survived unaltered in ancient rocks, groundbreaking new research reveals.

The fragments contain telltale potassium signatures not seen in any other rocks or meteorites that scientists have examined so far, according to a study published Oct. 14 in the journal Nature Geoscience. Theoretically, these signatures should have disappeared in the giant collision that formed the moon, but it now appears that a handful survived this cataclysmic event and subsequently withstood the test of time.

"This is maybe the first direct evidence that we've preserved the proto Earth materials," study co-author Nicole Nie, an assistant professor of Earth and planetary sciences at MIT, said in a statement. "This is amazing because we would expect this very early signature to be slowly erased through Earth's evolution."

Proto-Earth was a sizzling ball of bubbling, molten rock that formed from cosmic dust and meteorites in the early solar system. But after 100 million years, our early planet was rocked by a catastrophic impact with a Mars-size planet called Theia. The collision was so powerful that it completely scrambled proto-Earth's interior and blasted off a chunk of Earth's precursor that became the moon.

Theia also delivered vast amounts of new material to proto-Earth, irreversibly altering the chemistry of Earth's precursor and transforming it into a planet more like today's. Over the eons, plate tectonics emerged, and material was repeatedly recycled into Earth's interior. As a result, scientists didn't think it was possible to find intact fragments of proto-Earth in modern rocks.

Researchers have previously found rocks with unusual chemical signatures linked to the element ruthenium that possibly predate the moon-forming impact, but these signatures could equally have originated after the collision, so they don't provide robust evidence, Philip Carter, a computational planetary scientist and astrophysicist at the University of Bristol in the U.K., told Live Science.

The newly discovered potassium signatures, on the other hand, are the most definitive evidence to date that bits of proto-Earth still exist, Carter, who was not involved in the study, added. "The most reasonable explanation is that this is material that has survived from before the impact," he said.

Clues in potassium ratios

The newfound signatures are subtle imbalances in the proportion of different versions, or isotopes, of the element potassium compared with other materials on Earth. Potassium has three naturally occurring isotopes — potassium-39, potassium-40 and potassium-41 — that have the same number of protons but different numbers of neutrons, which gives them different atomic masses.

Potassium-39 and potassium-41 dominate in Earth's rocks, with potassium-40 existing only in trace amounts. In previous work, the new study's authors found abnormal quantities of potassium-40 in meteorites, which record changing conditions in the solar system over long periods of time. This suggested that potassium isotopic anomalies can mark out material that predates the formation of modern Earth.

For the new study, Nie and her colleagues sampled ancient rocks from a handful of locations that previously yielded weird ruthenium signatures, including outcrops in Greenland, Canada and Hawaii. To pick out any potential potassium isotopic anomalies, the researchers powdered the rocks and dissolved them in acid. They then isolated the potassium in the samples and measured the ratio of different potassium isotopes using a mass spectrometer.

The rocks were deficient in potassium-40 compared with the amounts in other materials on Earth, the researchers found. To work out whether this potassium isotopic anomaly could date back to proto-Earth, the team carried out computer simulations. Using data from every known meteorite that has landed on Earth, they modeled the effects of these impacts and the moon-forming impact on Earth's composition through the delivery of new material over the eons.

The simulations revealed that the collision with Theia, in particular, dumped lots of potassium-40 onto Earth, explaining the higher amount of potassium-40 we see in rocks today. "You have to add a significant amount of material to … change the overall signature and the overall isotopic composition of potassium in most rocks," Carter said. "Most of that change comes from the moon-forming impact itself — that's the argument that they use in the paper."

The potassium signature discovered in the ancient rocks is different to that which Nie and her colleagues previously found in meteorites, so it's unlikely that meteorites could have created Earth's current potassium profile after the moon-forming impact. "It's really saying that the proto-Earth formed from material that is isotopically distinct from any of the meteorites we have," Carter said.

The moon-forming impact is the only known event that could have significantly increased the amount of potassium-40 in rocks on Earth, Carter said. This means that the potassium-40-deficient rocks from Greenland, Canada and Hawaii are older than the moon-forming impact and date back to proto-Earth, he said.

Martin Schiller, an associate professor of geochemistry at the University of Copenhagen in Denmark who was not involved in the study, agreed that the results are convincing. "The really surprising/novel observation is that the potassium isotope signature [in the ancient rocks] cannot be explained with a mixture of primitive meteorites," he told Live Science in an email.

The results imply that remnants of proto-Earth survived geological processes like the constant mixing of the mantle, the layer of Earth that sits beneath the crust.

"It's a signature that's been preserved separate from the rest of Earth's rocks for some significant portion of time," Carter said. And there is likely more of this proto-Earth material hiding at the base of the mantle, he said. "We're only getting the little bits that come up."

Earth's surface is a turbulent place. Mountains rise, continents merge and split, and earthquakes shake the ground. All of these processes result from plate tectonics, the movement of enormous chunks of Earth's crust.

This movement may be why life exists here. Earth is the only known planet with plate tectonics and the only known planet with life. Most scientists think that's not a coincidence. By dragging huge chunks of crust into the mantle, Earth's middle layer, plate tectonics pulls carbon from the planet's surface and atmosphere, stabilizing the climate. It also pushes life-fostering minerals and molecules toward the surface. All of those factors add up to a place where life thrives from ocean abysses to towering peaks.

But researchers don't know why or when plate tectonics started, making it hard to determine how essential this process was to the evolution and diversification of life. Some think plate movement fired up as little as 700 million years ago, when simple multicellular life already existed. Others believe only single-celled organisms reigned when Earth's plates first cracked apart.

In fact, as new methods allow scientists to look ever-deeper into the past, some are now arguing that plate tectonics emerged very soon after Earth's formation — perhaps predating life itself. If this hypothesis is true, it may suggest that even the most primitive life evolved on an active planet — and that means plate tectonics could be an essential ingredient in the search for alien life.

"The only way we can reliably see a long-term history is on our own planet," said Jesse Reimink, a geoscientist who studies early Earth history at The Pennsylvania State University. "We really need to understand the life cycle of a planetary body before we can do a lot with the exoplanet data."

Destruction of evidence

Only Earth has jigsaw-like tectonic plates that crash together and pull apart like bumper cars. The other rocky planets in the solar system have a single, rigid shell of crust — a geological arrangement that scientists call "stagnant lid" or "single lid" tectonics.

In plate tectonics, pancake-like chunks of brittle crust and upper mantle ride on the hotter, more mobile mantle below. New crust forms at midocean ridges, where gaps between separating plates create space for magma from the mantle to rise. In a geologic balancing act, dense oceanic crust is destroyed at subduction zones, where one plate slides under another. The oldest known bit of oceanic crust, located in the Mediterranean, dates to just 340 million years ago, making it far too young to be useful for pinpointing when plate tectonics arose.

Continental crust is lighter than oceanic crust and floats above the destruction wrought by subduction. But still, very little remains from Earth's early days, and what is left is eroded and warped. Fewer than 7% of rocks on the surface today are older than 2.5 billion years. Go back before 4.03 billion years, to the Hadean eon, and the rock record has completely vanished. The first half billion years of Earth's life left not a single bit of basalt behind.

Because of this constant planetary recycling, the oldest incontrovertible evidence of plate tectonics — rocks formed solely in subduction zones — dates back only around 700 million years. Another strong bit of evidence, pieces of oceanic crust pushed up on continental crust during subduction initiation, emerged globally around 900 million years ago. In this geological time frame, multicellular animals, such as sea sponges and comb jellies, were just emerging.

Some geoscientists think plate tectonics has been operating only since that time. But more suspect that plate tectonics emerged earlier, in the Archean eon, which ran from 4 billion to 2.5 billion years ago. The evidence is based largely on chemical analyses of rocks. For example, around 3 billion years ago, there are hints of an increasing amount of crust melted and reformed rather than forming directly from mantle rocks. Around 3.8 billion years ago, a shift in the chemistry of Earth's oldest minerals suggests a change from a stable, long-lived crust to a shorter-lived, more modern-looking crust, perhaps indicating the start of subduction. Though there is no single agreed-upon date, the Archean looks promising as a time when big geological changes were happening on Earth.

"It points to a really important transition," said Nadja Drabon, an Earth and planetary scientist at Harvard University who led the study indicating the switch to shorter-lived crust.

A handful of sand

Whenever tectonics began, geoscientists agree that it probably helped fuel the evolution and complexity of life.

"There could be billions of planets with some kind of primitive life, but the ability to build a radio transmitter or launch a rocket ship requires a certain set of circumstances which are only likely to happen on a planet that has plate tectonics and both oceans and continents," Robert Stern, a geoscientist at the University of Texas at Dallas, told Live Science.

In prehistoric animals, plate tectonic activity has been tied to faster rates of evolution, probably because geological movements split up habitats and create new niches for life to evolve.

Plate tectonics also may have enabled life to recover from devastating mass extinctions. For instance, at the end of the Permian period, a mass extinction driven by carbon-dioxide-spewing volcanic eruptions killed off 90% of species on Earth. Life on the planet ultimately recovered because weathering of continental rocks breaks down carbon-bearing minerals and washes them into the ocean, where marine organisms turn them into reefs and shells that become limestone and are eventually subducted back into the planet's interior. When the atmosphere goes haywire, tectonics gradually shifts Earth back into an environment that's more conducive to life.

While nearly all geoscientists agree with the idea that, without plate tectonics, life on Earth might be limited to primitive organisms, a small group of researchers is now suggesting that plate tectonics could have emerged even earlier — perhaps contributing to the origin of life itself by bringing minerals that support life from the planet's interior to the crust.

This is tricky territory, pushing researchers back before 4 billion years ago, into the Hadean eon. The only direct evidence of the first 500 million years of Earth's existence is the presence of zircons, minerals that survive melting at mantle temperatures and pressures. Though the rocks once containing these minerals have melted away, the zircons — which are smaller than grains of sand — remain.

"They're teeny-tiny, and we just throw the kitchen sink at them trying to get every last little piece of information we can get from them," Drabon told Live Science.

These zircons from the Hadean are sparse; all of them found worldwide could likely fit in a thimble. Yet this handful has shown that Earth had an ocean as early as 4.4 billion years ago — just 200 million years after the planet formed and not long before the ancestor of all life today existed. By as early as 600 million years after Earth formed, according to a study published in June, the planet had both land and fresh water.

To some researchers, this suggests Earth's crust may have been recycling in the Hadean. Water weakens the crust, creating the potential for breakage and thus subduction, said Jun Korenaga, a geophysicist at Yale University. Because water is necessary for plate tectonics, the question becomes, "Why can't we have plate tectonics if we had surface water?" Korenaga said.

In experimental work published in 2023, researchers melted rocks at high pressures and found that conditions that mimic subduction create rocks similar to Earth's oldest rocks. Korenaga also argues that plate tectonics is the only effective way to reduce the amount of carbon dioxide in early Earth's atmosphere from the levels found on Venus to the more moderate concentrations that existed by the beginning of the Archean on Earth.

Intriguingly, another important event happened during the Hadean that makes Earth undeniably different from its rocky neighbors: About 100 million years after Earth first coalesced, a planet-size body slammed into it, thoroughly shattering and melting both bodies and flinging off the material that would become the moon. A paper published earlier this year modeled this impact and found that the mixing of the two bodies could have created plumes of hot material in Earth's mantle that may have kicked off subduction around 200 million years later.

"Why is Earth the only rocky planet to have plate tectonics?" said Qian Yuan, lead author of that paper and a postdoctoral fellow in geodynamics at the California Institute of Technology. "I think the moon-forming giant impact could be the main factor."

But not everyone is convinced by this story. A Hadean start to plate tectonics is an intriguing idea, T. Mark Harrison, a professor emeritus of geoscience at UCLA, told Live Science, but the evidence is still fairly minimal. He worries that geoscientists on all sides of the issue are overconfident in their claims. "But the last thing we need is a new form of groupthink based on, literally, a thimble-full of sand grains," Harrison wrote in an article with the appropriately blunt title "We don't know when plate tectonics began."

Life on other worlds

If plate tectonics fuels life, or even just complex life, the search for other organisms among the stars may lead humanity to a geologically active planet.

Unfortunately, we can't yet detect plate tectonics on far-off exoplanets, said Tobias Meier, an expert on mantle dynamics at the University of Oxford. But in 2021, Meier and his team used thermal data and computer modeling to determine that the rocky exoplanet LHS 3844 b, which sits 49 light-years from Earth, might have an active mantle and moving crust.

LHS 3844 b isn't likely to host life. It orbits very close to its star and has no atmosphere. Half of the planet is in permanent daylight, with a temperature of 1412 degrees Fahrenheit (767 degrees Celsius), while the other is a frigid minus 429 F (minus 273 C) at night. It's this temperature difference between the two sides of the planet that drives mantle motion in LHS 3844 b, Meier and his colleagues reported in 2021. If real, that version of plate tectonics looks nothing like Earth's. But it shows the diversity of planetary geology that could lurk elsewhere in the cosmos.

"In the end, understanding what causes tectonics and whether it could operate on different planets will help us understand whether these planets will be habitable," Meier said.

More powerful telescopes such as the James Webb Space Telescope may lead to better hints of exoplanet geology in the near future. But Earth's close neighbors deserve scrutiny, too, said Craig O'Neill, a geophysicist at Queensland University of Technology in Australia. Venus is right next door, and it's still controversial whether it had tectonics in the past. Understanding its current, single-lid geology could help scientists figure out why the two planets' fates diverged, and whether plate tectonics may explain why one planet hosts life and the other likely doesn't.

"A lot of the development of where we're going to go in plate tectonics is going to come from looking up," O'Neill told Live Science, "rather than navel-gazing in."

Scientists may have just toppled a 100-year-old theory about what holds up the highest mountain range on Earth, new research shows.

The Himalayan mountains formed in the collision between the Asian and Indian continents around 50 million years ago, when tectonic forces squeezed Tibet so hard that the region crumpled and its area shrank by almost 620 miles (1,000 kilometers). The Indian tectonic plate eventually slipped under the Eurasian plate, doubling the thickness of Earth's crust beneath the Himalayas and Tibetan Plateau to the north, and contributing to their uplift.

For a century, the prevailing theory has been that this doubling of the crust alone carries the weight of the Himalayas and the Tibetan Plateau. Research published in 1924 by Swiss geologist Émile Argand shows the Indian and Asian crusts stacked on top of each other, together stretching 45 to 50 miles (70 to 80 km) deep beneath Earth's surface.

But this theory doesn't stand up to scrutiny, researchers now say, because the rocks in the crust turn molten around 25 miles (40 km) deep due to extreme temperatures.

"If you've got 70 km of crust, then the lowermost part becomes ductile… it becomes like yogurt — and you can't build a mountain on top of yogurt," Pietro Sternai, an associate professor of geophysics at the University of Milano-Bicocca in Italy and the lead author of a new study analyzing the geology beneath the Himalayas, told Live Science.

Evidence has long suggested that Arnand's theory is erroneous, but the idea of two neatly stacked crusts is so appealing that most geologists haven't questioned it, Sternai said. Historically, "any data that would come along would be interpreted in terms of a single, double-thickness crustal layer," he said.

Related: Will Mount Everest always be the world's tallest mountain?

However, the new study reveals there is a piece of mantle sandwiched between the Asian and Indian crusts. This explains why the Himalayas grew so tall, and how they still remain so high today, the authors wrote in the paper, published Aug. 26 in the journal Tectonics.

The mantle is the layer of Earth that sits directly beneath the crust. It is much denser than the crust and, therefore, doesn't liquefy at the same temperatures. Meanwhile, the crust is so light and buoyant that it behaves similarly to an iceberg, lifting up higher above Earth's surface the thicker it gets.

Sternai and his colleagues discovered the mantle insert by simulating the collision between the Asian and Indian continents on a computer. The model showed that as the Indian plate slipped beneath the Eurasian plate and started to liquify, blobs of it rose and attached themselves not to the bottom of the Asian crust, but to the base of the lithosphere, which is the rigid outer layer of the planet composed of the crust and upper mantle.

This is fundamental, Sternai said, because it means there is a rigid layer of mantle between the stacked crusts solidifying the whole structure beneath the Himalayas. The two crusts give enough buoyancy to keep the region lifted, while the mantle material provides resistance and mechanical strength. "You've got all the ingredients you need to uplift topography and sustain the weight of the Himalayas and Tibetan plateau," he said.

The researchers then compared their results with seismic data and information gathered directly from rocks. The mantle sandwich in the simulation matched previous evidence that Arnand's theory couldn't explain, study co-author Simone Pilia, an assistant professor of geoscience at King Fahd University of Petroleum and Minerals in Saudi Arabia, told Live Science.

"Things actually start to make sense now," Pilia said. "Observations that seemed to be enigmatic are actually now more easily explained by having a model where you have crust, mantle, crust."

The study presents strong evidence for this model, but contradicting Arnaud's 100-year-old theory is controversial because it has been so widely adopted, Pilia said.

"I think the authors are correct that this is controversial," Adam Smith, a postdoctoral research associate in numerical modeling at the University of Glasgow in Scotland who was not involved in the study, told Live Science in an email. "All prior work generally agreed that all the material beneath the Himalayas came from the crust."

But the results are still plausible, and they explain a number of geological oddities in the Himalayas, Smith said. "The authors run lots of simulations using different thicknesses for all of the layers, and they seem to always get this bit of mantle sandwiched between the crust of the two plates."

Douwe van Hinsbergen, a professor of global tectonics and paleogeography at Utrecht University in the Netherlands who wasn't involved in the study, disagreed that the results are controversial. "It's a nice new finding and an elegant interpretation," he told Live Science in an email. "If a continent shoves below another continent, you’d expect a sandwich that consists from top to bottom of crust and mantle lithosphere of the upper (Tibet) plate, and then the crust of the lower (Indian) plate."

What's inside Earth quiz: Test your knowledge of our planet's hidden layers

Around 1.1 billion years ago, the oldest and most tectonically stable part of North America — called Laurentia — was rapidly heading south toward the equator. Laurentia eventually slammed into Earth's other landmasses during the Grenville orogeny to form the supercontinent Rodinia.

Laurentia's path during that period is known, thanks to paleomagnetism. By tracing the orientation and magnetism of rocks in the lithosphere, scientists can approximate the relative position and movement of Laurentia leading up to Rodinia's formation.

The rocks along Lake Superior in northern Wisconsin and Michigan are especially important for tracing Laurentia's movement. These rocks — dominated by red sandstones, siltstones, and minor conglomerates — were deposited during extensive sedimentation caused by the North American Midcontinent Rift and are rife with iron oxides like hematite. Hematite can acquire magnetization when it is deposited, which records where the rock was in relation to Earth's poles at the time.

Unfortunately, the existing paleomagnetic record is marred by a gap between 1,075 million and 900 million years ago, limiting our understanding of how, when, and where Rodinia formed.

To fill this data gap, Fuentes et al. collected new samples from the Freda Formation near Lake Superior, which formed in floodplain environments an estimated 1,045 million years ago. The authors combined these data with stratigraphic age modeling to estimate a new, sedimentary paleopole, or the position of the geomagnetic pole at a particular time in the past.

Previous studies indicate that for 30 million years, sometime between 1,110 million and 1,080 million years ago, Laurentia moved from about 60°N to 5°N at a rate of 30 centimeters (12 inches) per year — faster than the Indian plate's collision with Eurasia pushing up the Himalayas. This study showed that over the following 30 million years, Laurentia's progress slowed to 2.4 centimeters (1 inch) per year as it crossed the equator.

The paleocontinent's slowdown during Freda Formation deposition coincides with the onset of the Grenville orogeny. The results confirm that a stagnant single-lid regime — in which the lithosphere behaves as a single, continuous plate rather than multiple independent plates — was not in effect during this interval.

This article was originally published on Eos.org. Read the original article.

Diamonds aren't always colorless; they can also be blue, yellow, green and even pink. But what makes these jewels come in varied hues?

At their base, diamonds are made of a single element: carbon. "It's just pure carbon," forged into treasure under very high pressures, said Luc Doucet, a senior research fellow of geology at Curtin University in Australia. They typically form deep beneath Earth's surface, more than 100 miles (161 kilometers) down in the planet’s mantle. Here, the pressure and temperature are extreme enough for the carbon atoms to bind together in a tight lattice.

After forming, diamonds need to rise to the surface very quickly for their lattice to stay intact. This usually happens when volcanic eruptions eject the rocks up from the depths. If a diamond stays in the deep, they may melt or transform into graphite over the course of millions of years.

"We're actually very lucky that we even get to find them, because they have to then be expelled from the deep Earth," said Gabriela Farfan, the Coralyn Whitney curator of gems and minerals at the Smithsonian National Museum of Natural History.

The majority of diamonds are colorless. But there are a couple of ways normal diamonds can turn into "fancy color diamonds," Farfan said.

First, like all minerals, diamonds can get impurities when they form. These flaws are elements other than carbon that get integrated to the gem's structure. But because carbon molecules are so small and very tightly packed, very few elements can get introduced into diamonds. "There aren't very many elements that can substitute in," Farfan said.

Related: Which are rarer: diamonds or emeralds?

However, there are a few exceptions. Nitrogen, carbon's neighbor on the periodic table, can sneak into the diamond's lattice, making yellow or orange diamonds. Boron, another element with a small atomic radius, can make striking blue diamonds, such as the famous Hope Diamond.

Radioactive radiation can also make diamonds green. This can happen if the neighboring rocks near the gems have uranium, which can "expel atoms to create vacancies" in the diamond's structure, Farfan said.

Diamonds can also get their color through structural deformities. This is how pink and red diamonds form. These stones get these hues because their carbon lattices become warped when they are deep inside the planet.

A diamond has to be squished in just the right way to take on a pinkish or bright-red hue. "It's kind of like Goldilocks," Doucet said. If a diamond is put under too much pressure, it can turn brown; if it's not under enough pressure, it stays colorless. "There are a lot of brown diamonds, and very, very few pink diamonds," Doucet noted.

Interestingly, because of how pink and red diamonds form, scientists can analyze these gems and understand exactly where and when in Earth's crust they originate. The geologic processes of an area leaves behind a signature in a diamond’s deformities. "So in this way, pink [and red] diamonds are the only ones you could potentially try and trace back to a geographic region," Farfan said.

For instance, Doucet studied pink diamonds from the Argyle mine in Western Australia, one of the largest diamond mines in the world. By looking at the gems' structure, he and his colleagues pinpointed that the stones were made during the breakup of Earth's first supercontinent 1.3 billion years ago. The results were published in a 2023 study in the journal Nature Communications.

Farfan pointed out that the Winston Diamond, which was recently put on display at the Smithsonian National Museum of Natural History, is bright red. And based on an analysis published in the journal Gems & Gemology, it likely came from somewhere in Venezuela or Brazil.

Studying these fancy color diamonds can also be a useful tool for science. They can help researchers understand what was going on inside Earth and how carbon cycles shifted throughout the planet's history, Doucet said.

These diamonds are special because "Earth produced them under such unique circumstances,” Farfan said. "It's just a miracle that it even exists in the first place."

A giant blob of abnormally hot rock beneath the Appalachian Mountains formed when Greenland separated from North America around 80 million years ago, new research suggests.

Scientists previously thought that this hot zone, known as the Northern Appalachian Anomaly, was left over after North America broke away from Africa 180 million years ago, but this theory does not stand up to new scrutiny, according to the study, published Wednesday (July 30) in the journal Geology.

"This thermal upwelling has long been a puzzling feature of North American geology," lead author Thomas Gernon, a professor of Earth science at the University of Southampton in the U.K., said in a statement. "It lies beneath part of the continent that's been tectonically quiet for 180 million years, so the idea that it was just a leftover from when the landmass broke apart never quite stacked up."

Instead, the new findings indicate that the hot blob, which sits 125 miles (200 kilometers) deep and stretches 220 miles (350 km) across New England, appeared around 80 million years ago, when what are now Greenland and Canada were breaking apart. The results suggest that such blobs occasionally form in continent breakups, with possible knock-on effects for mountains, volcanoes and ice sheets.

Gernon and colleagues described how hot blobs form in a study published last year in the journal Nature. Hot blobs are created when material from Earth's mantle rises to fill gaps in the crust left by rifting. This material eventually cools and becomes so dense that it sinks, or "drips," setting off chain reactions in the mantle that the researchers called "mantle waves."

There may be special conditions required for mantle waves to form, Gernon told Live Science in an email, including a steep temperature gradient where the dripping material enters the mantle. This means that not all continent breakups create mantle waves, Gernon said.

Related: North America is 'dripping' down into Earth's mantle, scientists discover

For the new study, the researchers used direct geological observations and computer simulations to model plate tectonics and geodynamics. They simulated the initiation of a hot blob 1,120 miles (1,800 km) northeast of the Appalachians and found that geologic processes pushed the blob southwest at a rate of 12 miles (20 km) every million years. These results were consistent with previous estimates, according to the statement.

The team's simulations showed that the hot blob may have helped to uplift the Appalachian Mountains when it got there, solving the long-standing question of why the Appalachians remain so high despite major erosion over the past 20 million years.

"Heat at the base of a continent can weaken and remove part of its dense root, making the continent lighter and more buoyant, like a hot air balloon rising after dropping its ballast," Gernon explained in the statement. "This would have caused the ancient mountains to be further uplifted over the past million years."

Hot blobs elsewhere could explain why mountains with a geology similar to the Appalachians are still standing, Gernon said. These blobs could also explain rare volcanic eruptions that bring diamonds to Earth's surface, according to the statement.

Looking at Greenland's blob

The study focused mostly on the Northern Appalachian Anomaly, but the researchers also examined its "twin" — a hot blob currently sitting beneath north-central Greenland. That anomaly was born in the same continental breakup event, but on the other side of the rift, according to the statement. The team noted that it creates heat currents beneath the Greenland Ice Sheet that influence how the ice moves and melts today.

"Ancient heat anomalies continue to play a key role in shaping the dynamics of continental ice sheets from below," Gernon said. "Even though the surface shows little sign of ongoing tectonics, deep below, the consequences of ancient rifting are still playing out."

The Northern Appalachian Anomaly is still on the move, and the researchers estimate that it will continue on its path to reach New York in 10 million to 15 million years.

Once the hot blob leaves the Appalachians, Earth's crust there will settle again, Gernon said. "In the absence of further tectonic or mantle-driven uplift, erosion would continue to wear down the mountains, gradually lowering their elevation," he said.

Overall, the results reveal that continent breakups and other major geological events can continue to influence the planet for thousands, and even millions, of years, the researchers said in the statement.

"The idea that rifting of continents can cause drips and cells of circulating hot rock at depth that spread thousands of kilometers inland makes us rethink what we know about the edges of continents both today and in Earth's deep past," study co-author Derek Keir, an associate professor of Earth science at the University of Southampton and the University of Florence in Italy, said in the statement.

The highest point on Earth's surface is the top of Mount Everest, which towers more than 29,000 feet (8,800 meters) above sea level. But what's the lowest point on land?

The lowest spot on dry land are the banks of the Dead Sea in the Middle East. These lie about 1,300 feet (430 m) below sea level, according to the National Oceanic and Atmospheric Administration (NOAA).

The banks of the Dead Sea are the lowest point on dry land but not the deepest point on Earth's surface. That distinction belongs to the Challenger Deep in the Mariana Trench, a point in the Pacific Ocean that reaches about 35,876 feet [10,935 m] below the planet's surface.

The precise depth of the Dead Sea's surface can vary daily. According to NASA, on a hot, dry summer day, the water level can drop as much as 1 inch (2 to 3 centimeters) because of evaporation.

The Dead Sea, which is not really a sea but a large saltwater lake, is 47 miles (76 kilometers) long and up to 11 miles (18 km) wide. The "Dead Sea" was named by monks, who noticed that life seemed to be absent from the salty water, NOAA noted.

The Dead Sea lies along the Dead Sea Fault, which spans about 600 miles (1,000 km) from the Red Sea to the Taurus Mountains in Turkey and started forming nearly 20 million years ago, according to a 2006 study in the journal Earth and Planetary Science Letters. The fault helps form the boundary between the African tectonic plate to the west and the Arabian one to the east. NASA notes that the Dead Sea lies in the Great Rift Valley, which is currently ripping the African continent apart.

"The Dead Sea fault is primarily a transform fault, similar to the San Andreas Fault in California, where two plates are moving next to each other," Rob Pockalny, an associate marine research scientist at the University of Rhode Island, told Live Science.

Related: How many tectonic plates does Earth have?

Both sides of the fault are moving northward, "but the eastern side moves a bit faster, about 5 millimeters [0.19 inches] per year," marine geophysicist Zvi Ben-Avraham, director of the Minerva Dead Sea Research Center at Tel Aviv University in Israel, told Live Science. In comparison, "the San Andreas Fault moves 10 times faster."

Previously, researchers suggested the Dead Sea formed essentially because of a zigzag in the Dead Sea Fault. If the Dead Sea Fault was perfectly straight, one side could slide relatively smoothly next to the other. However, if the fault had a zigzag in it, then as one side slid past the other, a gap would form in the zigzag area where both sides of the fault were pulling apart. Such a "pull-apart basin" could have steep walls, helping to explain why the Dead Sea is so low in elevation, Pockalny said.

However, the standard model of pull-apart basins suggest they become long before they become deep. In contrast, the basin of the Dead Sea is significantly wider than it is deep, Ben-Avraham said. The sediment that makes up the floor of the southern Dead Sea "extends down close to 15 kilometers [9.3 miles], and that part of the basin is only about 10 kilometers [6 miles] wide."

Instead, Ben-Avraham and his colleagues suggest the Dead Sea is a "drop down basin." As both sides of the fault slid past each other, they spread apart a bit, "but then an isolated chunk of basalt detached from them and dropped down starting about 4 million years ago," Ben-Avraham said. "So the Dead Sea basin became deeper while its other dimensions stayed fixed."

Determining which model of the Dead Sea's formation might be correct is challenging "because these motions are very slow," Ben-Avraham said. "Understanding what is going on in this part of the crust in real time is very, very difficult and expensive."

The Pacific Ocean is by far the world's largest ocean, more than five times wider than our moon. But why is the Pacific so big?

Covering about 63 million square miles (163 million square kilometers) — more than 30% of Earth's surface — all of the world's continents could fit inside the Pacific basin, according to the National Oceanic and Atmospheric Administration (NOAA). The Pacific, which holds more than half of the free water on Earth, is also our planet's deepest water body, extending to a depth of more than 36,000 feet (11,000 meters) at Challenger Deep in the Mariana Trench, NOAA noted.

The predecessor of the Pacific Ocean was Panthalassa, or the Panthalassic Ocean, which was once Earth's only ocean. This world-spanning superocean existed when all of Earth's continental land was united in the supercontinent Pangaea.

"Panthalassa was the proto-Pacific," Susanne Neuer, founding director of the School of Ocean Futures at Arizona State University in Tempe, told Live Science. "The Pacific is essentially what remains of Panthalassa."

Oceans and continents past and present rest on top of tectonic plates, the giant slabs of rock that make up Earth's rigid outer shell. These plates are regularly on the move, sometimes colliding into each other, sometimes pulling apart from one another. About 230 million years ago, such motions led Pangaea to start breaking up.

"What became North America and Eurasia began to pull apart from what became South America and Africa and Antarctica and Australia," Adriane Lam, an assistant professor of Earth sciences at Binghamton University in New York, told Live Science.

Related: Do the Pacific Ocean and the Atlantic Ocean mix?

Eventually, Pangaea split apart. In the gap that emerged between the continents, the Atlantic Ocean was born. "The Atlantic is growing about two to three centimeters each year, or about an inch," Neuer said. "That doesn't sound like much, but when you multiply that by millions of years, it's a lot."

As the continents making up Pangaea were pushed apart, Panthalassa shrunk. At the "subduction zones" where these continental plates slid over Panthalassa's oceanic plates, the "Ring of Fire" emerged, a zone infamous for volcanoes and earthquakes surrounding what is now the Pacific Ocean, Neuer explained.

A 2016 study in the journal Science Advances revealed that about 200 million years ago, the Pacific Plate, the tectonic plate that now underlies the Pacific Ocean, was born at the junction of three tectonic plates under Panthalassa, dubbed Farallon, Phoenix and Izanagi.

"The most modern analogy with what happened with the Pacific can be found today with the Afar triple junction in East Africa, where you have three plates meeting together — the Nubian, Somali and Arabian," Lam said. "But at the Afar triple junction, those plates ultimately failed to pull apart. With the Pacific triple junction, those three plates succeeded, forming the Pacific Plate."

As the Pacific Plate expanded, it displaced these three older plates. The Izanagi Plate was pushed under Asia. Nearly all of the Farallon Plate was driven beneath North America, although remnants of it remain off North America's west coast. And "the Phoenix Plate is nothing but a small piece between the southern tip of South America and the Antarctic Peninsula, the area of ocean called the Drake Passage," Lam said.

Although the Pacific is currently the world's largest ocean, "it's getting smaller" as the Atlantic gets bigger, Lam noted. However, at 41 million square miles (106 million square kilometers), the Atlantic is still much smaller than the Pacific. And a 2024 modeling study predicts that the Atlantic will start shrinking in about 20 million years.

For Lam, the Pacific Ocean is one of a kind, she said, noting its size, geological history and geological complexity. "The Pacific is the most amazing ocean basin of all."

Mariana Trench quiz: How deep is your knowledge?

Earth's magnetic field and oxygen levels are inextricably linked, new research suggests.

The strength of the geomagnetic field has gone up in lockstep with the percentage of oxygen in Earth's atmosphere over the past 540 million years, a new study finds — but it remains unclear if one of these influences the other, or whether other unknown factors explain the link.

"This is the first discovery we've ever had to establish the link between the geomagnetic field and the oxygen level," lead author Weijia Kuang, a senior scientist in the Geodesy and Geophysics Laboratory at NASA's Goddard Space Flight Center, told Live Science.

Earth's magnetic field and oxygen levels have increased more or less in parallel since the start of the Cambrian period (541 million to 485.4 million years ago), and both factors spiked between 330 million and 220 million years ago, the results indicate.

The research could help to narrow down requirements for life on other planets, Kuang and study co-author Ravi Kopparapu, a planetary scientist at the NASA Goddard Space Flight Center, said in a joint video interview.

It may be that the geomagnetic field controls oxygen levels, or vice versa — but there is another possible scenario, which is that both factors are related to a third geochemical or geophysical process that the researchers haven't yet pinpointed, Kuang said.

For the new study, scientists used two independent datasets spanning the past 540 million years. One of the datasets showed atmospheric oxygen, derived from multiple indicators such as the abundance in sediments of fossilized charcoal, which remains after wildfires and gives clues about how much oxygen was available at a given time. The other dataset showed the strength of the geomagnetic field, derived from magnetic information that is recorded in ancient rocks and sediments. The researchers plotted these datasets against each other and found there was a strong correlation between them.

If the geomagnetic field controls oxygen levels, its influence would likely be due to the protection it offers Earth's atmosphere against space weather. Previous research indicates that the geomagnetic field can prevent or reduce the escape or erosion of atmospheric molecules. The magnetic field also shields life on the planet, including plants that produce oxygen, from X-ray and extreme ultraviolet radiation.

If, in contrast, atmospheric oxygen levels dictate the strength of Earth's magnetic field, then plate tectonics would play a central role. Plate tectonics is the process that continuously recycles Earth's crust into the mantle, which is the planetary layer that covers Earth's liquid outer core.

Earth's geomagnetic field originates from currents in the outer core, so it's possible that the recycling of crustal material and oxygen into the mantle could impact the lower mantle, which could then affect the geomagnetic field, Kuang said.

Related: Did plate tectonics give rise to life? Groundbreaking new research could crack Earth's deepest mystery.

"Plate tectonics [...] will definitely impact the thermal and the dynamical conditions at the base of the mantle where it borders the liquid outer core," he said. "On the other hand, plate tectonics also impacts the cycling of chemicals and other elements from the interior to the surface, which certainly will impact oxygenation, or the production of oxygen."

It's more likely that the geomagnetic field affects oxygen levels, rather than the other way round, Kuang said. That's because scientists know the geomagnetic field originates deep inside the planet and propagates to Earth's surface and into space. "The other direction is less well understood," he said.

The third possible scenario is that another, separate process is pushing the geomagnetic field and oxygen levels in the same direction over time. The study's authors don't know what that process might be yet, but a spike that exists in both datasets may hold the answer.

'A very enticing mechanism'

The spike coincides with the existence of the ancient supercontinent Pangaea, which formed about 320 million years ago and broke up about 195 million years ago. Due to the massive tectonic rearrangements involved, supercontinents might be the missing link between Earth's magnetic field and oxygen levels — but the evidence for this is still very tentative at this point, Kuang and Kopparapu cautioned.

"This is one of the conjectures we didn't really put out strongly in our paper, but it is something we think is a very enticing mechanism for us to pursue," Kuang said. The reason the researchers held back with this idea is that they have robust data for only one supercontinent — Pangaea — and not the ones that came before, he said.

"There seems to be some eye-sight correlation between oxygen and magnetic field and all the other supercontinents," Kopparapu said. "However, we don't have reliable data for oxygen [going farther back] than 540 million years, and so we are unable to make that kind of a conclusion for [farther back in time] and past supercontinents."

The researchers are already working on the next step, which is to search for other geophysical and geochemical factors that might link to the geomagnetic field and oxygen levels. For this, the authors say communication and collaboration between scientists is of paramount importance.

"One single mind cannot comprehend the whole system of the Earth," Kopparapu said. "We're like kids playing with Legos, with each of us having a separate Lego piece. We're trying to fit all of it together and see what's the big picture."

What's inside Earth quiz: Test your knowledge of our planet's hidden layers

Scientists have uncovered fresh evidence that Venus is not dead — geologically speaking. Venus and Earth are similar in size and were bombarded by comparable amounts of water billions of years ago. This shared origin has long fueled one of planetary science's biggest questions: Why did Venus become a hellish, uninhabitable world while Earth flourished into a cradle for life?

Now, more than three decades after NASA's Magellan spacecraft mapped Venus' surface, scientists have found signs of hot material rising from the planet's interior, indicating that its crust is still being sculpted from within.

The findings, published May 14 in the journal Science Advances, add to a growing body of evidence that Venus, despite lacking Earth's plate tectonics, may share more internal dynamics with our planet than scientists previously thought.

Related: Molecule responsible for robbing Venus of its water may finally have been identified

"This research has provided a new and important insight into the possible subsurface processes currently shaping the surface of Venus," Gael Cascioli, an assistant research scientist at NASA's Goddard Space Flight Center in Maryland who co-led the new study, said in a statement.

"We could hardly believe our eyes"

The latest evidence focuses on dozens of large, ring-shaped features on Venus' surface. These features, known as coronae, form when plumes of hot rock rise from deep within the mantle, pushing the crust upward. As the surface cools and collapses, a circular structure is left behind. Cascioli and his team simulated several formation scenarios for these features and compared their results with data from Magellan.

The predicted and actual data aligned so closely for some coronae that "we could hardly believe our eyes," Cascioli told Scientific American.

Of the 75 coronae they resolved in the Magellan data, 52 appear to sit above buoyant mantle plumes, according to the new study.

"We can now say there are most likely various and ongoing active processes driving their formation," Anna Gülcher, a planetary scientist at the University of Bern in Switzerland who co-led the new study, said in the statement. "We believe these same processes may have occurred early in Earth's history."

Venus hosts hundreds of such coronae, many of which are found in areas where the planet's crust is particularly thin and heat from below is high. Recent research simulated how different rock types behave under Venus' extreme conditions. The findings suggest that the planet's crust may break off or melt once it reaches around 40 miles (65 kilometers) thick, and in many areas, it is likely even thinner.

"That is surprisingly thin, given conditions on the planet," Justin Filiberto, deputy chief of NASA's Astromaterials Research and Exploration Science Division in Houston, who co-authored the study about Venus' crust, said in a different statement.

This shedding or melting of the crust not only helps regulate Venus' surface structure but could also recycle water and other materials back into the planet's interior, potentially fueling volcanic activity and influencing its atmosphere, Filiberto explained. "It resets the playing field for how the geology, crust and atmosphere on Venus work together," he said.

These recent findings offer testable predictions for upcoming missions to Venus that will gather direct data about the planet's crust and geology to refine existing models.

Scientists aim to pinpoint areas of surface activity using data from NASA's VERITAS mission, which will map the planet's surface at a resolution two to four times higher than previous missions. Another NASA mission, DAVINCI, slated for 2029, will focus on studying Venus' atmosphere and surface chemistry, while the European Space Agency's EnVision mission, targeted for 2030, will provide high-resolution surface mapping.

These missions will deliver "a level of detail that could revolutionize our understanding of Venus's geology and its implications for early Earth," study co-author Suzanne Smrekar, a planetary scientist at the Jet Propulsion Laboratory in California, said in the statement.

Iran's folded rocks are rugged mountain ridges and valleys to the southwest of the Caspian Sea. They are an extension of the Greater Caucasus mountain belt, which also stretches along Russia's border with Georgia and Azerbaijan.

The folded rocks sit at the intersection of Asia and Europe, where major tectonic forces converge. The rocks are formed of countless sedimentary layers, which were upturned and creased into the landscape we see today during the initial collision between the Arabian and Eurasian tectonic plates. The timing of this collision is hotly debated, with estimates ranging from 10 million to 50 million years ago.

"A tectonic collision between Eurasia and Arabia over millions of years compressed these colorful rock layers, bending them into large folds," NASA officials wrote on the social platform X in January 2024.

The Arabian and Eurasian plates are still converging, and recent research indicates a chunk of oceanic crust that separated the two plates before they collided is now being torn apart under Iraq and Iran. The Neotethys oceanic plate appears to be pulling the region down from below, resulting in an unusual accumulation of sediment at the surface.

Related: North America is 'dripping' down into Earth's mantle, scientists discover

Iran's folded rocks are colorful, with vibrant terracotta, greenish and blueish bands that are the result of different sedimentary layers deposited over time. These layers were eroded over millions of years after the initial tectonic collision, exposing the underlying rocks' alternating colors and textures.

Satellite images of the folded rocks reveal the extent to which the landscape was bunched together over the eons. Scientists at NASA's Jet Propulsion Laboratory colored one such image with infrared to show the various rock layers, as well as vegetation and the human-built Zanjan-Tabriz freeway, which cuts through the folded rocks and connects the cities of Tehran and Tabriz.

Another satellite image from NASA's Earth Observatory highlights the intricacy of Earth's surface in this region and shows the Qezel Ozan River, which hugs the southeast corner of the folded rocks and supplies water for agriculture in the area.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

The split between South America and Africa 135 million years ago was a fiery affair, new research finds.

The continental breakup spewed over 3.8 million cubic miles (16 million cubic kilometers) of magma that still persists as volcanic rocks in South America, in Africa, and on the seafloor of the Atlantic Ocean. In some places in Namibia and Angola, these volcanic rock layers are up to 0.6 mile (1 kilometer) thick.

The new study — which combines multiple sources of previously collected data from South America, Africa and the ocean floor — finds that the main magma eruptions occurred between 135 million and 131 million years ago, with a peak around 134.5 million years ago. This improved understanding of the eruption timing could give researchers a better idea of what triggered the breakup as well as its impacts on the climate.

"We get some extinctions and also some perturbations on the climate" around 134.5 million years ago, said study lead author Mohamed Mansour Abdelmalak, a geologist and geophysicist at the University of Oslo in Norway. Knowing the precise age of the magma helps tie the eruptions to these events.

The new research also finds evidence of a "thermal anomaly" beneath what was then southern Pangaea, the supercontinent that began breaking up 200 million years ago into the continents present today. This breakup was slow, with South America and Africa splitting 135 million years ago, and North American not completing its schism with Europe until 55 million years ago. Previous research has suggested that the breakup of southern Pangaea happened, in part, because of what's known as a mantle plume — a rising column of superhot rock from Earth's middle layer, the mantle. These plumes melt and thin the continental crust from below.

The new research hints that the thermal anomaly that helped separate South America and Africa may have been caused by that mantle plume, Abdelmalak told Live Science, but the hypothesis is still controversial.

"We don't have many samples, so we don't know exactly if this volcanism is related to the mantle plume," he said. Samples are particularly needed from the rock that now sits under the deep ocean off the coast of Argentina and Uruguay, where very little deep-sea drilling has been done, he said.

There is a modern-day example of a mantle plume leading to outpourings of magma in Iceland, however, Abdelmalak said. There, the Mid-Atlantic Ridge — which is still pulling apart at a rate of 0.8 to 2 inches (2 to 5 centimeters) a year — is on land. This land has been formed by the Iceland hotspot, which studies suggest is driven by a plume reaching deep into the mantle.

Additional deep rock samples from Africa and the deep ocean could help researchers understand how much magma erupted during the split between Africa and South America and how the eruptions affected the climate, Abdelmalak said. In most large eruptions, the climate warms because volcanoes spew huge amounts of greenhouse gases. But there was a period of cooling 134 million years ago, which may have been because the magma that erupted broke down, or weathered, quickly. In weathering, rocks break down and chemically react with the air, pulling carbon dioxide out of the atmosphere.

The findings appear in the May issue of the journal Earth-Science reviews.

As the name suggests, China's Rainbow Mountains are multicolored formations in the northwest of the country. The landscape in this region is otherworldly, with vibrant bands that look like they were spray-painted onto the rocks.

The Rainbow Mountains are located in the foothills of the rugged Qilian mountains and likely formed around the same time as the Himalayas, approximately 50 million years ago, according to NASA's Earth Observatory. Land that was once relatively flat was scrunched up and folded into jagged terrain when the Indian tectonic plate collided with the Eurasian plate. This was because these plates have a similar rock density, so neither could slip beneath the other to form a subduction zone, according to the U.S. Geological Survey (USGS).

But the basis for the mountains' rainbow pattern was laid long before the epic collision.

Related: Massive tectonic collision causing Himalayas to grow may also be splitting Tibet apart

The Rainbow Mountains are made of sandstone and siltstone — sedimentary rocks that form when sand and silt, respectively, are compacted and cemented together over long periods of time. These rocks — with their bands of different colors — were deposited before the Himalayas formed.

The colorful bands are the result of iron and other trace minerals in the stone. Each band has a different composition that determines its pigment. For example, the deep red stripes are rich in iron oxides, the yellow layers contain abundant iron sulfide and the green bands hold more chlorite and iron silicates, according to a 2016 article in Forbes.

Iron and other minerals accumulated in the rock while the sand and silt grains were still cementing together. Groundwater circulating in the pore space between the grains deposited the minerals, coating each grain and further gluing the rocks together.

The slanted bands we see on the flanks of the Rainbow Mountains today are upturned layers that would have remained buried and horizontal had the Indian and Eurasian plates not smashed into each other. The bunching of the land by plate tectonics was followed by intense erosion, which wiped away any sediment covering the colorful layers. Luckily for modern visitors, there is no vegetation to obscure the striking rainbow pattern.

The Rainbow Mountains are a popular tourist attraction. They are protected as part of the Zhangye Danxia National Geopark, but visitors can climb to the top of the hills and admire the view using wooden stairs and platforms.

Discover more incredible places, where we highlight the fantastic history and science behind some of the most dramatic landscapes on Earth.

Greek authorities have closed schools and deployed emergency crews as a swarm of earthquakes intensifies near the volcanic island of Santorini. Scientists aren't expecting Santorini or other volcanoes in the region to erupt, but they warn more powerful earthquakes could be coming.

People on Santorini began feeling tremors last week as a cluster of underwater earthquakes broke out beneath the Mediterranean's Aegean Sea. These small earthquakes — mostly magnitude 3.5 or less — continued to intensify on Monday (Feb. 3).

The largest earthquake so far was a magnitude 5, which struck 21 miles (34 kilometers) northeast of Santorini at 2:27 p.m. local time (7.27 a.m. EST), according to the University of Athens' earthquake tracking website.

The Greek authorities have responded to the earthquakes by ordering precautionary measures on Santorini and nearby islands, all of which are popular tourist destinations, the Associated Press reported.

Santorini sits on the exposed part of a largely underwater volcano called the Santorini caldera. However, researchers believe the earthquakes there are driven by the movement of plates, or plate tectonics, rather than volcanic activity.

David Pyle, a professor of Earth sciences at the University of Oxford who has studied volcanos in the Santorini caldera, told Live Science that the earthquakes by Santorini are likely caused by a series of faults — or zones where two blocks of rock move or slip against each other. However, he noted that the earthquakes were "unusual."

"The problem with this event is that we've just seen earthquake after earthquake after earthquake," Pyle said. "It's all underwater, and so it's really hard to anticipate what's going to happen next."

Related: Yellowstone National Park earthquake shakes hottest and oldest geothermal area

The Aegean Sea sits on a small plate of crust, which is stretching as the nearby African plate slides beneath the Eurasian plate. Pyle noted that stretching in the Aegean's crust creates stresses that move the faults driving the earthquakes.

This isn't the first time Santorini has experienced a series of small, concentrated earthquakes, known as an earthquake swarm. Magma moving beneath Santorini triggered a swarm around the island in 2011 and 2012, but that event was less severe than the ongoing swarm, which is northeast of the island.

"The area that is being affected is a little larger [than in 2011 and 2012,] the rate at which the detected earthquakes are occurring is also larger, and the focus of the events is outside the Santorini caldera," Pyle said.

Kolumbo volcano

Most of the earthquakes have occurred between another underwater volcano, Kolumbo, which is approximately 4.4 miles (7 kilometers) northeast of Santorini, and the small island of Anydros. While plate tectonics appear to be driving the earthquakes this time, Pyle noted that researchers are unsure whether there's a direct link between the tectonic activity and any potential volcanic activity at Kolumbo.

"We actually don't really know much about the deep systems supplying magma to the volcanos," Pyle said.

Kolumbo volcano last erupted in 1650, triggering a catastrophic tsunami that devastated islands in the region. Santorini was shaped by the earlier Minoan eruption in 1600 B.C., which was one of the largest volcanic eruptions in human history, according to Columbia University's Lamont-Doherty Earth Observatory in New York.

Plate tectonics give rise to Earth's mountain ranges, earthquakes and the long-term movement of continents, and may even have provided the right conditions for life on Earth. But as far as we know, no other bodies in the solar system exhibit plate tectonics today. Why is our world different?

"We don't know for sure," Bradford Foley, a geodynamicist at Penn State, told Live Science. "I think it's still considered one of the great unsolved problems in geophysics today."

Earth's lithosphere — its crust and rigid upper mantle — is split into roughly 15 constantly-moving plates. These plates are perpetually shifting, colliding and pulling apart from one another. Though scientists aren't sure how the lithosphere came to be divided into plates, certain aspects of Earth's geology keep the plate tectonic engine chugging along.

For a planet to sustain plate tectonics, it must have a convective mantle, Foley said. Cold, dense surface material sinks back into the mantle at subduction zones, where one plate slips beneath another, and new material rises up where plates spread apart. Without the convective mantle, there wouldn't be enough energy to move the plates.

But convection on its own isn't enough to guarantee that a planet or moon will exhibit plate tectonics. The lithosphere has to be both thin enough to break into plates in the first place and dense enough for those plates to eventually sink into the mantle, said Geoffrey Collins, a geologist at Wheaton College in Massachusetts.

Related: How many tectonic plates does Earth have?

Interactions between plate boundaries and liquid water might also play a role, said Russell Pysklywec, a geophysicist at the University of Toronto. "When we hydrate these rocks and they go down into the Earth, it actually serves to, for lack of a better explanation, lubricate the rocks a little bit more," Pysklywec told Live Science. "It might be that at subduction zones where the two plates are coming together, and with our liquid oceans, we're actually adding that lubricant in that helps facilitate plate tectonics."

The combination of these factors could explain why Earth is the only planet known to exhibit plate tectonics today. In a 2022 study, Collins and his colleagues found that Jupiter's icy moon Europa had exhibited "plate-tectonic-like" activity in the past: Parts of the moon's icy shell were broken into plates that spread and collided. The warmer water beneath the ice may have buoyed those plates along, but because ice is less dense than water, the plates didn't sink into the oceans the same way Earth's plates sink back into the mantle.

Europa's plate-like behavior also doesn't cover the moon's entire surface. "On Europa, it seems to just be patchy, like there's a little patch happening over here, there's a little patch happening over there, and then it doesn't seem to be happening in between," Collins told Live Science. "The other patchiness is that it's patchy in time, so it appears to turn on and off."

Other planets, such as Mars, adopt a "stagnant lid" configuration. These planets have convective mantles, but the surface isn't broken into plates. "Instead of being broken up into these separate plates that move around with that convective mantle, there's one big plate covering the whole planet," Foley said. "It's like a lid on top of its convective mantle."

But without any other nearby planets exhibiting plate tectonics to compare Earth's system to, it's hard to know precisely what causes a planet to develop plate tectonics, Foley said. "If we had hundreds of rocky planets, and all sorts of different conditions, we could probably empirically figure out what the key factors are. But it's hard to do with just one."

We finally know how a fault that gave rise to Denali, North America's highest mountain, first formed.

According to new research, the Denali Fault is actually an ancient suture mark where two land masses once joined together. Between 72 million and 56 million years ago, an oceanic plate called the Wrangellia Composite Terrane bumped into the western edge of North America and stuck there.

"Our understanding of lithospheric growth, or plate growth, along the western margin in North America is becoming clearer," Sean Regan, a geoscientist at the University of Alaska, Fairbanks and the lead author of a paper published in October in the journal Geology detailing the fault's history, said in a statement.

Massive fault

The Denali Fault is a strike-slip fault, a place where two chunks of continental crust slide past each other. On Nov. 3, 2002, the fault jolted, creating a magnitude 7.9 earthquake that knocked houseboats off their moorings more than 1,500 miles (2,414 kilometers) away in Seattle, according to an article in NASA's Earth Observatory blog.

Regan studied three sections of the fault: The Clearwater Mountains of southeastern Alaska, Kluane Lake in Canada's Yukon Territory, and the Coast Mountains near Juneau. These sites are hundreds of miles apart along the faultline. The sites are spread across about 620 miles (998 kilometers).

Research in the 1990s had suggested that despite this distance, these three fault sections were formed at the same time and place, only to be torn apart later as the two sides of the fault slid against one another. But no one had confirmed that finding.

Stitching of once-distant lands

In an attempt to do so, Regan studied a mineral called monazite at all three locations. This mineral, which is made of rare-Earth elements, changes as the rock hosting it is transformed or bent under pressure or high temperature, giving researchers a way to understand the rock's history.

“We showed that each of these three independent inverted metamorphic belts all formed at the same time under similar conditions," Regan said in the statement. "And all occupy a very similar structural setting. Not only are they the same age, they all behaved in a similar fashion. They decrease in age, structurally, downward."

This decrease in age is an effect of a phenomenon called inverted metamorphism, whereby rocks formed under high temperatures and pressures are found above rocks formed under lower temperatures and pressures — the opposite of the usual pattern, given that the deeper you go in the Earth's crust, the hotter and more pressurized it is. Inverted metamorphism is found in places where tectonic forces have warped the crust and pushed deeper rocks over shallower ones.

The findings reveal that these three regions formed at the same place and time. That place was the terminal suture zone between the North American plate and the Wrangell subplate, a mini tectonic plate that makes up part of the complex jigsaw of the northern Pacific coast.

"We’re starting to recognize those primary features involved in the stitching, or the suturing, of once-distant land masses to the North American plate," Regan said.

Around 700 million years ago, the Earth cooled so much that scientists believe massive ice sheets encased the entire planet like a giant snowball. This global deep freeze, known as Snowball Earth, endured for tens of millions of years.

Yet, miraculously, early life not only held on, but thrived. When the ice melted and the ground thawed, complex multicellular life emerged, eventually leading to life-forms we recognize today.

The Snowball Earth hypothesis has been largely based on evidence from sedimentary rocks exposed in areas that once were along coastlines and shallow seas, as well as climate modeling. Physical evidence that ice sheets covered the interior of continents in warm equatorial regions had eluded scientists — until now.

In new research published in the Proceedings of the National Academy of Sciences, our team of geologists describes the missing link, found in an unusual pebbly sandstone encapsulated within the granite that forms Colorado's Pikes Peak.

Related: 'Golden spike' showing the moment Earth turned into a giant snowball discovered in ancient Scottish rocks

Solving a Snowball Earth mystery on a mountain

Pikes Peak, originally named Tavá Kaa-vi by the Ute people, lends its ancestral name, Tava, to these notable rocks. They are composed of solidified sand injectites, which formed in a similar manner to a medical injection when sand-rich fluid was forced into underlying rock.

A possible explanation for what created these enigmatic sandstones is the immense pressure of an overlying Snowball Earth ice sheet forcing sediment mixed with meltwater into weakened rock below.

An obstacle for testing this idea, however, has been the lack of an age for the rocks to reveal when the right geological circumstances existed for sand injection.

We found a way to solve that mystery, using veins of iron found alongside the Tava injectites, near Pikes Peak and elsewhere in Colorado.

Iron minerals contain very low amounts of naturally occurring radioactive elements, including uranium, which slowly decays to the element lead at a known rate. Recent advancements in laser-based radiometric dating allowed us to measure the ratio of uranium to lead isotopes in the iron oxide mineral hematite to reveal how long ago the individual crystals formed.

The iron veins appear to have formed both before and after the sand was injected into the Colorado bedrock: We found veins of hematite and quartz that both cut through Tava dikes and were crosscut by Tava dikes. That allowed us to figure out an age bracket for the sand injectites, which must have formed between 690 million and 660 million years ago.

So, what happened?

The time frame means these sandstones formed during the Cryogenian Period, from 720 million to 635 million years ago. The name is derived from "cold birth" in ancient Greek and is synonymous with climate upheaval and disruption of life on our planet — including Snowball Earth.

While the triggers for the extreme cold at that time are debated, prevailing theories involve changes in tectonic plate activity, including the release of particles into the atmosphere that reflected sunlight away from Earth. Eventually, a buildup of carbon dioxide from volcanic outgassing may have warmed the planet again.

The Tava found on Pikes Peak would have formed close to the equator within the heart of an ancient continent named Laurentia, which gradually over time and long tectonic cycles moved into its current northerly position in North America today.

The origin of Tava rocks has been debated for over 125 years, but the new technology allowed us to conclusively link them to the Cryogenian Snowball Earth period for the first time.

The scenario we envision for how the sand injection happened looks something like this:

A giant ice sheet with areas of geothermal heating at its base produced meltwater, which mixed with quartz-rich sediment below. The weight of the ice sheet created immense pressures that forced this sandy fluid into bedrock that had already been weakened over millions of years. Similar to fracking for natural gas or oil today, the pressure cracked the rocks and pushed the sandy meltwater in, eventually creating the injectites we see today.

Clues to another geologic puzzle

Not only do the new findings further cement the global Snowball Earth hypothesis, but the presence of Tava injectites within weak, fractured rocks once overridden by ice sheets provides clues about other geologic phenomena.

Time gaps in the rock record created through erosion and referred to as unconformities can be seen today across the United States, most famously at the Grand Canyon, where in places, over a billion years of time is missing. Unconformities occur when a sustained period of erosion removes and prevents newer layers of rock from forming, leaving an unconformable contact.

Our results support that a Great Unconformity near Pikes Peak must have been formed prior to Cryogenian Snowball Earth. That's at odds with hypotheses that attribute the formation of the Great Unconformity to large-scale erosion by Snowball Earth ice sheets themselves.

We hope the secrets of these elusive Cryogenian rocks in Colorado will lead to the discovery of further terrestrial records of Snowball Earth. Such findings can help develop a clearer picture of our planet during climate extremes and the processes that led to the habitable planet we live on today.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

It's one of many unique things about Earth: Unlike every other known planet in the universe, Earth's surface is made up of rigid plates that shift, crash into each other and dive into the planet's interior.

But when did Earth's surface splinter into tectonic plates? And when did those plates start moving? It's an important question because plate tectonics seems to fuel the evolution and complexity of life.

Surprisingly, geologists don't have a good answer for when plate tectonics emerged, and estimates range from 700 million years ago to before 4 billion years ago, when Earth was still in its infancy.

The oldest unambiguous evidence of modern plate tectonics dates to the Neoproterozoic (1 billion to 541 million years ago), Robert Stern, a geoscientist at the University of Texas, Dallas, told Live Science. That's when the geological record reveals plentiful ophiolites — bits of oceanic crust shoved onto continents — and blueschists, which are metamorphic rocks that form in subduction zones, or areas where the plates collide and dive into the planet's interior. Subduction is a feature of plate tectonics, so these widespread rocks show with certainty that plates were crashing into and sliding under one another.

But many geologists think Stern's view is too conservative.

Critics agree that rocks indicative of plate tectonics became widespread for the first time 700 million to 900 million years ago. But these rocks could have existed earlier and been wiped away by time, they suggest.

For example, the Indian subcontinent collided with southern Asia a mere 55 million years ago, and many of those rocks have already eroded away, said Mark Harrison, a professor emeritus of geoscientist at UCLA. "The Tibet-India collision isn't over yet," Harrison told Live Science. If the evidence of tectonics is disappearing even as a plate-to-plate collision is occurring, what hope is there of finding these same rocks from the much more distant past?

Stern argues that there is evidence for a little episode of subduction 1.8 billion years ago that didn't quite take, bolstering his viewpoint that if there had been plate tectonics consistently before about 800 million years ago, it would be clearer in the rock record. (Other scientists see this blip as evidence that plate tectonics was well underway by then.)

Many researchers put the transition to plate tectonics much earlier. There are numerous signs of some kind of geologic shift during the Archean Eon (4 billion to 2.5 billion years ago), with estimates of exactly when ranging from 2.5 billion to 3.8 billion years ago. For example, at least one ophiolite preserved today dates back 2.5 billion years.

Another line of evidence is in the chemistry of the crust. If the crust is brand-new volcanic rock, its chemistry will look much like the mantle from whence it came. If it is remelted and recycled by plate tectonics, this chemistry shifts. An influential 2012 study found that more crust began to be recycled around 3 billion years ago. This could mark the shift to subduction destroying and reworking crust, said study co-author Chris Hawkesworth, an emeritus professor of geosciences at the University of St. Andrews in the U.K..

Research on zircons — minerals that survive even when the rocks around them melt and reform — suggests that Earth's crust shifted earlier, around 3.8 billion years ago. "We start to see zircon structures that start to look more and more like what we see in subduction zones today," study author Nadja Drabon, an Earth and planetary scientist at Harvard University, told Live Science. Crust also became shorter-lived around that time, again suggesting the recycling process of subduction.

But does this transition reflect true plate tectonics? Zircon research published in 2023, which investigated the magnetic field conditions on Earth when the minerals formed, suggests that these grains more or less stayed where they were made until 3.4 billion years ago, hinting that landmasses weren't on the move until that point.

It's possible that different aspects of plate tectonics emerged at different times, Drabon noted. Perhaps subduction started 3.8 billion years ago, but it took time for the continents to start drifting around the globe.

A newer and more controversial idea suggests that Earth developed plate tectonics in the Hadean (4.5 billion to 4 billion years ago). This idea springs from increasing evidence that the newborn Earth was a surprisingly modern-looking place with oceans and continents — a conclusion drawn from zircon research and the chemistry of Earth's oldest surviving rocks. Some studies of Earth's oldest zircons, which date to this mysterious period of geologic history, found that they look remarkably like zircons that form in volcanic arcs over subduction zones today. And theoretical modeling shows it's possible for plate tectonics to exist in Hadean conditions, Jun Korenaga, a professor of Earth and planetary sciences at Yale University, told Live Science.

Every piece of evidence for each of these origin stories comes with weaknesses. For instance, the vast majority of very old zircons come from one location, the Jack Hills in Australia, and might not represent what was happening on the rest of the planet. The oldest rocks might also be weird — perhaps they're still hanging around today because they weren't like all the other rocks on ancient Earth. And you don't want to get in the middle of computer modelers when they're arguing about assumptions of the state of the mantle 4 billion years ago.

"It's shocking to realize there's no consensus view on when [plate tectonics] started," Jesse Reimink, a geoscientist at The Pennsylvania State University told Live Science.

Editor's Note: This story was corrected at 2:40 p.m. EST to correct one mention of an age estimate for the emergence of plate tectonics. It may have emerged as recently as 700 million, not 700 billion, years ago.

Mount Everest is the world's tallest mountain as measured from sea level. But will it hold that title forever?

To answer this question, first we must understand how mountains form and how Mount Everest and the rest of the Himalayas got so tall. One way tall mountains form is when two tectonic plates collide. As one begins to subduct — or move under — the other, crust gets mushed around, upheaved, and turned into mountains.

According to Rob Butler, a geologist at the University of Aberdeen in Scotland, the heights of the mountains that form during these collisions depend on many factors. These characteristics include the thickness of the crust, which is determined by the intensity and length of the tectonic collision, and the crust's temperature, which is determined by its age.

"Think of the crust not as a solid, but as a viscous liquid, like maple syrup," Butler told Live Science. Like cold maple syrup, cold crust is more viscous and, therefore, firmer. So thicker, colder crust can form taller mountains than thinner, warmer crust can.

Other than the thickness and temperature of the crust, the most important factor in determining the height and growth of mountains is erosion.

Related: What's the oldest mountain range in the world? (How about the youngest?)

"It's because erosion is so effective that [the Himalayas] are one of the fastest rising systems of rocks on the planet," Butler said. This is because of a principle called isostasy. Much like a container ship floating in the ocean, the less material that's stacked on Earth's crust, the higher it floats above the mantle, the planet's middle layer.

So the more material that is transported away from a mountain — whether via a river, a glacier or heavy rains and landslides — the more the mountains around it can rise. In fact, a 2024 study found that the rapid erosion of a river network more than 45 miles (72 kilometers) from Mount Everest helped the peak grow between 49 and 164 feet (15 and 50 meters) in the past 89,000 years.

Although erosion is one factor in mountains' growth, it is also part of what causes them to shrink, explained Matthew Fox, co-author of the study and a geologist at University College London. "[Whether mountains grow or shrink] depends on this balance between the rates of erosion and the rates of uplift," Fox told Live Science. If the rate of uplift is higher, the mountain will grow. If the rate of erosion is higher, the mountain will shrink.

Some scientists have suggested that Nanga Parbat, one of Everest's Himalayan neighbors and the ninth-tallest mountain on Earth, is growing fast enough to one day overtake Everest in height. However, Butler and Fox doubt this will happen. Although Nanga Parbat is growing faster than Everest due to rapid erosion, it is also eroding faster due to the intensity of monsoons in that area. In contrast, Everest is growing and eroding more slowly, leaving it at a fairly constant 2,000 feet (610 m) taller than Nanga Parbat.

However, Butler doesn't discount the possibility that another Himalayan mountain may take the throne someday. Weather factors could change over time, he said, causing shifts in the peaks' growth rates. "[Tectonic collision in the Himalayas] is going to continue for another 10 million years," Butler said. "There's plenty of time to juggle these variables around a bit."

Nonetheless, Butler thinks it's unlikely there will ever be a peak significantly taller than Everest. The Himalayas sit in the sweet spot; they formed due to a very intense and long collision event with cold crust and high erosion rates due to monsoons. They were also penned in by surrounding mountain ranges, leaving little room for the crust to escape during the collision.

"If you squash things, they've got to go up or sideways," Butler told Live Science. "And when sideways is taken, they've got nowhere to go but up."

It's very rare for all of these factors to line up, Butler said, and it might not have happened before the Himalayas. Moreover, on Earth, gravity is too powerful to allow a mountain to get much taller than Everest's current height.

"If we're talking a few meters, or even a few hundred meters, there's every possibility that another mountain could overtake Everest," Butler told Live Science. "But in terms of doing something significant, like peaks that are 10 kilometers [6 miles] high, I would think probably not."

Earth's mantle is split by the Pacific Ring of Fire, an ancient schism that reflects the creation and destruction of the supercontinent Pangaea, a new study finds.

One of these sections contains most of Earth's land. Called the African domain, it stretches from the east coast of Asia and Australia across Europe, Africa and the Atlantic to the west coast of North America. The other section, the Pacific domain, covers the Pacific ocean. Under the African domain, the mantle is full of many elements and their variations (called isotopes), with far more diversity than the Pacific domain, according to the new research.

This reflects the last two supercontinent cycles over approximately the past billion years, study co-author Luc Doucet, a senior research fellow in Earth and planetary sciences at Curtin University in Australia, told Live Science. In that time period, there were two supercontinents: first, Rodinia, which formed around 1.2 billion years ago and broke up approximately 750 million years ago, and Pangaea, which formed about 335 million years ago and broke up about 200 million years ago.

"What we observe today is basically what happened during the transition from Rodinia to Pangaea and then the Pangaea breakup," Doucet said.

Related: Columbia, Rodinia and Pangaea: A history of Earth's supercontinents

These supercontinents came together over what is now the African domain. As the oceans closed between them, oceanic crust slid under the continents — a process known as subduction — sometimes dragging continental rocks down with it. This pulled elements and isotopes from continental crust down into the mantle under the developing supercontinent, Doucet explained.

This geological conveyer belt continued in a slightly different form once the supercontinents were assembled: Ocean crust on the edges of Rodinia, and later Pangaea, subducted under the continental crust, again eroding some of the continental rock as the tectonic plates ground together. This created a funnel effect, Doucet said.

"You concentrate everything below the supercontinent," he said.

Even after Pangaea broke up, these signatures persisted in both the deep and shallow mantle, Doucet and his team reported Oct. 18 in the journal Nature Geoscience. In a follow-up to 2020 research on magma from the deep mantle, Doucet and Zheng-Xiang Li, a professor emeritus at Curtin University, focused on shallow mantle magma in the new study. They examined the chemistry of 3,983 samples from midocean ridges, where the tectonic plates are spreading apart and magma from the shallow mantle is oozing and hardening into volcanic rock, or basalt.

The researchers then used machine learning to compare the elemental and isotopic compositions of basalts from around the world and from the same time periods. As in magma from deep mantle sources, they found that the shallow mantle was split into African and Pacific domains.

The findings shed more light on the processes that link the mantle and the surface, Doucet said. Why supercontinents break up isn't entirely understood, but it is thought to involve hot mantle material rising from deep mantle regions called large low-shear velocity provinces (LLSVPs), or mantle "blobs." There are two blobs: one below the Pacific domain and one below the African domain.

"The mantle domain compositions reflect what's going on at the surface, but also what's going on very deep," Doucet said. Understanding these processes can help geoscientists pinpoint where useful mantle materials might be concentrated, particularly rare Earth elements, which are metallic elements necessary for most of the tech we use every day. Plate tectonic processes are also responsible for cycling elements that are crucial for life, such as carbon and zinc, from deep within Earth to the surface, which suggests that an active planet is important for developing and sustaining life.

"Earth is the only planet with plate tectonics that we know so far," Doucet said, "and we want to understand how this whole system works and why it's so peculiar."

If you were to imagine all of Earth's history as just one day, as in Carl Sagan's cosmic calendar, humans wouldn't arrive until the last few seconds before midnight. A few hundred thousand years of our species amounts to only a tiny fraction of our planet's past. So how old is our planet, and how do we even know its age?

Earth formed about 4.54 billion years ago, about 10 million years after the solar system was born. After a gigantic cloud of gas collapsed to make the sun, bits of that cloud were left over to make planets.

"I like to think of early solar systems like a pizza," said Mark Popinchalk, an astronomer at the American Museum of Natural History and New York University. "If the gas cloud the star forms out of is a ball of dough, it might start out like a blob, but it will have some initial spin. The star will form out of 99% of that 'dough,' but the rest still has that spin — and, given enough time, it will flatten out like a pizza around the star. It's from that 1% of the 'dough' that all the planets are formed."

Baby Earth, however, was nothing like the lush, green world we know today. Right when it formed, it was still molten from the collisions that created it. The heavier bits, like iron, sank to make the core of our planet, and the lighter elements bubbled up to the surface. Eventually, this led to a layered Earth with a core, mantle and crust.

Related: How long will Earth exist?

Once the solar system calmed down and fewer asteroids were smacking into Earth, the oceans formed and life popped up almost immediately. "While humans couldn't exist for much of Earth's history, cellular life has an uninterrupted streak going for about 3.5 billion years," Popinchalk said. (New research shows that number may even be bigger, as long ago as 4.2 billion years!)

We owe our knowledge of this timeline to the literal ground we stand on; rocks are the key to determining the age of Earth and what it was like in the past. With a process known as radiometric dating, scientists can use the amounts of different radioactive elements to determine how old a rock is. Earth rocks can be tricky, though, because "Earth is an active, busy place," Popinchalk said. "Volcanoes, weathering and geologic processes mean that it's difficult to find rocks from when the Earth formed."

The moon, however, formed from a collision with our planet in its infancy, and it doesn't have pesky plate tectonics like Earth does. Samples of moon rocks from the Apollo era have helped refine our planet's age estimate, and new samples from missions like Chang'e 5 are adding to our understanding of the moon's history.

For nearby planets like Mars, we can send a rover to pick up rocks and analyze them to determine their age. But how do we determine the ages of planets around other stars, which are way too far for us to travel to?

"The best way to learn about planets around other stars is actually just to study the star itself," Popinchalk said. "I specialize in guessing the age of a star by looking at how quickly it is spinning. Young stars spin fast; old stars spin slow. If I can measure the spin rate of a planet-hosting star, I can estimate the age of the star and use a similar number for the planet."

As we discover and characterize new worlds beyond our solar system, we're learning more about the details of how planets form, which will help us understand the history of our own planet even better.

Earth's crust may "drip" into its middle layer under growing mountain ranges.

This odd process, called lithospheric dripping, has been proposed to occur under the Andes, in Central Asia, in the U.S. Pacific Northwest and along the west coast of Canada. Now, researchers have found that the Anatolian plateau in Turkey is undergoing a similar process.

The findings could reveal how mountains and basins are built on planets like Venus or Mars, where there are no mobile tectonic plates like the ones that crumple into one another to create topography on Earth.

"It's [about] understanding how tectonics might work on planets that don't have plates," said study author A. Julia Andersen, a doctoral student in tectonophysics at the University of Toronto. "Earth is the only planet we know of that has plates in the solar system, but the other planets aren't flat."

Volcanic eruptions can spill lava on these planetary surfaces. But landforms can also be created when the lithosphere, which consists of the crust and the relatively brittle upper layer of the mantle, gets especially thick. Mountains create a lot of pressure on the lower lithosphere. In the high-pressure zones underneath the towering peaks, new mineralization can occur, Andersen told Live Science. Some of these minerals are denser than the mantle below.

Related: 'Many more ancient structures waiting to be discovered': Lost chunk of seafloor hidden in Earth's mantle found off Easter Island

"In any sort of physical system, if you have a higher-density material on top of a lower-density material, then it sinks or drips," she said.

But the idea is still controversial, said Mitchell McMillan, a geoscientist at Georgia Tech who was not involved in the research. McMillan also thinks lithospheric dripping is likely happening on Earth, but it can be hard to untangle the signs of possible dripping from the geology created by the tectonic plates' horizontal movements.

One possible sign is that lithospheric dripping can pull the crust above into wrinkly ridges and valleys, forming small-scale mountains. In Turkey, though, there was no such telltale sign of hidden dripping. Previous research had shown that seismic waves traveling through the crust under the massive Anatolian plateau moved faster than average, suggesting some difference in density and temperature in those areas. At the surface, the only indication that something odd might be happening was the Konya Basin, a vaguely circular basin of about 1,620 square miles (4,196 square kilometers) in the southern portion of the plateau.

Andersen and her team conducted a geophysical analysis of the basin's topography and set up a lab-bench experiment to mimic the formation of this large depression.

They used a thick, gooey polymer to represent the middle mantle, and a mix of clay and the polymer for the more rigid upper mantle, topping it off with a silica-and-ceramic "crust." When left to sit, the clay-polymer layer began to drip into the faux mantle. Notably, the "crust" on top wasn't disturbed. Over time, a second drip event began, still leaving the surface unmarred.

The analysis of the real Konya Basin indicates that the same thing is occurring there, Andersen said. "The data indicated that, yes, there is a drip happening there, even if we aren't necessarily seeing many features in the crust that would indicate that it's happening," she said.

This method allowed for more detail than computer modeling alone would show, McMillan told Live Science. "Physical models like Dr. Andersen's are great because they show some results that our numerical models wouldn't be able to resolve," he said. "This is important for interpreting existing data."

The study, published Sept. 13 in the journal Nature Communications, suggests that a similar process could occur around many mountain ranges around the world, Andersen said. Next, she'd like to investigate lithospheric dripping under the Appalachian Mountains, which were once at least as high as the modern Himalayas.

Primeval fish that were thought to be "living fossils," largely unchanged since the time of the dinosaurs, are actually evolving dramatically — and they evolved faster when Earth's continents moved faster, fossils of a newly identified coelacanth species have revealed.

The findings suggest that the large-scale movement of continents may spur the evolution of life, the researchers reported Thursday (Sept. 12) in the journal Nature Communications.

Coelacanths are large fish that evolved 410 million years ago. Once known only from fossils, they were thought to be extinct until a fisher in South Africa hauled one up in 1938. Biologists dubbed the modern coelacanth a "living fossil" and believed it had not evolved much over millions of years.

The two coelacanth species alive today, Latimeria chalumnae and Latimeria menadoensis, are more closely related to other early fish, such as lungfish, than they are to today's modern ray-finned fish.

Related: How fast does evolution happen?

But now, new "bridge" fossils reveal that coelacanths never stopped changing. The fossils, beautifully preserved in three dimensions, are one of the best anatomical looks yet at coelacanth history. Combined with other coelacanth fossils, the discovery reveals that the more geologically active the environment was, the more evolutionary change the fish underwent.

"Somewhat surprisingly, plate tectonic activity had a strong influence on rates of evolution of coelacanths throughout their 400 million-year history," said study first author Alice Clement, an evolutionary biologist at Flinders University in Australia.

The newly identified species of coelacanth, Ngamugawi wirngarri, was found in the Kimberley region of northwestern Australia. It's now tropical, with landscapes ranging from mountains to grasslands. But 385 million years ago, it was a thriving reef with at least 50 species of fish, Clement told Live Science. "In a sense, it was Australia's first great barrier reef, stretching hundreds of kilometers offshore," she said.

Two specimens of the new coelacanth species were first found in 2008. It was the first coelacanth from the site, Clement said, so researchers knew they had something special. But it took years to prepare the fossils and analyze the finds.

The newly identified species' scientific name means "ancient fish" in the language of the First Nations Gooniyandi people, who live near the fossil beds. The species was small — only about 7.8 inches (20 centimeters) long. The modern species, by contrast, are about 6.5 feet (2 m) long.

The anatomy of the fish fell between the earliest "primitive" species, which date to 410 million years ago, and the species that still swim the oceans today. By looking at differences among the fossils over time, the researchers learned that while the fish's large-scale features, like its body shape, have stayed consistent since the Cretaceaous more than 66 million years ago, the bones of the jaw and skull have continued to evolve.

In fact, study co-author Richard Cloutier, an evolutionary biologist at the University of Quebec at Rimouski, told Live Science that if all researchers had to go on was the skull, "we would have never thought that it was a 'living fossil,' because it changed so much."

The change was associated with faster rates of continental drift, even more so than environmental factors such as oxygen levels in the ocean or water temperatures, the researchers found.

"I suppose," Clement said, "that greater tectonic plate activity drives the formation of new environments, or splits existing populations in half to continue upon their own natural evolutionary experiments."

Using information from inside the rocks on Earth's surface, we have reconstructed the plate tectonics of the planet over the last 1.8 billion years.

It is the first time Earth's geological record has been used like this, looking so far back in time. This has enabled us to make an attempt at mapping the planet over the last 40% of its history, which you can see in the animation below.

The work, led by Xianzhi Cao from the Ocean University in China, is now published in the open-access journal Geoscience Frontiers.

A beautiful dance

Mapping our planet through its long history creates a beautiful continental dance — mesmerising in itself and a work of natural art.

It starts with the map of the world familiar to everyone. Then India rapidly moves south, followed by parts of Southeast Asia as the past continent of Gondwana forms in the Southern Hemisphere.

Related: Weird mystery waves that baffle scientists may be 'everywhere' inside Earth's mantle

Around 200 million years ago (Ma or mega-annum in the reconstruction), when the dinosaurs walked the earth, Gondwana linked with North America, Europe and northern Asia to form a large supercontinent called Pangaea.

Then, the reconstruction carries on back through time. Pangaea and Gondwana were themselves formed from older plate collisions. As time rolls back, an earlier supercontinent called Rodinia appears. It doesn't stop here. Rodinia, in turn, is formed by the break-up of an even older supercontinent called Nuna about 1.35 billion years ago.

Why map Earth's past?

Among the planets in the Solar System, Earth is unique for having plate tectonics. Its rocky surface is split into fragments (plates) that grind into each other and create mountains, or split away and form chasms that are then filled with oceans.

Apart from causing earthquakes and volcanoes, plate tectonics also pushes up rocks from the deep earth into the heights of mountain ranges. This way, elements which were far underground can erode from the rocks and end up washing into rivers and oceans. From there, living things can make use of these elements.

Among these essential elements is phosphorus, which forms the framework of DNA molecules, and molybdenum, which is used by organisms to strip nitrogen out of the atmosphere and make proteins and amino acids — building blocks of life.

Plate tectonics also exposes rocks that react with carbon dioxide in the atmosphere. Rocks locking up carbon dioxide is the main control on Earth's climate over long time scales — much, much longer than the tumultuous climate change we are responsible for today.

A tool for understanding deep time

Mapping the past plate tectonics of the planet is the first stage in being able to build a complete digital model of Earth through its history.

Such a model will allow us to test hypotheses about Earth's past. For example, why Earth's climate has gone through extreme "Snowball Earth" fluctuations, or why oxygen built up in the atmosphere when it did.

Indeed, it will allow us to much better understand the feedback between the deep planet and the surface systems of Earth that support life as we know it.

So much more to learn

Modelling our planet's past is essential if we're to understand how nutrients became available to power evolution. The first evidence for complex cells with nuclei — like all animal and plant cells — dates to 1.65 billion years ago.

This is near the start of this reconstruction and close to the time the supercontinent Nuna formed. We aim to test whether the mountains that grew at the time of Nuna formation may have provided the elements to power complex cell evolution.

Much of Earth's life photosynthesises and liberates oxygen. This links plate tectonics with the chemistry of the atmosphere, and some of that oxygen dissolves into the oceans. In turn, a number of critical metals — like copper and cobalt — are more soluble in oxygen-rich water. In certain conditions, these metals are then precipitated out of the solution: in short, they form ore deposits.

Many metals form in the roots of volcanoes that occur along plate margins. By reconstructing where ancient plate boundaries lay through time, we can better understand the tectonic geography of the world and assist mineral explorers in finding ancient metal-rich rocks now buried under much younger mountains.

In this time of exploration of other worlds in the Solar System and beyond, it is worth remembering there's so much about our own planet we are only just beginning to get a glimpse of.

There are 4.6 billion years of it to investigate, and the rocks we walk over contain the evidence for how Earth has changed over this time.

This first attempt at mapping the last 1.8 billion years of Earth's history is a leap forward in the scientific grand challenge to map our world. But it is just that — a first attempt. The next years will see considerable improvement from the starting point we have now made.

The author would like to acknowledge this research was largely done by Xianzhi Cao, Sergei Pisarevsky, Nicolas Flament, Derrick Hasterok, Dietmar Muller and Sanzhong Li; as a co-author, he is just one cog in the research network. The author also acknowledges the many students and researchers from the Tectonics and Earth Systems Group at The University of Adelaide and national and international colleagues who did the fundamental geological work this research is based on.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

A failed miniature continent lies hidden beneath the sea between Canada and Greenland, scientists have discovered. 

The Davis Strait, which separates the two landmasses, ranges from about 200 to 400 miles (320 to 640 kilometers) wide on its path connecting the Labrador Sea and Baffin Bay. It's known to have an oddly thick seafloor, and now researchers know why: The crust is actually a crumb of a continent that didn't fully pull away when Greenland and Canada rifted apart. 

The findings, which the team will publish in the September issue of the journal Gondwana Research, is the most detailed look yet at this incomplete rifting process. The researchers also suspect they've discovered an ancient fault, similar to California's San Andreas fault, in the area. This fault may have acted like a guardrail, directing Greenland's initial movement as it started to pull away from Canada around 60 million years ago. 

Related: Scientists finally discover 'lost continent' thought to have vanished without a trace

The two landmasses never fully managed to separate. About 33 million years ago, Greenland stopped pulling away from North America and remains on the North American tectonic plate. But this failed rift zone is an interesting place to study how tectonic plates move and split, said study co-author Jordan Phethean, a geophysicist at Derby University in the U.K. 

"If we can understand why the plates are moving in the directions that they are, it allows us to understand what’s controlling plate tectonics," Phethean told Live Science. 

The researchers called the newfound chunk of continental crust beneath the Davis Strait a proto-microcontinent. Microcontinents are pieces of crust that have broken away from main continents. Many are submerged beneath the oceans, surrounded by denser oceanic crust, but some, like Madagascar, form their own islands. The Davis Strait example didn't quite fully break away; it's a 12- to 15-mile-thick (19 to 24 km) segment of continental crust, surrounded by thinned-out continental crust that is about 9 to 10.5 miles (14 to 17 km) thick on each side. That's why it gets the "proto" moniker, Phethean said. 

The researchers reconstructed the subterranean structure of the Davis Strait region using gravity data collected by satellites and seismic data collected by ships. Gravity data provide information about rock density by measuring minute variations in the pull of gravity, while seismic data use the reflection of acoustic waves to map deep rock layers and structures. The scientists used this information to build computer models of past plate movement. 

They found that North America and Greenland first started pulling apart around 120 million years ago. This sped up dramatically around 61 million years ago. The seafloor of the Davis Strait began to spread, creating more distance between what's now Canada and Greenland. At this point, Greenland may have been riding along the San Andreas-like fault called the Pre-Ungava Transform Margin, which guided its track mostly northeast. Then, around 56 million years ago, Greenland hit the end of that structure and shifted to a mostly northerly direction of travel. The Davis Strait proto-microntinent was born during this time. 

The North American plate seemed poised to break apart. But then, around 48 million years ago, it all fizzled out. A new major fault formed in the region and rifting in the Davis Strait ceased. Not long after, around 33 million years ago, Greenland crashed into Ellesmere Island, which may have further slowed its movement. Today, Phethean said, the area is relatively quiet, with no large, continent-reshaping earthquakes. 

While plate tectonics are often thought to be driven by deep-Earth processes, like the sinking of oceanic plates beneath the continents, the importance of the newfound fault in the Davis Strait suggests that features in the upper crust can have a major influence too, Phethean said.

"It seems like the lithosphere, which is the rocks on the outside of the planet, plays quite an important role in why the tectonic plates are moving the way that they are," he said.

The plate tectonics that cause earthquakes, build mountains and split continents may have started when Earth was in its infancy, new research finds — significantly earlier than many scientists previously thought. 

The new study suggests plate tectonics started more than 4 billion years ago — not long after the planet formed 4.5 billion years ago. In this era, known as the Hadean, Earth was fresh and piping hot, with an ammonia-and-methane atmosphere imbued with enough water to eventually condense into a planet-wide ocean. During this period, Earth cooled enough to have a solid outer crust. 

Today, that crust is shaped by the grinding movements of tectonic plates, which ride on the warmer, more mobile mantle below. But no one knows for certain when this arrangement of plate tectonics first began. Previously, researchers suggested it began in the Hadean, nearly as soon as the crust cooled. Others think plate tectonics started around 3.2 billion years ago, when geochemistry reveals some key changes in the crust's makeup. Others argue the phenomenon is even more recent, evolving to its modern form in the last couple of billion years. 

Scientists have struggled to determine exactly when plate tectonics began because there are no surviving rocks that are more than 4 billion years old, so the only direct window into the Hadean comes from tiny, tough crystals known as zircons — the oldest of which date back 4.4 billion years. A subset of those, known as S-type zircons, can reveal the presence of plate tectonics. These particular zircons are crystals that form in sedimentary rocks on land, then get pushed into the mantle by tectonics and re-emerge again in metamorphic granites. 

The problem is that S-type zircons can't be easily identified by one single feature but instead by a whole suite of trace minerals. 

In the new study, published July 8 in the journal PNAS, researchers used a machine-learning model to make this task easier. The scientists first fed the model data from 300 zircons of known origin and then tested the model's ability to determine whether 74 more zircons were S-type or not. With the model trained to differentiate between zircon types, the team next applied it to 971 new zircons from the Jack Hills of Australia, where most of the oldest zircons on Earth are found. 

The results indicated that 35% of the Jack Hills zircons were S-type. Some of these date to 4.2 billion years ago, suggesting that plate tectonics was moving rocks from the crust to the mantle and back again during the Hadean.

The research isn't the first to hint at very ancient tectonic movement. A 2023 experiment that melted rocks at high temperatures suggested that the oldest continental crust formed by subduction — the process of one tectonic plate diving under another. Some studies even suggest there may have been early continents during the Hadean. 

But the new study probably won't reconcile all of the controversy. Chris Hawkesworth, a geochemist at the University of Bristol who was not involved in the new study, told Science Magazine that other forces beyond plate tectonics, such as giant meteor impacts, could also have moved rocks between the crust and the mantle in Earth's early days.

The Argyle mine held the biggest cache of pink diamonds ever discovered on Earth. Unlike blue and yellow diamonds, which are tinted by impurities like nitrogen and boron, pink diamonds get their color through geological processes that distort their crystalline structure. Pink diamonds are extremely rare and can fetch more than $2 million per carat (1 carat is equal to 0.2 grams, or 0.007 ounces), according to the International Gem Society.

The Argyle mine closed in 2020 due to a dwindling supply of diamonds and unfavorable economic conditions, including a rise in operational costs. The mine sits on the shores of Lake Argyle in a remote region of northeast Western Australia, 340 miles (550 kilometers) southeast of Darwin. Mining operations there lasted 37 years and yielded more than 865 million carats (191 tons, or 172 metric tons) of rough diamonds — including white, blue, violet, pink and red diamonds, according to Rio Tinto, the company that owned and operated the mine.

Related: Fountains of diamonds that erupt from Earth's center are revealing the lost history of supercontinents 

The Argyle rock formation is an unusual spot for diamonds, because it sits on the edge of a continent rather than in the middle, where the precious stones typically emerge. In addition, diamonds are usually found in kimberlite rock formations, but the Argyle formation features a type of volcanic rock called olivine lamproite.

Researchers dated the rocks at Argyle shortly after the site was discovered in 1979. Initial results pinned their age somewhere between 1.1 and 1.2 billion years old, but last year, a new study revealed the rocks are 1.3 billion years old. This puts the Argyle formation's origins right at the start of the breakup of the supercontinent Nuna, revealing clues about how the diamonds formed — and why so many of them are pink.

Pink diamonds are born out of specific heat and pressure conditions that arise when tectonic plates collide. The sheer force of these collisions can bend the crystal lattice of pre-existing diamonds in a way that colors them different shades of pink — although too much force can turn them brown, Hugo Olierook, a senior research fellow at Curtin University in Australia and lead author of the 2023 study, previously told Live Science. 

The supercontinent Nuna formed when two sections of Earth's crust crashed into each other around 1.8 billion years ago. The region in which they are thought to have smashed together overlaps with the present-day Argyle formation, suggesting the collision gave rise to Argyle's pink diamonds. At that point in time, however, the diamonds would have been buried deep within the crust.

But 500 million years later, when Nuna began to break apart as the tectonic plates moved away from one another, the rocks carrying the diamonds rose to Earth's surface. Those rocks also contained an abundance of brown diamonds, which Rio Tinto mined and sold in huge numbers.

Argyle is an exceptional spot, and while it's possible there might be another such cache of diamonds somewhere, finding it will "take a lot of luck," Olierook said.

Strange "blobs" deep in Earth's middle layer may be chunks of ancient continental crust that have been dragged down by tectonic forces, new research suggests. 

These blobs, known as ultra-low velocity zones (ULVZs), have long puzzled scientists. They're deep in the mantle, near the boundary with Earth's core, so researchers can only glimpse them by studying earthquake waves as they reverberate around the planet's interior like a bell. These waves slow down significantly in the blob regions, which indicates they are different from the mantle around them. 

In the new study, published April 17 in the journal JGR Solid Earth, researchers suggest that these regions might be more widespread than previously believed — and that their composition varies dramatically from blob to blob. 

"There is more of that material down there," study lead author Samantha Hansen, a geologist at the University of Alabama, told Live Science. "Whatever that material is." 

Related: 2 giant blobs in Earth's mantle may explain Africa's weird geology

In 2012, Hansen and her team began a project to study the upper mantle via a network of seismic monitors in Antarctica, but they soon realized they had a unique dataset. To image the lower mantle with earthquake waves, scientists need the right combination of earthquake locations and sensors, and Antarctica offered a new window into structures beneath the Southern Hemisphere, she said. 

"One of the big advantages of using the Antarctic stations was that it let us examine part of the lowermost mantle that hadn't been looked at before," Hansen said. 

When the scientists analyzed the data, they found widespread ULVZs in the Southern Hemisphere, the team reported April 17 in the journal JGR Solid Earth. They also modeled global subduction, or the phenomenon of oceanic crust sinking into the mantle. Currently, this occurs in subduction zones such as those around the Pacific "Ring of Fire," where earthquakes and volcanoes are common. The ULVZs seemed to be in the positions that would be expected if they were ancient oceanic crust brought down toward Earth's center by subduction.

"Our best interpretation is that they're related to subducted materials," Hansen said. 

There are other hypotheses for ULVZs, including that they are simply mantle regions with temperature variations that cause partial melting, which could change the way earthquake waves move through them. Another hypothesis holds that they're remnants of the planetary collision that created the moon. But subduction might explain why ULVZs are not all created equal, Hansen said.

"You could potentially explain this really wide distribution of ULVZ characteristics that have been reported by the fact that the material is variable itself," she said. 

A major extinction in the midst of a huge expansion of life on Earth may have been driven by plate tectonics.

New research finds links between rock layers in Antarctica and Southern Australia, which at the time were part of the supercontinent Gondwana. This suggests that similar dynamics were occurring around the supercontinent roughly 513 million years ago: Mountains were uplifting, ancient reefs were dying, and eroded material from the continent was pouring into the sea. These moments in time coincide with the extinction known as the Sinsk event, said study leader Paul Myrow, a sedimentologist at Colorado College.

"Oddly, it was tectonics that triggered an extinction," Myrow told Live Science.

The Sinsk event occurred during the Cambrian period (540 million to 485 million years ago), which saw a huge diversification of life on Earth known as the Cambrian explosion.

But in the middle of this flourishing, the Sinsk extinction killed off several major groups, including cone-shelled animals called hyoliths and sponges called archaeocyathids, which once built enormous reefs all over the globe. Researchers know that the Sinsk event was linked to falling levels of oxygen in the oceans, but they haven't been able to pinpoint the precise cause.

Related: The 5 mass extinction events that shaped the history of Earth — and the 6th that's happening now

Now, Myrow and his colleagues say they have the answer. The tectonics of Gondwana, which formed between 600 million and 540 million years ago, triggered a series of events that drowned the archaeocyathid reefs and altered the oceans, they reported March 29 in the journal Science Advances.

The clue to these events was found in rock layers in Antarctica’s Transantarctic Mountains and on Kangaroo Island, Australia. Myrow and his colleagues collected samples in Antarctica in 2011, including trilobite fossils from long-dead archaeocyathid reefs. Then, about a year ago, Pomona College geologist Robert Gaines told Myrow he'd seen similar rocks on Kangaroo Island, which is also studded with fossil trilobites.

These trilobites were the key to the timing of the loss of the reefs. Because trilobites evolved quickly, researchers can tell how old a rock is by the species of trilobite fossilized inside it. In both Antarctica and Australia, the fossils dated to between 514 million and 512 million years ago — right around the time of the Sinsk event.

"Everything clicked into place," Myrow said. "There was the same geologic history all the way over in Australia as there was in Antarctica."

At the time of the Sinsk event, both continents were part of Gondwana, with today's Antarctica sitting on the equator and Australia at a higher latitude. The locations showed a similar story in the rock layers. The extinction of the archaeocyathid reefs coincided with giant mountain-building events. As the mountains popped up on land, the nearby shallow oceans right off the coast subsided in a kind of seesaw motion of the crust. This caused the archaeocyathid reefs to suddenly deepen, submerging them past their ability to survive. Next, erosion from the new mountain ranges dumped layers of cobbles and gravel over the drowned reefs.

Meanwhile, Myrow said, the tectonic movements that caused mountains to lift in some places also caused the crust to stretch out in others, allowing magma to rise to the surface and harden into the rock basalt, a geologic formation known as a “large igneous province.” These hot magmas brought lots of greenhouse gases, like sulfur dioxide and carbon dioxide, causing Earth's atmosphere to warm.

This warming, in turn, slowed the circulation in the ocean — a phenomenon that researchers worry may happen again today with human-induced climate change. This slowdown of ocean circulation led less-oxygen-rich water to sink to the ocean bottom. This killed off many existing organisms, Myrow said. 

"The older, more primitive ones didn't do so well," he said.

Large igneous provinces have been blamed for other extinctions, but with less certainty than the Sinsk event, Myrow said, "I don't know of any others that I could point to where it's so clearly laid out."

A subduction zone below the Gibraltar Strait is creeping westward and could one day "invade" the Atlantic Ocean, causing the ocean to slowly close up, new research suggests.

The subduction zone, also known as the Gibraltar arc or trench, currently sits in a narrow ocean corridor between Portugal and Morocco. Its westward migration began around 30 million years ago, when a subduction zone formed along the northern coast of what is now the Mediterranean Sea, but it has stalled in the last 5 million years, prompting some scientists to question whether the Gibraltar arc is still active today.

It appears, however, that the arc is merely in a period of quiet, according to a study published Feb. 13 in the journal Geology. This lull will likely last for another 20 million years, after which the Gibraltar arc could resume its advance and break into the Atlantic in a process known as "subduction invasion." 

The Atlantic Ocean hosts two subduction zones that researchers know of — the Lesser Antilles subduction zone in the Caribbean and the Scotia arc, near Antarctica. 

"These subduction zones invaded the Atlantic several million years ago," lead author João Duarte, a geologist and assistant professor at the University of Lisbon, said in a statement. "Studying Gibraltar is an invaluable opportunity because it allows observing the process in its early stages when it is just happening."

Related: 'We are approaching the tipping point': Marker for the collapse of key Atlantic current discovered

To test whether the Gibraltar arc is still active, Duarte and his colleagues built a computer model that simulated the birth of the subduction zone in the Oligocene epoch (34 million to 23 million years ago) and its evolution until present day. The researchers noticed an abrupt decline in the arc's speed 5 million years ago, as it approached the Atlantic boundary. "At this point, the Gibraltar subduction zone seems doomed to fail," they wrote in the study.

The team then modeled the arc's fate over the next 40 million years and found it painstakingly pushes its way through the narrow Gibraltar Strait from the present day over the next 20 million years. "Strikingly, after this point, the trench retreat slowly speeds up, and the subduction zone widens and propagates oceanward," the researchers wrote in the study.

Modeling of this kind requires advanced tools and computers that weren't available even a few years ago, Duarte said in the statement. "We can now simulate the formation of the Gibraltar arc with great detail and also how it may evolve in the deep future," he added.

If the Gibraltar arc invades the Atlantic Ocean, it could contribute to forming an Atlantic subduction system analogous to a chain of subduction zones that circles the Pacific Ocean, called the Ring of Fire, according to the statement. A similar chain forming in the Atlantic would lead to oceanic crust being recycled into the mantle via subduction on both sides of the Atlantic, gradually swallowing and closing up this ocean.

The Gibraltar arc's grinding advance over the last 5 million years could explain the relative lack of seismicity and volcanism in the region — which have been used as arguments to dismiss the idea that the subduction zone might still be active. The subduction zone's tectonic silence is a direct result of its extended period of stalled movement, the authors of the new study argue.

"If the movement along the subduction interface were small, the accumulation of the seismic strain would be slow and may take hundreds of years to accumulate," they wrote. "This agrees with the long recurrence period estimated for big earthquakes in the region."

Although many smaller earthquakes have been recorded since, the last major earthquake to rock the region was the 1755 Great Lisbon Earthquake, which reached an estimated 8.5 to 9.0 on the moment magnitude scale. An earthquake of this magnitude occurring anytime soon is "pretty much out of the question, since the last such tremendous event was only 250 years ago," experts previously told Live Science. 

A hazardous fault line that runs south of downtown Seattle may have formed when the edge of the North American continent tore apart 55 million years ago, a new study suggests.

Seattle sits atop the Cascadia Subduction Zone, where the Explorer, Juan de Fuca and Gorda tectonic plates slide beneath the much larger North American Plate. This eastward movement pulled a string of volcanic islands similar to present-day Iceland toward the continent and eventually caused a collision that's still visible in the bedrock beneath the city.

New maps of this bedrock reveal the collision was extremely messy, with the northern half of the island chain riding the oceanic crust and slipping under the continent and the southern half piling onto the continent. The twist in Earth's crust where the islands switched from being subducted to obducted, or added to the top of the continent, would have been under tremendous strain and likely ripped in half.

"It would have been this slow, ongoing tear, almost like the crust unzipping itself," study lead author Megan Anderson, a geophysicist with the Washington Geological Survey, said in a statement. "As this progressed, the tear fault got longer and longer."

Related: Nearly 75% of the US is at risk from damaging earthquakes, new map reveals

The tearing likely ended when the islands finished scrunching into the continent. Anderson and her colleagues tested this scenario using computer models and found that the resulting gash in Earth's crust overlapped perfectly with Seattle's fault line. The wear and tear the surrounding crust would have suffered also aligned with a network of shallow faults beneath the densely populated Puget Lowland area.

Previous research into the region's splintered geological past relied on seismic data, which are sound waves that travel at different speeds underground depending on the layers of rock they encounter. 

For the new study, published Feb. 6 in the journal Tectonics, the researchers mapped the density and composition of rocks beneath western Washington state using gravity and magnetic-field measurements. Then, they paired their results with seismic data and collected rock samples to build a clear picture of the area's geology.

The magnetic data revealed secrets that seismic data alone couldn't have unveiled — namely, that magneticity alternates within the bedrock and that rocks on each side of the Seattle fault line are angled away from each other. Slabs of rock to the north of the fault line lie in a northwest-to-southeast diagonal, whereas slabs to the south are angled from northeast to southwest.

"These are all very different orientations," Anderson said. "It's very hard to do that unless there's a place where the structures get disconnected from each other and then restart."

The results point to a new origin story for the Seattle fault line — one that could help scientists fine-tune their earthquake hazard models. The most recent damaging earthquake in western Washington state was the magnitude 6.8 Nisqually earthquake, which struck in 2001. Massive quakes also occurred in 1700 and around A.D. 900, when the simultaneous rupture of faults shook the Seattle area.

"There's a lot more uncertainty about the Seattle fault than, for example, the San Andreas fault," Anderson said. "The Seattle fault could generate something like a magnitude 7.2 earthquake, and we want to be prepared for it. There's still a lot to learn so that engineering geologists can do better simulations for earthquakes and understand the potential risks to our communities."

Magma flowed into the dike beneath Grindavík at an unprecedented rate of 261,000 cubic feet per second (7,400 cubic meters per second) before the volcano first erupted in Iceland's Reykjanes Peninsula, according to a new study.

"We were very surprised," lead author Freysteinn Sigmundsson, a geophysicist at the University of Iceland, told Live Science in an email. During the three previous eruptions in the region that took place between 2021 and 2023, magma flow into the dike was estimated to be less than 3,500 cubic feet per second (100 cubic m per second). "For the Grindavík dike it was almost 100 times higher," Sigmundsson said.

A 9.3-mile (15 kilometers) magma dike — a near-vertical tunnel running from the magma chamber beneath — formed beneath Grindavík in November, 2023,. At that point the region experienced a massive increase in seismic activity. Officials evacuated the fishing town, which has a population of around 3,800, given the risk of an eruption.

The volcano erupted on Dec. 18, with a 2.5-mile (4 km) fissure opening and sending lava spewing up to 100 feet (30 meters) into the air. The volcano erupted again on Jan 14., with two fissures opening on the outskirts of Grindavík. A third eruption occurred today (Feb. 8), with a 2-mile-long (3 km) fissure opening up near Mount Sundhnúkur to the north of Grindavík. The events are part of a millenia-long cycle that fuels eruptions.

Related: 'Time's finally up': Impending Iceland eruption is part of centuries-long volcanic pulse

In a new study published Feb. 8 in the journal Science, researchers examined the formation of the dike that led to the eruptions by combining satellite-based observations and seismic measurements, along with physical models. They found the magma flowed from the chamber into the dike at an exceptionally fast rate, comparable to the estimated rate of the 1783/84 eruption of Laki, which is around 130 miles (209 km) west of Grindavík . Within a year of the 8-month-long eruption, 60% of the country's livestock and 20% of the population died.

The Reykjanes Peninsula sits at the boundary of the Eurasian and North American tectonic plates. This section of the boundary has been stretching without any eruptions in the last 800 years. The Grindavík dike formed after magma accumulated about 3.1 miles (5 km) beneath the surface in what is known as a magma domain.

"A magma body is like an 'expanding balloon' inside the Earth, that can rupture," Sigmundsson said. The scientists found that the eruption took place with only modest overpressure — the amount of pressure that exceeds the surrounding pressure at that depth. This modest pressure alone could not have led to such immense speeds of magma flow.

"It means that other factors were important in explaining the fast magma flow — namely the forces due to the prior stretching of the crust (tension) as well as a large fracture on the boundary on the magma domain," Sigmundsson said. "The stretching forces contributed very significantly to the driving pressure for magma flow in the dike, causing the very fast flow."

Discovering such a high inflow rate of magma has implications for other volcanoes. A dike with a high inflow rate of magma is potentially more hazardous than those filling at lower speeds. But it's also important to place the fill rate in context of the geological setting, as this will help determine the likelihood of magma reaching the surface.

The ability of this chamber to fill so quickly also has implications for future hazards on the Reykjanes Peninsula — even areas not in the direct path of erupting magma.

"The consequences of extensive faulting and fracturing above the dike in Grindavík, showed how very destructive such events can be, even without an eruption," Sigmundsson said.

Tibet may be tearing in two beneath the rising Himalayas, with pieces of the continental plate peeling off like the lid off a tin of fish, researchers have discovered.

According to new research presented at the annual meeting of the American Geophysical Union and posted as a pre-peer-reviewed pre-print online, this shows that the geology beneath the world's highest mountain range may be even more complex than previously believed.

The Himalayas are growing because two continental tectonic plates, the Indian and Eurasian plates, are colliding beneath the colossal mountain range. In cases where oceanic and continental plates collide, the denser oceanic plate slides beneath the lighter continental plate in a process called subduction. When two similarly dense continental plates collide, however — as is the case below the Himalayas — it's not so simple to predict which plate will end up under the other, and geoscientists are still unsure exactly what's going on in Tibet.

Some suggest that the bulk of the Indian plate may simply be sliding under the Eurasian plate without diving deeply into the mantle, a process called underplating; others believe that perhaps deeper parts of the Indian plate are subducting, while the upper parts are wedging themselves stubbornly against the bulk of Tibet.

Related: Fountains of diamonds that erupt from Earth's center are revealing the lost history of supercontinents

The new research suggests that the answer could be both these explanations. The researchers found evidence that the Indian plate is subducting, but it's warping and tearing as it does so, with the upper half delaminating, or peeling away.

"We didn't know continents could behave this way, and that is, for solid earth science, pretty fundamental," Douwe van Hinsbergen, a geodynamicist at Utrecht University in the Netherlands, who was not involved in the work, told Science Magazine.

To get a clearer picture of what's happening below Tibet, the  researchers investigated earthquake waves traveling through the crust at the region where the two plates collide. They reconstructed images from these waves showing what appear to be tears in the slab of the Indian plate's crust. In places, the bottom of the Indian plate is 124 miles (200 kilometers) deep, Science Magazine reported. In others, it is only 62 miles (100 km) to the bottom of the plate, suggesting some of it has peeled away.

Previous work, published in 2022 in the journal PNAS, also showed variations in the types of helium bubbling up from geothermal springs in the region. One variation of helium, known as helium-3, is found in mantle rocks, while helium with lower concentrations of helium-3 is likely to come from the crust. By mapping the variations in helium over multiple springs, the researchers found the boundary where the two plates currently meet just north of the Himalayas. The findings from these geochemical studies support the earthquake wave results in hinting at a splintering plate, the researchers wrote.

The new research may also point to areas of increased earthquake risk along the plate boundary, according to Science, though researchers don't yet fully understand how tearing and warping deep within the crust translates to the buildup of stress at the surface.

The continents we live on today are moving, and over hundreds of millions of years they get pulled apart and smashed together again. Occasionally, this tectonic plate-fueled process brings most of the world's landmasses together to form a massive supercontinent.

There's no strict definition for a supercontinent, but researchers like Joseph Meert, a professor of geosciences at the University of Florida, say they should include around 75% of the available landmass.

Scientists are still debating how many supercontinents have existed in Earth's history, but they're sure of at least three. Here are all of the known supercontinents that have existed and a few honorable mentions. Live Science spoke with Meert, to check the dates of the supercontinents on this list, but keep in mind they're still only estimates.

Related: The tantalizing link between diamond-spewing eruptions and the destruction of supercontinents

Columbia/Nuna

The first supercontinent, called Columbia, or Nuna, existed from around 1.7 billion years ago to 1.45 billion years ago in the Precambrian period (4.6 billion to 541 million years ago). It is named "Columbia" because scientists posited that the landmass connected what is now eastern India with the Columbia basalts region in what is now the U.S., according to a 2017 study in the journal Gondwana Research.

While Earth is much older than the Columbia supercontinent, scientists aren't sure supercontinents formed before 2 billion years ago, and it's possible only smaller and separated landmasses existed back then, according to a 2021 review of the supercontinent cycle published in the journal Nature Reviews Earth & Environment.

Read more: Earth's biggest cache of pink diamonds formed in the breakup of the 1st supercontinent 'Nuna'

Rodinia

Rodinia was the second supercontinent to form in the Precambrian period, coming together around a billion years ago and breaking up around 700 million years ago. Researchers don't know exactly how big Rodinia was, but North America was likely the core of the landmass, according to Smithsonian Ocean.

The continents we know today were unrecognizable when Rodinia existed. For example, the Americas were merged while Asia and Africa were broken up into pieces. Rodinia was still around when the first animals evolved around 800 million years ago.

Read more: Lava outburst 3 times the size of Texas may have triggered Snowball Earth 717 million years ago

Pangaea

The most recent supercontinent, Pangaea, formed around 320 million years ago and broke up around 175 million years ago. Geophysicist and meteorologist Alfred Wegener first proposed the existence of Pangaea and the concept of supercontinents in 1912 after noticing that the shorelines of Africa and South America seemingly fit together like giant jigsaw puzzle pieces. His theory that continents moved, named continental drift, was rejected for decades until scientists confirmed some of his ideas with the modern theory of plate tectonics, which explains Earth's crust is split into plates that move across the mantle.

The name "Pangaea'' comes from Ancient Greek words meaning "all Earth." However, Pangaea never included all of Earth's landmasses. For example, modern-day north and south China were independent islands separated to the east of Pangaea throughout the Carboniferous period (359 million to 299 million years ago).

Pangaea split when the Central Atlantic Ocean opened, and Gondwana (what are now Africa, South America, India and most of Antarctica and Australia) separated from Laurasia (modern-day Eurasia and North America). The two landmasses then further broke apart and eventually formed the seven continents we live on today.

Read more: Mangled 'dragon' fossils were cooked by ancient continents colliding to form Pangaea

Honorable mentions

Gondwana and Pannotia

Gondwana formed around 530 million years ago and was the largest landmass on Earth for more than 200 million years, before becoming part of Pangaea, but the jury is still out on whether it was a supercontinent. Gondwana brought together around 64% of today's landmass, according to a 2013 study published in the journal Gondwana Research. Pannotia is another debated supercontinent, which may have briefly existed around 560 million years ago, combining parts of Gondwana, North America and Northern Europe.

Read more: Zealandia, Earth's hidden continent, was torn from supercontinent Gondwana in flood of fire 100 million years ago

Amasia and Pangaea Ultima

Scientists believe that supercontinents form on a cycle every several hundred million years or so, and we should expect another one in around 250 million years. Researchers have proposed a few different scenarios for how the next supercontinent will form. One of these hypothesizes that the Americas and Asia drift northward and merge as the Arctic Ocean closes, meaning many of Earth's future inhabitants could live on "Amasia." Another option is Pangaea reforms, with the Atlantic Ocean closing and the Americas, Europe and Africa coming together as "Pangaea Ultima."

Massive supercontinent will form hundreds of millions of years from now

Tsunami waves 92 feet (28 meters) high could hit parts of New Zealand in a worst-case earthquake scenario, research finds. 

In the study, researchers used a new method of examining simulated earthquakes to understand possible tsunami risks to New Zealand's North and South Islands. They found that the largest waves are likely to strike along the northeast coast of North Island. That's because the Hikurangi subduction zone, where the Pacific tectonic plate dives under the Australian tectonic plate, sits just offshore. 

"There’s a really short timespan [between] when these earthquakes happened and when the tsunami waves hit," study first author Laura Hughes, a doctoral student at Victoria University of Wellington, told Live Science. 

Because of New Zealand's proximity to subduction zones, which can create large, tsunami-generating earthquakes, it's important to understand the risk of these devastating waves. 

Previous efforts have used historical quakes to try to understand future risk, study senior author Martha Savage, a geophysicist at Victoria University of Wellington, told Live Science. But historical records only go back about 150 years. Geological studies can turn up evidence of older quakes, but those records are incomplete. 

Related: 1st mega-tsunami on record since antiquity was triggered by Tonga volcanic eruption

Instead, the researchers turned to a different method: synthetic earthquakes. This method used computer models, into which researchers added everything they know about the geometry and physics of fault systems, including things like the locations of faults and the amount of friction on them. They then simulated tens of thousands of years of quakes to try to determine how often major ones occur. 

The method isn't perfect because the fault systems aren't fully known, Savage said, but it complements the historical and geological record. 

"We’re able to put in a variety of properties we think may exist and get that range of potential earthquakes and range of potential tsunamis that may happen," Hughes said.

In the new study, published Nov. 29 in the journal JGR Solid Earth, the researchers created a catalog of 30,000 years of simulated time focused on the fault systems around New Zealand. The results revealed 2,585 earthquakes with magnitudes between 7.0 and 9.25. 

The model suggests that the Hikurangi subduction zone is the most dangerous source of tsunami quakes near New Zealand, though the Tonga-Kermadec subduction zone north of North Island can also generate large, tsunami-causing quakes, just a bit further from shore. The researchers were surprised to find that the tsunami hazard was caused by smaller, shallower faults called crustal faults, rather than the subduction faults themselves, Hughes said. 

"Yes, the subduction zones are doing what we expect them to do," she said, "but our crustal faults also have a significant component of the hazard that we also need to account for." 

The team found the maximum height of a tsunami was 92 feet, which would result from a 9.13 magnitude earthquake about 394 miles (634 kilometers) northeast of Auckland in the South Pacific. The 2011 Tohoku tsunami in Japan was a 130-foot (40 meter) wave, for comparison. 

The results suggest that New Zealand can expect a tsunami of 16.4 feet (5 m) approximately every 77 years, with a wave of at least 49.2 feet (15 m) approximately every 580 years. 

Tsunamis over 3.3 feet (1 meter) high trigger land evacuations, Hughes said, while smaller waves can damage ports and harbors. 

Though this is the first time the synthetic earthquake method has been used to study tsunamis, the same thing could be done for other at-risk places around the globe, Hughes said. There is also more work needed to map out the risk to New Zealand, she added. The current study didn't take into account far-flung earthquakes around the Pacific, which can cause tsunami waves that resonate around the entire ocean. 

"It is this huge step forward in risk assessment that we can now create a chain from what is creating the earthquakes, to what the earthquake looks like, and then what that looks like for the tsunami," Hughes said. 

The mystery of what happened to a lost continent that seemingly vanished 155 million years ago may have finally been solved, after scientists unearthed evidence of the landmass and retraced its steps. 

It turns out the lost continent, known as Argoland, had a messy divorce from western Australia. It disintegrated as tectonic forces stretched the landmass out and drove it away from the rest of the continent, before scattering it across Southeast Asia, a new study has found.

Researchers have long known that a landmass rifted from Australia 155 million years ago, thanks to clues left in the geology of a deep ocean basin known as the Argo Abyssal Plain off the country's northwest coast.

But unlike India, which broke off the ancient supercontinent Gondwana 120 million years ago and still forms an intact landmass today, Argoland splintered into fragments. And until now, scientists were left scratching their heads as to where those continental fragments ended up.

Related: Zealandia, Earth's hidden continent, was torn from supercontinent Gondwana in flood of fire 100 million years ago

"We knew it had to be somewhere north of Australia, so we expected to find it in Southeast Asia," lead study author Eldert Advokaat, a researcher in the department of Earth sciences at Utrecht University in the Netherlands, told Live Science.

In the new study, published online Oct. 19 in the journal Gondwana Research, Advokaat and his colleagues reconstructed the breakaway continent's journey. The researchers found fragments of ancient land scattered around Indonesia and Myanmar, but when they tried to reconstruct Argoland out of these fragments, "nothing fit," he said. 

The team then worked backward, gathering evidence in Southeast Asia to retrace Argoland's northward journey. Amid the scattered fragments of ancient land, they discovered the remnants of small oceans dating to roughly 200 million years ago. These oceans likely formed as tectonic forces stretched and fissured Argoland prior to the 3,100-mile-long (5,000 kilometers) landmass breaking off, Advokaat said.

"That process goes on for 50 to 60 million years and around 155 million years ago, that whole collage of these ribbon continents and intervening oceans starts drifting over to Southeast Asia," he said. "We didn't lose a continent; it was just already a very extended and fragmented ensemble."

To reflect this, Advokaat and his colleagues referred to Argoland as an "Argopelago." Their reconstruction of the continent's history may shed light on the region's past climate, which would have cooled as oceans formed between the shreds of Argoland, Advokaat said. 

As fragments of Argoland collided with landmasses in Southeast Asia, they also shaped the rich biodiversity we see today. This could help explain the uneven distribution of species along an invisible barrier that runs through Indonesia, Advokaat added.

Overall, piecing together Argoland is "a springboard for new research," he said.

The "lost continent" of Zealandia, which includes New Zealand and the French islands of New Caledonia, have been mapped out in full in a world first, providing scientists with a new understanding of how it formed tens of millions of years ago.

Zealandia, known as Te Riu-a-Māui in the Māori language, was first recognized as a continent in 2017 and is now the first to have its rock composition, volcanic activity and sedimentary features fully mapped out at its margins. 

This is despite the continent being almost completely underwater, with only about 5% of Zealandia peeking above sea level. Researchers published their findings Sept. 12 in the journal Tectonics. 

Overall, the area of Zealandia is estimated to be 1.9 million square miles (4.9 million square kilometers). In 2019, scientists mapped the geology of a region of south Zealandia spanning 0.6 million square miles (1.5 million square km). These findings revealed that Zealandia stretched, twisted and thinned as it broke off from the supercontinent Gondwana between 60 million and 100 million years ago. 

Related: Is Africa splitting into two continents?

In the latest study, researchers mapped out the underwater region of north Zealandia, located between New Zealand, New Caledonia and Australia. 

The scientists discovered that the separation of Zealandia from Gondwana was partly driven by a giant volcanic region containing magnetic lava rocks, which spanned the length of the boundary between the two land masses.

"Molten magma flooded out of cracks and fissures as the continent stretched and thinned like pizza dough," Nick Mortimer, a geologist at the Institute of Geological and Nuclear Sciences Limited (GNS Science), said in a statement. This volcanic activity eventually helped to break Zealandia away from Gondwana.

"Until now, the role of magma in Gondwana breakup has been underestimated," Wanda Stratford, a marine geophysicist at GNS Science, said in the statement. These lavas cover an area of 100,000 square miles (250,000 square km) across the continent — which is about the size of New Zealand, she added. 

By studying rock samples collected from the seabed near New Caledonia, the scientists were also able to fully map out a 100 million to 250 million-year-old backbone of granite that winds through the middle of the Zealandia. 

The map of Zealandia could help to shed light on New Zealand’s resources, environment and natural hazards, GNS Science said in the statement.

The excerpt below is taken from "Our Fragile Moment: How Lessons from Earth's Past Can Help Us Survive the Climate Crisis" (Hachette Book Group, 2023), by Michael Mann. It looks at how climate change following the Cambrian explosion caused the biggest mass extinction on Earth — dooming the creatures set to dominate and set the stage for dinosaurs to rule.  

The mechanisms that can freeze the planet, as was the case with Snowball Earth can also lead to inhospitably hot climates, when enough carbon dioxide enters the atmosphere. Arguably the greatest extinction event of all time — called the Great Dying — appears to have resulted, at least in part, from a massive heat-inducing release of carbon into the atmosphere 250 million years ago. 

Is this ancient event a possible analog for a sixth, human-caused, climate-change-driven mass extinction today? In answering this question, we will at times work our way through some details of the science, but the payoff is that we will see not just that scientists are able to unravel such mysteries, but how they do it.

In the late Proterozoic eon, around 550 million years ago, Earth had thawed out from a series of major glaciations, perhaps even global snowball conditions. The end of the Proterozoic marked the beginning of a brand new era — the Paleozoic, which extended from around 540 million to 251 million years ago.

The first period of the Paleozoic — the Cambrian — saw a remarkable explosion in the diversity of life, known, appropriately, as the Cambrian explosion. Most of the life that exists today emerged during the first 10 million years of that period, including the first complex multicellular life and familiar groups such as mollusks and crustaceans. 

Among the reasons for this remarkable diversification was a sustained rise in oxygen from photosynthetic life. Higher levels of oxygen allowed for more diverse, multicellular organisms because they require oxygen in high enough concentrations that it can reach interior cells. The stratospheric ozone layer, which had developed during the Neoproterozoic era (1 billion to 538 million years ago), protected animals from the sun's damaging ultraviolet rays and helped populate the land. Some researchers even argue for a possible "bottleneck" effect, where the few life-forms that survived the Neoproterozoic ice ages (Snowball Earth or not) were able to rapidly fill emerging niches as Earth thawed.

Related: 'Once again, innovation and proliferation ended with catastrophe': The environmental disaster of plants taking over the world

A major glacial event occurred at the end of the following period of the Paleozoic, the Ordovician, around 450 million years ago, as chemical weathering outpaced the volcanic emissions of gas and atmospheric CO2 levels dropped. The resulting cooling caused a buildup in ice mass on the large South Pole–centered supercontinent of Gondwana. Sea levels dropped. Much of the coastal habitat that had been home to primitive mollusks and crustaceans disappeared. Some of the creatures scraped by, but about half of all existing genuses perished. Much as we can only wonder today what knowledge was lost in the ransacking of the Library of Alexandria, we can also ponder what sort of magnificent creatures born of the Cambrian explosion were lost. Welcome to the first of the widely recognized global mass extinction events. It will hardly be the last we encounter.

The most well-known extinction event ended the reign of the dinosaurs roughly 66 million years ago. But the deadliest extinction event took place at the end of the Permian period, roughly 250 million years ago. It is referred to in the scientific community as the Permian-Triassic (or P-T for short) extinction, but because an estimated 90% of all Permian species disappeared from the face of the planet, it has earned a nickname: the Great Dying. Marine organisms were hit especially hard, with 96% of species perishing. Gone were the trilobites so familiar to amateur fossil collectors everywhere — primitive arthropods that were the distant ancestors of the modern horseshoe crab. Having survived the earlier Ordovician extinction event, their own nearly 300-million-year moment had come to an end.

Not only were the vast majority of marine invertebrates gone, but so were the earliest fish species. On land, more than two thirds of amphibian and reptile species and nearly one third of insect species were wiped out. Another iconic species, a giant dragonfly called Meganeuropsis with a nearly three-foot (0.9 meter) wingspan that is often included in artist depictions of the Carboniferous period — and to this day still haunts my nightmares — was now gone.

The P-T extinction event wiped out many of the groups that had dominated life on land, freeing up ecological niches to be filled by new organisms, including reptiles such as crocodiles and the earliest dinosaurs. Once again, there were both winners and losers. Who won and who lost, in this case, came down to geology and geochemical weathering cycles.

Midway through the Paleozoic, around 420 million years ago, we saw the emergence of plants with roots, stems, and leaves, which as we now know helped accelerate chemical weathering by producing acids that dissolve rock, helping cycle water from the soil back into the atmosphere. This may have led to a slow, steady decrease in atmospheric CO2 levels through the late Paleozoic. The spread of these vascular plants, however, also led to a new source of organic matter that could be buried on land or carried off in rivers for ocean burial. Increased burial of organic matter causes rising atmospheric oxygen levels because that organic matter is the product of photosynthesis, which splits up oxygen and carbon atoms. The carbon, once buried, is no longer available to cannibalize the liberated oxygen. In the Paleozoic, oxygen concentrations climbed as high as 35% (almost twice the current concentration of 21%).

Those high oxygen levels favored synapsids, creatures with a high metabolism, featuring a single hole in each side of their skull that led to improved jaw function. They were part of a diverse group of four-legged terrestrial animals, including carnivores, insectivores, and herbivores, that first arose in the late Carboniferous and would evolve into the group we today know as mammals. 

By the early Permian, they were the dominant terrestrial species. By the mid-Permian, another group of proto-mammals — the possibly warm-blooded, somewhat rodent-like therapsids — emerged and became the new dominant species. By the late Permian, they may have even developed fur. One group, known as Theriodontia (Latin for "beast tooth"), displayed a number of evolutionary innovations: A shift in the bones supporting the jaw allowed the jaw to open wider, and may have aided hearing as well. The skull and teeth became larger, the teeth more specialized, and the jaw more powerful. They seemed primed to take over. But it was not to be.

Everything changed at the Permian-Triassic boundary. Levels of CO2 spiked. That led to massive warming. Plate tectonics by now had brought all the continents together into a single giant continent — Pangea — straddled across the equator. It was already difficult for maritime moisture to penetrate deep into the center of the continent. Rapid greenhouse warming made it even hotter and drier, according both to climate model simulations of the end of the Permian and analyses of the fossil river deposits from Pangean floodplains. The sudden drying would have led to the massive die-off of the tenuous, moisture-dependent forests that had arisen over the course of the Paleozoic. That meant less burial of organic matter on land, assisted perhaps by decreased carbon export to the deep oceans due to a collapsing marine food web. Atmospheric oxygen levels appear to have dropped precipitously as a result, reaching concentrations as low as 15% at the P-T boundary.

The drop in oxygen was a further contributor to the mass die-off. The combination of greenhouse warming and low oxygen would have led to widespread hypoxia — a state where organisms simply cannot take in enough oxygen to support metabolism. That's where the dinosaurs come in. The proto-mammals that had come to dominance during the Permian — the synapsids and therapsids — had thrived off high oxygen levels. But as oxygen concentrations dropped, they were now poorly suited to their environment. 

Enter the diapsids, a wide-ranging group of tetrapod vertebrates that first emerged during the Carboniferous around 300 million years ago. They include the reptiles, birds, and now-extinct dinosaurs. What distinguished them from their relatives, the synapsids and therapsids, was the presence of two holes (instead of one) on each side of their skull. One subgroup of synapsids, known as archosaurs — which includes crocodilians and the earliest dinosaurs — exploited that innovation to develop a more efficient respiratory system that could make more effective use of the available oxygen. That gave them a leg up on the competition when oxygen levels plummeted at the P-T boundary. Dinosaurs, it turns out, were direct beneficiaries of the P-T extinction event.

Only a handful of proto-mammals survived. One group that did was known as Cynodontia ("dog teeth"). They were our ancestors, and the ancestors of all mammals. At first, they probably looked somewhat like a huge, scaly rat, growing to as much as six feet (1.8 m) in length. Truly a Rodent of Unusual Size if ever there was one. But by the end of the Triassic, they had shrunk to the size of modern-day field mice, hiding behind rocks from their reptilian predators.

Excerpted from "Our Fragile Moment: How Lessons from Earth's Past Can Help Us Survive the Climate Crisis" by Michael E. Mann. Copyright © 2023. Available from PublicAffairs, an imprint of Hachette Book Group, Inc.

The Himalayas, which include the world's tallest mountains, weren't born the way geoscientists thought. The tectonic plates that collided to form the peaks 45 million to 59 million years ago were already pushing against each other, causing the Himalayan mountains to rise to more than half their current elevation, before the big crash gave them a violent shunt upward, scientists say.

This means the iconic mountains may have started their ascent into the sky far earlier than previously believed — around 63 million to 61 million years ago — due to the subduction of the oceanic part of the Indian tectonic plate.

"Previously it was assumed that continent-continent collision (India plate with Eurasian plate) was required for such high elevation to be obtained," study lead author Daniel Enrique Ibarra, an assistant professor of Earth, environmental and planetary sciences at Brown University, told Live science in an email.

In a new study published Thursday (Aug. 10) in the journal Nature Geoscience, Ibarra and his colleagues found that the Himalayas attained roughly 60% of their current elevation before the continental plates collided. The discovery may influence our understanding of the region's climate in the past, they said, and challenge assumptions about how other mountainous areas, such as the Andes and the Sierra Nevada, formed.

Related: Is Mount Everest really the tallest mountain on Earth?

"Our study shows for the first time that the edges of the two tectonic plates were already quite high prior to the collision that created the Himalayas — about 3.5 kilometers [2.2 miles] on average," senior study author Page Chamberlain, a professor of Earth and planetary sciences at Stanford University, said in a statement.

The Himalayas now have an average elevation of 20,000 feet (6,100 meters) and host the world's tallest mountain, Mount Everest, which towers 29,032 feet (8,849 m) above sea level. 

The researchers reconstructed the mountain range's past by measuring the amount of different versions, or isotopes, of oxygen in its sedimentary rocks — a technique called triple oxygen analysis that is typically used to study meteorites.

The windward slope of a mountain — the first to be hit by air circulating around the mountain — gets more rain than the opposite side, known as the leeward slope. The chemical composition of this rain changes as the air moves up the windward slope towards the mountain's peak, with heavier isotopes of oxygen declining at lower altitudes and lighter isotopes dropping out near the top.

By tracking these changes, the researchers determined the historic altitude of rocks. They found the makeup around 62 million years ago was consistent with an elevation of 11,480 feet (3,500 m). "That's a lot higher than many thought," Ibarra said in the statement.

This initial uplift may have been caused by the oceanic part of the Indian tectonic plate, which at that time was pushing its way underneath the continental slabs at a low angle and forcing the overriding plate up.

So, "the oceanic part of the India plate initiated convergence," Ibarra told Live Science. "This gave the roughly 60% elevation that we find in our study."

A huge collision 45 million to 59 million years ago then forced the edges of the Indian and Eurasian tectonic plates up by an additional 0.6 miles (1 km), according to the study. These tectonic forces are ongoing and contribute to the growth of the mountains even today. "The final push is the onset (and continuation today) of continent-continent collision," Ibarra said.

The discovery could help explain several climatic phenomena, including the establishment of the east and south Asian monsoon system, according to the study.

"This new understanding could reshape theories about past climate and biodiversity," Ibarra said in the statement. 

Earth's surface is ever-changing, with tectonic plates grinding and shifting, building mountain ranges, pulling apart sea floors and causing dramatic earthquakes. 

Now, new research adds to the growing body of evidence that these dynamics started 3.2 billion years ago. While there is controversy within the geoscience community about exactly when Earth became more than just a blob of hot, undifferentiated rock, the new study suggests that this transition happened about 1.3 billion years after the planet formed.

"Three-point-two billion is the tipping point," study co-author Zheng Xiang Li, a geodynamicist at Curtin University in Australia, told Live Science. 

In 2020, Li and his colleagues reported there was a shift in the chemistry of the rocks that formed in the mantle about 3.2 billion years ago, hinting that a "remixing" process took place. This process would have involved minerals being transported from the crust down into the mantle, and mantle rocks moving up to the surface — the fingerprints of plate tectonics. Other researchers have also seen evidence of a shift at this same time period; for example, a 2020 study in the journal Science Advances found magnetic evidence for large-scale plate motion 3.2 billion years ago.

But there is still debate about when and how these processes started, Li said. 

When did plate tectonics begin? 

In the new study, he and Luc Doucet, a geochemist at Curtin University, along with their colleagues, focused on large lead-zinc deposits in Australia. The scientists used the ratios of molecular variations of uranium, thorium and lead as a clock to measure events that happened deep in Earth's history. 

Related: Is Africa splitting into two continents?

The deposits in Australia span from 3.4 billion years ago to 285 million years ago, study co-author Denis Fougerouse of Curtin University said in a statement.

The new analysis again pointed at 3.2 billion years as a turning point, Li said. Before then, Earth had differentiated into the "layer cake" pattern of core, mantle and crust that is still seen today. This layering was driven by gravity, with heavier elements sinking to the core and lighter elements rising to the crust, Li said. 

However, 3.2 billion years ago, these layers started to remix, with plate tectonics driving slabs of crust back into the mantle, and forces such as volcanism bringing mantle elements up to the surface. 

The researchers also found that the initiation of this process was complicated and not necessarily timed exactly the same all across the planet. The new findings, reported in the August edition of the journal Earth-Science Reviews, show that researchers need to recalibrate the uranium-thorum-lead dating system to capture these nuances.

"If we don't deal with it carefully, we might have tens of millions or hundreds of millions of years of error in the age," Li said.

The researchers are now using computer simulations to understand how plate tectonics likely started 3.2 billion years ago. The cooling of the planet from a magma ocean to something more temperate and solid may have played a major role, Li said. 

"Our first motivation is to document how the whole Earth evolved from the early red ball through plate tectonics to the green marble we have now," he said. 

A giant plume of super-heated rock rising up from near Earth's core could help explain mysterious distortions linked with a giant tear in the planet's surface that appears to be splitting Africa in two, a recent study finds.

Across the planet, huge gashes in Earth's surface known as continental rifts are ripping landmasses apart. The largest active continental rift is the East African Rift, a network of valleys that is about 2,175 miles (3,500 kilometers) long, stretching from the Red Sea to Mozambique.

Continental rifting is driven by the deformation of the lithosphere, the planet's outermost rigid layer. As the lithosphere stretches thin, its shallowest parts can distort in a variety of ways, from pulling apart like dough to shattering.

Study co-author D. Sarah Stamps, a geophysicist at Virginia Tech in Blacksburg, likens these responses to Silly Putty — if you hit Silly Putty with a hammer, it can crack and break, but if you slowly pull it apart, it stretches. Over different time scales, Earth's lithosphere can also behave in different ways.

The direction in which Earth's surface deforms at continental rifts is usually at right angles to the length of a rift — imagine two halves of a continent pulling apart, with land stretching or breaking where those halves meet.

Related: Scientists extract a kilometer of rock from Earth's mantle in record-breaking mission

After examining the East African Rift for more than 12 years, the researchers found that deformation is perpendicular — as expected — moving east and west. However, they also discovered deformation parallel to the rift, moving north. These surface motions "are quite unusual and have not been observed elsewhere," Stamps told Live Science.

In the study, the team found that a giant, mushroom-shaped "superplume" of scorching-hot, buoyant rock ascending up Earth's mantle may help explain these mysterious distortions. 

"This work suggests plumes may play an active role in deforming the Earth’s surface, particularly in continental rifts where the lithosphere has thinned," Stamps said.

Scientists have long known of mantle plumes on Earth. For example, Iceland and the island chains of Hawaii and the Galapagos formed as tectonic plates slowly drifted over mantle plumes, which seared overlying material like a blowtorch.

The researchers focused on the African Superplume, which rises beneath southwest Africa and goes northeast across the continent, becoming shallower as it extends northward.

The scientists used GPS technology to monitor surface motions at the East African Rift with millimeter precision. They also used seismic instruments to analyze the directions in which mantle rock slowly flowed over a broad area.

Finally, 3D computer simulations developed by study lead author Tahiry Rajaonarison, a geophysicist at New Mexico Tech in Socorro, analyzed the GPS and seismic data to work out the underground activity underlying the East African Rift.

The 3D models showed that the unusual deformations parallel to the rift may be driven by northward mantle flow associated with the African Superplume.

"Imagine a stronger Silly Putty on top of a weaker Silly Putty, which represent the highly viscous lithosphere and the less viscous plume material, respectively," Rajaonarison told Live Science. "If you move the weaker Silly Putty, it will progressively stick together with the stronger Silly Putty at their interface until the stronger Silly Putty moves in the same direction."

All in all, "for me the most important implication of these findings is the improvement of our understanding of how continents breakup," Rajaonarison said. 

The scientists published their findings March 27 in the Journal of Geophysical Research: Solid Earth.

A giant rift is slowly tearing Africa, the second-largest continent, apart. This depression — known as the East African Rift —  is a network of valleys that stretches about 2,175 miles (3,500 kilometers) long, from the Red Sea to Mozambique, according to the Geological Society of London. 

So will Africa rip apart completely, and if so, when will it split? To answer this question, let's look at the region's tectonic plates, the outer parts of the planet's surface that can collide with each other, making mountains, or pull apart, creating vast basins.

Along this colossal tear in eastern Africa, the Somalian tectonic plate is pulling eastward from the larger, older part of the continent, the Nubian tectonic plate, according to NASA's Earth Observatory. (The Somalian plate is also known as the Somali plate, and the Nubian plate is also sometimes called the African plate.)

The Somalian and Nubian plates are also separating from the Arabian plate in the north. These plates intersect in the Afar region of Ethiopia, creating a Y-shaped rift system, the Geological Society of London noted.

Related: Which is the largest continent? The smallest?

A slow break

The East African Rift started forming about 35 million years ago between Arabia and the Horn of Africa in the eastern part of the continent, Cynthia Ebinger, chair of geology at Tulane University in New Orleans and a science adviser to the U.S. State Department's Bureau of African Affairs, told Live Science. This rifting extended southward over time, reaching northern Kenya by 25 million years ago.

The rift consists of two broadly parallel sets of fractures in Earth's crust. The eastern rift passes through Ethiopia and Kenya, while the western rift runs in an arc from Uganda to Malawi, the Geological Society of London noted. The eastern branch is arid, while the western branch lies on the border of the Congolese rainforest, according to NASA's Earth Observatory.

The existence of the eastern and western rifts and the discovery of offshore zones of earthquakes and volcanoes indicate that Africa is slowly opening along several lines, which together amount to more than 0.25 inch (6.35 millimeters) per year, Ebinger said.

"The rifting right now is very slow, about the rate that one's toenails grow," Ken Macdonald, a distinguished professor emeritus of Earth science at the University of California, Santa Barbara, told Live Science.

The East African Rift most likely formed because of heat flowing up from the asthenosphere — the hotter, weaker, upper part of Earth's mantle — between Kenya and Ethiopia, according to the Geological Society of London. This heat caused the overlying crust to expand and rise, leading to stretching and fracturing of the brittle continental rock. This led to substantial volcanic activity, including the formation of Mount Kilimanjaro, the highest mountain in Africa, NASA's Earth Observatory noted.

If Africa does rip apart, there are different ideas for how that might happen. One scenario has most of the Somalian plate separating from the rest of the African continent, with a sea forming between them. This new landmass would include Somalia, Eritrea, Djibouti, and the eastern parts of Ethiopia, Kenya, Tanzania and Mozambique, Ebinger said. "Another scenario has only eastern Tanzania and Mozambique separating," Ebinger noted.

If the African continent does rupture, "the rift in Ethiopia and Kenya may split to create a Somali plate in the next 1 million to 5 million years," Ebinger said.

However, Africa may not split in two. The geological forces driving the rifting might prove too slow to separate the Somalian and Nubian plates, Ebinger said. One notable example of a failed rift elsewhere on the globe is the Midcontinent Rift, which curves for about 1,900 miles (3,000 km) across the Upper Midwest of North America, according to a 2022 review in the journal GSA Today.

"Failed rifts mark continental landmasses worldwide," Ebinger said.

The eastern branch of the East African Rift is a failed rift, according to the Geological Society of London. However, the western branch is still active.

"What we do not know is if this rifting will continue on its present pace to eventually open up an ocean basin, like the Red Sea, and then later to something much larger, like a small version of the Atlantic Ocean," Macdonald said. "Or might it speed up and get there more quickly? Or it might stall out?"

New "unprecedented" animations of the Earth show how the planet's surface has shifted and changed over the past 100 million years. 

These animations are the most detailed view of the history of Earth's topography ever, depicting the rise of mountains, the development of basins, and the transport of large masses of sediments around the globe through erosion.  

The animations show the movements of tectonic plates, the large rafts of crust that bump up against each other to form mountain ranges and pull apart to form ocean basins. When these plates dive into the mantle, or Earth's middle layer, at subduction zones they give rise to planet-shaping volcanoes and earthquakes. But there are other forces shaping the surface, too: Precipitation erodes away the surface, while the rate of weathering alters levels of carbon dioxide in the air, creating a feedback loop that links the land to the atmosphere. 

"While the dance of the continents has been studied extensively, we are still limited in our understanding and representation of how the Earth's surface has evolved," said Tristan Salles, a senior lecturer in geosciences at the University of Sydney and the lead author of a new paper describing the model, which was published March 2 in the journal Science.

"What we bring with this new model," Salles wrote in an email to Live Science, "is a way to evaluate how this surface has changed (globally and over geological time scales) shaped by its interactions with the atmosphere, the hydrosphere, the tectonic and mantle dynamics."

Related: A tiny magma blob may rewrite Earth's history of plate tectonics

The model begins 100 million years ago in the midst of the breakup of the supercontinent Pangaea, which started to occur around 200 million years ago. In the beginning of the animation, the continents that will become Africa and South America are already recognizable, with the Northern Hemisphere continents coming together tens of millions of years later. Blue shows the flow of water, while red shows the intensity of the deposition of new sediments by erosion. 

"This unprecedented high-resolution model of Earth's recent past will equip geoscientists with a more complete and dynamic understanding of the Earth's surface," study co-author Laurent Husson, a geologist at the Institute of Earth Sciences (ISTerre) in Grenoble, France, said in a statement.

Putting together all of these different pressures on the evolution of Earth, from the movements of the plates to the flow of water to the slow changes in the mantle, provides a new way to ask questions about everything from the regulation of the climate to the ways the circulation of the atmosphere affect erosion on land. 

The researchers found that the rate of sediment movement across the globe was likely much larger than what scientists believe based on observation, probably because the sedimentary record is fragmented. Overall erosion rates have been fairly steady for the past 100 million years, Salles said, but there have been changes in whether the sediment ends up trapped in low-elevation basins on land or ultimately flows out to sea. For example, there was a doubling of sediment flow to the oceans between about 60 million and 30 million years ago, which was likely associated with the rise of the Himalaya Mountains and the Tibetan Plateau, the researchers wrote. 

Such nuances could be important, Salles said. For example, some of the earliest life formed in shallow marine environments, where microorganisms harnessed photosynthesis for the first time and left behind mineralized formations known as stromatolites. 

"It is thought that sedimentation flux may have provided a source of nutrients to these early organisms, allowing them to thrive and evolve over time," Salles said. "We envision that our model could be used to test such long-standing hypotheses regarding the origin of life on Earth."

One of the biggest crash scenes on Earth, a subduction zone is a spot where two of the planet's tectonic plates collide and one dives, or subducts, beneath the other, according to the National Oceanic and Atmospheric Administration (NOAA). This tectonic process can produce some of the planet’s most powerful earthquakes, tsunamis and volcanoes.

What happens at a subduction zone?

Tectonic plates are pieces of the Earth’s rigid outer layer that slowly move across the planet's surface over millions of years, according to NOAA. (This is the main tenet of plate tectonics, the theory that portions of Earth's shell glide over the lower mantle, taking continents with them.) That outer layer, known as the lithosphere, consists of the Earth’s crust and the upper section of the mantle, a dense, hot layer beneath the crust, according to the U.S. Geological Survey (USGS). When two tectonic plates meet at a subduction zone and one slides underneath the other, this lithosphere material curves down into the hot mantle.

This subduction process frequently occurs because of the two different types of lithosphere that make up tectonic plates: Continental and oceanic. Because oceanic material is denser than continental lithosphere, when the two collide at a subduction zone, the oceanic portion sinks into the mantle beneath the more buoyant continental lithosphere, according to NOAA.  

Subduction zones can also occur when both colliding plate sections consist of oceanic material. In these cases, older, denser oceanic lithosphere sinks below younger, more buoyant oceanic lithosphere. (New oceanic lithosphere forms at the spots where plates separate, allowing hot mantle material to rise to the surface. As it moves away from those boundaries, this lithosphere cools and gets denser, according to Columbia University. Thus, older oceanic lithosphere can more easily sink.)

The sinking plate, or "slab," at a subduction zone tends to bend at an angle of about 30 degrees from Earth's surface, though some angles are flatter or steeper than this, according to the University of Colorado. Sometimes, the slabs may tear, like a gash in wrinkled paper, and break off and fall into the mantle, according to a 2008 study in the journal Tectonics. Modeling research in 2021 revealed that these sinking slabs don’t vanish, but rather weaken and become pliable, Live Science previously reported.

Tectonic plate smash-ups don’t always result in a subduction zone. When two sections of continental lithosphere converge, it creates a collision zone and the plates crumple together like crashing cars, pushing up material, according to the California Academy of Sciences in San Francisco. The massive Himalaya mountain chain was created this way, when the Indian tectonic plate slammed into the Asian plate.

Where do subduction zones typically occur?

Subduction zones occur in a horseshoe shape around the edge of the Pacific Ocean, offshore of Washington state, Canada, Alaska, Russia, Japan and Indonesia and down to New Zealand and the southern edge of South America, according to NOAA.

Called the "Ring of Fire," these subduction zones comprise “the most seismically and volcanically active zone in the world,” according to the USGS, responsible for more than 80% of the world's biggest earthquakes and most of the planet’s active volcanoes, according to NOAA.

How do subduction zones form?

The formation of subduction zones has been difficult to study, because these zones destroy material by their nature, Live Science previously reported. A 2021 study, however, investigated a relatively young subduction zone at the Puysegur Trench south of New Zealand to probe the origins of subduction. There, the subduction process got started via stretching and shifting of the submerged "secret" Zealandia plate, which surrounds and encompasses New Zealand, researchers found. That movement repositioned the plate to allow oceanic crust to subduct beneath it, the scientists said.  

Sometimes, subduction can begin spontaneously, without forces of collision between plates, a 2004 study in the journal Earth and Planetary Science Letters found. This happens as lithosphere becomes unstable and sinks under the force of gravity, the study said, and as Live Science previously reported, oceanic lithosphere may grow so old and dense that it collapses and spontaneously forms a subduction zone.

When did subduction start?

That modeling research from 2021 also suggested that in the younger, hotter Earth of roughly 1 billion years ago, modern plate tectonics wouldn’t work. That’s because subducting slabs would break up quickly and cease pulling the material behind them into the mantle. The action of plate tectonics depends on subduction, because "the sinking of lithosphere in subduction zones provides most of the power for plate motions," according to a 2018 review published in the journal GSA Today. 

However, the history of subduction remains controversial, and researchers in 2022 detected evidence of ancient subduction in eclogite, a rare rock dating to 2.5 billion years ago that formed from subducting oceanic material. And in a 2021 study, scientists described evidence of plate tectonics from 3.6 billion years ago preserved in zircon crystals from Australia, Live Science previously reported.

Experts introduced the term subduction in 1970, as the theory of plate tectonics was taking hold, though descriptions of the phenomena appeared as early as the 1960s, according to the 2018 review in GSA Today. Seismographs placed around the globe in the 1960s to detect nuclear tests also aided in the development of tectonic theory and subduction zone science, according to the National Park Service. Now, new instruments can precisely track the shifting tectonic plates, according to the University NAVSTAR Consortium (UNAVCO), a nonprofit for geoscience research and natural hazard mitigation.

"We can see very clear pictures of how the plates move, mostly due to GPS data," said Vasily Titov, senior tsunami modeler for NOAA's Center for Tsunami Research in Seattle, Washington.

Why do earthquakes occur in a subduction zone?

Shoving two massive slices of Earth's crust together resembles rubbing two pieces of sandpaper against each other. The crust sticks in some places, storing up energy that is released as earthquakes, according to the USGS. These "megathrust earthquakes" are the largest temblors on Earth, according to Natural Resources Canada. The biggest ever recorded include a magnitude 9.5 in Chile in 1960 and a magnitude 9.2 in Alaska in 1964, both on subduction zones, according to USGS. Because they occur where oceanic lithosphere subducts beneath continental or other oceanic lithosphere, these quakes strike along coastlines or in the ocean.

Smaller earthquakes also strike all along the descending slab of a subduction zone, according to USGS. Seismic waves from these temblors and tremors can help scientists "see" inside the Earth, much as computed X-ray tomography, or CT scans, allow medical doctors to peer inside the human body. 

Why are subduction zone earthquakes the biggest in the world? The main reason is the enormous size of the faults in subduction zones, according to USGS. The greater the area colliding, the more energy is stored up and released in the process. "Subduction zones are huge boundaries, so they generate very large earthquakes," Titov told Live Science. The Cascadia subduction zone stretches about 600 miles (960 kilometers) from Northern California to British Columbia, Canada, located about 70 to 100 miles (100 to 160 km) offshore, according to the Oregon Department of Emergency Management.

Megathrust quakes occur repeatedly along subduction fault lines as energy gets stored up and then released. The Cascadia zone has caused a mega quake an estimated 13 times over the last 6,000 years — about one every 500 to 600 years on average — and this will continue to happen, according to Natural Resources Canada.

In 2020, researchers found that a fault in the Cascadia zone could one day cause a massive earthquake off the coast of Portland, Live Science previously reported. Known as the Gales Creek fault, it could today produce a quake of magnitude 7.1 to 7.4, enough for some very strong, possibly life-threatening shaking, though such quakes are rare in this fault, researchers said.

In 1700, this subduction zone triggered a gigantic earthquake, measuring an estimated 8.7 to 9.2 in magnitude and spawning a tsunami that reached Japan. Researchers found in 2021 that what looks in the geologic record like one monster quake may have actually consisted of several relatively smaller quakes, Live Science previously reported. These smaller earthquakes would still have been extremely powerful, however, so a series of such quakes today could be even worse for the region than one larger temblor. That makes it important to figure out the most likely past and future scenarios, the researchers said.

Do subduction zones cause tsunamis?

A megathrust earthquake along a subduction zone can jostle the surface of the ocean floor vertically, causing a tsunami, or giant sea wave, according to USGS. This can happen with earthquakes larger than a magnitude 7.5, USGS says. However, other factors affect whether or not a subduction zone earthquake will cause tsunamis; for example, the earthquake must happen in a shallow marine region, USGS says. 

Some earthquakes can also trigger tsunamis by setting off underwater landslides, according to the UN International Tsunami Information Center.

Subduction zones are frequently along coastlines, given that these zones occur where oceanic and continental plate material meet. So tsunamis will frequently be generated close to where people live; however, "There's a silver lining," Titov said. "If these earthquakes happened underneath a city, the city would have no chance."

Government agencies such as NOAA in countries around the Pacific Ocean monitor the tsunami threat from subduction zones, providing warnings to those in danger. These waves may strike quickly, too, as tsunamis can move as fast as jet planes — over 500 mph (800 km/h), according to NOAA. For coastal areas near an earthquake, the giant waves may arrive in minutes.

Why do volcanoes form at subduction zones?

As a tectonic plate slides into the hotter mantle, the increased heat and pressure release surface seawater in the slab and water trapped in its minerals, according to San Diego State University (SDSU). These fluids rise into the upper mantle, lowering the melting temperature of rocks there and forming magma (molten rock). Magma above a subducting slab will rise into the crust and form an arc of volcanoes, according to Columbia University in New York City. (The hot, molten magma rises because it is less dense and more buoyant than the rock around it, according to the Arizona Geological Survey.)

When oceanic lithosphere subducts beneath continental material, a belt of volcanoes called a volcanic arc forms on the continental crust. This happened in the Pacific Northwest of the U.S. and Canada, for example, in the Cascade Volcanic Arc, which includes Mount Rainier in Washington state, according to SDSU. When an oceanic plate drops beneath another oceanic plate, it forms a string of volcanoes known as an island arc, such as Alaska's Aleutian Islands along the Ring of Fire. 

In 2021, those islands scored a triple whammy, with three volcanoes erupting simultaneously, a rare but not unheard of event, Live Science previously reported. The Toba volcanic eruption in Indonesia, the largest volcanic eruption in the past 2 million years, was from a subduction zone volcano, according to Oregon State University.

Additional resources

Read how subduction zones helped create some of the beautiful landmarks found in U.S. parks at the U.S. Park Service. Learn how to prepare for tsunamis with the Red Cross Tsunami Survival Guide or the U.S. Department of Homeland Security’s Ready.gov: Preparing for Tsunamis page. Follow seismic activity in the U.S. with the USGS earthquake monitoring site. Read about the earthquake dangers posed to the Pacific Northwest in the book "Cascadia's Fault: The Coming Earthquake and Tsunami That Could Devastate North America" (2011, Counterpoint) by journalist Jerry West.

This article was originally written May 7, 2015 by Live Science contributor Becky Oskin and has since been updated on August 31, 2022 by Michael Dhar.

The sun has a temper and often unleashes it in the form of solar storms, which spew gobs of plasma swarming with charged particles that can seriously mess with satellites, internet and GPS on Earth.

With all the destruction these fiery tantrums are potentially capable of, could they actually trigger a tsunami on Earth?

The short answer is not directly. For a tsunami to be unleashed on Earth, there has to be an earthquake rumbling below the ocean floor that displaces water and generates a colossal, ultra-fast wave through the entire water column, according to the National Oceanic and Atmospheric Administration (NOAA). Such earthquakes are caused by the same type of tectonic plate movement that makes volcanoes erupt and cities tremble. But however terrifying it may seem for Earth to get lambasted by plasmatic winds from a solar flare (an intense burst of electromagnetic radiation from the sun) or coronal mass ejection (a giant cloud of electrically charged particles from the sun moving at high speeds), those forces cannot directly cause an actual tsunami to rise up from the bottom of the ocean. 

Nevertheless, some researchers argue that solar storms may indirectly lead to tsunamis on Earth. 

Related: Could a solar storm ever destroy Earth?

Scientists agree that solar storms can generate tsunami-type shock waves or "solar tsunamis" that wreak havoc on the sun rather than Earth, as NASA reported when the phenomenon was caught by its Solar Terrestrial Relations Observatory (STEREO) in 2006. This shock wave, also known as a Moreton wave, was powerful enough to compress and heat up hydrogen and other gases in the sun until the entire star was burning brighter. This happened in only minutes.

Some solar outbursts are so extreme that they can leave their mark on Earth, a team of researchers found in a 2022 study in the journal Nature, when they unearthed evidence of fallout from one that hit Greenland over 9,000 years ago. Particles that had been swept in with the solar wind were trapped in ice cores that were later examined in a lab. This particular major event did not trigger a tsunami, but a 2020 study in Scientific Reports described a possible link between solar storms and massive earthquakes on Earth — and earthquakes are known to cause tsunamis.

"[We found] evidence for a high correlation between large worldwide earthquakes and the proton density near the magnetosphere, due to the solar wind," researchers, led by Vito Marchitelli, a satellite analysis expert at the University of Basilicata in Potenzo, Italy wrote in the study. "This result is extremely important for seismological research and for possible future implications on earthquake forecast." 

Solar storms that affect Earth are the result of solar flares or coronal mass ejections, which usually occur when magnetic fields on the sun tangle or break. Both explode with gargantuan amounts of energy and send intense solar winds rocketing into space. When the charged particles in solar winds reach Earth and interact with the ionosphere — the outermost part of our atmosphere on the edge of space — they can cause satellite and GPS signals to glitch, according to NASA. But an interaction with the magnetosphere may do more than that. Earth's magnetosphere is further out than the ionosphere. This is the area in space surrounding the planet where magnetic fields have especially strong effects, and it is shaped by the solar wind running into those magnetic fields.

Marchitelli and his colleagues proposed that particles in the solar wind that hit the magnetosphere could impact the intensity of earthquakes. The researchers believe these particles are potentially associated with tectonic plate movement because their electricity could aggravate an existing disturbance, such as subduction, in which one tectonic plate is pushed under another. They reasoned that the more protons were in the solar wind that jolted the magnetosphere, the more likely they were to exacerbate earthquakes, some of which could trigger tsunamis.

However, Marchitelli's study didn't examine the number of tsunamis in periods of high and low solar wind, so this idea is still very much just that — an idea.

There is more support for this thinking. A 2011 study published in the journal Scientific Research observed that earthquakes increased during the solar maximum — the stretch of time during the sun’s 11-year cycle when it is most active and most likely to release blasts of solar wind that warp the shape of Earth's magnetic field. This could put extra pressure on the crust by pushing Earth’s magnetic field against the tectonic plates that lie beneath, influencing tsunami-causing earthquakes.

For now, these findings are still controversial. In a 2012 rebuttal published in Scientific Research, geophysicists argued that a relationship between earthquakes and solar storms could not yet be proven.

"The influence of the solar activity on earthquakes proves to be an elusive phenomenon," they wrote in the study.

So, solar storms, which are much more terrifying near the sun than Earth, don't directly cause tsunamis on Earth. Regular tectonic activity continues regardless of solar wind activity. Whether the particles released by solar winds really can exert any force on plate tectonics, however, remains a mystery.

Originally published on Live Science.