A powerful earthquake struck southwestern Japan Tuesday afternoon local time, collapsing part of a shopping mall, toppling a stone wall at the centuries-old Kumamoto Castle, and sending more than 150,000 people to evacuation shelters, the BBC reported.

The quake, which the U.S. Geological Survey (USGS) measured as a magnitude 6.8, hit at 4:27 p.m. local time near Kumamoto, a city of more than 700,000 people located on the island of Kyushu in southern Japan.

Thousands of homes lost power, and roads buckled across the region. The second floor of a shopping center collapsed, trapping shoppers inside, according to the BBC report; some of these people were evacuated and later hospitalized. A brief tsunami warning was issued and lifted within an hour.

The USGS measurement is different from the magnitude 7.1 reported by the Japan Meteorological Agency, "primarily because the agencies are reporting different magnitude types," the USGS reported. While Japan is looking at local magnitude, the USGS measured the moment magnitude, which is derived from the physical size of the fault rupture and gives the "most reliable estimate of earthquake size" for large earthquakes, since local-magnitude scales can lose accuracy once a rupture grows big enough, the USGS reported.

These measurements are helpful, as "different magnitude types capture different characteristics of earthquake source processes," the USGS noted. Local magnitude, for example, reflects how strongly the ground shook nearby, while moment magnitude reflects the total energy released across the fault.

Why this quake is scientifically interesting

Japan sits atop one of the most active plate boundaries on Earth, where the Philippine Sea Plate dives beneath the Eurasia Plate. That process, known as subduction, is responsible for the massive, tsunami-generating earthquakes that periodically strike offshore Japan, and it's been studied intensively for decades.

But Tuesday's earthquake didn't occur at the boundary itself. Instead, the rupture happened within the Eurasia Plate, more than 60 miles (100 kilometers) inland from where the plates meet, Jeffrey Park, a theoretical seismologist at Yale University, told Live Science. Roughly 90% of earthquakes happen at plate boundaries, where the constant grinding of two plates builds up stress until a fault gives way. Quakes that strike farther inside a plate — sometimes called intraplate earthquakes — are rarer and less understood, though scientists suspect that stress transmitted through the plate can reactivate old, dormant faults far from the boundary that produced it.

According to Park, the fault in Tuesday's earthquake moved in a way that suggests the plate tore horizontally as it was twisted by subduction occurring at an angle.

The USGS describes this event as shallow strike-slip faulting: the two sides of the fracture slid past each other horizontally, rather than one side thrusting up and over the other. This faulting style, combined with the shallow depth of just 6 miles (10 kilometers) down, points to the same type of rupture behind Kyushu’s deadly 2016 Kumamoto earthquake sequence.

That inland location is also why the quake didn't generate a damaging tsunami, despite the brief precautionary warning. Tsunamis are produced when a big event ‪—‬ such as an earthquake, volcanic eruption or landslide ‪—‬ displaces water; the force from that displacement then propagates as a wave.

Tuesday's rupture stayed entirely on land, so it never pushed the seafloor up the way offshore quakes do. That's why the tsunami risk stayed low, even with the brief precautionary warning. Still, an inland quake isn't automatically off the hook: if the shaking triggers a landslide that spills into the sea, that alone can generate a tsunami.

The depth mattered just as much as the location. The quake was shallow enough to concentrate its energy near the surface, which Park said explains the structural damage.

"Because it is shallow it will cause more structural damage than a similar-sized event that might occur deeper and offshore," he told Live Science in an email.

Earthquake country

Several earthquakes have already clustered in the area, and numerous aftershocks are expected over the coming days. Japan experiences roughly 1,500 earthquakes annually, making it one of the most seismically active countries on the planet — a byproduct of sitting at the junction of several tectonic plates.

To protect itself, Japan has spent decades — and learned from painful lessons from disasters like the 2011 Tohoku earthquake and tsunami — engineering a response system built for exactly this scenario.

Bullet trains are programmed to halt automatically the instant seismic sensors detect a major earthquake, a safeguard Park pointed to as a defining feature of the country's earthquake readiness. That automatic shutdown extends to other transit and utility systems, part of a broader early-warning network that alerts the public within seconds of a quake's detection, giving people crucial time to take cover before shaking arrives.

Japan's investment in its infrastructure may help to explain why, even after a magnitude 7 event near a city of 700,000, Japan's death toll and damage have historically been far lower than those from comparable quakes elsewhere in the world.

Search-and-rescue efforts are continuing in Kumamoto, with CNN reporting that between 20 and 30 employees remained unaccounted for at the Aeon Mall in Kashima Town, where the building’s second floor had collapsed. Firefighters were also working to reach the site and contain nearby fires.

This striking satellite photo shows a multicolor "fan" of folded rocks sculpted by a longtime collision between two of Earth's tectonic plates.

The geological feature, known as an imbricate fan, is located around 3 miles (5 kilometers) east of the town of Murgha Kibzai in Pakistan's Balochistan province. The photographed section of folded rocks measures around 9 miles (15 km) across, but the fan stretches up to 55 miles (89 km) from end to end, well beyond the area in this image.

The dramatic structure sits at an altitude of around 5,000 feet (1,500 meters) in the Sulaiman Range, a series of mountains that covers around 2,500 square miles (6,500 square kilometers) of Pakistan and Afghanistan. ("Sulaiman" means "of Solomon," in reference to the biblical figure King Solomon, and the range's largest peak is Takht-e-Sulaiman, which translates to "Throne of Solomon.")

This is one of several unique features that emerged along the boundary between the Eurasian and Indian tectonic plates, which have been colliding for more than 60 million years. At one point during this tectonic tug-of-war, the two plates became somewhat intertwined, allowing the fan to take shape, according to NASA's Earth Observatory.

"As India moved northward, it began to rotate in a counter-clockwise direction, wrenching the northwestern part of the Indian plate backwards into part of the Eurasian plate," Earth Observatory representatives wrote. "The countervailing forces put the rocks of the Sulaiman Range in a unique compressional vice, causing many of its faults to curve and stretch in convoluted ways."

The fan is made up of alternating layers of sandstone, which appear dark in the image, and limestone, which has a much lighter hue. These sedimentary rocks were formed by "thrust faults" that shot upward from the boundary between the Eurasian and Indian plates and became entangled as the boundary moved back and forth.

The satellite image is false-color, meaning it includes wavelengths of the electromagnetic spectrum that are not normally visible to humans. This helps to accentuate the differences between the two rock types, although they can also be easily distinguished with the naked eye. Pockets of vegetation appear in red throughout the image.

The photo is a small part of a larger, wide-field image (see above), which showcases several other intriguing geological features across the Sulaiman Range in false color.

Continental collision

The collision between the Eurasian and Indian plates became inevitable around 80 million years ago, when dinosaurs still ruled Earth, according to the Earth Observatory. At this point, the pair became locked on a collision course, with each plate moving more than 8 inches (20 centimeters) per year — around twice the speed of the fastest tectonic plates today.

Around 60 million years ago, the plates slowly slammed together. Normally, this would cause the smallest tectonic plate to sink below the other. However, the two plates' massive size meant neither receded. Instead, the continental crust along the boundary grew thicker, and the ground buckled, folded and pushed upward.

This process created not only the Sulaiman Range but also the Karakoram (a huge mountain range that spans the borders of China, India, Pakistan, Tajikistan and Afghanistan) and the Himalayas — the two tallest mountain ranges on Earth, according to the Earth Observatory.

This collision continued at full speed for around 30 million years, before eventually slowing down. However, the two plates are still technically colliding today, making the region a major earthquake hotspot.

See more Earth from space

Science word of the day: Cenozoic

Pronunciation: See-noh-ZOH'-ihk

What it means: The ascendency of mammals, the birth of the Himalayas, the diversification of birds ‪—‬ Earth's in its Cenozoic era, baby!

The Cenozoic is the geological era happening right now. It started 66 million years ago with the abrupt mass extinction known as the Cretaceous-Paleogene extinction event, when a massive asteroid hit Earth and wiped out the nonavian dinosaurs. It's been a busy few tens of millions of years, ushering in such hits as Earth's first cacti, whales and most (if not all) of the Grand Canyon.

How to use it in a sentence: The Cenozoic is called the Age of Mammals, but the University of California Museum of Paleontology in Berkeley would like you to know it could have been called the Age of Teleost Fish, if mammals weren't so dang self-centered.

Can you crack our science word of the day puzzle, Chain Word?

Heaven Lake is a crater lake at the top of Mount Changbaishan (also called Changbai Mountain) — a colossal, dormant volcano on the border between China and North Korea that formed through successive eruptions over the past 2.6 million years.

Known in China as Tianchi, the lake is the highest and largest crater lake in Northeast Asia, according to UNESCO. It is also the deepest lake in China, according to a study published in March. The lake sits at an elevation of around 7,200 feet (2,200 meters), covers roughly 3.6 square miles (9.2 square kilometers), and has a maximum depth of 1,224 feet (373 m), according to the study.

Heaven Lake is surrounded by 16 peaks that belong to Mount Changbaishan. The lake fills a caldera created by past eruptions, the biggest of which was the "millennium eruption" that took place in A.D. 946 and remains one of the largest eruptions in modern history.

Water started to pool on Mount Changbaishan's summit after the prehistoric Tianwenfeng eruption, which scientists dated to between 70,000 and 40,000 years ago. Heaven Lake has periodically emptied and refilled since then due to precipitation, snowmelt, and an active geothermal system beneath the volcano that forces water up through fault lines.

Although hundreds of reports in the early 2000s claimed there was a creature with a head shaped like that of a horse living in the water, scientists have repeatedly said they are skeptical that any large creature could survive in Heaven Lake.

Mount Changbaishan is one of the best-preserved stratovolcanoes from the past several million years, according to UNESCO. Stratovolcanoes, also known as composite volcanoes, are volcanic mountains built from alternating layers of solidified lava, volcanic ash and rocky debris. Mount Changbaishan is an "open-air classroom for volcanism" because it recorded the different stages of multiple eruptions in astounding detail.

In North Korea, Mount Changbaishan is known as Mount Paektu or Paeku Mountain, meaning "white-topped mountain." The volcano's Chinese name means "forever white mountain."

China, North Korea and South Korea have clashed over the volcano in the past, as the mountain holds cultural and geopolitical significance for the three countries. Two border treaties between China and North Korea in 1962 and 1964 divided the volcano and Heaven Lake roughly down the middle, with North Korea securing 54.5% of the lake.

In the 2000s, China moved to develop the region around the volcano, opening the Mount Changbai Airport and the Mount Changbai Eastern Railroad to connect the region with the rest of the country.

A geological park surrounding the Chinese site of the volcano was officially designated a UNESCO Global Geopark in 2024.

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

A large pit discovered by an amateur astronomer on Google Maps in 2024 is actually a 390 million-year-old meteor impact crater, scientists have confirmed.

Joël Lapointe was planning a camping trail through Quebec's Côte-Nord region when he stumbled upon a large indentation in the terrain, CBC reported at the time. The pit, centered around Lake Marsal, was about 25 kilometers (15.5 miles) in diameter and a near-perfect ring — it didn't seem like a normal ditch. Lapointe eventually got in touch with French geophysicist Pierre Rochette, who said that the surrounding topography was "very suggestive" of an impact crater.

Initial testing of samples retrieved from the site contained a mineral called zircon often formed during meteor impacts. However, zircon's presence alone was not enough to prove the crater's extraterrestrial origin story. So a team of scientists had visited the pit in person.

"One of the key things we look for is evidence for shock metamorphism, which can only occur due to the immense pressures created by asteroid or cometary impacts — or nuclear explosions," Gordon Osinski, a professor of planetary geology at Western University, told Live Science in an email. "Most of these features are microscopic, so you can only confirm in the lab with samples."

But there is one feature Osinski said can be seen with the naked eye: grooves or lines in the rock's surface called shatter cones, which are caused by shockwaves passing through the ground.

In October 2025, Osinski and a team of geologists visited the site to investigate whether any of these features were present. "This was one of the most arduous expeditions I’ve ever done — and I’ve done 25 expeditions to the Arctic and 6 continents," he said. "The terrain was incredibly rough and rugged, plus [there were] lots of bugs."

But they eventually found what they were looking for — shatter cones. They also discovered big cliffs of impact melt rock, created by the intense temperatures and pressures produced by a meteor impact. "You can melt literally tens of cubic kilometres of the Earth's crust when you get a big enough asteroid hitting," Osinski told CBC.

Taking samples from the rocks, the team dated the crater at 390 million years old.

Osinski, who runs a website called Impact Earth dedicated to verifying meteor impact sites, is used to getting emails about strange looking satellite images. "I get lots of messages from the public thinking they have found a crater and 99/100 turn out not to be the case," he told Live Science. "This is one of those rare examples that shows this is possible."

So far, we know of roughly 200 impact craters on Earth, 31 of which have been found in Canada. "Typically about 1 or 2 craters are discovered per year, but these are typically less than 5-10 km [3 to 6 miles] in size," Osinski said. "[A crater of this size] is pretty rare."

The last meteor crater confirmed in Canada was in 2010.

After the new investigation confirmed the pit was punched out by a meteor impact, Osinski, Rochette and their team named it Uhaachatik Crater following discussions with the Ekuanitshit Innu council, a council representing the indigenous people in the area. The researchers will present their work at the Annual Meeting of the Meteorological Society in Germany next month.

Speaking to Radio-Canada, Lapointe said that he was very happy to hear his discovery had been confirmed as a genuine meteor crater. "It's not every day that an ordinary citizen finds a 390-million-year-old crater," he said. “I encourage everyone to not ignore intuition or an observation, even if it isn’t part of your field of expertise.”

Osinski and the team will continue their work on the collected samples to learn more about the impact site. "Any crater discovered offers us insight into how craters form and the effects that they can have on Earth’s geology, biology, and climate," he told Live Science.

This ethereal satellite snap shows beautiful, "painting-like" folds within an ancient underwater structure in the Bahamas.

The Great Bahama Bank (GBB) is a massive submerged platform stretching around 330 miles (530 kilometers) across a shallow ocean channel between Andros Island and the Exuma islands, according to Britannica. The crescent-shaped bank surrounds a darkly colored ocean drop-off known as "The Tongue of the Ocean," which plunges to depths of 6,500 feet (2,000 meters), according to NASA's Earth Observatory.

The photographed section of the GBB is around 23 miles (37 km) across and features a series of submerged sandbanks — most of which are covered with dense seagrass beds — that lie between 7 and 40 feet (2 to 12 m) below the ocean's surface.

The varying water depth and seagrass concentration cause multiple hues of green and blue to shine across the sandbanks, which have been carved into smooth, folding ribbons by ocean currents over thousands of years.

"The varying colors and curves remind us of graceful strokes on a painting," Earth Observatory representatives wrote.

This section of the GBB was first photographed in 2001 by the Landsat 7 satellite and has often appeared on lists of the most iconic aerial images of our planet.

"There are many nice seagrass and sand patterns worldwide, but none like this anywhere on Earth," Serge Andréfouet, an oceanographer at the French National Research Institute for Sustainable Development who first shared the 2001 image, told the Earth Observatory. "I am not surprised it is still a favorite, especially for people who see it for the first time."

The sandbanks are like giant underwater dunes carved out by ocean currents.

"Tides and ocean currents in the Bahamas sculpted the sand and seaweed beds into these multicolored, fluted patterns in much the same way that winds sculpted the vast sand dunes in the Sahara Desert," Earth Observatory representatives wrote in 2001.

The GBB lies atop a roughly 3-mile-thick (5 km) bed of limestone dating to the age of the dinosaurs, more than 65 million years ago. This hefty mass, made up of the remains of long-dead coral reefs, is so large that Earth's crust directly below the GBB has "sagged under the weight," according to the University of Texas at Austin's Marine Science Institute.

Before the end of the last ice age, around 12,000 years ago, this limestone slab had risen to more than 400 feet (120 m) above sea level and only resubmerged as global sea levels rose due to the melting of glaciers, according to the Marine Science Institute.

The Bahamas has more than 3,000 islands and smaller cays and is home to several other intriguing oceanographic features, including deep tidal channels off the coast of Great Exuma Island (which once harbored famous pirate ships) and a series of aurora-like sandbanks that appear to shine along the nation's northernmost islands.

See more Earth from space

Earth's oldest known impact crater formed when a meteorite slammed into what is now Australia about 3 billion years ago ‪—‬ 470 million years later than scientists previously claimed, a new study suggests.

The impact crater, known as the North Pole Dome crater, is located in Western Australia's Pilbara region, which is home to some of the planet's oldest rocks. It remains a record-breaking structure, beating the world's next-oldest known meteorite impact crater — the Yarrabubba impact structure, also in Western Australia — by roughly 800 million years.

"While the site had previously been identified as an ancient impact structure, its exact age remained uncertain," study first author Chris Kirkland, a professor in the School of Earth and Planetary Sciences at Curtin University in Australia, said in a statement. "The impact left a 'mineral clock' behind. By dating minerals that were remade or newly grown in the damaged rocks, we can now pin down when this extraordinary event happened."

In a study published last year, Kirkland and his colleagues said they had "unequivocal evidence" that the North Pole Dome crater was 3.47 billion years old, based on an analysis of cone-shaped chunks of rock known as "shatter cones" that form when the shock waves from a meteorite impact propagate downward.

However, a study published four months later in the journal Science Advances called the other team's results "inaccurate," arguing that the impact occurred no earlier than 2.7 billion years ago.

For the new study, Kirkland and his colleagues used advanced mineral dating techniques to estimate the ages of zircon, apatite, calcite and muscovite in shatter cones from the North Pole Dome crater. The researchers analyzed two samples of shatter-cone-bearing rocks, as well as a shocked quartz vein — a sheet-like deposit that typically forms when superhot, mineral-rich water circulates in the cracks between shocked rocks.

"The key evidence comes from zircon, a tiny but extraordinarily resilient mineral that can keep geological time for billions of years," Kirkland said. "Some zircons at North Pole Dome have unusual branching, skeletal shapes. We interpret these as impact-modified crystals, formed when older zircon was disrupted, partly recrystallised, and in places regrown during the intense heating caused by the impact."

The age recorded in zircon was the same as that locked inside apatite minerals, giving the researchers confidence that the impact occurred a little more than 3 billion years ago. The younger shatter cones in the Science Advances study may have formed subsequently due to tectonic and thermal activity, the team wrote in the new paper, which was published Tuesday (June 23) in the journal Geology.

"Ancient impact craters are incredibly difficult to date because over billions of years, rocks are altered by heat, pressure and fluids, which can obscure or reset the original impact signals," Kirkland said. "The new age places the North Pole Dome structure as Earth's oldest known impact crater and the only recognised example from the Archean eon [4 billion to 2.5 billion years ago], a time when the planet's earliest continents were forming."

Planet Earth quiz: What do you know about our planet's most amazing features?

The San Andreas and San Jacinto fault systems are at their highest levels of tectonic stress in 1,000 years, raising the threat of a major, imminent earthquake that could devastate Southern California, a new study finds.

The faults could rupture separately or together, thanks to an "earthquake gate" between them at Cajon Pass, where the San Jacinto fault splits from the main trace of the San Andreas fault. Researchers discovered that Cajon Pass can prevent or facilitate earthquakes moving between the faults, depending on how similar their stress levels are at the time of rupture.

And right now, the San Andreas and San Jacinto faults appear to have comparable, extremely elevated stress levels, potentially spelling trouble for Los Angeles, San Bernardino, Riverside and the Coachella Valley, the team warned.

"Our results show that stress levels on multiple fault segments are now at or above the highest values seen in the past millennium and that the region may be capable of a large through-going rupture involving both fault systems," study first author Liliane Burkhard, a planetary geologist at the University of Bern in Switzerland and at the University of Hawaii at Manoa, said in a statement.

The San Andreas and San Jacinto faults have caused 36 earthquakes with magnitudes of 6.4 or above in the past 1,000 years. Southern California's last "big one" was a magnitude 7.9 event in 1857, when a 205-mile (330 kilometers) segment of the San Andreas fault slipped horizontally between Parkfield and Cajon Pass. That rupture did not propagate through Cajon Pass, but a similar megaquake in 1812 did, suggesting this could happen again in what is now a much more built-up and densely populated environment, according to the study.

Almost 170 years have passed since the 1857 megaquake, raising fears that another huge earthquake could be due to hit soon.

To estimate this risk, Burkhard and her colleagues built a model replicating the last 1,000 years of major earthquake activity along the southern San Andreas and San Jacinto fault systems.

The researchers used observations such as tree-ring records and age data from sediments that have been displaced to reconstruct Southern California's earthquake history. They fed this information into the model, which simulated the accumulation, release and propagation of tectonic stress in the San Andreas and San Jacinto faults.

The results, published June 3 in the Journal of Geophysical Research: Solid Earth, suggest the San Andreas and San Jacinto faults are primed for an Earth-shattering rupture, which may involve the earthquake gate at Cajon Pass opening to unleash more destruction than a single-fault event would on its own.

If a rupture were to occur along the two branches of the San Andreas fault that connect at Cajon Pass, it would be a joint rupture, according to the study. If both branches of the San Andreas fault and the San Jacinto fault were involved, this would constitute a tripartite rupture.

The chance of each event happening and the timing of a potential rupture are unknown, but understanding how much stress is building up inside the system could help planners and policymakers prepare for whatever comes next, Burkhard said.

"What we can say is that the system is critically stressed, and that physics-based models like this one give us a clearer picture of the range of scenarios we should be prepared for," she said. "That information matters for hazard assessment, infrastructure planning, and emergency preparedness."

The researchers say their model could apply to other fault junctions and be used as a tool for hazard assessment globally. "We are using rigorous, quantitative science to better understand the risk facing millions of people," Burkhard said.

Scientists have discovered a giant, fan-shaped structure that connects several well-known basins deep beneath the East Antarctic Ice Sheet — and it may have formed in the breakup of the ancient supercontinent Gondwana.

The feature is the product of a tectonic process known as distributed rotational extension, in which Earth's crust deforms outward from a fixed, central point, like fingers spreading out on a human hand. The gaps between the "fingers" in East Antarctica are triangular basins that were previously described but not recorded as belonging to a single system, researchers reported in a new study.

"Rotational extension is known from other tectonic settings, but recognizing a feature of this scale, hidden beneath the East Antarctic Ice Sheet, is quite remarkable," first author Egidio Armadillo, an associate professor and researcher in the Applied Geophysics Laboratory at the University of Genoa in Italy, told Live Science in an email. "If our interpretation is correct, this may be one of the largest and clearest examples of distributed rotational extension yet recognized in continental crust."

The discovery began with the simple observation that many buried basins in East Antarctica seem to radiate from the same place. From there, Armadillo and his colleagues examined the region's subglacial landscape and geology, as well as gravitational, magnetic and seismic data. They also used models to simulate the formation of the structure, which they named the East Antarctic Fan-Shaped Basin Province.

The results, published June 3 in the journal Nature Geoscience, support the idea that some of East Antarctica's best-known features — including the Wilkes and Aurora basins and the basin that hosts Lake Vostok, the largest known subglacial lake on Earth — were formed by distributed rotational extension. But it's unclear exactly when this happened, Armadillo said.

"The structure may have developed in more than one phase," he said. "However, we think it is likely connected to the long tectonic evolution that preceded and accompanied the breakup of Gondwana, especially the separation between Antarctica and Australia."

Gondwana splintered around 180 million years ago, creating the landmasses and continents we know today. The split between Antarctica and Australia occurred roughly 70 million years ago, toward the end of the Cretaceous period (145 million to 66 million years ago). The East Antarctic Fan-Shaped Basin Province may have facilitated this late separation by weakening a zone to the north of the province that eventually tore apart, but the province may have continued to fan out after Antarctica and Australia broke apart, Armadillo said.

The precise mechanism that drove East Antarctica's distributed rotational extension remains unknown. "In my view, this is one of the most exciting aspects of the study: it does not close the problem, but opens a new research direction," Armadillo said.

Overall, the results suggest East Antarctica has a much more dynamic tectonic history than scientists previously thought. "East Antarctica is often regarded as an old, cold and relatively stable cratonic [ancient and deeply rooted] region," Armadillo said. "In our model, the formation of the fan-shaped basin province strongly influences the surrounding landscape."

The structure opened several enormous basins that are now concealed under more than 1.8 miles (3 kilometers) of ice. To the west, the structure's formation may have contributed to the uplift of the Gamburtsev Mountains, which are similar to the European Alps in scale and shape but completely buried in ice. And to the east, the spreading of the "fingers" likely helped rotate and break up the Transantarctic Mountains, which divide East and West Antarctica, Armadillo said.

"The main message is that a large part of East Antarctica may not simply be a collection of separate subglacial basins, but a coherent tectonic province produced by a continent-scale deformation process," he said. "At the same time, our model is a hypothesis that can and should be tested further. In particular, better constraints on the timing of deformation will be essential."

The discovery could shed light on how the East Antarctic Ice Sheet will respond to climate change, because tectonic processes influence the paths followed by glaciers and ice streams when they melt. However, the broader significance of the findings is that Antarctica still conceals many geological secrets, Armadillo said.

"More than 99% of the bedrock is hidden beneath the ice, so integrating subglacial topography, gravity, magnetics, crustal structure and ice-sheet observations is essential," he noted.

Antarctica quiz: Test your knowledge on Earth's frozen continent

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.

Fingal's Cave is a sea cave in Scotland whose walls are made of hexagonally joined basalt columns. These structures may have formed within the same lava flow that shaped the Giant's Causeway, a geological formation in Northern Ireland composed of more than 40,000 interlocking basalt pillars.

Fingal's Cave extends 230 feet (70 meters) deep and 60 feet (18 m) high inside the small, uninhabited island of Staffa, located in Scotland's Inner Hebrides. It was carved by a volcanic eruption sometime during the Paleocene epoch (66 million to 56 million years ago).

As giant lava flows from this eruption began to cool and solidify, their top and bottom parts contracted and fractured into hexagonal shapes similar to those formed by desiccation cracks in muddy sediments. Eventually, these fractures extended and combined in the center of the flow, forming hexagonal pillars whose sides were later revealed by waves eroding the margins of the flow, according to the National Trust for Scotland.

The cave gets its name from an Irish myth about a warrior called Fionn Mac Cumhaill. According to the legend, Fionn — whose full name was shortened to Fingal, meaning "white stranger" — built the Giant's Causeway across the sea to Scotland to fight a rival called Benandonner, and Fingal's Cave is what remains of Fionn's path over the ocean on the Scottish side.

The 18th-century Scottish writer James Macpherson popularized the name Fingal's Cave with a book titled "Fingal, an Ancient Epic Poem in Six Books" that was published in 1762. Then, after visiting the cave in 1829, the Romantic composer Felix Mendelssohn wrote an overture — a musical introduction to a ballet or opera — known as the "Hebrides Overture" or "Fingal's Cave Overture."

Mendelssohn was inspired by the natural acoustics and eerie echoes inside Fingal's Cave, according to the National Trust for Scotland. A nod to these unique sounds is also found in the cave's Gaelic name, "Uamh-Binn," meaning "cave of melody" or "musical cave." Mendelssohn's overture established Fingal's Cave as a tourist destination, and other famous visitors include the authors Jules Verne and Robert Louis Stevenson, the poets John Keats and Lord Alfred Tennyson, and Queen Victoria.

The cave can still be visited today through organized sightseeing cruises that take tourists inside the cathedral-like cavern when ocean conditions are calm enough.

The National Trust for Scotland owns Fingal's Cave as part of a nature reserve that was established in 2001. The cave and its surroundings host several types of birds and marine animals, including puffins, fulmars, basking sharks, dolphins, gray seals, minke whales and pilot whales.

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

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!

The Appalachian Mountains hold massive untapped reserves of extractable lithium — enough to make 500 billion cellphones, 180 billion laptops or 130 million electric vehicles, new research from the U.S. Geological Survey (USGS) suggests.

The region holds 2.5 million tons (2.3 million metric tons) of the key element, which would replace U.S. lithium imports for 328 years if imports stayed at last year's level. Therefore, mining this mountain system could lessen the U.S.' dependence on countries like China, Argentina and Chile, but the environmental consequences of doing this are unclear.

The lithium resources, peppered across the eastern U.S. from Alabama to Maine, exist within extremely coarse-grained rocks called pegmatites, geologists reported in two new studies of the northern and southern Appalachians.

"This is the first USGS mineral resource assessment of the lithium resources in the region," said Christopher Holm-Denoma, a USGS research geologist and a co-author of the northern Appalachians analysis, which was published April 18 in the journal Natural Resources Research. "Assessing these deposits is part of a nationwide USGS assessment of lithium resources in pegmatites, in brines and dried lakebeds, and in ancient volcanoes."

Lithium is an essential component in electronics, military equipment and rechargeable electric vehicle batteries. It is also used in aerospace alloys, mood stabilizers and industrial lubricants. Demand for lithium to produce batteries, in particular, has risen sharply in the U.S. in recent years, highlighting a large gap between domestic supplies and needs, Holm-Denoma told Live Science in an email.

"The U.S. has some of the largest lithium reserves in the world," he said, yet "more than half the lithium we use in the U.S. is imported," because there is currently only one operational lithium mine in the country, in Clayton Valley, Nevada. Lots of products containing lithium are also made in countries like China, meaning the U.S. imports embedded lithium as well as the raw resource.

The northern Appalachians — which include parts of Maine, New Hampshire, Vermont, New York, Massachusetts, Connecticut, Rhode Island, Pennsylvania, New Jersey and Delaware — hold around 990,000 tons (900,000 metric tons) of lithium, Holm-Denoma and his colleagues found. To get this estimate, the researchers analyzed geologic maps, geochemical and geophysical data, records of mineral occurrences, and the region's tectonic history. They also ran a model with a global dataset of lithium pegmatites to simulate the distribution and size of lithium deposits in the study area.

Lithium-rich pegmatites are relatively small deposits, measuring tens to hundreds of feet wide and hundreds of feet long. However, "when these resources are summed across the region, they represent a significant amount of lithium," Holm-Denoma said.

Lithium in the northern Appalachians is concentrated in Maine and New Hampshire. Several deposits there, such as the Plumbago North pegmatite in Maine, contain the mineral spodumene, which has a high lithium content by weight of 3.5% and well-established extraction steps, Holm-Denoma said.

The southern Appalachian study, published May 11 in Natural Resources Research, revealed that the lower half of the ancient mountain system — which encompasses parts of Maryland, Virginia, North Carolina, South Carolina, Georgia, Tennessee and Alabama — holds approximately 1.57 million tons (1.43 million metric tons) of lithium. These resources are concentrated in South Carolina and North Carolina, which hosted the first large-scale mining of lithium pegmatite in the U.S. between 1942 and the 1990s.

Pegmatite hard-rock mining in places like the Carolinas used to produce most of the lithium used in the U.S., but no such mines are currently active, Holm-Denoma said. Lithium in Clayton Valley, Nevada, is extracted from dry lake beds, he noted.

Lithium-rich pegmatites crystallized from lithium-rich magma more than 250 million years ago during the formation of the Appalachian Mountains. Mining these deposits would involve opening giant pits and destroying wildlife habitats, affecting the landscape and regional biodiversity. It would also create harmful pollution due to waste products such as fluids and finely ground rock that can leach trace elements into the ground and waterways. Additionally, the heavy machinery that would be required for hard-rock mining in the Appalachians would pump huge amounts of carbon dioxide into the atmosphere, and extracting lithium from those rocks would involve toxic chemicals and more greenhouse gas emissions.

Thríhnúkagígur is a dormant volcano near Reykjavík whose last eruption 4,500 years ago left a hollow magma chamber with bronze-and-indigo-colored walls. It's the only place in the world where people can climb into a volcano's plumbing system and explore the cavern that held sizzling molten rock before an eruption.

Since 2012, visitors have been allowed to enter Thríhnúkagígur's magma chamber via an open cable elevator that was built in 2010 for scientists. The chamber is about 700 feet (210 meters) deep, or more than double the height of the Statue of Liberty with the pedestal. Visitors are lowered to the bottom of the cave in a metal cage, and then they are free to roam the 33,600-square-foot (3,120 square meters) cave floor.

Volcanoes don't usually have empty magma chambers beneath them. Typically, during an eruption, there comes a point when the pressure in the chamber isn't high enough to eject any more liquid. The leftover magma slowly solidifies inside the chamber, filling the ground beneath the volcano.

Thríhnúkagígur is an exception, but researchers don't really understand why. The magma that fed the most recent eruption seems to have disappeared, and scientists think it may have been sucked back down into Earth's crust.

"It's like somebody came and pulled the plug and all the magma ran down out of it," Haraldur Sigurdsson, a volcanologist and professor emeritus of marine geology and geophysics at the University of Rhode Island, told Inside the Volcano, a company that organizes tours of Thríhnúkagígur.

The colors inside the chamber are attributed to microbes, but not much is known about the organisms that live there. Sulfur-rich gases likely painted some parts of the cave yellow and orange, while rocks falling off the walls formed the indigo and blue patches. Visitors occasionally see puffs of steam rising from corners of the chamber, but these are caused by water dripping onto lamps that illuminate the cave and are not signs of an impending eruption.

Evidence suggests Thríhnúkagígur has erupted three times over the past 50,000 years. The volcano presents three peaks at the surface — hence its name, which translates to "Three Peaks Crater." They are similar in height ‪—‬ about 115 feet (35 m) tall ‪—‬ and they form a line, with about 660 feet (200 m) between each peak.

The youngest peak dates to the eruption 4,500 years ago. At the top sits the opening where scientists and tourists start their journey into the heart of the volcano. The next peak in the line formed 5,000 years ago, and it is partly encircled with solidified lava from the most recent eruption, according to Inside the Volcano. The oldest peak formed 50,000 years ago, when Iceland was covered with a thick ice sheet. It is composed of hyaloclastite, a volcanic rock characterized by sharp, glassy fragments that appear when lava comes into contact with water and ice.

It's unlikely that Thríhnúkagígur will erupt anytime soon, even though the volcano sits within the Mid-Atlantic Ridge, a tear in Earth's crust where the Eurasian and North American tectonic plates are separating, according to Inside the Volcano.

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

Researchers may have found a new way to locate deposits of rare earth elements that are vital to the tech and energy industries.

Rare earth elements crystallize in Earth's mantle inside blobs of magma that are rich in alkali metals, such as sodium and potassium, and carbonate minerals, such as calcite and dolomite. In a new study, scientists found that these types of magma, known as alkaline and carbonatite magmas, form above ancient subduction zones, where one tectonic plate dives beneath another.

"This research shows that the ingredients for these critical mineral deposits were put in place many million[s] to even billions of years ago," study lead author Carl Spandler, a professor of mineralogy, petrology, geochemistry and economic geology at Adelaide University in Australia, said in a statement. "By identifying where these ancient processes occurred, we can significantly narrow down the search areas for future discoveries."

The study, published April 8 in the journal Science Advances, challenges previous theories that linked rare earth deposits primarily to mantle plumes — giant, mushroom-shaped columns of red-hot molten rock that originate near Earth's core. It's possible that mantle plumes are involved in making rare earth elements, the researchers wrote in the study. However, there is no clear overlap between the two, and plumes may be too hot to produce alkaline and carbonatite magmas.

In the study, the team used advanced modeling techniques to reconstruct Earth's plate tectonics and subduction processes over the past 2 billion years. (Scientists think plate subduction started at least 3.1 billion years ago, but the best models go back only 2 billion years.) Then, the researchers compared the positions of subduction zones with the locations of present-day rare earth deposits and regions of the mantle where alkaline and carbonatite magma blobs are known to exist.

Spandler and his colleagues found that, globally, known deposits of rare earth elements and the pockets of magma that host them frequently appear above ancient subduction zones.

When a tectonic plate plunges beneath another plate at a subduction zone, fluids (such as water) and halogen elements (fluorine, chlorine, bromine, iodine, astatine and tennessine) are released into the overlying mantle. The researchers proposed that these substances react with rocks such as peridotite, creating "fertilized" mantle regions that can remain stable for millions of years, before gradually melting to produce alkaline or carbonatite magma and, subsequently, rare earth deposits.

Various geological processes could theoretically melt the fertilized mantle material, including a mantle plume, the stretching and thinning of continents above, and a decrease in pressure resulting from deglaciation at Earth's surface, the researchers wrote in the study. Regardless of the specific process, the huge age gap between some subduction zones and overlying magma blobs and rare earth deposits in the study suggests that fertilized regions can endure for eons.

"This time lag is one of the most surprising aspects of our findings," Spandler said in the statement. "It shows that the Earth's mantle can store these enriched zones for incredibly long periods before the right conditions arise to form mineral deposits."

The results showed that 67% of known alkaline and carbonatite magma blobs and 72% of known rare earth deposits sit on top of fertilized mantle material. Because older rare earth deposits tend to be larger and of a higher grade than newer ones, the researchers redid the analysis for deposits older than 540 million years — and found that 92% of them are located above fertilized mantle regions.

The rare earth deposits that weren't connected to fertilized mantle regions in the study are probably linked to subduction zones older than 2 billion years, the researchers wrote. Notably, there were more alkaline and carbonatite magma blobs and rare earth deposits in regions of the world where multiple fertilized mantle areas overlap, they wrote.

There are 17 rare earth elements — yttrium, scandium and the 15 metallic elements found at the bottom of the periodic table. These elements are essential components in electric vehicle batteries, wind turbines and smartphones, but until now, locating deposits big enough to mine has been challenging.

The results could help countries and corporations find more rare earth element deposits, study co-author Andrew Merdith, a researcher in Adelaide University's School of Physics, Chemistry and Earth Sciences, said in the statement. "By focusing on these ancient tectonic zones, exploration companies and governments can take a more targeted and efficient approach to finding new deposits," Merdith said.

The best places to look may be areas that have ancient subduction zones, as well as magma that formed at low temperatures and highly stable crust and upper mantle regions, the researchers wrote in the study.

Refining the models and going further back in time could help scientists locate even more prospective regions, they added.

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

This intriguing astronaut photo shows a series of rocky rings and their distinctive "hat" towering above a dune sea in the Sahara. The concentric, shadow-filled walls are home to ancient artworks and, occasionally, herds of cattle.

The colossal structure, known as Mount Arkanu (sometimes spelled Arkenu), is a massif, or group of mountains, that stands up to 2,600 feet (800 meters) above the surrounding sands and stretches up to 15.5 miles (25 kilometers) across at its widest point. The peaks are located in southeast Libya, near the border with Egypt.

Due to the mountains' shape, scientists previously assumed that the massif was an ancient impact crater that formed when a giant space rock slammed into the northeast Sahara. But more recent research has shown that the rocky rings are not of extraterrestrial origin.

Instead, the mountains were created when "magma [repeatedly] rose toward the surface and intruded into the surrounding rock," according to NASA's Earth Observatory. This formation process likely ended hundreds of millions of years ago but has not been properly dated.

"Repeated intrusion events produced a series of overlapping rings, their centers roughly aligned toward the southwest," Earth Observatory representatives wrote. "The resulting ring complex — composed of igneous basalt and granite — is bordered to the north by a hat-shaped formation made of sandstone, limestone, and quartz layers."

The massif has two large gaps in its outermost southern wall (bottom right in the photo). These have been slowly carved out by a pair of wadis, or ghost rivers, which sporadically fill with water when it rains. The phantom waterways can also be seen snaking through the dark plateau surrounding the complex.

This region of the Sahara is hyperarid; it gets only 1 to 5 millimeters (0.04 to 0.2 inches) of rain each year, according to the Earth Observatory. However, the massif receives between 5 and 10 mm (0.2 to 0.4 inches) of rain annually, due to a phenomenon known as "orographic precipitation," which occurs when clouds form over raised landforms, according to the U.K. Met Office.

As a result of this additional water, the rings are partially filled with grasses, bushes and trees that the shadows from the towering peaks shelter from the desert's scorching temperatures.

Cattle herding

The combination of shade, vegetation and occasional water has historically made the massif a popular destination for nomads traversing the surrounding dune seas.

Another massif, Mount Awaynat (sometimes spelled Uwaynat or Uweinat), is located roughly 12 miles (20 km) southeast and has provided similar benefits to desert wanderers for generations.

Some of the canyon-like walls of both Mount Arkanu and Mount Awaynat are covered with rock carvings, or petroglyphs, that were first discovered in 2003. These ancient artworks depict human fugures, along with cattle and other tethered animals, such as giraffes.

Early-20th-century explorers noted that members of the local bedouin tribe trekked their cattle herds to the massifs and left them inside to graze for up to three months at a time — and blocked up the holes created by the wadis to stop the animals from wandering off.

The cattle carvings within both structures suggest that this practice has been going on for thousands of years.

See more Earth from space

NASA's Curiosity rover has snapped stunning new photos of giant "spiderwebs" zig-zagging across the surface of Mars. One of these images has revealed never-before-seen, egg-like spheroids covering the sprawling structures — and scientists are struggling to explain them.

Over the last 8 months, Curiosity has been closely examining a series of interconnected rocky ridges, dubbed "boxwork," on the slopes of Mount Sharp, in the Gale Crater. These ridges, which cover an area up to 12 miles (20 kilometers) across, were created billions of yars ago as ancient Martian groundwater seeped beneath the planet's surface. They were first spotted by orbital spacecraft in 2006, but they have remained largely unexplored until now.

The web-like structures should not be confused with the infamous "spiders on Mars" — a series of geological features that are created when carbon dioxide ice sublimates beneath the Red Planet's surface and look like swarming arachnids when viewed from above. (These faux spiders were also recently recreated on Earth, while a similar "wall demon" was also spotted on Jupiter's moon Europa.)

NASA released Curiosity's first boxwork photos in June 2025, shortly after reaching the rocky ridges. But on Monday (Feb. 23), the agency released two more snaps, which showed the structures in much greater detail.

One of these photos, captured Sept. 26 last year, shows off a ground-level view of the ridges, which stand 3 to 6 feet (1 to 2 meters) above Mars' surface. But a second close-up image, snapped on Aug. 21, revealed that some of these ridges are covered in tiny irregular-shaped lumps, or nodules, that have not been seen until now.

These nodules bear a striking resemblance to mini spheroids on the surface of a mysterious "spider egg" rock, which was discovered in the Jezero Crater by NASA's Perseverance rover last year and has an unknown origin. And researchers are also having a hard time explaining exactly how the tiny boxwork "eggs" formed.

"We can't quite explain yet why the nodules appear where they do," Tina Seeger, a planetary scientist at Rice University in Houston who is leading Curiosity's boxwork investigations, said in a statement. "Maybe the ridges were cemented by minerals first, and later episodes of groundwater left nodules around them," Seeger said. But more work is needed to confirm if this is the case.

However, while the nodules and boxwork have an eerily biological appearance, there is no suggestion that they have any direct ties to extraterrestrial life.

Martian spiderwebs

Boxwork is made up of criss-crossing ridges of mineral-rich rocks that litter the surface of Mars. Similar yet smaller structures are found on Earth, predominantly within caves, and form when calcite-rich water flows between rocks that are eventually eroded, much like how stalagmites and stalactites form, according to the National Speleological Society.

However, on Mars, the boxwork was shaped by the fierce winds that scour the planet's surface: "The bedrock below these ridges likely formed when groundwater trickling through the rock left behind minerals that accumulated in those cracks and fissures, hardening and becoming cementlike," NASA representatives previously wrote. "Eons of sandblasting by Martian wind wore away the rock but not the minerals, revealing networks of resistant ridges within."

The team is particularly interested in the patch of boxwork on Mount Sharp because it formed in isolation and is surprisingly high up the mountain's slopes, which has implications for the planet's puzzling watery past.

"Seeing boxwork this far up the mountain suggests the groundwater table had to be pretty high," Seeger said. This hints that the water in this area may have "lasted much longer than we thought," she added.

Researchers hope that further investigation will also shed light on the specific conditions that formed these structures and whether they might have been favorable to any potential ancient Martian microbes.

"These ridges will include minerals that crystallized underground, where it would have been warmer, with salty liquid water flowing through," Kirsten Siebach, a Curiosity mission scientist at Rice University who has also studied the area, previously said. "Early Earth microbes could have survived in a similar environment. That makes this an exciting place to explore."

Uneven terrain

While the latest stage of Curiosity's mission is yielding fascinating results, it is also proving to be one of the hardest to navigate.

The boxwork is arguably the hardest terrain that the car-sized robot has had to traverse since it landed in the Gale Crater in 2012. The rover must balance along the ridges "like a highway" and avoid slipping "down into the hollows" between them, Ashley Stroupe, a systems engineer at NASA's Jet Propulsion Laboratory in Southern California, said in the statement.

The task of controlling the rover has also become increasingly challenging due to a gaping hole in one of the robot's wheels, which was first spotted in late 2024.

"There’s always a solution," Stroupe said. "It just takes trying different paths."

Mars quiz: Is your knowledge of the Red Planet out of this world?

This striking satellite photo shows a recently uncovered meteor crater in China that is likely the youngest impact structure on Earth and the largest in its wider age bracket. The horseshoe-shaped depression is also only the second impact crater ever discovered in the country.

The Yilan crater is an incomplete, nearly circular impact crater located in the Lesser Xing'an (also spelled Khingan) mountain range of China's Heilongjiang province, around 12.5 miles (20 kilometers) northwest of the town of Yilan. It is approximately 1.15 miles (1.85 km) across at its widest point, and its ringed walls reach up to 500 feet (150 meters) above the crater floor.

Chinese researchers discovered that the incomplete ring was an impact crater in mid-2021, around three months before this photo was taken. Until then, it had largely gone unnoticed because it is surrounded by thick forests. Although locals knew about the structure, they called it Quanshan, meaning "circular mountain ridge," which suggests they had no idea of its extraterrestrial origins.

However, when the research team dug up to 1,440 feet (440 m) beneath the crater's floor, they found "shocked quartz, melted granite, glass containing holes formed by gas bubbles, and tear-drop-shaped glass fragments" — all clear signs that a sizable space rock had slammed down there, according to NASA's Earth Observatory.

Carbon dating revealed that the crater formed sometime between 46,000 and 53,000 years ago, meaning it could be the youngest of the roughly 200 major impact craters on Earth.

Until this discovery, the most widely accepted "youngest major crater" on Earth was Barringer Crater (also known as Meteor Crater) in Arizona, which dates back 50,000 years, according to the Lunar and Planetary Institute. Given the uncertainty around the Yilan crater's age, researchers cannot be sure that it is younger than Barringer Crater, although it is thought likely.

The Yilan crater is also the largest of any impact crater under 100,000 years old, so it beats another record previously held by Barringer Crater, which is around 0.75 mile (1.2 km) across.

As you can see in the satellite photo, the southern third of the crater's rim is missing. Researchers are unsure exactly when or how this section of the crater's rim disappeared. However, sediment found on the crater's floor hints that there was formerly a lake within the crater, which strongly suggests that the structure was once fully intact, according to the Earth Observatory.

Chinese craters

The Yilan crater is the first impact crater to be discovered in China since the 1.1-mile-wide (1.8 km) Xiuyan crater in Liaoning province, which dates back to between 330,000 and 1.1 million years ago, was confirmed in 2009.

Given how large China is — around the same size as the U.S. by land area — it has long been a mystery as to why more impact craters haven't been found there. However, others have been uncovered following the discovery of the Yilan crater.

In September 2023, scientists discovered a third Chinese crater, around the same size as the Yilan crater. Carved into the summit of a mountain near the North Korean border, the crater dates back at least 150 million years.

Then, in October 2025, scientists confirmed a fourth impact structure, dubbed the Jinlin crater, on a mountain near Zhaoqing in China's Guangdong province. This crater is only around 3,000 feet (900 m) wide and may date to as recently as the current epoch, known as the Holocene, which began 11,700 years ago, according to Sci News, although its age is unconfirmed.

See more Earth from space

This intriguing astronaut photo reveals the hidden beauty of the expansive Great Dyke of Zimbabwe, a massive seam of ancient magmatic rock that's chock-full of valuable minerals.

The Great Dyke stretches approximately 342 miles (550 kilometers) across central Zimbabwe, from outside the capital city, Harare, in the northeast, to near the country's second-largest city, Bulawayo, in the southwest. It ranges from 2 to 8 miles (3 to 13 km) wide and contains hills that rise up to 1,500 feet (450 meters) above the surrounding plateaus, according to NASA's Earth Observatory.

Despite its name, the gigantic structure is not actually a dike — a vertical sheet of frozen magma that cuts through existing rock layers. Instead, it is a lopolith, which is similar to a dike but forms parallel to existing rock sheets and is both flatter and more lenticular, or saucer-shaped.

The Great Dyke is thought to be the longest continuous igneous intrusion, or structure of elevated magmatic rock, anywhere on Earth, according to the Zimbabwe Geological Survey.

The astronaut's snap shows the southernmost tip of the structure, around 78 miles (125 km) from Bulawayo. In 1983, astronauts on board the space shuttle Challenger also captured a striking photo of the structure's southern half, and in 2003, NASA's Terra satellite imaged the lopolith's entire length (see below).

Geologists think the lopolith formed around 2.5 billion years ago, when magma from Earth's mantle gradually seeped upward through tectonic plate faults. This means the structure has existed for more than half of Earth's roughly 4.5 billion-year history.

This magma was full of valuable minerals that are normally locked deep below Earth's crust, which has made the area a hotspot for mining. Today, there are at least half a dozen major mines along the lopolith's length, according to Mining Zimbabwe magazine.

The Great Dyke is full of important metals, including gold, nickel, copper, titanium, iron, vanadium and tin, according to the Earth Observatory.

However, it is best known for its expansive platinum deposits, which are collectively the third largest of their kind on Earth, as well as its unusually pure chromite, which contains high levels of chromium — a key component in the production of stainless steel, according to Mining Zimbabwe.

The Great Dyke is also rich in rocks that are used for sculpting, "resulting in an artist's paradise akin to the Greek marble quarries," local artist Michael Nyakusvora wrote on their website.

"The Great Dyke of Zimbabwe is more than a line on a map — it's a lifeline of economic opportunity [and] a geological marvel," according to Mining Zimbabwe.

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It's not easy to determine how much water there is across a landscape. A measly 1% of Earth's freshwater is on the surface, where it can be seen and measured with relative ease. But beneath that, measurements vary massively depending on water table depth and ground porosity we can't directly see.

Reed Maxwell, a hydrologist at Princeton University, likes to think of rainfall, snow, and surface water as a checking account used for short-term water management needs and groundwater as a savings account, where a larger sum should, ideally, be building up over time.

"We're operating in a situation where we don't know how much is going into the savings account every month, and we don't know how much is in our savings account," he said.

But a new groundwater map by Maxwell and colleagues offers the highest-resolution estimate so far of the amount of groundwater in the contiguous United States: about 306,500 cubic kilometers. That's 13 times the volume of all the Great Lakes combined, almost 7 times the amount of water discharged by all rivers on Earth in a year. This estimate, made at 30-meter resolution, includes all groundwater to a depth of 392 meters, the deepest for which reliable porosity data exist. Previous estimates using similar constraints have ranged from 159,000 to 570,000 cubic kilometers.

"It's definitely a move forward from some of the previous [mapping] efforts," said Grant Ferguson, a hydrogeologist at the University of Saskatchewan who was not involved in the research. "They're looking at much better resolution than we have in the past and using some interesting techniques."

Well, Well, Well

Past estimations of groundwater quantity have been based largely on well observations.

"That's the really crazy thing about groundwater in general," said Laura Condon, a hydrologist at the University of Arizona and a coauthor of the paper. "We have these pinpricks into the subsurface where there's a well, they take a measurement of how deep down the water table depth is, and that's what we have to work with."

But not all wells are measured regularly. For obvious reasons, there tend to be more wells in places where more groundwater is present, making data on areas with less groundwater scarcer. And a well represents just one point, whereas water table depth can vary greatly over short distances.

Researchers have used these data points, as well as knowledge of the physics of how water flows underground, to model water table depth at a resolution of about 1 kilometer. They've also used satellite data to capture large-scale trends in water movement. But those data are of lower resolution: Data from NASA's GRACE (Gravity Recovery and Climate Experiment) Tellus mission, for instance, have a resolution of about 300 kilometers, about 10,000 times coarser than the new map.

To demonstrate the value of high-resolution data, the team showed what happened when they decreased the resolution of their entire map from 30 meters to 100 kilometers—the spatial resolution of many global hydrologic models. The resulting more pixelated map estimated just above 252,000 cubic kilometers of water, an underestimation of 18% compared to the new map.

In addition to identifying groundwater quantities at high resolution, the new map reveals more nuanced information about known groundwater sources.

For instance, it shows that about 40% of the land in the contiguous United States has a water table depth shallower than 10 meters. "That 10-meter range is that range where you can have groundwater— plant— land surface interactions," Condon said. "And so that's just really pointing to how connected those systems are."

Bias for Good

The new work used direct well measurements as well as satellite data — about a million measurements, made between 1895 and 2023 — along with maps of precipitation, temperature, hydraulic conductivity, soil texture, elevation, and distance of streams. Then, the scientists used the data to train a machine learning model.

In addition to its being able to quickly sort through so many data points, Maxwell noted another benefit of the machine learning approach that might sound unexpected: its bias. Early groundwater estimates were relatively simplistic, not accounting for either hydrogeology or the fact that humans themselves pump water out of the ground. The team's machine learning approach was able to incorporate that information because evidence of groundwater pumping was present in the data used to train it.

"When you hear about bias in machine learning all the time, it's usually in a negative connotation, right?" Maxwell said. "As it turns out, when you can't disentangle the signal of groundwater pumping and groundwater depletion from the almost 1 million observations that we used to train this machine learning approach, it implicitly learned that bias.… It's learned the pumping signals, it's learned the human depletion signal."

Maxwell and the other researchers hope the map can be a resource for regional water management decisionmakers, as well as for farmers making decisions about irrigation. Condon added that she hopes it raises awareness of groundwater in general.

"Groundwater is literally everywhere all the time," she said. The map is "filled in everywhere, wherever you are. Some places it's 300 meters deep, some places it's 1 meter deep. But wherever you're standing, dig down, and there's water down there somewhere."

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

Earth's core contains up to 45 times more hydrogen than the oceans do, making it the largest hydrogen reservoir on the planet, a new study suggests.

Researchers found that this vast amount of hydrogen entered the core during its formation around 4.5 billion years ago, and did not arrive via comets that pummeled Earth once the core was established. The finding could settle the debate about when and how hydrogen was delivered to our planet.

"That hydrogen on Earth, including hydrogen in the core, was delivered during planet formation is an established hypothesis," study lead author Dongyang Huang, an assistant professor in the School of Earth and Space Sciences at Peking University in China, told Live Science in an email. "What differentiates the community is when hydrogen was delivered along Earth's formation."

This debate has continued because hydrogen deep inside Earth is extremely difficult to quantify. Hydrogen is the smallest and lightest element in the universe, so most techniques do not have the resolution to properly detect it in high-pressure and high-temperature environments such as Earth's core.

But estimating how much hydrogen is locked inside the core is a key to understanding how the hydrogen got there in the first place, Huang said.

Previous research used a technique called X-ray diffraction to estimate the amount of hydrogen in Earth's core. This method quantifies the minerals and other substances in a material by analyzing how that material scatters X-rays. Because Earth's core is made almost entirely of iron, scientists added hydrogen to a sample of iron in the lab and measured the expansion of the iron's crystal structure to calculate how much hydrogen could be trapped inside the core.

The downside of X-ray diffraction in this case is that it makes a couple of crucial assumptions, Huang said. First, it assumes researchers have an accurate understanding of iron crystal structures and how they react under certain conditions. Second, it supposes that silicon and oxygen, both present in the core, do not deform the crystal structure when they dissolve into iron — which, it turns out, they do.

For the new study, Huang and his colleagues employed an alternative method known as atom probe tomography. This technique can "provide 3D nanoscale compositional mapping of all the elements in the periodic table" and is "ideal for high-pressure samples," Huang said.

The researchers simulated the conditions that likely existed when Earth's core was forming. To begin, they coated a tiny sample of iron metal with hydrous silicate glass to model the core covered in magma. Then, they placed this object inside a diamond anvil cell — a device in which two diamond crystals squeeze together to generate extreme pressure similar to that found in Earth's core. To create high-temperature conditions, the scientists used lasers that heated the object to about 8,730 degrees Fahrenheit (4,830 degrees Celsius).

The researchers used atom probe tomography in this context. They discovered that hydrogen, oxygen and silicon dissolve into iron crystal structures simultaneously under extreme conditions, thus altering the crystals in previously unknown ways.

Crucially, equal amounts of hydrogen and silicon entered the "core" from the "magma" in the experiment, which helped the researchers estimate that hydrogen makes up 0.07% to 0.36% of Earth's core by weight.

The results, published Tuesday (Feb. 10) in the journal Nature Communications, suggest Earth's core contains nine to 45 times as much hydrogen as the planet's oceans. If comets had delivered hydrogen to Earth after the core had finished forming, hydrogen would mostly occur in Earth's shallower layers. But the finding that the core is Earth's biggest hydrogen reservoir indicates that hydrogen was delivered before the core was fully formed, Huang said.

"This is the first time that the mechanism of how hydrogen enters the core was identified," he said.

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

Newly discovered fossil imprints of ancient microbial colonies suggest that researchers need to broaden their search for the oldest life to deeper and more unstable areas.

The wrinkled fossil structures, found in the Central High Atlas Mountains of Morocco, are imprinted on turbidites, which are deposits laid down by underwater landslides. The researchers were surprised to see the imprints on these turbidites, because most microbial mats today grow in shallow water, where photosynthetic bacteria can draw energy from light filtering through the waves.

The turbidites in Morocco, on the other hand, were at least 590 feet (180 meters) below the surface when they were laid down 180 million years ago.

Wrinkle structures "shouldn't be in this deep-water setting," Rowan Martindale, a geobiologist at the University of Texas at Austin, said in a statement.

Martindale is the lead author of a paper published Dec. 3 in the journal Geology describing this surprising find. She stumbled — almost literally — across the fossils while studying ancient reefs in Morocco's Dadès Valley. While walking, she noticed wrinkly, ripple-like structures on the fine sandstone and siltstone below her feet.

These wrinkle structures looked like imprints of photosynthetic microbial mats, which are layered communities of bacteria that often form on sediments in ponds, oceans and other bodies of water. But those fossils are usually older than 540 million years because the delicate pattern is normally wiped away by animal activity over time, and there were few animals before 540 million years ago.

The fossils also couldn't have been photosynthetic, the researchers reported in their paper, because very little light would have penetrated the water to their level. However, chemical analysis revealed high levels of carbon in those rock layers — a sign that the wrinkles were formed by life.

This life was likely chemosynthetic, meaning it got its energy via chemical reactions rather than from sunlight, Martindale and her colleagues wrote. Instead, these organisms would have lived off of sulfur or other compounds. Today, chemosynthetic microbial mats form on continental shelves, where underwater landslides and turbidites also occur.

Those landslides may have been crucial to the cycle that allowed the microbes to thrive, the researchers found. Landslides tumbling from the continent toward the deep ocean would have dragged down organic material, which would have decomposed and created compounds such as methane or hydrogen sulfide — tasty snacks for chemosynthetic life. Between landslides, microbial mats would have thrived. Sometimes, they would have been washed away by another debris flow, but in other cases, their traces were preserved.

The finding suggests that scientists should widen their search for signs of wrinkle structures from shallow formations to rocks that were originally formed in deeper waters. This may lead them to more information about the oldest chemosynthetic organisms.

"Wrinkle structures," Martindale said, "are really important pieces of evidence in the early evolution of life."

The Bandera Volcano Ice Cave is a hollow in the ground in New Mexico where temperatures never exceed 31 degrees Fahrenheit (minus 0.6 degrees Celsius).

The cave formed roughly 10,000 years ago, when the nearby Bandera Volcano violently erupted, spewing lava that solidified at the surface while caverns formed in the layers below. The cave's unusual geology has preserved frigid conditions, which have caused ice to form inside it for at least 3,400 years.

The ice inside the Ice Cave is up to 20 feet (6 meters) thick on the floor year-round. Due to the freezing conditions, Arctic algae have colonized the cave, growing on top of the ice to form a blue-green, living blanket, according to the Ice Cave's website.

The cave is "one of New Mexico's weirdest spots, where it's both hot and cold all at the same time," Paul Mauermann, an environmental educator and director of New Mexico's Sandia Mountain Natural History Center, said in a video.

The Ice Cave is freezing because it is nestled inside a collapsed lava tube. Lava tubes are natural tunnels that form beneath surface lava flows during volcanic eruptions. Because surface flows are in contact with air, they cool and solidify more quickly than the lava flowing closer to the ground. As a result, when a volcano stops erupting, the core of a lava flow drains away while the outside hardens, leaving an empty conduit, or cave.

The Ice Cave has porous walls and an opening that's just the right shape to trap cold air inside the lava tube while keeping the warm air outside. This "natural icebox" is continually replenished through rainfall and snowmelt that freeze upon contact with the icy floor, according to the Ice Cave's website.

Bandera Volcano is also remarkable, as it represents one of the best and most accessible examples of a cinder cone volcanic eruption in North America. This type of eruption is short but explosive, with sprays of lava that crystallize in the air before landing on the ground. This results in steep cones covered in loose fragments that make it hard for anyone to climb some of the volcano's vents.

Bandera is now dormant. One of its vents collapsed during the eruption, forming a 800-foot-deep (240 m) crater that visitors can view from a breach on the south side. Lava likely flowed through this gap and into the valley below, forming a 23-mile-long (37 kilometers) river of molten rock that has since solidified into lava fields, according to the website.

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

New mapping in Australia has revealed a strange dent in the magnetic field beneath the country's Northern Territory.

The Australia Magnetic Anomaly, named after its similarity in shape to the country, holds valuable information about Australia's geological history, including how different rock layers formed and acquired their distinctive magnetic properties.

"Magnetic data allows us to see through the ground and understand geological architecture that would otherwise remain completely hidden," project lead Clive Foss, a senior research geoscientist with the Commonwealth Scientific and Industrial Research Organisation (CSIRO), said in a statement.

A magnetic anomaly is a local variation in Earth's magnetic field caused by the magnetic properties of certain minerals and rocks, such as iron ore deposits, in the crust.

From the moment they form, rocks start to develop magnetic signatures that incorporate information about the direction of Earth's magnetic field at that specific time. This "magnetic memory," known as remanent magnetism, helps scientists reconstruct rocks' past.

However, the magnetic field occasionally flips, and tectonic processes can change rocks' orientation, which muddles the picture. But if scientists can decipher the various clues encrypted in a rock's magnetic signature, they can reconstruct exactly what the rock went through and when.

The Australia Magnetic Anomaly contains structures such as faults, folds and basins that traditional mapping techniques haven't been able to detect, according to the statement. To explore these hidden layers, Foss and his team used advanced modeling techniques to better visualize magnetic data collected during the Northern Territory Government's 1999 Bonney Well Survey.

For that survey, planes fitted with magnetometers — instruments that measure magnetic fields — flew across the Northern Territory in regular lines separated by about 1,300 feet (400 meters). Scientists previously tried to map these data, but the maps didn't always render magnetic signals clearly — particularly along the flight lines, according to the statement.

The new modeling has solved this problem. "My colleague, Dr Aaron Davis, created an innovative gridding algorithm which refined the dataset and produced cleaner, more consistent images," Foss said. "By improving how we process and model these datasets, we can extract more geological information than ever before."

The researchers identified subtle magnetic layers, as well as buried geological boundaries and structures that previous mapping didn't pick up.

The team is still working to interpret these findings, but preliminary results show that the western margin of the Australia Magnetic Anomaly is exposed at the surface in the Northern Territory's Hatches Creek Formation — a geological unit composed of sandstones and volcanic rocks that were deposited between 2.5 billion and 1.6 billion years ago.

Ultimately, mapping the Australia Magnetic Anomaly could lead to important geological discoveries, including opportunities for resource exploration, according to the statement. Companies and Australia's government could benefit from research that creates more detailed maps of mineral deposits.

A massive blob deep under Hawaii seems to be solid and iron-rich, new research finds.

This blob — scientifically known as a mega-ultralow velocity zone — may anchor the Hawaii hotspot, an area where hot material rises through the mantle and drives the volcanic activity that created the Hawaiian Islands.

"Because it's iron-rich material, it is going to be electrically more conductive, and that will actually promote thermal conduction — so it will actually help localize the plume to last longer," said Doyeon Kim, a seismologist at Imperial College London and the first author of the new study, published Jan. 28 in the journal Science Advances.

Ultralow velocity zones (ULVZs) are giant hunks of the planet that sit near the boundary of the mantle and the core, at about 1,800 miles (2,900 kilometers) below the Earth's surface. They get their name from the fact that seismic waves from earthquakes slow down dramatically in these regions. Mega-ultralow velocity zones are the largest of these regions, which often span hundreds of kilometers. They're often found near volcanic hotspots, such as Hawaii, Iceland and the Marquesas Islands of the South Pacific.

"It actually makes them one of our few direct windows into deep-Earth composition and dynamics," Kim told Live Science.

Because these blobs are so deep, scientists typically study them using compressional waves generated by earthquakes. But these pressure waves, or P waves, provide limited information. So Kim and his colleagues used a method they developed in 2020 that could also incorporate S waves, or shear waves, which create vertical motion. By combining data from both types of waves and then modeling rocks and minerals that could match those data, the researchers could get a clearer picture of why the waves slow down in those zones.

They found that the mega-ULVZ under Hawaii is likely rich in iron and solid rock. That largely rules out a competing hypothesis that suggested the area might be extra-melty.

With this information, "we can think about where it is coming from," Kim said. "It could be coming from the relics of Earth's earliest evolution, particularly from the crystallization of a basal magma ocean or recrystallized melt from past mantle melting."

Not every mega-ULVZ may be created equally, Kim added. Some might form from the subduction of water-rich oceanic crust deep into the mantle. Perhaps others involve material from the core itself. The approach in the new paper can help differentiate these types of ULVZs worldwide, he said, as well as shedding light on how planets form in the first place.

"We have to first clearly understand what's happening on Earth to understand fully what's happening on other planets," he said.

Geologists may have finally solved a longstanding mystery surrounding the Colorado River's largest tributary, which appears to have defied gravity and flowed uphill when it first formed.

The Green River originates in Wyoming and links up with the Colorado River in Canyonlands National Park in Utah. Around 8 million years ago, the Green River carved its way through the 13,000-foot-tall (4,000 meters) Uinta Mountains in northeastern Utah and northwestern Colorado instead of flowing around the formation. But in a new study, researchers argue this isn't possible without a mechanism to lower the mountains.

"It's such a weird path," study lead author Adam Smith, a researcher in numerical modeling at the University of Glasgow in the U.K., told Live Science. "We know from dating and other stuff that the mountain range is 50 million years old and the river has only been running that course since 8 million years ago, but possibly as soon as 2 million years ago."

The Green River flows through the Canyon of Lodore, where it has eroded a ravine with 2,300-foot (700 m) walls. Two competing theories have previously tried to explain why the river ran this course, but neither is particularly convincing, Smith said.

One hypothesis is that the Yampa River to the south of the Uinta Mountains cut northward through the formation and created a channel for the Green River. This would have required a tremendous amount of force, which the Yampa River is unlikely to have produced, because it isn't particularly big. "If this were credible, then you would expect giant canyons running through all mountain ranges, but that's not the case," Smith said.

The other theory is that sediments accumulated and temporarily elevated the Green River so that it overtopped the Uintas and carved its path through them, but the available evidence doesn't support this either. "The sediments that you find here aren't as high as the Canyon of Lodore," Smith said.

Instead, the researchers behind the new study suggest the Uinta Mountains subsided to the point where the Green River could flow over them. The researchers propose that a phenomenon called a "lithospheric drip" tugged the mountains down before a rebound effect caused the landscape to rise upwards once more, resulting in the topography we see today.

The findings were published Monday (Feb. 2) in the Journal of Geophysical Research: Earth Surface.

Lithospheric drips are high-density regions that can form directly beneath mountains, where Earth's crust meets the top of the mantle — the layer of the planet between the crust and the outer core. The weight of the mountains increases the pressure at the base of the crust, forming minerals like garnet that are heavier than mantle rocks. Eventually, these minerals form a blob that drips from the base of the crust, dragging the mountains down and reducing their elevation at Earth's surface.

Lithospheric drips trigger a rebound effect when they finally detach and sink into the mantle. The concept of these drips is relatively recent, but evidence of them has been found in several places, including the Andes. "They can happen wherever you have had a mountain range form, and they can happen at any time," Smith said.

A telltale sign of lithospheric dripping is a bullseye-like pattern of uplift on Earth's surface. Smith and his colleagues modeled geological processes in the Uinta Mountains based on the unusual profiles of rivers there and found such a pattern.

The researchers also analyzed seismic tomography images — 3D maps of Earth's interior that are created using seismic waves — from a previous study. They found a blob 120 miles (200 kilometers) deep in the mantle beneath the Uintas that looked very much like an old lithospheric drip, providing strong evidence for this mechanism, Smith said.

Next, the researchers used the observed drip's depth and size to calculate when it detached from the bottom of the Uinta Mountains. They found that it likely broke free between 2 million and 5 million years ago, which fitted with the model's predictions of when the mountains rebounded and matches estimates of when the Green River first cut through the mountains.

The drip lowered the mountains so much that they became "the path of least resistance," Smith said. Once the Green River started flowing over the Uintas, it kept incising the mountains, creating structures like the Canyon of Lodore, he added.

Other experts who weren't involved in the research suggested this explanation could ultimately solve the longstanding mystery.

Mitchell McMillan, a research geologist at the Georgia Institute of Technology, said that lithospheric dripping is a plausible explanation for why the Green River flows the way that it does.

"The most exciting aspect of this study is that it uses clues on Earth's surface to understand mantle processes and how they might affect mountain belts," McMillan told Live Science in an email. "Whether or not the drip hypothesis ultimately ends up being correct here, this study is a valuable demonstration of such an approach."

The Chocolate Hills are a formation made of 1,776 limestone, grass-covered mounds in the Philippines.

This landscape is lush green during the rainy season from February to May, but in the dry season, the hills turn cocoa brown, giving the formation its name.

The Chocolate Hills were designated a national geological monument of the Philippines in 1988 and were granted protection as a natural monument in 1997. There is no other formation quite like them in the world, with just one region in Java, Indonesia, having a similar, but less impressive geology.

The hills are between 100 and 390 feet (30 to 120 meters) tall and have tapering tops. They are examples of what geologists call "mogotes" — steep-sided mounds that occur in tropical karst landscapes, or areas that have a soluble bedrock and host sinkholes and cave systems. Numerous underground caverns and springs have been documented around the Chocolate Hills, according to a 2001 research article, with some caves potentially existing directly beneath the mogotes themselves.

Evidence suggests the Chocolate Hills formed sometime at the start of, or just before, the last ice age (2.6 million to 11,700 years ago), when tectonic processes lifted coral and other marine deposits. These deposits were then exposed to rainfall and erosion, which carved the landscape into regular mounds.

Local myths have tried to explain how the Chocolate Hills formed. According to one legend, the mounds formed after a mud-throwing fight between two giants. Another tale says the region was once inhabited by giant children, who, while competing to make the most mud cakes, baked them under coconut half shells that eventually became the Chocolate Hills.

The land between the hills is flat and cultivated with rice and other crops. When the Chocolate Hills were declared a natural monument in the late 1990s, farmers, small-scale miners and landowners rose up against the government because they feared environmental protections would curb their property rights and livelihoods.

These protests escalated into violent conflicts between the military and a guerilla group dubbed the "Chocolate Hills Command," according to the 2001 article. Two armed fights broke out, one of which caused 10 deaths in October 1999.

Balancing the diverse and sometimes conflicting needs of environmental protection, tourism and local residents still poses a challenge today; the construction of a resort in the middle of the Chocolate Hills sparked public outcry in 2024.

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

Glacial earthquakes are a special type of earthquake generated in cold, icy regions. First discovered in the northern hemisphere more than 20 years ago, these quakes occur when huge chunks of ice fall from glaciers into the sea.

Until now, only a very few have been found in the Antarctic. In a new study published in Geophysical Research Letters, I present evidence for hundreds of these quakes in Antarctica between 2010 and 2023, mostly at the ocean end of the Thwaites Glacier — the so-called Doomsday Glacier that could send sea levels rising rapidly if it were to collapse.

A recent discovery

A glacial earthquake is created when tall, thin icebergs fall off the end of a glacier into the ocean.

When these icebergs capsize, they clash violently with the “mother” glacier. The clash generates strong mechanical ground vibrations, or seismic waves, that propagate thousands of kilometres from the origin.

What makes glacial earthquakes unique is that they do not generate any high-frequency seismic waves. These waves play a vital role in the detection and location of typical seismic sources, such as earthquakes, volcanoes and nuclear explosions.

Due to this difference, glacial earthquakes were only discovered relatively recently, despite other seismic sources having been documented routinely for several decades.

Varying with the seasons

Most glacial earthquakes detected so far have been located near the ends of glaciers in Greenland, the largest ice cap in the Northern Hemisphere.

The Greenland glacial earthquakes are relatively large in magnitude. The largest ones are similar in size to those caused by nuclear tests conducted by North Korea in the past two decades. As such, they have been detected by a high-quality, continuously operating seismic monitoring network worldwide.

The Greenland events vary with the seasons, occurring more often in late summer. They have also become more common in recent decades. The signs may be associated with a faster rate of global warming in the polar regions.

Elusive evidence

Although Antarctica is the largest ice sheet on Earth, direct evidence of glacial earthquakes caused by capsizing icebergs there has been elusive. Most previous attempts to detect Antarctic glacial earthquakes used the worldwide network of seismic detectors.

However, if Antarctic glacial earthquakes are of much lower magnitude than those in Greenland, the global network may not detect them.

In my new study, I used seismic stations in Antarctica itself to look for signs of these quakes. My search turned up more than 360 glacier seismic events, most of which are not yet included in any earthquake catalogue.

The events I detected were in two clusters, near Thwaites and Pine Island glaciers. These glaciers have been the largest sources of sea-level rise from Antarctica.

Earthquakes at the Doomsday Glacier

Thwaites Glacier is sometimes known as the Doomsday Glacier. If it were to collapse completely it would raise global sea levels by 3 meters (10 feet), and it also has the potential to fall apart rapidly.

About two-thirds of the events I detected — 245 out of 362 — were located near the marine end of Thwaites. Most of these events are likely glacial earthquakes due to capsizing icebergs.

The strongest driver of such events does not appear to be the annual oscillation of warm air temperatures that drives the seasonal behavior of Greenland glacier earthquakes.

Instead, the most prolific period of glacial earthquakes at Thwaites, between 2018 and 2020, coincides with a period of accelerated flow of the glacier's ice tongue towards the sea. The ice-tongue speed-up period was independently confirmed by satellite observations.

This speed-up could have been caused by ocean conditions, the effect of which is not yet well understood.

The findings suggest the short-term scale impact of ocean states on the stability of marine-terminating glaciers. This is worth further exploration to assess the potential contribution of the glacier to future sea-level rise.

The second largest cluster of detections occurred near the Pine Island Glacier. However, these were consistently located 60–80 kilometers [37 to 50 miles] from the waterfront, so they are not likely to have been caused by capsizing icebergs.

These events remain puzzling and require follow-up research.

What's next for Antarctic glacial earthquake research

The detection of glacial earthquakes associated with iceberg calving at Thwaites Glacier could help answer several important research questions. These include a fundamental question about the potential instability of the Thwaites Glacier due to the interaction of the ocean, ice and solid ground near where it meets the sea.

Better understanding may hold the key to resolving the current large uncertainty in the projected sea-level rise over the next couple of centuries.

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

Move aside, Bermuda Triangle: The newest North Atlantic mystery lies beneath this enigmatic archipelago. Scientists have discovered a strange, 12.4-mile-thick (20 kilometers) rock layer below the oceanic crust under Bermuda. This level of thickness has never been seen in any other similar layer worldwide.

"Typically, you have the bottom of the oceanic crust and then it would be expected to be the mantle," said study lead author William Frazer, a seismologist at Carnegie Science in Washington D.C. "But in Bermuda, there is this other layer that is emplaced beneath the crust, within the tectonic plate that Bermuda sits on."

While the origin of this layer is not entirely clear, it may explain an ongoing mystery about Bermuda, Frazer told Live Science. The island sits on an oceanic swell, where the ocean crust is higher than its surroundings. But there is no evidence of any ongoing volcanic activity creating that swell — the island's last known volcanic eruption was 31 million years ago.

The discovery of the new giant "structure" suggests the last eruption may have injected mantle rock into the crust, where it froze in place, creating something like a raft that raises the ocean floor by about 1,640 feet (500 meters).

Bermuda has long had a reputation for mystery, largely because of the Bermuda Triangle, an area between the archipelago, Florida and Puerto Rico where a supposedly unusual number of ships and aircraft have gone missing. (This reputation, however, has been largely exaggerated.) The real mystery, though, is why the Bermuda oceanic swell exists.

Island chains such as Hawaii are thought to exist because of mantle hotspots, which are places in the mantle where hot material rises, creating volcanic activity. At the point where the hotspot meets the crust, the ocean floor often buoys up. But when tectonic movement slides the crust away from that hotspot, the oceanic swell typically subsides.

Bermuda's swell hasn't subsided, despite 31 million years of volcanic inactivity there, Frazer said. There is some debate over what's happening in the mantle beneath the island, but there are no eruptions happening at the surface.

Frazer and study co-author Jeffrey Park, a professor of Earth and planetary sciences at Yale University, used recordings from a seismic station on Bermuda of distant large earthquakes around the world to get an image of Earth down to about 31 miles (50 km) below Bermuda. They examined places where the seismic waves from these quakes suddenly changed. This revealed the unusually thick layer of rock, which is less dense than the other rock around it.

Their findings were published Nov. 28 in the journal Geophysical Research Letters.

"There is still this material that is left over from the days of active volcanism under Bermuda that is helping to potentially hold it up as this area of high relief in the Atlantic Ocean," Sarah Mazza, a geologist at Smith College in Massachusetts who was not involved in the work, told Live Science.

Mazza's own research into Bermuda's volcanic history found that the types of lavas there are low in the mineral silica, which is a sign that they come from rock high in carbon. Mazza's examination of variations in zinc molecules in samples from Bermuda, published in September in the journal Geology, found that this carbon comes from deep in the mantle. It was likely first pushed there when the supercontinent Pangea formed between 900 million and 300 million years ago, Mazza said. This is different from what is seen at hotspot-formed islands in the Pacific or Indian oceans, she added. This difference may be because the Atlantic, which opened up when Pangea split apart, is a young ocean compared to the Pacific or Indian oceans, which were at Pangea's edges.

"The fact that we are in an area that was previously the heart of the last supercontinent is, I think, part of the story of why this is unique," she said.

Frazer is now examining other islands around the world to find out if there are any similar layers to the one found under Bermuda, or whether the archipelago is truly one of a kind.

"Understanding a place like Bermuda, which is an extreme location, is important to understand places that are less extreme," Frazer said, "and gives us a sense of what are the more normal processes that happen on Earth and what are the more extreme processes that happen."

In 1987, a worker lit a cigarette by a new water well near the village of Bourakebougou in Mali.

But as he did, an explosion reverberated inside the well. We now know this was due to previously undetected clouds of flammable hydrogen wafting from a gas reservoir beneath the hole.

The well was plugged and temporarily abandoned. Then, in 2011, the oil and gas company Petroma (which later became Hydroma) uncemented it to examine whether they could extract hydrogen for profit. By 2012, the company had developed the well to make electricity for Bourakebougou, and the village still relies on this hydrogen for power today.

Bourakebougou's well is the world's first and only productive hydrogen well. Mixed with oxygen in fuel cells, hydrogen — the smallest and simplest molecule in existence — can generate electricity without greenhouse gas emissions and with only heat and water as byproducts. This makes hydrogen a clean source of energy, and demand for it is expected to rise fivefold by 2050 to produce microelectronics, supply industry, and power vehicles and buildings.

Hydrogen is lighter than air and very reactive, so scientists long thought it didn't accumulate inside Earth's crust in the same way fossil fuels do. But the discovery in Bourakebougou, along with more recent finds, has completely shifted this paradigm.

Resource exploration companies are now rushing to find reservoirs of natural hydrogen, also known as "gold" hydrogen. To help them, scientists have identified the key "ingredients" needed to form such accumulations. And thanks to this knowledge, techniques to boost or mimic natural hydrogen generation that were once considered impracticable are gaining traction, experts told Live Science.

"We just keep finding more and more the more we start looking for it," Geoffrey Ellis, a petroleum geochemist with the U.S. Geological Survey, told Live Science.

Paradigm shift

Hydrogen is a source of energy, but it is also a critical component of fertilizer, refined oil and rocket fuel. Industry produces almost all of its hydrogen by heating natural gas with steam to form a mixture of hydrogen and carbon monoxide from which hydrogen can be extracted.

This method makes "gray" hydrogen, and it pumps about 1 billion tons (920 million metric tons) of carbon dioxide into the atmosphere every year — equivalent to 2.4% of global annual emissions. In theory, renewable energies can replace natural gas to generate "green" hydrogen, while "blue" hydrogen is made from fossil fuels but with carbon capture, meaning carbon doesn't enter the atmosphere. But these collectively make up a tiny fraction of hydrogen production worldwide.

"Hydrogen is a clean source of energy, but how you get your hydrogen is critical," Chris Ballentine, a professor of geochemistry at the University of Oxford, told Live Science.

However, a new source of hydrogen could slash the industry's carbon footprint, as it turns out that huge quantities of hydrogen can accumulate belowground. Scientists have long known that rocks in Earth's crust produce hydrogen, but experts previously concluded that the gas couldn't collect in reservoirs because only tiny concentrations of it were being found in oil and gas wells.

The discovery in Mali toppled that theory. Researchers realized that the places where companies drill for oil and gas are not the best places to find hydrogen.

Massive reservoirs, waiting to be found

The Mali discovery has kicked off a worldwide hunt for hydrogen reservoirs. But before geologists initiate costly exploration projects, they need a sense of just how much hydrogen might be lurking underground.

New estimates suggest it's a staggering amount. Earth's continental crust has produced enough hydrogen over the past 1 billion years to meet society's current energy needs for 170,000 years, a recent review by Ballentine and his colleagues found. Though much of this hydrogen has escaped into the atmosphere, the figure is "a starting point for realizing that the hydrogen generation in the crust is significant," Ballentine said.

Other estimates double the figure in the Ballentine paper. Ophiolites are chunks of oceanic crust that have been thrust onto the continental crust, and some estimates suggest these ocean-crust remnants may produce as much hydrogen as the continental crust does, Ballentine said.

But how much of this hydrogen is left in Earth's crust? In 2024, Ellis and his colleagues calculated that the planet holds 6.2 trillion tons (5.6 trillion metric tons) of hydrogen, or about 26 times the amount of oil known to be left in the ground. Where these hydrogen stocks are located is largely unknown. Most are likely too deep or too far offshore to be accessed, and some reservoirs might be too small to be worth extracting — but the researchers emphasized that just 2% of the total hydrogen could supplant our current fossil fuels for 200 years.

"The potential that's down there is quite, quite large," Ellis said. What's more, natural hydrogen, unlike the type made via industrial processes, comes with built-in storage because it sits in Earth's crust. It also has a much smaller carbon footprint than manufactured hydrogen, with emissions coming only from extraction, Ellis said.

The ingredients

In January 2025, Ellis and his colleagues published a map showing where hydrogen reservoirs might exist in the lower 48 U.S. states. The researchers used gravity and magnetic signal data to estimate the composition of rocks throughout Earth's crust and determine where hydrogen may have migrated underground.

"This was the first time that anyone had attempted to do this type of mapping exercise," Ellis said.

The researchers estimated the likelihood of productive hydrogen reservoirs, known as prospectivity, based on six geological requirements that make and trap hydrogen in Earth's crust. On the map, prospectivity ranges from 0 to 1, with 0 meaning there is likely no hydrogen and 1 indicating hydrogen is very likely present.

To form a hydrogen reservoir, the first and second requirements are that a region must have abundant groundwater and hydrogen-producing rocks. The water requirement limits hydrogen production to the top 10 miles (16 kilometers) of the crust, Oliver Warr, an assistant professor of geochemistry at the University of Ottawa, told Live Science.

The best hydrogen-producing rocks are iron-rich rocks, which generate hydrogen through "hydration reactions," where water reacts with the rocks. Other good sources of hydrogen are uranium- and thorium-rich rocks, which produce alpha particles as the radioactive elements decay. These alpha particles can then split water into oxygen and hydrogen — a process known as radiolysis, Warr said.

Iron-rich rocks include basalt and gabbro. Earth's mantle, the layer beneath the crust, heats groundwater, producing steam that reacts with iron and generates hydrogen. Uranium- and thorium-rich rocks include granites, and these can trigger the radiolysis of water.

The third requirement is that the source rocks be very, very hot — between 480 and 570 degrees Fahrenheit (250 to 300 degrees Celsius), which guarantees rapid rates of reaction, Ellis said.

Fourth, the region must have reservoir rocks that can hold the hydrogen after it is produced and migrates through the crust. Reservoir rocks are typically porous sandstones, but other types of rock can also work if they are highly fragmented, Ellis said.

The fifth criterion to form a hydrogen reservoir is an impermeable "seal" to trap the gas inside the reservoir. "A thing like a shale, or maybe a salt, would be really ideal to be sitting on top of that porous rock," Ellis said. Crucially, the seal must exist when the hydrogen is produced, or else the gas escapes into the atmosphere, he said.

The sixth and final condition is that there must be minimal microbial activity where hydrogen is generated and accumulates, because microbes consume hydrogen, Warr said.

These six conditions, or ingredients, occur across all continents, Ballentine said. Currently, hydrogen companies are drilling exploratory wells mostly on the Midcontinent Rift — where North America started, but ultimately failed, to split apart 1 billion years ago — which is abundant in iron-rich rocks.

Looking ahead

Researchers are also investigating hydrogen deposits in Oman, where there are ophiolites. University of Colorado geologists are running a pilot project in the country to test the feasibility of "stimulated hydrogen" production, Ellis said.

Stimulated hydrogen production takes inspiration from what scientists have learned about the geology that makes and accumulates hydrogen. It involves injecting water into Earth's crust to kick-start either hydration reactions or radiolysis.

One year ago, people in the hydrogen industry were skeptical that stimulated hydrogen production would ever materialize, Ellis said. But now, "I've seen a big shift," he said.

If we can find natural hydrogen and extract it, the gas could reduce emissions across a wide range of sectors. For example, abundant hydrogen is found in mines, because this is where humans drill deepest into the crust, so the gas could power mining operations, Warr said.

Natural hydrogen could also slash emissions from industries such as fertilizer manufacturing. "If we can replace hydrogen generated from hydrocarbons with clean hydrogen, then we can very rapidly make a massive difference," Ballentine said.

Natural hydrogen won't solve the climate crisis, but it can mitigate some of the risks. "It needs to be one of many strategies," Warr said. "We just need to understand the true potential and how it can best be capitalized on."

Some of the key considerations for companies are whether the benefits of developing natural hydrogen reservoirs when we find them would justify the cost of building production plants on-site, or shipping the gas to the industries that need it.

"If you're remote and you find a really big gas field, it still may not be worthwhile producing it, because the costs of getting hydrogen to market are too great," Ballentine said. "There's a trade-off."

But overall, experts are optimistic. "There have been, I think, over a dozen wells that have been drilled now in the U.S.," Ellis said. "They've found a lot of hydrogen."

In 1903, residents of the small town of Dexter, Kansas, gathered to celebrate a newly drilled natural gas well.

Crowds flocked to the well for the lighting of the escaping gas, which officials had said would produce "a great pillar of flame." But when they rolled a burning bale of hay onto the well, nothing happened.

An analysis in 1905 revealed that most of the gas was nonflammable nitrogen, just 15% was methane — and a little less than 2% was a colorless, odorless, elusive element that scientists had discovered only a few decades earlier. This marked the first discovery of helium in a natural gas field.

Helium is the second-most-abundant element in the universe after hydrogen, yet it is scarce on Earth. Helium does not react with other elements, and it mostly accumulates in Earth's crust as radioactive uranium and thorium decay, which takes billions of years. Because it takes much longer to replenish helium reserves than it does to deplete them, helium is a nonrenewable resource.

The discovery in Dexter paved the way for the helium industry, which mushroomed during World War I as fighting countries realized that helium was an excellent way to lift military airships. Unlike hydrogen-filled airships, those carrying helium didn't explode when the enemy shot them down. And helium's properties, particularly its ability to be liquid at close to absolute zero (minus 459.67 degrees Fahrenheit, or minus 273.15 degrees Celsius), meant it could cool machine parts like engines and magnets better than any other element could.

Today, helium is an essential cooling component in nuclear reactors, rockets and medical diagnostic equipment such as MRI machines. The gas keeps fiber optics, superconductors, quantum computers and semiconductors cool, but skyrocketing demand has pushed supply chains to their limit, resulting in a global shortage that has persisted for more than a decade. Helium extraction also has a huge carbon footprint — almost equivalent to the U.K.'s per year — because currently, it is exclusively produced together with natural gas.

However, in recent years, pioneering discoveries have led to a pivotal change in scientists' understanding of the geology that helps helium accumulate. Researchers have uncovered reservoirs of primary, "carbon-free" helium — large accumulations of the gas that are highly concentrated and don't contain methane — that could revolutionize the industry.

This new understanding has fueled exploration projects in a handful of regions around the world. From Yellowstone to Greenland to the East African Rift, a helium "rush" is starting to address shortages and helium's enormous carbon footprint.

"It's a new industry," Thomas Abraham-James, co-founder and CEO of the exploration company Pulsar Helium, told Live Science.

Perfect seals, imperfect yields

After World War I, helium discoveries multiplied and the U.S. emerged as the world's leading producer. Gas wells with helium levels of 0.3% and above were tapped to fuel a growing number of industries and form a stockpile, the Federal Helium Reserve in Amarillo, Texas. (The stockpile was sold in 2024 to the industrial gas firm Messer.)

But helium has been produced only as a minor byproduct, usually found in tiny amounts mixed in with natural gases such as methane.

That's because gases like methane and carbon dioxide (CO₂) are required to transport helium from the middle part of Earth's crust to shallower regions, Chris Ballentine, a professor of geochemistry at the University of Oxford, told Live Science in an email.

Helium forms in the top 16 miles (25 kilometers) of Earth's crust when uranium and thorium break down into other radioactive elements, emitting alpha particles, or helium nuclei, in the process. These helium nuclei gain two electrons from atoms in their environment to form helium atoms, which then migrate and gradually collect in groundwater down to 10 miles (16 km) below Earth's surface, Ballentine said.

But for helium atoms to form a gas, they need to reach their "bubble point" — the concentration of a dissolved gas in a liquid required to make buoyant gas bubbles. Helium in groundwater rarely accumulates in sufficient quantities to reach this bubble point, Ballentine said. So other, more ubiquitous gases, like methane and CO₂, are typically needed to entrain helium and form the bubbles that rise toward geological traps, Ballentine said.

These geological traps are often natural gas fields. But helium also gets trapped, because natural gas fields often have strong seals, research suggests.

Natural gas reservoirs form beneath layers of fine-grained "cap" rocks "and minerals. In Australia's Amadeus Basin, for example, helium and natural gas are locked beneath a thick layer of salt, which is a "perfect" seal, Jon Gluyas, a professor of geoenergy, carbon capture and storage at Durham University in the U.K., told Live Science.

Most places, however, don't have a perfectly sealed reservoir to trap helium underground, so the gas escapes into the atmosphere. "All systems are leaky," Gluyas said. As a result, most regions with helium-producing rocks emit some helium, so "if you went out with a sensitive enough instrument, you would find it," he said.

Helium's association with natural gas means producers can extract both at the same time, but this approach has major drawbacks. For one, the helium industry currently has an indirect carbon footprint of about 350 million tons (320 million metric tons) per year, which is bigger than all but 20 countries' carbon footprints.

A second downside is that countries with natural gas deposits and the companies drilling these deposits control the world's supply of helium. The U.S. used to dominate global helium production, but Qatar took the lead in 2022. Depending on other countries for helium introduces risks related to regional geopolitics, Gluyas said. Algeria and Russia are also leading helium producers, raising similar concerns.

But the biggest problem with helium extraction is that natural gas contains minuscule amounts of helium. In the U.S., the lower profitable limit to separate helium from natural gas is 0.3%, but some countries with different production and transport methods have much smaller thresholds. For example, Algeria's Hassi R'Mel gas field contains 0.19% helium and Qatar's North Dome deposits contain 0.04% helium, yet both countries extract helium at these locations.

Groundbreaking discoveries

Data show that only about 1 in 6 natural gas reservoirs in the U.S. has helium levels higher than 0.3% and that levels above 7% are extremely rare, meaning economically useful helium concentrations are the exception in the U.S.

The trend is similar in other countries. So when scientists found a nitrogen gas reservoir that contained up to 10.4% helium in Tanzania in 2016, they were flabbergasted. The gas was bubbling out of the ground in the Rukwa Rift Basin, which is located on a divergent plate boundary called the East African Rift.

Crucially, the Rukwa Rift Basin doesn't have reservoirs of natural gas or other hydrocarbons. This was the first major confirmed discovery of a hydrocarbon-free helium reservoir, and it sparked an ongoing worldwide hunt for other such reservoirs.

Ballentine, Gluyas and Abraham-James were part of the team that made the discovery in Tanzania. "The approach we adopted essentially is similar to that which any explorer would use for petroleum — we went looking for seeps," Gluyas said. Helium seeps are "all over the show," he said, but locating them is trickier than finding petroleum because helium is odorless, colorless and usually at low concentrations.

From then on, researchers and exploration companies tried to determine whether known helium seeps led to hydrocarbon-free reservoirs with high concentrations of the noble gas. In 2021, for example, the exploration company Pulsar Helium acquired land near Babbitt, Minnesota, where a company searching for nickel had previously found gas with high helium concentrations. Pulsar Helium drilled a well down to 2,200 feet (670 meters) in early 2024 and found a huge gas reservoir with helium concentrations up to 14.5% — the highest the industry has ever seen in North America.

The other gases in the reservoir were nitrogen and CO₂. But the site contains no natural gas, so it counts as a primary helium accumulation, Pulsar Helium representatives say. CO₂ concentrations were above 70%, but the company views this as an opportunity rather than a problem, because the gas is pure enough to be used for carbonated beverages, water treatment, food preservation and medicine.

Unique geology

The more reservoirs of hydrocarbon-free helium that researchers and companies find, the more information they learn about the geology that forms these reservoirs. Shortly after the discovery in Tanzania, geologists identified five key conditions needed to form accumulations of helium without natural gas.

First, the region must have helium-producing rocks miles below the surface. The best helium source rocks are ones that contain uranium or thorium, and are usually composed entirely of crystallized minerals, Gluyas, Ballentine and their colleagues wrote in a 2024 article for the Energy Geoscience Conference Series.

That's because crystalline rocks solidify from magma cooling extremely slowly underground. This unhurried process concentrates radioactive uranium and thorium, which are unstable elements in mineral structures and therefore among the last to be incorporated. Granite is one of the best helium sources, Ballentine said.

Ideally, the rocks should also be hundreds of millions to billions of years old, because the radioactive versions of uranium and thorium that decay into alpha particles have half lives of 4.5 billion and 14 billion years, respectively, according to the article. That means it would take that long for half of a sample of those elements to decay into helium. As a result, it takes millions of years to accumulate enough helium to fill a large reservoir.

The second criterion needed to form a hydrocarbon-free helium reservoir is a heat source around the rocks.

Normally, helium is frozen in a mineral's lattice structure because that structure is "blocked" — or doesn't exchange molecules with its surroundings. For minerals to release that helium, they must exceed their "closure temperature" — the temperature at which the lattice becomes unblocked. That temperature varies, but can be above about 160 F (70 C) for one of the most common helium-containing minerals.

Often the source of heat is volcanism or geothermal heat, so hydrocarbon-free helium reservoirs typically occur in regions where there is, or once was, volcanism. Beneath the Rukwa Rift Basin, for example, eastern Africa is pulling away from the rest of the continent, causing magma to rise to the surface. Similarly, Pulsar Helium's exploration site in Minnesota sits on an ancient tear in North America's crust called the Midcontinent Rift System. This rift system started and then failed about 1.1 billion years ago, producing intense volcanic activity during the roughly 100,000 years it was active.

The third condition to form a hydrocarbon-free helium reservoir is the presence of nitrogen in groundwater, because nitrogen bubbles can transport helium upward through the crust in the same way methane and CO₂ bubbles can, while completely removing greenhouse gases.

The fourth condition is the need for relatively airtight "cap rocks" that sit near the surface above the helium-forming rocks in Earth's crust. That's because when nitrogen reaches its bubble point, it captures helium atoms and taxies them until the gases either escape into the atmosphere or are trapped. But for that to happen, the cap rocks must form an impermeable seal.

The fifth and final condition is that these cap rocks must sit atop fractured, porous "reservoir" rocks that can store gas, Ballentine, Gluyas and their colleagues wrote in the 2024 article.

The growth rate of a reservoir depends on the rates at which gases enter from below and escape via cracks in the seal, the researchers wrote. The more helium that enters a reservoir and the less that escapes through the seal, the bigger an accumulation can get. In other words, reservoirs ideally have porous or highly fragmented rocks down below, and nonporous, intact rocks above.

Helium reservoirs with impermeable seals can hold gases for long periods of geological time. For example, the link between the reservoir in Minnesota and the Midcontinent Rift System suggests helium has been building up there for 1.1 billion years.

Appraisal and development

Pulsar Helium recently announced that it will start engineering work for a helium production plant at its site in Minnesota, signaling that hydrocarbon-free, U.S.-produced helium could reach the market in just a few years.

Early this year, the company more than doubled the depth of its first well to reach the bottom of the reservoir and drilled a second well down to 5,638 feet (1,718 m). Tests over the summer showed high flow rates to the surface and stable helium concentrations of up to 8% at both wells, "providing a robust foundation for future development," Abraham-James said in a September statement. Since then, Pulsar Helium has drilled an additional well down to 3,507 feet (1,069 m) and opened two more wells.

Pulsar Helium is also progressing with a helium project in East Greenland — the first helium discovery on the island, Abraham-James told Live Science.

"What we've learned in Minnesota and elsewhere, we then applied it to Greenland and we found the helium there," he said. "Like Minnesota, its helium is not associated with hydrocarbons. We conducted a seismic survey last year, and that went some ways to mapping the reservoir."

Located about 3 miles (5 km) from the coastal settlement of Ittoqqortoormiit, the site in East Greenland looks promising for helium and geothermal energy production, which could limit the settlement's dependency on fossil fuels, Abraham-James said. Mapping in 2024 revealed a zone of crust with temperatures reaching 266 F (130 C), as well as a fractured reservoir that researchers linked to gas emissions at the surface containing up to 0.8% helium, according to a statement from Pulsar Helium.

Any helium produced in East Greenland would likely go to the local community, Abraham-James said. Similarly, helium produced in Minnesota would be sold inside the U.S. to supply MRI scanners, semiconductor fabrication and space launches, he said.

Helium shortages in the U.S. have eased somewhat since early 2024, partly thanks to additional supplies from natural gas fields, said Nicholas Fitzkee, a professor of chemistry at Mississippi State University. "But having a larger domestic supply would be valuable, because it could insulate the U.S. from geopolitical instabilities that have contributed to past helium shortages," Fitzkee told Live Science in an email.

Halfway across the globe, prospecting in Tanzania is also ongoing, with two exploration companies currently reporting helium levels of 5.5% and 2.46% at different ends of the Rukwa Rift Basin. Called Helium One Global and Noble Helium, these companies are still in the early phases of exploration, Gluyas said.

"Both Helium One and Noble Helium have successfully shown elevated concentrations of helium in the wells they've drilled," he said. But these wells don't provide a clear picture of the reservoir yet, and the reservoir may not end up fulfilling researchers' expectations.

"They could speculate, based upon the seismic information, what the geometry of the accumulation might be, but they haven't yet drilled sufficient wells to say, 'It really is that,'" Gluyas said.

Beyond Tanzania, there may be opportunities for helium exploration in India's Bakreswar-Tantloi geothermal area, which is located in the east of the country and straddles the states of West Bengal and Jharkhand. The Bakreswar-Tantloi area sits on ancient granitic rocks that are rich in uranium and therefore produce helium. The region also has a fault system and a high heat gradient as a result of ongoing tectonic activity along the Son-Narmada-Tapti rift zone, research suggests.

Closer to home, researchers are analyzing the conditions for potential helium accumulations beneath and around Yellowstone National Park. Yellowstone is rooted in the Wyoming Craton, a prehistoric region of crust and upper mantle that contains 3.5 billion-year-old rocks known to produce huge quantities of helium. Thanks to Yellowstone's countless geothermal features and volcanic structures, helium may be accumulating in reservoirs beneath or peripheral to the park, although it's more likely that the gas is circulating and escaping into the atmosphere through a complex system of natural pipes.

"What's happened over the millions or hundreds of millions of years in the area in which Yellowstone occurs is that helium has been building up, and now in the last [roughly] 5 million years, the supervolcano beneath is flushing it out," Gluyas explained.

That means the chances of extracting this helium are remote, not least because of the scorching temperatures of up to 275 F (135 C) that drillers would encounter belowground. "Will your drilling equipment survive? Almost certainly not," Gluyas said.

But beyond Yellowstone, it's important for existing hydrocarbon-free helium projects to complete their evaluations and start selling the gas as soon as possible, Gluyas said. "There is a huge need for helium," he said.

However, Fitzkee sees another way forward — rolling out technologies that can recycle or lower our helium consumption. That could be through installing helium recovery systems or engineering room-temperature alternatives to current helium-hungry technologies, he added.

Topping up our helium supply is a good stopgap solution, but not a permanent fix, he argued.

"Ultimately, we cannot mine our way out of future helium shortages," he said. "Helium is non-renewable, and we have no easy way to make more at scale."

This intriguing astronaut photo shows a trio of ancient "black mesas", which sit side-by-side in the Sahara desert. The dark structures have enabled a series of rare sand dunes to form around them while also creating a surprising "dune-free zone."

The three mesas, or flat-topped hills, are located around 8 miles (13 kilometers) northwest of the town of Guérou in southern Mauritania, which is home to around 22,000 people. The mesas are made from sandstone and rise steeply above the surrounding plains, reaching between 1,000 and 1,300 feet (300 and 400 meters) above the ground. The largest of the trio is approximately 6 miles (9.5 km) across at its widest point, while a fourth mesa is located just north of the trio, but is positioned just out of frame.

The dark color of these circular hills is the result of "rock varnish" — a black, clay-based coating, rich in manganese and iron oxides, that forms on exposed and arid rocks over thousands of years, according to NASA's Earth Observatory. This coating was likely partly fixed in place by microorganisms and is made up of multiple micrometer-thick laminations, according to Science Direct.

To the west of the mesas (on the left of the photo) is a barren rocky plain with a surprising lack of sand dunes. But to the east of the flattened hills, you can see several sizable dunes that are seemingly flowing away from the black rocks like a rippling tail.

There are two main types of sand dunes visible in the image. The first type are rare "climbing dunes," which are the larger, ridge-like piles of sand that have piled up along the mesas' eastern walls. The second type are "barchan dunes," which are more common and make up the mesas' stripy tail. In both cases, the dunes have a distinctive reddish-yellow hue.

The sand dunes only form on the eastern side of the mesas because the wind predominantly blows from that direction, carrying sand that then gets caught on the sloped elevations surrounding the black rocks.

Sand does not accumulate to the west of the mesas because of a phenomenon known as "wind scour," which results from superfast vortices within the wind that gets squeezed in between the mesas, which blow sand away from the flattened hills, according to the Earth Observatory.

Another astronaut photo, taken in 2014, shows this odd effect over a larger area (see below). In this shot, you can see the barchan dunes extend much further away from the mesas in the photo, as well as another larger mesa further east.

During the Paleozoic era, which lasted from 541 million to 251.9 million years ago, all these mesas were likely part of a single massive rock formation that has since been broken up by millennia of water and wind erosion, according to the Earth Observatory.

This formation may have been similar to the Richat Structure — a massive set of concentric rings of rock, also known as the "Eye of the Sahara," which is located in Mauritania around 285 miles (460 km) north of Guérou.

Mesas can be found across the globe but there is a particularly high concentration of them in the Sahara, as well as throughout parts of the U.S., such as Colorado, New Mexico, Utah, and Arizona, according to the National Park Service.

Elsewhere in the solar system, mesas are a prominent geological feature on Mars, having been carved out of the Red Planet by billions of years of wind erosion, according to Live Science's sister site Space.com.

For more incredible satellite photos and astronaut images, check out our Earth from space archives.

Sistema Ox Bel Ha, meaning "three paths of water" in the local Mayan language, is a gigantic submerged labyrinth that runs for at least 326 miles (524 kilometers) underground, according to the Investigation Center of the Aquifer System of Quintana Roo (CINDAQ). This makes it the longest submerged system and the second-longest cave system in the world, after the 426-mile-long (686 km) Mammoth Caves in Kentucky.

The Yucatán Peninsula is home to several massive cave systems because it has a thin layer of top soil covering limestone, which is soluble, enabling rain water to quickly pass through into caverns below the surface, according to a 2020 study. This is also the reason why the region has few rivers or streams.

The caverns form through a process called karstification, in which rain water dissolves calcium carbonate from the limestone. In the case of Ox Bel Ha, this process is supercharged as the fresh water meets salt water that's entered the system from the ocean.

The fresh and salt water form distinct layers and meet at a point in the cave water called the halocline. This line varies in Ox Bel Ha, varying from 33 feet (10 meters) near the coast, where there is more salt water, to 66 feet (20 m) deep further inland. CINDAQ estimated that 27% of the system is salt water and 73% fresh water. This fresh water feeds the vast Maya aquifer, which is the only source of drinking water in the region.

The karstification process can cause cavern roofs to collapse, creating an exposed pool or sinkhole, known as a cenote. Ox Bel Ha has at least 160 cenotes, and they are important water sources for animals and ecosystems, according to CINDAQ. The organization has recently recorded a number of species around the cenotes, such as cougars (Puma concolor), jaguars (Panthera onca) and various deer and other animals.

The system also supports a range of creatures below the surface. In 2018, scientists discovered that the subterranean system supports its ecosystem with methane. Methane forms below the jungle floor and then migrates down into the caves, where microbes and bacteria consume it. These in turn become food for cave-dwelling crustaceans as well as several species of fish, including an eyeless albino cave fish.

Ox Bel Ha runs near the historical Maya town of Tulum. The ancient Maya believed that cenotes were gateways to Xibalba, the Maya underworld, and these pools, along with those of the nearby Sistema Sac Actun, have yielded a number of important archaeological finds.

Most notably, researchers found the remains of a 25- to 30-year-old woman, named Eve of Naharon, whose remains may date to 13,700 years ago — potentially making these the oldest human remains found in the Americas. However, a 2021 review noted that this date has not been replicated or verified. Evidence suggests the woman was deliberately placed on the cave floor, which wasn't flooded at that point, although this also isn't clear, a 2020 study noted.

Ox Bel Ha's system is under threat from construction and developments, including the Maya Train and Tulum International Airport, and it already runs under a number of urban areas, CINDAQ said. This makes studying and mapping the vast underwater system critically important, CINDAQ added.

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

The Gulf of Suez, which partially divides Africa and Asia, may still be widening, researchers have discovered.

Beginning about 28 million years ago, the Arabian tectonic plate pulled away from the African plate, opening up today's Gulf of Suez. This kind of rift is how new oceans are born — but about 5 million years ago, the rifting stopped, and Suez stayed a gulf, not an ocean.

That's the conventional story, anyway. But new research suggests that the Suez rift never stopped rifting. Instead, it simply slowed down. A new paper published Nov. 3 in the journal Geophysical Research Letters has revealed that the Suez rift is still pulling apart by about 0.02 inches (0.5 millimeters) a year.

"We believe our work fundamentally changes how we think about rift evolution," study lead author David Fernández-Blanco, a geoscientist at the Chinese Academy of Science's Institute of Deep-Sea Science and Engineering, told Live Science in an email. "The current conceptual model is rather binary: rifts either succeed (forming new ocean basins like the Red Sea) or fail (becoming completely inactive). We're showing there's a middle path by which rifts can decelerate without truly failing."

The Gulf of Suez is typically seen as the textbook example of a failed rift, Fernández-Blanco said, but there have been scattered hints that the region might still be rifting. In some places along the gulf, ancient coral reefs have been lifted above sea level; small earthquakes sometimes shake the area; and there are signs of faults lifting portions of the ground.

"What struck us was the disconnect between the conventional narrative of complete tectonic quiescence and the hints of ongoing activity," Fernández-Blanco said.

In the new study, the researchers studied the 186-mile (300 kilometers) extent of the rift zone, examining the topography and the paths of rivers cutting through rock, which can reveal unusual profiles that can't be explained by erosion alone and so must come from tectonic movement. They also studied the elevations of coral reefs that formed around sea level during warm interglacial periods but now tower up to 60 feet (18.5 meters) above the gulf.

Together, the evidence pointed to continual rifting that slowed 5 million years ago, when the plate motions changed and the tectonic action shifted to the Dead Sea, where a new plate boundary between the African and Arabian plates was forming.

The rifting didn't stop, though. It continues to pull apart the Gulf of Suez at a similar rate to the current extension of the western United States. This extension in the western U.S. is creating a series of mountains and valleys known as the Basin and Range province.

"Changing plate boundary conditions don't necessarily shut down rifting," said Fernández-Blanco. "The forces driving rifting are more persistent and complex than simple plate motion would suggest."

The findings could mean that areas like the Gulf of Suez are more prone to damaging earthquakes than has been believed, he added. It also suggests other supposedly failed rifts might deserve a second look with modern tools to see if they've really stopped rifting, he said.

"We may reveal that Earth's tectonic systems are more dynamic and persistent than we previously thought," he said.

Satellite data reveals that some areas in Arizona’s Willcox Basin are sinking more than 6 inches (15 centimeters) per year — the fastest rate of subsidence in the state.

This sinking is the result of intensive groundwater extraction to support agriculture in the region, which lowers the water table in the basin, taking the land surface down with it. Past research has shown that since the mid-20th century, parts of the basin have sunk by up to 12 feet (3.6 meters).

The extraction and subsidence have caused wells to run dry and cracks to open up in the ground. The findings were presented Oct. 20 at The Geological Society of America Connects 2025 in San Antonio.

Groundwater in the basin fills the spaces between dust and dirt particles below the surface. When this groundwater is removed, the spaces it once filled collapse because the sediment can't support its own weight. Once the spaces that used to hold water collapse, the change is permanent, and the basin loses its ability to replenish its groundwater.

"Over time, those pore spaces that were once being held open by water pressure start to collapse," Brian Conway, a geophysicist at the Arizona Department of Water Resources who was not involved in the research, said in a statement. "That causes the overlying surface to sink because of the compaction that's happening in the subsurface."

In the new research, Danielle Smilovsky, a researcher at the Conrad Blucher Institute at Texas A&M University-Corpus Christi, used a satellite-based technique known as interferometric synthetic aperture radar (InSAR) to measure changes to Willcox Basin's surface height between 2017 and 2021. InSAR measures the distance between a satellite orbiting Earth and a point on the planet's surface. After averaging several measurements that have been taken in sequence, scientists can detect small changes in surface elevation over time.

The research revealed that some parts of Arizona sank nearly 3 feet (1 m) during the study period.

Even heavy rains in 2022 and early 2023 weren't enough to stop the sinking. Though higher-than-usual precipitation and snowmelt temporarily boosted groundwater levels in the basin, the land kept sinking. In some areas, it even sped up. This suggests that letting the groundwater naturally recharge is unlikely to keep up with extraction.

Regulating groundwater pumping could slow the sinking in the future. In 2024, policymakers declared Willcox Basin an active management area (AMA), which could limit extraction and preserve the basin's ability to store groundwater. The details of the management plan have not been finalized, but similar plans have helped manage water elsewhere in the state.

"Especially in the Phoenix and Tucson areas, groundwater levels are recovering, and we've seen subsidence rates decrease quite a bit," Conway said in the statement. "In the Tucson area, we're not even seeing subsidence anymore with the groundwater management."

Smilovsky took a more cautious long-term view. "I don't think subsidence will ever stop," she said in the statement. "But an AMA might slow it down a bit."

The breakup of the ancient supercontinent Nuna during Earth's "Boring Billion" years drastically shook up the planet, and the reshuffle may have created the conditions that gave rise to complex life, new research shows in unprecedented detail.

The Boring Billion refers to the period between 1.8 billion and 800 million years ago. Even though this interval encompassed the breakup and assembly of two ancient supercontinents, Nuna and Rodinia, scientists gave the period this name due to a perceived lack of upheaval.

"The term was coined to describe what appeared to be a long interval of geochemical, climatic, and biological stability in Earth's history," Dietmar Müller, a professor of geophysics at the University of Sydney who led the new research, told Live Science in an email. "However, we now know that this interval was less boring in terms of plate tectonics and evolutionary changes than previously thought."

Nuna's breakup set off a chain of events that made Earth more hospitable to life, according to a study published Oct. 27 in the journal Earth and Planetary Science Letters. As pieces of Nuna drifted away from the supercontinent's core, shallow seas mushroomed in the gaps between them that were more temperate and oxygen-rich than previous oceans had been, first-of-their-kind simulations revealed.

The researchers reconstructed tectonic-plate movements and related changes in carbon storage and emissions over the past 1.8 billion years, using a cutting-edge model they recently released. The novelty of the method lies in its ability to reconstruct carbon fluxes in greater detail than has been possible so far, the team wrote in the study.

Over the course of 350 million years during the Boring Billion, the total length of shallow seas around landmasses doubled to about 81,000 miles (130,000 kilometers), equivalent to more than three times Earth's circumference at the equator, the team found. At the same time, subduction zones — where one tectonic plate dives beneath another — shortened overall due to how the plates were shifting, according to the study.

Subduction zones trigger volcanic activity at the surface because they inject seawater that lowers the melting temperature of rocks into Earth's mantle, the layer that sits beneath the crust. This facilitates the formation of magma, which then rises into the crust and erupts from volcanoes along with debris and gases such as carbon dioxide (CO₂).

As subduction zones shortened, the amount of CO₂ escaping from Earth's interior into the atmosphere decreased. This cooled the planet and helped establish the oxygen-rich conditions in the newly formed shallow seas, and these relatively stable ecosystems gave rise to more complex life than had existed so far, the researchers suggested.

"We think these vast continental shelves and shallow seas were crucial ecological incubators," study co-author Juraj Farkaš, an associate professor in the School of Physics, Chemistry and Earth Sciences at the University of Adelaide in Australia, said in a statement. "They provided tectonically and geochemically stable marine environments with presumably elevated levels of nutrients and oxygen, which in turn were critical for more complex lifeforms to evolve and diversify on our planet."

Specifically, shallow seas may have sped up the diversification of eukaryotes — organisms whose cells have specialized structures called organelles and a membrane-bound nucleus that houses the DNA. All animals, plants and fungi are eukaryotes, so the emergence of eukaryotic cells during the Boring Billion was a key step in the evolution of complex life, the study authors proposed.

Researchers already knew that eukaryotes evolved during the Boring Billion thanks to fossil evidence dating to 1.05 billion years ago. But the conditions under which these organisms emerged remained unclear.

"The breakup of Nuna created a lot of new ocean floor in young ocean basins that previously did not exist," Müller explained. And this ocean floor contributed to the decline of atmospheric CO₂ already triggered by the shortening of subduction zones, he said. That's because when seawater seeps into cracks in the seabed, carbon gets stripped out to make limestone.

"This ocean floor was altered by hydrothermal fluid circulation and stored carbon in the form of carbonate cements in voids and fractures, drawing down atmospheric CO₂," Müller said.

In short, ancient supercontinent Nuna's breakup sparked three major changes that benefited complex life: It created shallow seas, diminished outgassing from volcanoes, and locked carbon away in ocean sediments, leading to a more oxygen-rich atmosphere and temperate conditions.

"The next steps will be to discover more well preserved eukaryote fossils to document their earliest evolution," Müller concluded.

Triple Divide Peak is a mountain in Montana's Glacier National Park where a drop of water could flow into one of three oceans: the Pacific, the Atlantic or the Arctic Ocean.

Other triple divides — also known as "hydrological apexes" — exist in the world, but Triple Divide Peak is the only place on Earth that links three oceans rather than three seas or a mix of seas and oceans. However, some experts dispute this.

Snowmelt from the peak can travel west through the Columbia River drainage basin and end up in the Pacific Ocean, or it can ride along the Missouri and Mississippi rivers and into the Atlantic, according to the National Park Service. Alternatively, meltwater or raindrops landing on Triple Divide Peak can flow into Hudson Bay via the Saskatchewan River.

The International Hydrographic Organization considers Hudson Bay to be part of the Arctic Ocean, so by that reckoning, Triple Divide Peak feeds three separate oceans.

The peak sits on North America's Continental Divide, an imaginary line that runs through the Rocky Mountains and separates major river systems flowing to the Pacific, Atlantic and Arctic oceans. Triple Divide Peak is one of just two hydrological apexes on the Continental Divide and across North America, the other one being Snow Dome in Canada.

Meltwater from Snow Dome can flow into the Pacific Ocean via the Columbia River, into the Arctic Ocean via the Mackenzie River or into Hudson Bay via the Nelson River. Some scientists argue that Hudson Bay is part of the Atlantic Ocean, so in their view, Snow Dome is the only triple divide on Earth that connects three oceans. For them, water on Triple Divide Peak only flows into either the Pacific or the Atlantic Ocean.

Triple Divide Peak and Snow Dome also sit on other "great divides," with these divides marking out different watersheds. As well as the Continental Divide, Triple Divide Peak sits on the Laurentian Divide, which separates the Hudson Bay watershed to the north from the Gulf of Mexico watershed to the south. Snow Dome, meanwhile, sits on the Arctic Divide, which separates the Arctic Ocean watershed to the northwest from the Hudson Bay watershed to the southeast.

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

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.

Eternal Flame Falls is a waterfall in New York State that houses one of the world's few natural "eternal" flames.

The waterfall is about 30 feet (9 meters) tall and consists of two tiers; one at the top measuring 8 feet (2.5 m) high and the other at the base making up the remaining height. The cascade flows over an outcrop of shale, a type of sedimentary rock made of compacted clay, silt, mud and organic matter.

As its name suggests, Eternal Flame Falls features a fire that burns uninterrupted behind the waterfall. The small blaze grows up to 8 inches (20 centimeters) tall, protected from any spray and wind by the walls of a small grotto around it.

The air surrounding Eternal Flame Falls is filled with a smell like rotten eggs, according to the website NY Falls, which publishes guides to waterfalls in New York. That's because the cascade is surrounded by natural gas seeps that release hydrogen sulfide, methane and other gases into the atmosphere. And the biggest of these seeps is located directly beneath the eternal flame.

Gases like methane are highly flammable. Thanks to the shelter of the small grotto, the natural gas escaping from this seep can be ignited with a match or lighter and burn permanently. Other seeps around Eternal Flame Falls aren't protected in the same way, so lighting them would not produce a lasting fire. These seeps are invisible, unless they are located at the bottom of the stream and pools near the waterfall, in which case the gas can be seen bubbling up, according to NY Falls.

The natural gas at Eternal Flame Falls originates from decomposing organic matter in buried layers of shale. Specifically, the gas comes from a geological formation called the Hanover Shale that dates to the Devonian period (419.2 million to 358.9 million years ago). Organic matter breaking down in this 90-foot-thick (27.5 m) formation releases gases that accumulate underground. As the pressure builds, these gases escape via fissures in the rock and soil above, giving rise to seeps at the surface.

The best time to visit Eternal Flame Falls is in early spring, when the waterfall and eternal flame look the most impressive, according to NY Falls. The waterfall is highly dependent on meltwater and rainfall, so it usually dries up in the summer and fall. The flame, meanwhile, relies on relatively dry conditions. It burns stronger in the summer but looks better in the spring, because the waterfall diffuses the light like a lampshade, creating an otherworldly glow.

Eternal Flame Falls is fed by the Shale Creek, which joins another waterway called Eighteenmile Creek about 2 miles (3 kilometers) away, according to NY Falls. The water then empties into Lake Erie.

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

Miners have unearthed a rare, two-colored natural diamond in Botswana — and experts say it likely formed in two stages.

The diamond is half pink, half colorless. It measures about 1 by 0.63 by 0.57 inches (24.3 by 16 by 14.5 millimeters) and weighs an "astounding" 37.41 carats (0.25 ounces, or 7.5 grams), according to the Gemological Institute of America (GIA), a nonprofit research center based in Carlsbad, California.

The pink half probably formed first, but from what scientists know about colorful diamonds, there's a good chance that it wasn't always this rosy, Sally Eaton-Magaña, senior manager of diamond identification at GIA, said in a statement emailed to Live Science. "The pink section likely was initially colorless and then plastically deformed, perhaps by a mountain-forming event millions of years ago, resulting in its pink color, with the colorless section forming at a later time," she said.

Pink diamonds are incredibly rare, and it's still unclear exactly how they form. Diamonds originate more than 100 miles (160 kilometers) beneath Earth's surface, inside a planetary layer called the mantle. Extremely high temperatures and pressure bind carbon atoms together into a tight lattice, and this structure can rise quickly to the surface through volcanism, giving us rough diamonds.

Diamonds can acquire color through impurities that get locked inside the lattice, but this is very rare because few elements are small enough to penetrate the mineral structure. Another way diamonds can become tinted — usually green — is through radiation, if nearby rocks contain elements such as uranium that can "steal" carbon atoms and create vacancies in the mineral structure.

But pink diamonds are the product of structural deformity, meaning their lattice structure has been bent or compressed through geological processes. Temperature and pressure conditions have to be just right for diamonds to turn pink, because too much deformation turns the gems brown.

"It's kind of like Goldilocks," Luc Doucet, a senior research geologist at Curtin University in Australia, previously told Live Science. "There are a lot of brown diamonds, and very, very few pink diamonds."

For a diamond to have two distinct color zones, it must have formed in two phases, according to GIA. First, the pink half assembled and deformed; then, the colorless half sprouted, and its lattice remained unaffected by temperature and pressure.

The new diamond is not the first pink-and-colorless natural diamond ever discovered. However, GIA experts said similar diamonds they have examined were much smaller, weighing no more than 2 carats (0.014 ounces, or 0.4 g).

The new find is from Botswana's Karowe mine, which has previously yielded other spectacular diamonds. For example, it's where the second-largest rough diamond ever recovered — a giant, 2,488-carat (1.1 pounds, or 0.5 kilograms) gem dubbed the "Motswedi" diamond — and the 62-carat (0.44 ounces, or 12.4 g) "Boitumelo" pink diamond were discovered, GIA said.

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."

A newly discovered way to monitor magma movements beneath Mount Etna could help scientists forecast when it might erupt.

Mount Etna, located on the Italian island of Sicily, is Europe's largest active volcano. Humans have documented its activity for the past 2,700 years, but the volcano's eruptive history stretches as far back as 500,000 years.

Etna's most recent eruption, in June 2025, ejected a giant, 4-mile-high (6.5 kilometers) cloud of ash and triggered an avalanche of hot lava blocks and other debris. The eruption was expected, so officials were able to issue warnings on the morning of the event, but predictions don't always hit the nail on the head.

The novel method could make it easier to predict Mount Etna's eruptions. In a new study, researchers at Italy's National Institute of Geophysics and Volcanology (INGV) analyzed a parameter called the b value, which describes the ratio of low-magnitude to high-magnitude earthquakes in a region of Earth's crust. This ratio can change as magma rises through the crust to the summit of a volcano, the researchers reported in a study published Oct. 8 in the journal Science Advances.

"Changes in the b value over time reflect how the stress inside the volcano is evolving," study lead author Marco Firetto Carlino, a geophysicist at INGV's Etna Observatory, told Live Science in an email. "Since magma ascent induces stress changes within the crust, tracking the b value can help reveal different stages of magma transfer from depth to the surface."

The b value is an established parameter in volcanology, but the researchers examined it in a novel way, with an updated statistical model. By compiling 20 years' worth of earthquake data from Mount Etna, they found a "very strong" correlation between the b value and Etna's volcanic activity, Firetto Carlino said.

Mount Etna sits in the collision zone between the African and European tectonic plates. As a result, a vertical fracture in Earth's crust known as a strike-slip fault underlies the volcano, thus facilitating the rise of magma to the surface, according to the study.

The crust beneath Mount Etna is up to 19 miles (30 km) thick. Magma rises through this volume before an eruption, but instead of replenishing a single magma chamber, the molten rock feeds a series of interconnected storage zones that are embedded in the crust at different depths.

The deepest magma storage zone is 7 miles (11 km) below sea level, Firetto Carlino explained, and it feeds an intermediate storage system with different zones likely extending 2 to 4 miles (3 to 7 km) deep. As magma rises, it travels through an intricate network of fractures and eventually reaches the last storage zone, which is located above sea level inside the volcano edifice.

The researchers had a wealth of data to work with and extract b values from, due to Etna's frequent activity. They analyzed seismic patterns in the 19 miles of crust beneath the volcano from 2005 to 2024, paying particular attention to how these patterns varied between crustal regions.

Generally, regions of Earth's crust with active magma storage zones show higher b values than more stable regions do, because the active zones experience more small earthquakes than bigger ones.

"This happens because rocks affected by moving magma become weak and highly fractured," Firetto Carlino said. "For example, when magma inside a storage releases volatiles, they permeate the surrounding rocks, making it easier for small fractures to slip."

Conversely, regions of Earth's crust that are more stable typically experience more big earthquakes than smaller ones, because it takes more force to break the rock. "Rocks with good mechanical properties can store stress for longer periods," Firetto Carlino said. "When they finally break, they produce larger earthquakes, corresponding to lower b values."

So, by tracking the b value over time, it may be possible for researchers to follow the movement of magma through the deep crust to the first storage zone, up from there to the intermediate storage system, and up again to the shallow storage zone. This method could help experts estimate the timings of eruptions at Mount Etna.

"Monitoring the b value offers a powerful way to track magma movement within the crust and assess the volcano's evolving state before eruptions," Firetto Carlino said.

Mount Etna was a good test for the study due to its layered magma storage zones and enormous seismic catalog, but the results might also apply elsewhere.

"In principle, the b value could also be used to track magma movements in other volcanic areas, provided that a sufficient number of earthquakes is available and that their locations are distributed across different crustal sectors, well constrained by previous geological studies," Firetto Carlino said.

Stalagmites all adhere to a mathematical rule, scientists have discovered after creating equations showing how the dramatic mineral formations develop into different shapes.

The new mathematical descriptions could help scientists extract more accurate data about past climate conditions, the researchers noted in a study to be published the week of Oct. 13 in the journal PNAS.

"It turns out that the rich diversity of stalagmite shapes can be explained by one simple parameter," study co-author Piotr Szymczak, a physicist at the University of Warsaw, said in a statement. "This is a rare case where the beauty we see in nature corresponds directly to a clean mathematical law."

Stalagmites can grow up to hundreds of feet tall from cave floors and take many different shapes — from sharp, narrow cones to wide, flat-topped mounds. They're created when mineral-rich water drips from the ceiling of a cave onto roughly the same spot for thousands of years, where it steadily deposits calcite in a tower growing from the cave floor.

In the new study, Szymczak and his colleagues developed a set of mathematical equations that describes how all of these shapes come to be. They found that the shape a stalagmite eventually adopts is controlled by the rate at which water drips from the cave's ceiling onto the stalagmite, and how quickly the calcite in that water gets left behind. These can be represented by a single value called the Damköhler number.

Fast-flowing water dripping from a cave ceiling tends to create pointy, cone-shaped stalagmites, while water that drips more slowly onto the same spot forms thicker, column-like stalagmites. When the water drips down from a great height, or doesn't drip in exactly the same place, wide stalagmites with flat tops can form.

The scientists then validated their equations by comparing the expected shapes of stalagmites under different conditions to actual stalagmites taken from Postojna Cave in Slovenia.

"When we compared our analytic solutions with real cave samples, the match was remarkable," study co-author Matej Lipar, a physical geographer at the Research Centre of the Slovenian Academy of Sciences and Arts, said in the statement. "It shows that even under natural, messy conditions, the underlying geometry is there."

Scientists could use this geometry to get more accurate data about past climate from the formations, the authors wrote in the study. Much like tree rings, stalagmites grow in layers, recording information about rainfall and temperature over time. Scientists use the ratios of different forms, or isotopes, of carbon in each layer to extract that information. The stalagmites' shape affects how those layers are deposited, which could in turn affect how scientists interpret the conditions under which they grew.

"Stalagmites are natural climate archives, but we now see that their geometry leaves its own imprint on the isotopic record," study co-author Anthony Ladd, a chemical engineer at the University of Florida, said in the statement. "Recognizing this effect will allow us to extract more reliable information about past climates."

An artificial intelligence (AI) model has revealed never-before-seen geological structures at Italy's Campi Flegrei volcano, including a clear "ring fault" that could unleash magnitude 5 earthquakes.

So far in 2025, Campi Flegrei has produced five earthquakes above magnitude 4, and the volcano has been showing signs of unrest since 2005. But most of the earthquakes triggered in the region are going undetected, according to a new study that used AI to pinpoint tens of thousands of seismic events that have gone under the radar over the past few years.

"We've known that this is a risky place for a long time," study co-author William Ellsworth, a professor emeritus of geophysics at Stanford University, said in a statement. "Now we're seeing for the first time the geologic structures that are responsible."

Over the past 40,000 years, Campi Flegrei has produced two of the largest eruptions in Europe, and evidence suggests the volcano's earlier history was just as explosive. Scientists have been recording unrest at Campi Flegrei since the 1950s, but monitoring efforts increased in the 1980s after a swarm of 16,000 earthquakes prompted the evacuation of 40,000 residents.

To investigate modern threats from Campi Flegrei, Ellsworth and his colleagues developed an AI tool capable of identifying earthquakes that previous methods couldn't pick out.

Traditionally, seismologists identify earthquakes by analyzing seismograms, which are graphs with wiggly lines that represent shaking in the ground over time. Researchers look for a sudden increase in the wiggles' size, and this process is known as "phase picking," said study co-author Greg Beroza, a professor of geophysics at Stanford University.

"That's a simple and often effective means of picking a phase, but it doesn't 'learn' how to do it better so that it improves with time," Beroza told Live Science in an email. "In our approach, we train a machine learning model to pick phases. We base it on the collection of millions of examples where experts have done this already, and our method is designed to learn how to do this more effectively."

The team chose to have their tool analyze Campi Flegrei before other volcanoes for several reasons, including there being an urgent need to better understand this volcano's behavior, Beroza said. More than 360,000 people live inside Campi Flegrei's 7-mile-long (11 kilometers) caldera, and roughly 1.5 million people reside in the wider area. Unrest over the past 20 years ticked up in 2018 — and while there are currently no signs of an eruption, a particularly violent or shallow earthquake could present a huge danger to people as well as damage buildings, according to the statement.

The results from the AI tool, published Sept. 4 in the journal Science, reveal that three-quarters of earthquakes at Campi Flegrei between 2022 and mid-2025 went undetected. While traditional methods documented 12,000 earthquakes in this period, AI shows the number was closer to 54,000.

By mapping the location of these earthquakes, the researchers discovered faults — cracks in Earth's crust that can grind against each other and cause earthquakes — that previous methods hadn't highlighted. Notably, the team found two faults converging beneath Pozzuoli, a town west of Naples where evacuations took place in the 1980s. The location of these faults suggests "an earthquake in the magnitude 5 range is not out of the question," Ellsworth said.

This wasn't the only striking finding. Pozzuoli experienced uplift in the 1980s, and the same is happening again now, with the ground beneath the town rising by about 4 inches (10 centimeters) each year. It turns out, the area of uplift is encircled by several faults, forming a thin, well-marked "ring fault" that extends offshore, according to the statement.

"Our Italian colleagues were surprised to see the ring so clearly," study lead author Xing Tan, a doctoral student in Beroza's lab, said in the statement. "They expected to see something in the south where previous data had revealed scattered seismicity, but in the north, they'd never seen it so clearly."

Seismic activity along the ring fault could help predict changes in the system, as well as hint at the magnitudes of future earthquakes, Beroza said. But it doesn't provide new information about the likelihood or timing of Campi Flegrei's next eruption.

"All the analyzed seismicity from 2022 to mid-2025 is shallow, at depths above 4 kilometers (2.5 miles) and does not indicate any migration of magma towards the surface," Beroza said.

The team's results for Campi Flegrei indicate that the AI tool could be useful for other volcanoes, too. Places that have recently seen an uptick in seismic activity, such as Santorini in Greece, could benefit from a clearer understanding of the underlying geology, the researchers said in the statement.

Earth may respond to the huge quantities of carbon dioxide (CO₂) that humans are pumping into the atmosphere by "overcorrecting" the imbalance, which could result in the next ice age arriving on time instead of being delayed by tens of thousands of years, as had previously been predicted.

This is due to a newfound "thermostat" that buries mountains of carbon beneath the seafloor so efficiently, it could do away with human carbon emissions within 100,000 years, researchers have discovered.

That's several times quicker than scientists assumed would happen with a previously described "lazy thermostat" that locks away carbon on timescales of 500,000 to 1 million years, the team reported in a study published Sept. 25 in the journal Science.

With both thermostats working in tandem, it's possible that the next ice age could start on time, instead of being delayed by the effects of climate change, study co-author Andy Ridgwell, a professor of geology at the University of California, Riverside, told Live Science.

The newfound thermostat does not protect humans living now from the effects of global warming, said study co-author Dominik Hülse, a mathematician and biogeochemical modeler at the University of Bremen in Germany. "It's not to say that we will be safe from global warming in the next 100 or even 1,000 years," he told Live Science.

Scientists have long suspected that Earth regulates its climate on geological timescales. Since the 1980s, researchers have theorized about a mechanism called the silicate weathering feedback, which occurs when rain captures CO₂ from the air and sprays it onto silicate rocks — rocks with minerals made of oxygen and silicon that constitute about 90% of the planet's crust. CO₂ reacts with these rocks, dissolving them and forming molecules that leach into the ground and eventually end up in the ocean. Once there, what was once CO₂ forms limestone and chalk, meaning it is locked away for millions of years.

The silicate weathering feedback is like a thermostat because the more CO₂ that is in the atmosphere, the warmer Earth gets and the more the water cycle intensifies. As precipitation increases, silicate weathering accelerates, meaning more CO₂ is transferred to the ocean and atmospheric CO₂ sinks to background levels again.

The feedback also works the other way around. "If you get too cold and CO₂ is too low, then the thermostat is consuming too little CO₂ compared with a background of constant release of CO₂ from the mantle, from volcanoes and other magma features," Ridgwell said. In this scenario, less CO₂ ends up in the ocean and atmospheric levels slowly increase back to average levels, he said.

But the silicate weathering feedback moves slowly; it can take up to 1 million years after a perturbation to rebalance CO₂ levels. As a result, there are climate events it can't explain, including Earth's glacial and interglacial cycles, which are characterized by huge fluctuations in CO₂ levels and temperature that occur roughly every 100,000 years, Ridgwell said.

Silicate weathering also can't explain snowball Earth events, which completely cover the planet in ice, Hülse said. If silicate weathering were the only thermostat regulating Earth's climate, its smooth balancing act would prevent it from tipping into such extreme conditions, Hülse explained.

A second "thermostat"

The new research was inspired by Hülse's doctoral dissertation, in which he calculated how much organic carbon was preserved in ocean sediments during past climatic events. His results showed that after periods of intense volcanic activity and warming, mountains of organic carbon were deposited onto the seafloor. This finding suggested there might be a link between atmospheric CO₂ levels and organic carbon burial in the ocean.

"There are definitely times in Earth's history when a lot of organic carbon has been deposited," Ridgwell said. "We've sort of known that there must be other things going on [besides silicate weathering], but it's much more complex to put in a model."

But Hülse and Ridgwell tackled this challenge in the new study by amalgamating their individual projects into a single global climate carbon cycle model that accounted for organic carbon burial in the seafloor. Their results revealed a second "thermostat" rooted in Earth's phosphorus cycle, which starts on land with rocks containing minerals such as apatite, the researchers said.

Weathering of these rocks due to precipitation releases phosphorus, which leaches into the ground, enters streams and rivers, and eventually ends up in the ocean. There, phosphorus is a key nutrient for tiny photosynthetic creatures known as phytoplankton, which use it to fuel cellular processes. When phytoplankton die, they sink to the ocean bottom, where they deposit organic carbon, phosphorus and other nutrients.

In a warmer world, more phosphorus is washed into the ocean and phytoplankton proliferate, meaning more organic carbon and phosphorus reach the seafloor. However, warmer oceans also hold less oxygen because oxygen becomes less soluble as temperatures increase. This deoxygenation releases deposited phosphorus back into the water column while burying organic carbon in sediments.

"Exactly how that happens is not mechanistically entirely known, but we know it happens," Ridgwell said. "Where we've had these events in the past where we see massive amounts of organic carbon being buried after a warming event, there's very, very, very little phosphorus in that material compared with normal material. If it's not being buried, it must have been returned to the ocean."

As phosphorus gets recycled, it reenters the food chain and phytoplankton continue to proliferate as they feast on phosphorus from both the land and the ocean. This leads to a phytoplankton boom, which sucks more and more CO₂ out of the atmosphere and deposits more and more organic carbon onto the seafloor, which brings down global temperatures.

So, the warmer the world gets, the more productive the oceans become and the more carbon is locked away, which cools the climate. But the difference between phosphorus and silicate weathering is that phosphorus in the ocean doesn't decline as soon as Earth cools, because it continues to be released at the seafloor.

"The organic carbon thermostat is a little bit like the silicate thermostat, except it has this supercharger," Ridgwell said. "You end up with so many nutrients in the ocean — and they're being recycled very efficiently — that it's very difficult to get rid of them again."

The phosphorus cycle eventually regains its balance, but the planet can "overcorrect" in the meantime, triggering events like snowball Earth, the researchers said. It's unclear how this second thermostat will respond to climate change now, but the ocean is so rich in oxygen compared with in the past that a snowball Earth is unlikely, they said.

Instead, it's possible that the organic carbon thermostat will make up for the delay expected for the next ice age. Climate change is disturbing Earth's natural cycles, and previous research suggests it could push back the next glacial period, which is due in about 11,000 years, by tens of thousands of years. But if the organic carbon thermostat activates, atmospheric CO₂ could return to background levels much faster, ensuring that the next ice age arrives on time.

"Whatever delay we'll end up with for the next ice age ... thinking about this mechanism might bring it back forward again," Ridgwell said. "One is going to start at some point for sure; it's all about when it starts."

Satellites detected a strange gravity signal off the coast of Africa nearly 20 years ago, suggesting something unusual had happened deep within the planet to distort its gravitational field, according to a recent study.

The large gravitational anomaly lasted for about two years over the eastern Atlantic Ocean. It peaked in January 2007, the same month Steve Jobs announced the first iPhone (though, of course, there was no connection between the two events).

Researchers recently discovered the signal while analyzing data collected by the Gravity Recovery and Climate Experiment (GRACE) satellites between 2003 and 2015. The gravitational anomaly happened around the same time as a geomagnetic "jerk" — an abrupt change in the variation of Earth's magnetic field.

The strange anomaly, and the jerk, were caused by a previously unknown geological process, the researchers suspect. Their findings, published Aug. 28 in the journal Geophysical Research Letters, indicated that a shift in minerals may have caused a rapid redistribution of mass in the deep mantle, near the core, altering Earth's magnetic field.

Study co-author Mioara Mandea — a geophysicist at the National Centre for Space Studies (CNES) in France and a principal investigator for the European Research Council's Gravimetry, Magnetism, Rotation and Core Flow project — told Live Science that she questioned the validity of the signal at first.

"As is often the case in scientific research, my initial response was one of questioning: is the signal genuine, how can it be validated, and how should it be interpreted?" Mandea said in an email. "While the result and its publication were certainly a source of satisfaction, the dominant thought was to consider the next steps and possible implications."

The GRACE satellites were a pair of identical spacecraft operated as part of a joint mission between NASA and the German Aerospace Center (DLR). Scientists used these satellites, which were active from 2002 until they ran out of fuel in 2017, to measure variations in Earth's gravity. The satellites moved in tandem (one behind the other) around Earth, and researchers measured the distance between the two objects to look for any changes that occurred as a result of variation in Earth's gravitational force, according to NASA.

Such gravity variations are often caused by variations in the concentration of mass — more mass means more gravity. For example, water currents shift mass around in the ocean, which can lead to localized variations in Earth's gravitational field. In the new study, the researchers scoured GRACE data for anomalous gravity signals that potentially originated deep within Earth, rather than from water shifting on or near the surface.

The signal was a north-south-oriented gravity anomaly, stretching about 4,350 miles (7,000 kilometers) — close to the length of the entire African continent — from 2006 to 2008, according to the study.

Researchers are still learning about Earth’s deep mantle and the boundary between the rocky layer and our planet’s liquid outer core, but the lower section of the mantle is largely made up of magnesium silicate (MgSiO₃). The study authors suggested that the mass redistributions they attributed to the signal occurred as a result of a perovskite to post-perovskite phase transformation in this lower mantle section, whereby the structure of magnesium silicate changed under pressure, shifting mass deep within the Earth.

Mandea noted that the main message of the study was that Earth is complex and that different datasets and methods are required to understand its internal processes.

"Earth is a complex system that must be studied using diverse datasets and complementary methods of analysis," Mandea said. "This synergy gives us the opportunity to uncover and better understand hidden processes in the Earth's deep interior."

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."

This striking satellite image shows the stark difference between a giant field of sandy "stars" and a barren rocky wilderness in the Sahara Desert. The contrasting biomes also overlap with the border where two African countries meet.

The sea of orange sand visible in this image is part of the Grand Erg Oriental — a giant field of dunes, or erg, that covers around 55,000 square miles (140,000 square kilometers) in the northern Sahara.

This part of the erg has hundreds of prominent "star dunes," which have at least three ridges coming from a central peak, giving them a star-like appearance when viewed from above. Star dunes can grow to be over 300 feet (90 meters) tall and only form in locations where wind directions change constantly, which allows their different slopes to form, according to the National Park Service.

The dunes overlap with a windswept rocky terrain, which is among "the driest parts of the Sahara Desert" and almost completely devoid of vegetation, according to NASA's Earth Observatory. This terrain is covered with overlapping geological features, giving it an otherworldly quality.

One of the most striking features is a large white patch in the heart of the rocky terrain, which is the remnant of an ancient lake. You may also be able to see a series of parallel grooves in the rock (in the top half of the rocky terrain), which were carved by eons of unidirectional winds that blew long before the multi-faced dunes were formed.

Related: See all the best images of Earth from space

The dunes in the image are all located within Algeria, while most of the rocky terrain is in Libya. The invisible boundary between the two countries is largely located down the very center of this image. However, at one point, just to the left of a Libyan town called Ghadames (visible as a dark spot near the top of the image), the border between the countries almost exactly overlaps with the line where the sand and rock meet.

While the contrasting ecosystems appear to have nothing to do with each other, they are more linked than you might imagine. Geologists believe that a majority of the erg's sand was deposited by ancient rainwater that took loose sediments from the rocky terrain and dumped them within a natural depression, or sink, in the landscape.

This process likely took hundreds of thousands, if not millions, of years — and if you look closely, you can see that some of the erg's sand has spilled back out into the ancient "winding water courses" that helped to deposit the sand within the erg, according to the Earth Observatory.

The erg is also partly formed above the bed of an ancient river. When rain infrequently falls on the erg's sands, the moisture is funneled away into underground aquifers, which can support pockets of vegetation on the surface. If this did not happen, this valuable moisture would quickly evaporate back into the atmosphere.

A pair of diamonds that formed hundreds of kilometers deep in Earth's malleable mantle both contain specks of materials that form in completely opposing chemical environments — a combination so unusual that researchers thought their coexistence was "almost impossible." The substances' presence provides a window into the chemical goings-on of the mantle and the reactions that form diamonds.

The two diamond samples were found in a South African mine. As with plenty of other precious gemstones, they contain what are called inclusions — tiny bits of surrounding rocks captured as the diamonds form. These inclusions are loathed by most jewelers but are an exciting source of information for scientists. That's especially true when diamonds form deep in the unreachable mantle, because they carry these inclusions basically undisturbed to the surface — the only way those minerals can rise hundreds of kilometers without being altered from their original deep-mantle state.

The two new diamond samples each contain inclusions of carbonate minerals that are rich in oxygen atoms (a state known as oxidized) and oxygen-poor nickel alloys (a state known as reduced, in the parlance of chemistry). Much like how an acid and a base immediately react to form water and a salt, oxidized carbonate minerals and reduced metals don't coexist for long. Typically, diamond inclusions show just one or the other, so the presence of both perplexed Yaakov Weiss, a senior lecturer in Earth sciences at the Hebrew University of Jerusalem, and his colleagues — so much so that they initially put the samples aside for a year in confusion, he says.

But when they reanalyzed the diamonds, the researchers realized that the inclusions capture a snapshot of the reaction that made the sparkling stones and confirm for the first time that diamonds can form when carbonate minerals and reduced metals in the mantle react. The new samples are the first time scientists have ever seen the midpoint of that reaction captured in a natural diamond.

"It's basically two sides of the [oxidation] spectrum," says Weiss, the senior author of the new study describing the find, which was published on Monday in Nature Geoscience.

The find has implications for what lies in the mantle's mysterious middle. As you travel deeper into the earth, away from the surface, the rocks and minerals become increasingly reduced, with fewer and fewer oxygen molecules available, but there is little direct evidence of this shift from the mantle.

Theoretical calculations have given researchers a notion of how the planet shifts from oxidized to reduced with depth. "We knew about that reduction with some empirical data, with real samples down to maybe 200 kilometers," says Maya Kopylova, a professor of Earth, ocean and atmospheric science at the University of British Columbia, who was not involved in the new study but who wrote an editorial accompanying the paper. "What happened below 200 km [was] just our idea, our models, because it's so difficult to get the materials." There are only a few samples from below this depth, she said.

These new samples, which come from between 280 and 470 km below Earth's surface, provide the first real-world fact-check on this theoretical mantle chemistry. One finding, Weiss says, is that oxidized melted material exists deeper than expected. Kimberlites, the erupted rocks that bring diamonds to the surface, are oxidized, so researchers had thought they couldn't originate much below 300 km of depth. But these findings suggest that oxidized rocks occur deeper than that — and thus so might kimberlite rocks.

Diamond-forming reactions likely happen when carbonate fluids are dragged down by subducting tectonic plates, which bring oxygen-heavy minerals in contact with the metal alloys of the mantle, Weiss says. (Another way chemists think diamonds may form is by precipitating out of carbon-rich fluids that cool as they rise upward in the mantle, like sugar crystalizing from syrup. The new paper doesn't rule out that process happening as well.)

The nickel-rich inclusions might also help explain an odd occurrence in some diamonds: occasional atoms of nickel seem to replace the carbon of these diamonds' crystal lattice. That's been a mystery, Kopylova says, because nickel is so much heavier than carbon that it shouldn't be able to easily swap into the crystal structure. "Now, looking at these data, I see that it might be just a sign of diamond formation at certain depths," she says. "That would be very interesting to investigate further."

This article was first published at Scientific American. © ScientificAmerican.com. All rights reserved. Follow on TikTok and Instagram, X and Facebook.

Natural glass found only in Australia could be evidence of an unknown, ancient asteroid impact, researchers say.

A new analysis of impact-created "tektites" points to a powerful collision millions of years ago that hurled debris across southern Australia. Scientists are still looking for the impact crater.

"These glasses are unique to Australia and have recorded an ancient impact event we did not even know about," study co-author Fred Jourdan, a geochemist at Curtin University in Australia, said in a statement.

Tektites are naturally formed glasses created when meteorites crash into Earth, throwing melted surface rock in all directions. Most tektites come from one of five major splash zones, including one that spread debris across Australia and southeast Asia nearly 800,000 years ago.

In 1969, researchers studied tektites from this Australasian field. Most of the glasses had similar compositions, but a few appeared older and chemically different from the rest. A 1999 study found that the odd tektites were several million years old — but there was considerable wiggle room in previous estimates, and there wasn't enough information to determine whether the strange rocks had formed in a different major impact.

Now, in a new study published Aug. 29 in the journal Earth and Planetary Science Letters, scientists measured the densities and magnetic properties of several thousand tektites in the South Australian Museum's collection, gathered from that region. They brought 417 unusual samples to France where, after further examination, they identified six tektites that had the same chemical makeup as the anomalous tektites that had been studied decades ago.

The team determined that the tektites were different enough in both age and composition from most of the other tektites in the region that they were most likely not formed in the impact that created the Australasian tektite field. Instead, they could be from a previously unidentified impact that occurred nearly 11 million years ago.

"These tiny pieces of glass are like little time capsules from deep in our planet's history," Jourdan said.

The team dubbed tektites from this ancient impact "ananguites." Some of the tektites landed in areas home to the Pitjantjatjara and Yankunytjatjara people, who refer to themselves as Anangu, meaning "human being," the researchers wrote in the study.

"What makes the discovery even more intriguing is that, although the impact must have been immense, scientists are yet to locate the crater," Jourdan said. While there aren't any known craters of the appropriate age nearby, the team proposed some possible sites in the Philippines, Indonesia and Papua New Guinea. In volcanically active areas like Papua New Guinea, the impact crater might have been mistaken for a volcanic feature, or it may have been obscured over the years.

The findings could give scientists a better idea of how often Earth undergoes extreme impacts and could indicate that impacts large enough to produce tektites are more common than previously thought.

"Understanding when and how often large asteroids have struck Earth also helps us assess the risk of future impacts, which is important for planetary defense," Jourdan said.