Science word of the day: Seamount

Pronunciation: SEE'-mount

What it means: A seamount is an undersea mountain that rises at least 3,300 feet (1,000 meters) above the seafloor but does not come close to breaking the surface. According to the National Oceanic and Atmospheric Administration, there are at least 100,000 seamounts in the oceans, and less than 0.1% of them have been explored. Seamounts typically form from volcanic activity, and many host dramatic communities of sea life ‪—‬ from coral, to sharks, to an assortment of weird jellyfish-looking things.

How to use it in a sentence: Every time marine biologists explore a seamount with their remotely operated vehicles, they seem to discover a new universe of strange and blobby deep-sea creatures.

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

Runoff from Greenland's rapidly melting ice sheet could severely disrupt currents in the Atlantic Ocean that regulate the global climate, researchers say. But the fresh water won't trigger the complete and irreversible collapse of the circulation that some research predicts, a new study suggests.

By 2100, Greenland meltwater could cause a reduction in the strength of the Atlantic Meridional Overturning Circulation (AMOC) equivalent to an additional 10% to 20% on top of the weakening that many scientists already expect for this huge system of currents, researchers found.

Previous research suggests the AMOC, which moves heat from the tropics to the Northern Hemisphere and cold water back south toward Antarctica, is at its weakest in more than 1,000 years due to Arctic ice melt and soaring ocean temperatures. Models indicate that the circulation will continue to weaken for decades to come, potentially unleashing freezing weather in Northwest Europe, additional sea-level rise along the U.S. East Coast and droughts around the equator.

The new study revealed that by 2300, Greenland's ice sheet could cause a whopping 40% of AMOC weakening on top of the declines projected by some climate models if we continue to cook the planet. The results highlight the effects on the AMOC of a growing freshwater pulse from Greenland that most climate models currently don't take into account, the authors said.

"By the year 2100, yes, we have something, but the greatest fraction is what we add later," study co-author Jost von Hardenberg, a professor in the Department of Environment, Land and Infrastructure Engineering at the Polytechnic University of Turin in Italy, told Live Science.

Meltwater from the Arctic and Greenland slows the AMOC by preventing the formation of deep currents in the North Atlantic that drive the circulation south toward Antarctica. Deep currents form when masses of cold, salty water sink to the seabed, but inputs of fresh water and rising water temperatures are blocking this step by diluting and warming surface waters.

While Arctic meltwater is commonly integrated into climate simulations, researchers have been slower to include runoff from the Greenland ice sheet in models, partly because this runoff may not be as disruptive as Arctic meltwater on shorter timescales, von Hardenberg said.

"In order to represent correctly the Greenland melt, you need a specific, dynamic model for the Greenland ice sheet. It's nice to have, but it requires a lot of resources to develop," von Hardenberg said

The Community Ice Sheet Model version 2 (CESM2) is one of the few available simulations of the Greenland ice sheet. For the study, von Hardenberg and his colleagues used a global climate model called EC-Earth3, which does not include the Greenland ice sheet. The team added the ice sheet from CESM2 to explore how it might affect the AMOC over the next few centuries. Adding the ice sheet separately enabled them to compare AMOC weakening with and without Greenland, clearly revealing the impact of the ice sheet on the AMOC's strength.

The results, published June 19 in the journal Science Advances, suggest the Greenland ice sheet will have a big influence on Atlantic ocean currents, especially after 2100.

"Greenland starts really melting strongly only after that date," von Hardenberg said. "If you go farther in our simulation — we go up to the year 2300 — that is also when this meltwater really becomes extremely strong."

Yet unlike other studies that show the AMOC collapsing irreversibly under climate change, in this model, the circulation recovered once the team switched off the meltwater or dialed down greenhouse gas emissions. Both the simulations that didn't include the Greenland ice sheet and those that did had similar results, recovering partially when the meltwater was turned off and fully when greenhouse gas emissions were stopped.

The recovery in the model suggests that the AMOC is more stable than previously thought and doesn't suddenly flip from an active state into a collapsed one, von Hardenberg said. "It's consistent with a strong weakening, but not a shutdown," he said.

Overall, the findings show that it is important to include the Greenland ice sheet in climate models — something von Hardenberg and his colleagues are planning to do in the next version of the EC-Earth3 model.

"It's really something which is worthwhile doing to better constrain the uncertainty of these future simulations," von Hardenberg said. "If we have a larger set of models which include this component, we will be in a better position to try to answer the question, 'How much do we expect AMOC to decrease in different scenarios?'"

Other experts agreed that integrating the Greenland ice sheet in climate models will increase the accuracy of AMOC predictions.

"What makes the study particularly interesting is that it directly tests a process that has often been highlighted as an important source of uncertainty in future AMOC projections," said Jonathan Baker, a senior climate scientist at the Met Office in the U.K. who was not involved in the study.

The results are consistent with previous research showing that Greenland meltwater causes additional AMOC weakening, but whether the system could collapse is still uncertain, given that the team used only one model, Baker told Live Science in an email. "Repeating these experiments across a wider range of models will be important to assess how robust the findings are," he said.

Nicholas Foukal, an assistant professor at the University of Georgia's Skidaway Institute of Oceanography who was not involved in the study, said he doesn't think the use of a single model limits the analysis.

"I think this result is robust and I am glad to see the authors come to this conclusion in such a high-resolution and realistic coupled climate model," Foukal told Live Science in an email. "This finding also agrees with other modeling results that require immense amounts of fresh water, much more fresh water than is available on Greenland, to cause irreversible change in the AMOC."

However, a third expert said the model used in the study is unrealistic, because its parameters make the AMOC more resilient than those of other models. Therefore, the study should be replicated in other models to draw unbiased conclusions.

"While the experiment reported is interesting, its outcomes are neither surprising nor should be interpreted as exemplary for the whole model ensemble," Sybren Drijfhout, a professor of physical oceanography at the University of Southampton in the U.K., told Live Science in an email.

Researchers should investigate the impact of the Greenland ice sheet on the AMOC further, von Hardenberg said. "It would be interesting in the future to check it [the AMOC's recovery with Greenland meltwater] with other models, but of course it's encouraging to see it in one case," he added.

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

A giant blob of abnormally cold water in the North Atlantic Ocean is shifting the Indian summer monsoon, threatening the livelihoods of more than 1 billion people, new research suggests.

The link between these two systems highlights a previously unrecognized connection that could inform weather forecasts in South Asia and shed light on climatic events elsewhere, scientists say.

The Indian summer monsoon is a rainfall pattern that lasts from June to September and is driven by temperature differences between the warm northern Indian Ocean and cooler seawater below the equator. Historically, the monsoon triggered heavy rainfall along the west coast of India and a huge region of northern India called the Indo-Gangetic Plain. But since 1999, this pattern has changed dramatically, the researchers reported in a new study.

Northwest India now receives about 25% more rain during the monsoon season than it did before 1999, while the Indo-Gangetic Plain gets roughly 4% less, the team found. This is disastrous for farmers, in particular, because their soils and crops are adapted to the old rainfall pattern, said study first author Mahendra Nimmakanti, a climate scientist at the Indian Institute of Science's Centre for Atmospheric and Oceanic Sciences.

"India is largely dependent on agriculture," Nimmakanti told Live Science in a joint interview with study co-author Matthew Huber, a professor in the Department of Earth, Atmospheric, and Planetary Sciences at Purdue University in Indiana. Higher-than-normal precipitation in northwest India is causing flash floods and crop losses, because agriculture in this region is adapted to dry conditions. Meanwhile, the Indo-Gangetic Plain has seen periods of drought that also caused crop declines and impacted farmers' livelihoods, Nimmakanti said.

Previous studies have linked shifts in the Indian summer monsoon to changes in the Atlantic Meridional Overturning Circulation (AMOC), a giant web of ocean currents in the Atlantic that regulates the global climate and carries heat to the Northern Hemisphere. Data suggests the AMOC is slowing due to climate change and releasing less heat in the North Atlantic Ocean than it did before. This may be causing a southward shift of the Intertropical Convergence Zone, a band of low-pressure atmospheric conditions around the equator that drives tropical monsoons, including the Indian summer monsoon.

But these studies didn't specify how the Indian monsoon might shift or explain the underlying mechanism in detail, Nimmakanti said. "They generally explain that if there is a weakening of AMOC, that suppresses the Indian summer monsoon," he said.

One part of the problem is that current climate models do not show the changes in the Indian monsoon that have happened in real life, possibly because they also don't fully capture shifts in North Atlantic sea surface temperatures. This is especially true for a region southeast of Greenland known as the "cold blob," where the water was colder between 1901 and 2021 than it was in the late 1800s, even as the ocean around it heated up.

The cold blob suggests the AMOC is weakening because it points to a reduction in the amount of heat reaching the North Atlantic.

To pinpoint how and why the Indian monsoon has changed, the researchers fed precipitation data, sea surface temperature records and other real-life observations into dozens of climate models. This reproduced the shifts observed over the past 27 years. However, the results only implied a correlation between shifts in the North Atlantic and changes in the monsoon, not that the former directly caused the latter.

To figure out if North Atlantic sea surface temperatures caused the Indian monsoon to behave strangely, the team added and removed the cold blob in a simulation. The results showed that the cold blob has shifted the Indian monsoon by creating a strong temperature gradient over the North Atlantic, which, in turn, affects jet stream winds and pressure systems in the atmosphere above Eurasia.

Specifically, the jet stream above the North Atlantic has intensified, and a "blocking" system over the Ural Mountains in western Russia has strengthened, Huber said. As a result, weather systems in India have changed, sucking moist air toward the country's northwest and away from other regions.

"It's a shifting of the high- and low-pressure systems," Huber said. "Realizing that these two systems were directly linked through this wave train coming off the North Atlantic, that was novel."

More than 1 billion people in India and other parts of South Asia depend on the monsoon for food security and economic stability. The new results, published April 27 in the journal AGU Advances, could help forecasters predict extreme rainfall and drought events in India and neighboring countries like Pakistan during the monsoon season.

Some researchers think the Indian monsoon is a key tipping point within the global climate, and the findings suggest the system crossed a threshold in 1999. Since then, the cold blob has caused a "persistent jet stream reorganization," leading to abrupt shifts in the monsoon, according to the study.

It's unclear how the Indian monsoon will evolve under intensifying climate change, because climate models produce different predictions of what will happen in the North Atlantic, and other drivers may come into play as the world changes, Huber said.

"What we do now know is that this is one of the key building blocks of formulating a theory for what will happen in the future," he said.

A mysterious "cold blob" in the Atlantic Ocean is a sign that key ocean currents are weakening, a new study has found, with potentially devastating long-term impacts on our climate and weather.

The cold blob, or North Atlantic Warming Hole, is an area south of Greenland and Iceland where average sea surface temperatures have actually been going down. Researchers have been working to understand the blob for years, given that it bucks the global trend of Earth getting warmer.

The new research, published May 28 in the journal Geophysical Research Letters, supports previous interpretations that the blob's existence points to a weakening of ocean currents known as the Atlantic Meridional Overturning Circulation (AMOC).

The AMOC maintains Europe's relatively mild temperatures, particularly in winter, and helps regulate climate across Europe, Africa and America. Researchers have warned that a weakening AMOC has serious environmental consequences, with its collapse considered a major potential tipping point, or key threshold within Earth's systems, beyond which substantial and irreversible environmental change will occur.

Scientists are uncertain about the rate at which the AMOC is weakening, with one recent study projecting that it will slow down by around 50% by 2100. If the AMOC were to collapse completely, temperatures in parts of the Northern Hemisphere could plummet by some 18 to 27 degrees Fahrenheit (10 to 15 degrees Celsius), extreme droughts would be unleashed in southern Europe, and the sea level would rise along the northeastern coastline of North America.

"Given the well-established existence of a tipping point of the AMOC, as well as recent studies finding a range of different "early warning signals" of the ocean circulation approaching such a tipping point, the strong evidence for a weakening AMOC is a serious concern for society and policy," the authors of the new study wrote in the study.

The AMOC acts like a conveyor belt, carrying water, nutrients, and absorbed carbon dioxide from the tropics northward. This warm water heats up the atmosphere, with westerly winds then carrying the resulting warm air towards land, keeping Europe relatively mild.

Many researchers have posited that cooling in the blob is due to reduced ocean heat transport. In other words, slowing ocean currents are delivering less heat to that region, leading to a patch of cooling. However, some researchers have also suggested that the blob could be the result of increased heat loss at the ocean surface, according to the study.

The authors of the study analyzed measurements of ocean heat content and surface flux changes in the blob region, based on data collected by Copernicus satellites and other sources. They concluded that the blob was a deep-reaching loss of ocean heat content and thus couldn't be explained by heat changes at the surface. Rather, their findings support the theory that the blob is caused by changes in ocean heat transport and the AMOC, a conclusion backed by a previous study published in 2025 in the journal Communications Earth & Environment.

"Our analysis supports the interpretation of the observed "cold blob" as a sign of a weakening AMOC," the authors wrote.

There are still uncertainties surrounding the cold blob and the weakening AMOC, with work ongoing to better understand these phenomena. Meanwhile, the Trump administration is set to remove 900 deep-sea monitoring instruments from the Atlantic and Pacific Oceans, which include sensors that would have kept tabs on the AMOC.

The Trump administration is targeting one of the world's most trusted sources of climate and oceanic data — the Ocean Observatories Initiative (OOI). According to the New York Times, ships will be dispatched this month to remove the more than 900 deep-sea instruments that comprise the network, which, for the past decade, has collected crucial data on physical, chemical, geological and biological conditions from all layers of the Atlantic and Pacific Oceans on a continuous basis.

In a statement dated May 21, the OOI confirmed that the National Science Foundation (NSF) had begun a "descoping" process, including removing all in-water infrastructure from four of the OOI's five deployed arrays. "This plan includes the removal of all in-water infrastructure from the Irminger Sea, Station Papa, Endurance and Pioneer Arrays, subject to ship scheduling and other operational constraints," the OOI said in the statement. This covers instruments stationed in the Pacific, as well as others in the waters off the U.S. Atlantic coast and Greenland and Iceland. The initiative was originally meant to run for 25 years.

In a statement, an NSF spokesperson said the intention was not to cancel the OOI but to transition to a "nimbler approach to prioritize support for evolving scientific priorities and emerging technologies, as well as smart lifecycle management within its research infrastructure portfolio."

"NSF remains committed to ocean science and will continue working with the scientific community on high-priority research objectives," he added.

Among the arrays that are set to be taken apart is the Coastal Endurance Array, which lies off the coasts of Oregon and Washington State. Its data is vital to scientists studying a region of ocean that accounts for about a quarter of the annual global fish catch. And the station in the Atlantic's Irminger Sea has gathered crucial data on the Atlantic meridional overturning circulation (AMOC), which some scientists suspect is weakening — if it collapses, the weather effects could be devastating.

"Sustained ocean observations are how we detect emerging risks in real time, from shifts in circulation to changes in chemistry and ecosystem health. Without them, we are effectively choosing to navigate an increasingly volatile ocean with diminishing visibility," said Helen Findlay, a biological oceanographer at the Plymouth Marine Laboratory in England, in a statement. "We already know the AMOC plays a critical role in regulating climate and sustaining marine ecosystems, and there is growing evidence that it may be weakening. Growing uncertainty around its future is precisely why long-term, consistent monitoring is more vital than ever."

Removing the sensors is a loss that will be keenly felt by scientists studying ocean wildlife. Rebecca Helm, a marine biologist at Georgetown University, points out that expeditions are both costly and limited in the time they can remain at sea, while the sensors provide a continuous influx of data.

"Ocean observing systems are important because they are like our eyes and ears in the water," says Helm. "They're providing invaluable information on the state of the ocean that is hard to get any other way."

The loss won't just be felt in the scientific community, but also by human industries that depend on marine systems, she adds.

According to the OOI's May 21 statement, one network of seafloor sensors — the Regional Cabled Array, which extends from the Oregon coast to the Juan de Fuca tectonic plate in the Pacific Ocean — will remain in service "for the foreseeable future." The NSF's Fiscal Year 2026 budget request had proposed to cut funding for the OOI by 80 percent.

Conditions in the world's ocean can have enormous effects on the climate, and vice versa. Deep water stores an enormous amount of carbon, which, if released into the atmosphere, could tremendously speed up climate change. Ocean currents also play a vital role in maintaining weather patterns that, if affected by warming waters, could lead to wide-scale chaos.

Still, dismantling the ocean monitoring system is the Trump administration's latest effort to scale down the U.S. government's support for climate research. Separately, last December the administration announced it would shutter the National Center for Atmospheric Research, a key research facility for the study of climate and weather. A court ruling has since temporarily blocked that effort.

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

This beautiful satellite snap captured a series of "brushstroke-like patterns" that emerged in the mouth of an Indonesian river. The striking striations were triggered by a particularly high tide following a full "Strawberry Moon."

The Rokan River is a roughly 220-mile-long (350 kilometers) waterway on Indonesia's Sumatra island. The landmass covers around 170,000 square miles (440,000 square kilometers) in the Indian Ocean, making it the sixth-largest island on Earth.

The river runs from the Barisan Mountains in Sumatra's west to the island's north coast, where it drains into the Strait of Malacca. Here, the river morphs into a brackish estuary that flows on each side of Halang Island (photographed).

The Rokan River often has a yellow hue due to high levels of sand and silt in its waters. The sediment gets dragged up from the river's floor, partially due to the constant rising and falling of the tide, according to NASA's Earth Observatory.

In this image, the tide is on its way out, which causes the sediment to be slowly dragged out to sea. When viewed from above, these "brushstroke-like patterns" transform the river into what looks like an abstract painting, Earth Observatory representatives wrote.

When the photo was taken, the high tide was at its peak ‪—‬ up to 16 feet (5 meters) higher than low tide. The water was especially high because it was the day after the full "Strawberry Moon" rose in the sky, according to the Earth Observatory. (June's full moon is nicknamed the Strawberry Moon because it coincides with the strawberry harvesting season in the Northern Hemisphere, not because of its color.)

The tidal range is greatest when there is a full moon because the sun and the moon are aligned in a straight line, so they gravitationally push and pull Earth's oceans in sync. This is known as a "spring tide," but it happens throughout the year.

In addition to having a significant tidal range, the Rokan River is home to a regular tidal bore — a powerful surge of water that rushes upstream like a giant wave during high tides. This rare phenomenon occurs only in estuaries with a narrow mouth and a high tidal range.

A 2022 study revealed that the surge is responsible for transporting large amounts of sediment back up the river. If a bore occurred before the satellite photo was taken (which may or may not have happened), it could have stirred up some of the sediment streaks visible in the image.

All of this tidal action can have a significant impact on the estuary itself. A 2016 study compared satellite images of the estuary between 2000 and 2014, and found that the shoreline along the north of Halang Island (which clearly extends beyond the small landmass in the image) is growing at an average rate of 220 feet (67 m) per year.

See more Earth from space

Building a giant dam between Russia and Alaska might save a key Atlantic current that is crucial to regulating the climate in northern Europe. However, that massive undertaking presents other risks, researchers explain in a new study.

By stretching across the Bering Strait and disconnecting the Pacific Ocean from the Arctic Ocean, this huge geoengineering scheme could buy more time for the threatened conveyor belt of currents known as the Atlantic Meridional Overturning Circulation (AMOC), according to the study. However, the study authors and other researchers caution that the effect is variable, the results are preliminary, and further modeling studies are needed to see if such a bold course of action might be merited.

Impending AMOC collapse

The AMOC moves warm, salty water from the tropics northward, where it cools and sinks, and shifts cold water south, sustaining marine life and regulating the climate across Europe, Africa and the Americas. It is why Europe has a relatively mild climate despite its high latitude.

Numerous studies have suggested that the AMOC is weakening and may collapse. Research published earlier this month says it will slow down between 43% and 59% by 2100 — a 60% stronger weakening than past models predicted — so it may be closer to collapse than previously thought. If it does fail, the consequences could be catastrophic, causing temperatures in Northern Europe to plummet, bringing drought, raising the sea level along the northeast coast of North America by at least 1.6 feet (50 centimeters), as well as disrupting food production.

"The evidence is pointing towards collapse, but it's very uncertain," lead author Jelle Soons, a researcher who studies the AMOC at the Institute for Marine and Atmospheric Research at Utrecht University in the Netherlands, told Live Science.

There are two ways global warming could stop the AMOC. One possibility is that warmer North Atlantic waters could prevent the warm, salty water it is carrying from cooling and sinking. Another is that melting ice sheets in the North could add more fresh water to the mix, thereby diluting the saltiness of the arriving water and stopping it from sinking.

Previous research showed that the AMOC was stronger in the mid-Pliocene some 3 million years ago, primarily because there was a land bridge closing off the Bering Strait. "So I wondered what would happen if we closed off the Bering Strait again," Soons said.

Three dams across the strait

In the new study, published Friday (April 24) in the journal Science Advances, Soons and his colleague Henk Dijkstra, a physical oceanographer at the Institute for Marine and Atmospheric Research, modeled what would happen if that passage were closed. First, it would require three dams to cover the 51-mile-wide (82 kilometers) stretch of water, because two islands sit in the middle of the strait. The longest would need to be about 24 miles (38 km) in length.

They found that with lower levels of carbon dioxide (CO₂) emissions and a minor weakening of the AMOC, the closure of the Bering Strait could strengthen the AMOC and allow it to continue to function as CO₂ emissions rise. However, they also discovered that with a much weaker AMOC, a closure of the Bering Strait would accelerate AMOC weakening.

"This means it is not a straightforward solution," Jonathan Baker, an ocean scientist at the U.K. Met Office who wasn't involved in the study, told Live Science in an email. This means a dam might put off AMOC collapse only in some situations, he added.

The result is very interesting and provides an alternative way to mitigate the effects of rising CO₂ levels, said Aixue Hu, an oceanographer at the National Center for Atmospheric Research who wasn't involved in the work.

"However, the overall effect is not consistent and highly depends on the AMOC strength and CO₂ levels," Hu told Live Science via email. "Even if the closure of the Bering Strait can strengthen the AMOC and allow for more CO₂ emissions in the near future, the long-term effect is still uncertain."

The engineering of a Bering Strait dam should be technically feasible, Soons said. The longer parts wouldn't be much longer than the Afsluitdijk dam in the Netherlands, which covers 20 miles (32 km), or the Saemangeum Seawall in South Korea, which is 21 miles (33 km) long, he said. A Bering Strait dam would have a maximum depth of 194 feet (59 meters), which isn't much deeper than the deepest part of the Saemangeum Seawall, which goes down to 177 feet (54 m).

However, both of those constructions are in relatively calm coastal waters, not in remote locations with strong currents and sea ice, or with rival geopolitical powers on opposite sides.

Severing the connection between the Pacific and Arctic oceans would also affect wildlife, fishing industries, shipping and Indigenous communities who are dependent on the strait for food and trade, Soons said.

"Blocking the strait would alter the exchange of water, heat, nutrients and marine life between the Pacific and Arctic Oceans, with potential impacts on marine ecosystems and regional ocean circulation," Baker said. "It could also lead to changes in climate that are not yet fully understood. Any intervention of this scale would need to carefully consider potential unintended consequences alongside any intended benefits."

Soons, Baker and Hu all say more modeling work is needed to explore the findings and get a more detailed picture of what would happen under different scenarios.

There is also a more straightforward way to save the AMOC. "Closing the Bering Strait might delay a collapse under some conditions, but it does not remove the underlying risk from continued warming," Baker said. "The most reliable way to reduce AMOC risk remains cutting greenhouse gas emissions."

Catastrophic water shortages are in store for the 40 million people living in areas fed by the Colorado River, even if cities in the region such as Denver, Phoenix and Las Vegas make dramatic cuts to their usage, recent research suggests.

Water shortages could start as soon as this summer, as snowpack levels reached a record low over Lake Powell and the spring runoff into the Colorado River is expected to be minimal, experts told Live Science. And the region's major cities, which have already slashed their per capita water consumption by up to 58% between 2002 and 2025, can't solve the problem alone.

"We can't just shove it all onto the residents of these cities and tell them to use less water, because it's still not going to be enough [to prevent water shortages]," Renee Obringer, an assistant professor in the Department of Energy and Mineral Engineering at Penn State and the first author of the new study, told Live Science. "Regardless of what mitigation we do, we're still going to have to adapt to this warmer world that is going to have more intense droughts and more frequent droughts."

The findings reveal that bolder measures will be needed to head off disaster in the Colorado River basin. But exactly what are those steps?

One piece of the puzzle

Seven states — Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming — pull water from the Colorado River, and the amount allocated to each region is governed by a century-old document called the Colorado River Compact.

But the Colorado River basin, along with the rest of the U.S. Southwest, has been in a megadrought for 25 years. Between 2000 and 2019, the river's flows shrank by 20% due to climate change and water overuse to supply cities, agriculture and industry.

Finding new water supplies is unlikely, so Obringer and her colleagues analyzed what would happen if three large cities fed by the river — Denver, Las Vegas and Phoenix — reduced their consumption by around 25% under various climate scenarios, ranging from a global temperature increase of about 2.9 degrees Fahrenheit (1.6 degrees Celsius) to an increase of 7.7 F (4.3 C) compared with preindustrial levels.

Their results were published in December 2025 in the journal Water Resources Research. In most climate scenarios, demand management — which encompasses broad strategies such as raising awareness, offering rebates, and subsidizing low-flow devices — did not make up for lower water storage in urban reservoirs caused by higher temperatures and lower precipitation in the region. Denver, which is technically not located in the Colorado River basin but gets half of its water from the Colorado River, was the lone exception. Demand management compensated for river flow reductions in two high-emissions climate scenarios for the city. However, Obringer suspects some of those more optimistic results could be an artifact of the way the model handles uncertainties.

Cities fed by the Colorado River basin have reduced water use through programs aimed both at demand and reuse. In Las Vegas, for example, residents receive cash rebates for replacing water-heavy lawns with desert plants. The city, which gets 90% of its water from the Colorado River, also returns, after treatment, 40% of the water it uses to Lake Mead, where it can then be reused.

Cities have taken significant steps to reduce their footprint, and they will likely continue to improve, said Brad Udall, a senior water and climate research scientist at Colorado State University’s Colorado Water Center who was not involved in the study. As a result, some of the region's biggest cities use less water per capita than they did a few decades ago.

But the more efficient cities get, the fewer opportunities they will have to save and reuse water, Udall told Live Science.

Bigger water users

The results highlight a reality scientists have long known: Demand management alone cannot offset the Colorado River's dwindling flows, said Sharon Megdal, a professor and director of the Water Resources Research Center at the University of Arizona, who was not involved in the study.

Cities make up only 18% of water use in the region, while agriculture guzzles more than 70% of the basin's water. "Agriculture's the big user," Megdal told Live Science.

"You can't solve this problem without dealing with agriculture in a major way," Udall agreed. "Because agriculture is 70% of the problem, it needs to be at least 70% of the solution."

Individual farmers have senior water rights to Colorado River water, meaning they receive their full allocation regardless of whether there is a shortage, but political pressure is rising to allocate more water to cities and cut farmers' consumption, Udall said. For example, water managers may decide that farmers in Arizona have to relinquish water to supply the Central Arizona Project canal, which delivers water from the Colorado River to the central and southern parts of the state, including Phoenix and Tucson.

Since 2019, the Colorado River has shrunk so much that it is now 35% smaller than it was on average in the 20th century. "We've never seen flows like this," Udall said. "If these flows continue to drop, I do see agriculture in the Lower Basin not getting the supplies they do [now] and those supplies being reallocated to cities."

The problem is that farmers in the Lower Basin grow crops that benefit the region economically through exports, including alfalfa, cotton, vegetables and citrus fruit. In Arizona, roughly 20% of cropland is used to grow alfalfa for cattle feed. The state is also the biggest cotton producer in the Colorado River basin, and it grows up to 90% of leafy greens consumed in the U.S. and Canada.

To cut their water consumption, farmers can change their irrigation techniques and crop patterns, Megdal said. Drip irrigation, which delivers water directly to the roots, cuts evaporation and reduces water use by up to 50% compared with methods such as flood irrigation used for cotton and alfalfa. Thirsty crops such as alfalfa could be replaced with low-water forage mixes consisting of wheat, barley, oats, rye and peas. Recently, there has also been a focus on guayule, which is a substitute for rubber, as an alternative crop for farmers, Megdal said.

But farmers respond to demand and may have long-term contracts with buyers. "It has to be economical," Megdal said.

Agriculture should switch to more efficient irrigation, but it's also important to realize that some seemingly wasteful methods, such as furrow or flood irrigation, can replenish aquifers, which are also being depleted, Udall said.

Some farmers are letting their fields go fallow, which could happen more and more as water shortages intensify, Megdal added.

Renegotiating water rights

The Colorado River Compact is up for renewal this year, meaning there is an opportunity to devise a more sustainable agreement, Obringer said. But negotiations have stalled between the Upper Basin, which includes Colorado, New Mexico, Utah and Wyoming; and the Lower Basin, which encompasses Arizona, Nevada and California. While officials wrangle over the precise wording in the document, the underlying problem is that the Lower Basin needs more water than it's getting, even though the Upper Basin already uses less water than it was allocated in the compact.

Officials in the Upper Basin have argued that cuts should now fall exclusively upon the Lower Basin. But that can't happen, Udall said, because cuts need to be deep across the Colorado River basin to make a difference. No matter what the Upper Basin thinks it is entitled to, it must accept reductions in water use, he said.

Reality check

Solutions must be found and implemented immediately, because the Colorado River's future has never looked bleaker.

Winter brought barely any snow, and the little that fell melted in early March instead of April, meaning river flows this spring and summer could hit record lows. "It's unprecedented; it's human-caused; it's scary, frightening, awful," Udall said.

Udall estimates that Lake Mead, which serves almost 25 million people in cities such as Las Vegas and Los Angeles, and Lake Powell, which supplies Lake Mead and Indigenous tribes, will be only about 20% full over the coming months. Without adjustments in reservoir release, water levels could drop low enough to prevent energy production at Glen Canyon Dam, which usually produces enough electricity to power over 350,000 homes.

"We're close to dead pool," Udall said. This is when the water level in a reservoir falls so low that it can't flow downstream. "That's never happened, and it's very serious."

It would take years of unusually high precipitation and runoff to recover from the current state, according to Megdal. "It is a challenging situation," she said. "You really have to adjust to a new normal."

To make matters worse, "data centers are popping up everywhere in this region," Obringer said. A midsize data center uses up to 300,000 gallons (1.4 million liters) of water per day for cooling, and this number will only increase as temperatures rise. Much of the water that runs through the system can be reused, but some is consumed to generate the electricity to power data centers.

Some small steps to mitigate the problem are already in the works. Some municipalities are buying water rights and groundwater from rural areas in the region, Megdal said. For instance, the rapidly-growing town of Queen's Creek, Arizona, is purchasing groundwater from farmers and investors in the sparsely populated Harquahala valley. Arizona is also drawing up agreements with California and Mexico to obtain desalinated water.

"I do think there's a tremendous capacity to adapt," Megdal said.

But a more durable solution will require a major overhaul of the existing agreements and water rights to reflect reality, Udall said.

"We've got to have an agreement on how to share the water we have and not pretend we live in the past," he said. "We need to adjust this system to deal with a completely new reality of much less water flow. We've got to balance the books here."

Oil spills in the Persian Gulf are visible from space after Iranian and U.S.-Israeli air strikes hit oil facilities and tankers across the region, satellite images reveal.

One image, taken April 10, shows oil leaking into the waters off Iran's Lavan Island and heading toward Shidvar Island, a protected wildlife refuge known as "Iran's Maldives." Another snap from April 6 captures an oil trail leaving Kuwait's Port of Shuaiba, located about 30 miles (50 kilometers) south of Kuwait City, after Iran said it targeted energy and petrochemical facilities in the Gulf countries April 5. And on March 18, April 2 and April 7, huge oil spills were visible in the Strait of Hormuz off Iran's Qeshm Island, which houses key military and civilian infrastructure.

These oil spills will likely affect the Persian Gulf's marine life and the filtering systems of desalination plants, which supply clean, drinkable water to almost 100 million people in the region, CNN reported.

The oil spill off Lavan Island, in particular, is a "major environmental emergency" due to its proximity to Shidvar Island, Wim Zwijnenburg, a project leader in humanitarian disarmament at the Dutch peace organization PAX, told CNN. Shidvar Island is an uninhabited coral island that hosts seabird colonies and turtle nesting grounds. At least five locations on Lavan Island have been hit by U.S.-Israeli forces, Zwijnenburg said, including an oil refinery.

Pools of oil off Qeshm Island measured more than 5 miles (8 km) long, threatening the entire marine ecosystem, from microorganisms to dolphins and whales. It also includes fish, which thousands of people living along the coast of Iran rely on for income and food, CNN reported.

Oil spills devastate marine life by coating animals in harmful sludge, destroying the water repellency of birds' feathers and the insulating effects of mammals' fur, which can cause hypothermia. It also induces poisoning, leading to mass die-offs. The 1991 Gulf War oil spill, which was caused by Iraqi forces intentionally dumping 6 to 8 million barrels of crude oil into the Persian Gulf, harmed or killed an estimated 114,000 animals, including birds, turtles, bottlenose dolphins and whales.

The Persian Gulf is home to dugongs (Dugong dugong), green sea turtles (Chelonia mydas), hawksbill sea turtles (Eretmochelys imbricata) and Arabian Sea humpback whales (Megaptera novaeangliae).

It's unclear exactly how much damage these oil spills will do, and there may be more on the horizon, especially if the warring parties continue to target ships carrying oil. Dozens of oil tankers filled with a total of around 5 trillion gallons (20 billion liters) of crude oil are currently trapped in the Persian Gulf, waiting to exit through the Strait of Hormuz.

Due to the conflict, it's unlikely that the existing oil spills will be cleaned up in time to prevent the worst impacts, Nina Noelle, a spokesperson for Greenpeace Germany, told CNN.

This dazzling satellite photo shows a glowing ring of plankton surrounding a remote group of New Zealand islands. The illuminated landmasses are hotspots for deadly whale stranding events, which are tied to the same underwater structure that birthed this spectacular bloom.

The gleaming ring encircles the Chatham Islands — a group of 10 islands in the Pacific Ocean around 520 miles (840 kilometers) west of Christchurch, on the east coast of New Zealand's South Island. The largest of those islands, Chatham Island and Pitt Island, are approximately 36 miles (58 km) and 9 miles (15 km) across, respectively. (The other landmasses are much smaller and are not clearly visible in the image.)

The Chatham Islands are surrounded by the Chatham Rise — a shallow underwater plateau that extends up to 900 miles (1,450 km) from the South Island's east coast. This hidden structure acts like a giant ramp that funnels cold, nutrient-rich waters to the ocean's surface. In the summer, warmer seasonal currents mix with this nutrient-rich water, providing the perfect conditions for algae to bloom.

The circular bloom in the photo was one of the largest in recent decades. It consists mostly of coccolithophores, a group of photosynthetic plankton, or "phytoplankton," that convert sunlight into energy and surround themselves with intricate calcium carbonate armor.

The satellite image was captured with a special near-infrared filter, which likely enhanced the algae's vivid hues. However, the blooming microorganisms would have been clearly visible to the naked eye from space, according to NASA's Earth Observatory.

Phytoplankton are the base of the pelagic (open-water) food web, similar to plants' role in terrestrial environments. As a result, the Chatham Islands are marine biodiversity hotspots that are home to various animals, including penguins, albatrosses, seals and sea lions, as well as commercially important populations of cod and lobsters.

At least 25 species of whales and dolphins, or cetaceans, are also drawn to the islands to feed, including orcas (Orcinus orca), sperm whales (Physeter macrocephalus) and pilot whales (Globicephala), according to New Zealand's Department of Conservation (DOC). However, this is not always a good thing for the visitors.

Large groups of cetaceans often get disoriented in the shallow waters and can end up accidentally swimming too close to shore and getting trapped as the tide goes out, which is often fatal without human intervention.

Chatham Island has experienced multiple strandings over the past few years, including an event in October 2022 when nearly 500 pilot whales were euthanized on Chatham Island after washing up over the space of around four days, according to a DOC report. In 1918, more than 1,000 pilot whales are also believed to have died there after washing ashore, which remains the most deadly whale stranding event in recorded history. (Pilot whales are particularly prone to stranding because they are highly social, so an entire pod can be dragged into danger by a single injured or disoriented individual.)

Cetaceans are not the only creatures that have met an untimely end on the Chatham Islands. The archipelago was previously home to at least eight endemic bird species that have since gone extinct, including the Chatham penguin (Eudyptes warhami). Most of these species disappeared between 150 and 200 years ago due to the island's first human settlers, who arrived there from Polynesia in the 15th century.

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The Colorado River may have carved out the Grand Canyon after pooling as a giant lake in what is now northern Arizona and spilling downstream, a new study suggests.

Scientists found that tiny sediment grains in the Bidahochi Basin, upstream of the canyon, were carried from the upper Colorado River watershed by 6.6 million years ago.

The findings fill in a 5 million-year gap about where the Colorado River was during this early period, said John He, a geologist at UCLA and the first author of the new study, published today (April 16) in the journal Science.

"Our new evidence shows that it pooled just east of the Grand Canyon, feeding a vibrant ecosystem," He told Live Science.

The findings, in turn, suggest that a giant ancient lake in the basin slowly filled and overflowed, causing the Colorado River to flow through and carve out what is now the Grand Canyon around 5.6 million years ago.

However, this study will likely not be the last word on the Grand Canyon's origins. "I don't think their data support that [lake spillover] conclusion," said Karl Karlstrom, a geologist at the University of New Mexico who was not involved in the new study. But researchers are zeroing in on some points of agreement about when the canyon formed, he told Live Science, even if they are still hashing out the "how."

The question of the Grand Canyon's formation comes down to how the waters of the Colorado River gathered from their headwaters (now in Rocky Mountain National Park in Colorado) and funneled through what is now northern Arizona, gouging out the 5,000-foot-deep (1,500 meters) canyon. The Colorado River dates back 11 million years in western Colorado but didn't reach the sea until 4.6 million to 4.8 million years ago.

Scientists already knew that, downstream of Lake Mead more than 5 million years ago, the river flowed into a series of previously isolated lakes, filling each with sediment and water until the water level reached high enough to flow out of the lake basin and head downhill to another low spot. It's hotly contested whether something similar happened upstream of the Grand Canyon as the river slowly forged a path from its origins to the ocean.

There are other mysteries, too. The Colorado River cuts through the Kaibab Arch, a high point visible from the South Rim today, raising questions about how and why it went over a high-elevation feature rather than around it.

To learn more, He and his colleagues examined Bidahochi Basin zircons — tiny, weather-resistant mineral grains that contain chemical information about their age and where they formed. Beds of volcanic ash helped the researchers pin down the ages of these zircon deposits.

The zircons in the basin matched those of the ancestral Colorado River, He said. This shows that an ancient lake in the basin (sometimes known as Hopi Lake) was fed by the Colorado River, which indicates the lake-spillover hypothesis is plausible, he said. This would not have been a catastrophic flood, but rather a steady flow from an overfull lake that would have been high enough elevation to cross the Kaibab Arch.

Other evidence, such as fossils of large fish species adapted for a living in fast currents and an increase in sediment flowing into the Bidahochi, also points to the development of a fast-moving river system, the researchers wrote.

"I think it's pretty convincing in terms of arguing that lake spillover was important for the canyon higher and farther north than it had previously been thought to be the case," Barra Peak, a postdoctoral researcher in Earth and planetary science at the University of Texas at Austin who was not involved in the study, told Live Science.

However, not all researchers are convinced. Karlstrom and his collaborator (and spouse) Laura Crossey, a University of New Mexico geochemist, contest He and his colleagues' interpretations that the Bidahochi Basin held a large lake. They also point to data suggesting there was a notch in the Kaibab Arch carved by the Little Colorado River (a tributary of the modern-day Colorado) 10 million years before the main Colorado River made its way to the area, which would have let water flow rather than pool. (Crossey and Karlstrom collaborate on related research with some of the co-authors of the new paper but were not directly involved in the study.)

That disagreement highlights some of the differences in interpretation and uncertainties in the data from around the canyon, He said.

But both sides of the debate are starting to agree on some basic facts, such as the timing of the river's travels, its path through the Bidachochi, and its development north to south in several steps, Karlstrom and Crossey told Live Science.

"It's heading in the direction of a consensus toward solving these long-debated issues," Karlstrom said.

Scientists have discovered a freshwater reservoir beneath Utah's Great Salt Lake that could span the entire area of the lake and beyond, a new study shows.

The reservoir extends up to 2.5 miles (4 kilometers) deep beneath specific spots in the lake's eastern margin, where strange, reed-covered mounds have sprouted from dried-up surfaces in recent years. If future studies can confirm that the reservoir is as large as the preliminary results suggest, its fresh water could help to restore the lake bed in places where it is cracking and creating toxic dust, the researchers said.

"When I first realized that we found this, I was very excited," study lead author Michael Zhdanov, director of the Consortium for Electromagnetic Modeling and Inversion and a distinguished professor of geology and geophysics at the University of Utah, told Live Science. "I think it's very important."

Researchers have suspected a source of fresh water beneath Great Salt Lake for years, thanks to the appearance of mysterious mounds choked with common reeds, or phragmites, on a dried up patch in the lake's southeast corner. Phragmites need abundant fresh water to grow, prompting researchers to think groundwater must be rising beneath the dry lakebed in Farmington Bay.

Samples from the mounds showed fresh water is present, Zhdanov said. "So the question was, where does this water come from? And the hypothesis was that probably it's underground water, which comes from the surrounding mountains," he said.

To understand the plumbing beneath the mounds, Zhdanov and his colleagues conducted an airborne electromagnetic survey over a 10-square-mile (25 square kilometers) portion of Great Salt Lake. With the help of the company Expert Geophysics, the researchers flew a helicopter with a hanging circular device that sent electromagnetic pulses downward in long lines over the lake. A ball suspended at the center of the device intercepted these signals as they bounced back, producing data that could then be deciphered with software to map freshwater deposits beneath the lake.

Great Salt Lake is a huge saltwater lake with a surface area of around 1,700 square miles (4,400 square km). Saline water is very conductive, so the scientists weren't sure if the electromagnetic pulses would penetrate the lake and the sediments beneath to give a crisp picture. "It was just a pilot project to see if really we can get this result," Zhdanov said.

But when the maps came back, they showed an underground layer of fresh water across the entire survey area. The sediments beneath Great Salt Lake are saturated with fresh water that likely trickled down from the surrounding mountains as snowmelt and accumulated there for thousands, if not millions, of years, Zhdanov said.

"The result was amazing," he said. "Of course, it was a very small fraction of the entire area of Great Salt Lake. In order to make any definitive conclusions that this water reservoir is located under the entire area, we need to expand the survey."

The results, published Feb. 27 in the journal Scientific Reports, showed a layer of fresh water in the sediment beneath the lake ranging between 330 feet (100 m) and 2.5 miles deep. Some kind of "cap" rock likely prevents the fresh water from mixing with the lake's salt water, but more research is needed to figure this out because fresh water can rise beneath the reed-covered mounds, Zhdanov said.

In addition to capturing electromagnetic data, the airborne survey collected magnetic data, which the scientists used to map the geology deep beneath the lake. They discovered that watertight "basement" rocks form the lower boundary of the freshwater reservoir, with faults in these rocks potentially explaining abrupt changes in the reservoir's depth, Zhdanov said.

If the reservoir spans the entire area of Great Salt Lake, it could provide a solution to clouds of toxic dust that emanate from stretches of the exposed lake bed. Since 1986, the lake has dropped by about 22 feet (6.7 m) due to human water consumption, drought and high evaporation rates from climate change.

Exposed patches of the lake bed have dried to a crisp and eroded, generating dangerous dust pollution for populated areas nearby. For example, Salt Lake City is directly downwind of the lake and could see a huge increase in poisonous air pollution in the coming years, according to a 2023 study.

Fresh water from the reservoir could be used to dampen the lake bed and mitigate pollution, Zhdanov said. Farmers in the region could also potentially extract the water for irrigation, but more studies are needed, he added.

The results imply that there may be freshwater reserves hiding elsewhere in Utah or beyond, Zhdanov said. "The bottom line is that this project demonstrated that airborne geophysics work can be used to identify these groundwater reserves in deserts like Utah," he said.

Lençóis Maranhenses is a national park on Brazil's northeast coast that is famous for its white sand dunes peppered with thousands of temporary, crystal-clear lagoons.

The lagoons form every year during the wet season, between January and June, when rainwater collects in natural basins between the dunes. A compact, impermeable sediment layer prevents the water from draining, thereby creating freshwater pools that vary in shape, size, depth and color, according to UNESCO, which designated Lençóis Maranhenses National Park as a World Heritage Site in 2024.

Sand dunes cover about two-thirds of Lençóis Maranhenses, which spans 580 square miles (1,500 square kilometers) within a transition area between the Brazilian Amazon, the Cerrado ecoregion and the Caatinga ecoregion. The Cerrado features tropical savannas, wetlands and abundant biodiversity, and it's one of the best carbon sinks in the world. The Caatinga, meanwhile, is a semiarid landscape covered in dry forests with thorny shrubs and stunted trees. The name Caatinga comes from the term "ka'atinga," which means "white forest" or "white vegetation" in the Tupi language.

Lençóis Maranhenses does not belong to any of those ecoregions. Instead, it forms its own unique landscape that, in some places, looks like a desert but isn't one.

The remaining third of Lençóis Maranhenses is home to mangrove swamps and lush vegetation. Rare and endangered species live these ecosystems, including the neotropical otter (Lontra longicaudis); the West Indian manatee (Trichechus manatus); the scarlet ibis (Eudocimus ruber); and the oncilla (Leopardus tigrinus), a type of small, spotted cat.

The national park includes 50 miles (80 kilometers) of coastline, with a dry plain separating the beach from the sand dunes. Sand is dumped ashore by the tides and then eroded by winds and transported across the plain to the dunes. This action shapes the dunes into huge crescents, also known as barchans, that grow taller the farther inland they are, because the farthest dunes from the beach are those that have been around the longest and accumulated the most sand via wind deposition. The dunes that hug the plain are up to 3.3 feet (1 meter) high, while those farthest inland can measure up to 100 feet (30 m) tall, according to UNESCO.

Lençóis Maranhenses is surrounded by a large buffer zone to protect it from human activities. The best time to visit the national park is between June and September, when the lagoons are full. Lagoa da Gaivota, Lagoa Azul and Lagoa Bonita are some of the largest lagoons in the national park.

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

The seven U.S. states that make up the Colorado River basin are struggling to agree on how best to manage the river's water as its supply dwindles due to climate change and a period of prolonged drought. Their negotiations, which are not open to the public, missed a Feb. 14, 2026, deadline the federal government had established, after which federal officials said they would impose their own plan.

The federal government has not yet done so, but the prospect of such an action is not good news for the nearly 40 million people who depend on the Colorado River for water, energy, agriculture and recreation, nor for the estimated US$1.4 trillion in economic activity the river supports.

We have led or participated in complex water management discussions from the river's headwaters in Colorado to its delta in Mexico and elsewhere in the arid Southwest and around the world. Even on less contentious issues, the keys to success involve learning together, understanding one another's interests, working through conflict and developing inclusive solutions for diverse participants. And that works best with an outside facilitator.

The five most common sources of conflict between people are values, data, relationships, interests and structure. The current Colorado River negotiations include all five. We believe a process designed and facilitated by negotiation experts could help break the logjam.

We recognize it can be very hard to reach an agreement when what’s at stake are countless lives, massive amounts of money, enormous quantities of hydroelectric power and not nearly enough water.

But compromise on Colorado River management is possible and, in fact, was achieved to curb California's water use in the 2000s, to negotiate an interim agreement to coordinate operations at the Lake Mead and Lake Powell reservoirs in 2007, and to enact contingency plans to manage drought in 2019. But this time around, circumstances are different.

Previous negotiations

The negotiations leading up to those agreements were often facilitated by officials from the U.S. Bureau of Reclamation who focused on reaching broad agreements on general principles and concepts before delving into details. Federal staff also actively guided key agreements and provided the science and computer models to make well-informed decisions. And the states' negotiators knew the Department of Interior would act unilaterally to make damaging cuts to water supply if states couldn't come to their own agreement.

The negotiators for the states had long-standing relationships and built trust by frequently communicating outside formal meetings and seeking to listen to and understand other states' perspectives, even if they didn’t agree.

The states also agreed to use the bureau's computer model for analyzing scenarios of climate change and management decisions. That meant all the negotiators were looking at the same data when delving into possible options. And the political and social environment was less polarized than today.

The current situation

In this round of negotiations, federal leadership has been lagging. The Department of the Interior has not made clear what the consequences might be for the states if they fail to agree. The U.S. Bureau of Reclamation has been without a permanent commissioner since President Donald Trump retook office in January 2025.

And federal staff have only recently begun helping to facilitate the discussions.

The states are fractured into subgroups, according to whether they are in the river's Upper Basin – Colorado, Wyoming, Utah and New Mexico – or the Lower Basin, which includes Arizona, Nevada and California. Each basin group holds strong positions and has generally been unwilling to shift.

Each basin group is using a different set of assumptions for the bureau’s computer model to explore options. And the discussion often gets stuck on details, which prevents progress toward broader agreements.

In addition, the political context has shifted significantly, with increased polarization and politicization of the issues, creating barriers to effective dialogue and deliberation. Today, compromise can seem unattainable.

But those relatively new challenges to Colorado River compromise are not an excuse for failure.

A way forward?

The current negotiations have all been done behind closed doors. From talking with people involved in the negotiations, we understand the negotiators have been left to set their own agendas and meeting plans and conduct their own communications and follow-up, with no formal facilitators.

It's reasonable to expect the negotiators to be ready to represent their states' interests, working through an incredibly complicated landscape of hydrology, climate and management scenario modeling, water law and administration, and politics. But we believe it's unreasonable — and unrealistic and unfair — to expect them to also be experts at designing and facilitating an effective process for sorting out their differences.

Federal officials are not necessarily the best people to run the process either. And if the agency that ultimately needs to approve any deal is the one leading the process, real or perceived biases about the states or key issues in the agreement could further complicate the discussions.

We believe that agreement between the seven states is still possible. It may be less effective to bring in a third-party facilitator at this stage in the negotiation process, though, because of the degraded trust, hardened positions and shortage of time.

One possible outcome is that the Bureau of Reclamation will select and enforce one of the five management alternatives it outlined in January 2026. But that could lead to decades of litigation going up to the Supreme Court. No one wins in this scenario.

A more hopeful possibility is that the bureau adopts short-term rules that would give the states another chance to negotiate a longer-term deal — ideally with an unbiased third-party facilitator for support.

A collaborative and consensus-based planning process in the Yakima River Basin in Washington state in the early 2010s is evidence that while nobody gets everything they want in a negotiated agreement, "if they can (all) get something, that's really the basis of the plan," as a Washington state official told The New York Times.

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

This striking satellite photo shows a bright plume of swirling marine mud that was whipped up off the coast of Florida following a blast of cold air from the Arctic, which brought severe winter weather to large parts of the U.S. earlier this year.

In late January, an extreme cold front descended across the eastern half of North America as the polar vortex — the ring of cold air that circles in the atmosphere above the Arctic — stretched southward, just as it did approximately a year previously.

This phenomenon, known as an Arctic blast, brought temperatures as low as minus 43 degrees Fahrenheit (minus 42 degrees Celsius) to parts of the Midwest, according to the National Weather Service's Weather Prediction Center. It also sparked fears that trees might start exploding.

In addition to dumping snow as far south as Georgia, this weather front also helped create a giant underwater plume in the West Florida Shelf — a large area of shallow water created by a submerged continental shelf that extends off Florida's southwest coast.

The plume, which consists mostly of calcium carbonate scattered across the seafloor, stretched up to 150 miles (240 kilometers) from the coast at its widest point, which extended outward from Key West (partly visible as three large landmasses in the right of the photo), according to NASA's Earth Observatory. It also stretched around the same distance from north to south (beyond the upper border of the photo).

Calcium carbonate (CaCO₃) is an inorganic chemical compound. While it is commonly found in rocks, such as limestone, the swirls in the photo are made of biological CaCO₃ — created by corals, algae and crustaceans — that builds up on the seafloor as the creatures die and fall to the ocean floor. The West Florida Shelf collects high levels of this material due to its shallow waters and is often described as a "carbonate ramp" as a result.

When the cold Arctic air descended on North America, it triggered strong winds across the shelf's surface, which created currents that dragged the calcium carbonate and other seafloor sediments closer to the surface, James Acker, a chemical oceanographer at the University of South Florida and NASA's Goddard Earth Sciences Data and Information Services Center, told the Earth Observatory.

Similar plumes have appeared in this area after hurricanes, which can also whip up seafloor sediments. However, such plumes are often less intricate than the one in this image because the disturbance to the ocean floor is much more violent.

Recent research has suggested that Arctic blasts like the one that painted this plume could become more common in the future as a result of human-caused climate change, which has made it more likely that the polar vortex will stretch southward. Therefore, we may see many more seascapes like this in the coming decades.

Hidden details

The plume is most highly concentrated in a line stretching directly between Key West and Dry Tortugas National Park, which comprises seven small islands (visible in the left of the photos).

Faint sediment swirls can also be seen farther from the coast. They include a rare pair of counter-rotating eddies, also called a "hammerhead eddy" (visible in the upper left of the image), which was created when the cold waters of the plume collided with the warmer waters in the Gulf of Mexico, according to the Earth Observatory.

This swirling sediment is also partly tied to the cold weather. "The cold air cools off the shallow water on the banks and makes it denser than the surrounding warmer open ocean water," Acker said. When this dense water sinks and flows offshore with the tides, it can carry some of the sediment toward the shelf’s edge, he added.

In the opposite direction, a thin trail of sediment can be seen snaking beneath the plume and terminating in a distinctive curl. This "loop current" formed when sediment-filled water spurted into the deeper waters of the Atlantic Ocean through hidden channels in the shelf's floor.

The last time such a visible loop current was seen in this area was in the aftermath of Hurricane Ian, which bashed into Florida in 2022 after pummeling Cuba, according to the Earth Observatory.

See more Earth from space

A 2024 study that claimed to have discovered an entirely new source of oxygen in the deep sea — dubbed "dark oxygen" — was flawed, inconsistent with previous research, and "fundamentally at odds with thermodynamics," critics argue in a new opinion article.

Despite this pushback, the researchers behind the 2024 study recently announced that they will deploy robots to the seafloor between Mexico and Hawaii in May to confirm the findings and determine what's causing the phenomenon.

But even without this new investigation, "we have more than enough evidence to quash all their [critics'] statements," study lead author Andrew Sweetman, a professor and leader of the seafloor ecology and biogeochemistry research group at the Scottish Association for Marine Science, told Live Science in an email. Some of this evidence is currently under review for publication in the journal Nature Geoscience, where the original study was published, Sweetman said.

The 2024 study proposed that potato-size metallic lumps on the deep seafloor could split seawater through electrolysis to make dark oxygen, so called because there is no light involved in the suggested reaction. If the discovery stands up to scrutiny, it will radically change our understanding of natural oxygen production, challenge the widespread idea that the deep seafloor is an oxygen sink, and raise key questions about the origin of life on Earth.

But in the opinion article, published in December 2025 in the journal Frontiers in Marine Science, critics say the study's methods were questionable and the researchers didn't provide enough evidence to support their extraordinary claims.

"We downloaded the data and replotted everything," said Anders Tengberg, co-author of the opinion article. "Everything just speaks against this being correct," Tengberg, a product manager and scientific adviser at the water technology company Aanderaa-Xylem and a researcher at the University of Gothenburg in Sweden, told Live Science.

It appears that the authors of the 2024 study didn't ventilate their measuring equipment properly once it landed on the seafloor, Tengberg and Per Hall, co-author of the opinion article and a professor emeritus of marine science at the University of Gothenburg, said in a joint interview. As a result, oxygen trapped inside the equipment may have skewed the gas concentrations measured at the seafloor — an unwanted effect that Tengberg, Hall and colleagues cautioned against in a 2021 study.

Even if Sweetman and his colleagues had measured oxygen concentrations correctly in their study, the mechanism they gave for how oxygen was produced by the metallic lumps, also known as polymetallic nodules, doesn't make sense, said Angel Cuesta Ciscar, a professor of electrochemistry and physical chemistry at the University of Aberdeen in Scotland and co-author of the opinion article.

"That explanation of how it's formed is simply impossible, because it violates the laws of thermodynamics," Cuesta Ciscar told Live Science. "Thermodynamics tells you what's possible and what's not possible if the laws of the universe are what we think they are. Until now, there's nobody in four centuries of science that has been able to show that the laws of thermodynamics [do not apply]."

"Experimental artifact"

Sweetman and his colleagues drew their original conclusions from experiments they conducted in the Clarion-Clipperton Zone (CCZ), a gigantic abyssal plain 13,000 to 20,000 feet (4,000 to 6,000 meters) deep in the North Pacific Ocean between Mexico and Hawaii. The CCZ is littered with polymetallic nodules, which are accretions of cobalt, nickel, manganese and other metals that are critical to produce batteries and electronics, making the area a target for deep-sea mining exploration companies.

The researchers received funding for the study from The Metals Company, a Canadian deep-sea mining firm, and UK Seabed Resources, a subsidiary of the British arm of Lockheed Martin that focuses on deep-sea mining. Yet the results, published at what the authors of the opinion article called "a critical juncture in the development of international regulations for deep-sea mining," implied that mining polymetallic nodules could have worse impacts on the ecosystem than previously understood.

The study described steady emissions of oxygen from the seabed that Sweetman and his colleagues attributed to polymetallic nodules. Specifically, the researchers proposed that the difference in electric potential between metal ions within the nodules could lead to a redistribution of electrons, triggering a charge that could split seawater into hydrogen and oxygen.

The result initially seemed significant, but when Tengberg and his colleagues looked closer, "it became clear that it could not have been true," he said. Sweetman used special chambers to measure oxygen concentrations at the seafloor that must be flushed with bottom water before monitoring starts to avoid contamination with gas bubbles from higher up in the water column. This means that oxygen readings inside the chambers should be similar at the start of each experiment, but they are "all over the place," Tengberg said.

"You have to start your chamber incubations with bottom water composition equal — identical — to the ambient bottom water outside the chambers," Hall said, adding that Sweetman's starting oxygen measurements were consistently higher than bottom oxygen concentrations usually obtained in the CCZ. "That is a clear sign that they did not do good chamber incubations and that their oxygen fluxes … cannot be trusted."

Traditionally, experiments in the deep sea using chamber incubations also measure other gases to get a clear picture of the environment and its chemistry, but Sweetman and his colleagues did not provide this data, Tengberg said. Notably, no previous study has found oxygen production from polymetallic nodules at the seafloor, Tengberg and his colleagues wrote in the opinion article.

The 2024 study did not present data from "negative control experiments," which in this case would have been incubations without polymetallic nodules to confirm an absence of oxygen production when nodules aren't present, the critics wrote. But according to the opinion article and a 2024 preprint paper on the server Earth ArXiv that has not been peer-reviewed, this data exists — and it shows oxygen production even in the absence of nodules.

"This strongly suggests that the oxygen production is an experimental artifact," Hall said. The increase may have resulted from oxygen bubbles that got trapped and gradually dissolved inside the chambers after they reached the seafloor and sat there unventilated, he added.

Seawater electrolysis

Electrochemists on the opinion-article team gave additional arguments for why polymetallic nodules are unlikely to be a source of oxygen at the deep seafloor.

For one, seawater electrolysis requires a significant amount of energy and cannot proceed spontaneously, they argued. And Sweetman and his colleagues did not identify a source of energy big enough to generate an electric charge and split seawater, they said.

"The explanation that Sweetman and his collaborators are proposing is equivalent to suggesting that there is energy being created out of nothing, or, if you want, that things go uphill spontaneously, instead of going downhill," Cuesta Ciscar said. "We know that the energy in the universe is constant, and it's not being created out of nothing."

The study also provided no hydrogen concentration measurements to support the idea of seawater electrolysis. For each oxygen molecule produced by water electrolysis, two hydrogen molecules also form, so the presence of hydrogen is a telltale sign of the reaction.

"There's just, I would expect, an honest error that has not been recognized," Cuesta Ciscar said.

In response to the arguments in the opinion article, Sweetman said he and his team cannot reply meaningfully until the review of their additional evidence concludes at Nature Geoscience (NG). "If the rebuttal at NG is rejected we will of course submit a response to the Frontiers piece," he said.

The researchers are now preparing for a spring expedition to the CCZ, where they will deploy two highly specialized landers to identify exactly how dark oxygen may be produced. The project is funded by the Nippon Foundation, a private organization in Japan that promotes humanitarian work, diplomacy and industrial maritime development.

The search for dark oxygen continues, but many experts doubt it will lead to anything substantial, Hall said. "We don't believe in this," he said. "I hope that Nature Geoscience retracts the paper."

Thirsty plants are sucking up water that would otherwise end up in the Colorado River, according to a new study. The findings could have important implications for water management in regions that rely heavily on snowmelt for their water, including Arizona and California.

More than 1.4 billion people around the world rely on water from snowmelt-driven mountain rivers. In the United States, more than 10% of the population gets the majority of their water from the Colorado River alone.

But as global temperatures rise, less water is flowing into the Colorado River and many other rivers, and an understanding of what is driving that change is essential to managing water in a hotter and drier future.

Most water in mountain ecosystems is lost through a combination of evaporation from the soil and a process called plant transpiration, in which plants release water vapor from their leaves. This combined process is known as evapotranspiration. Scientists had thought plants mostly drew on shallow soil moisture from recent rain or snow, which would mean hot, dry conditions should reduce evapotranspiration while leaving river flows relatively constant.

But recent studies have uncovered a "drought paradox": Plants actually maintain, or even increase, transpiration during dry periods.

To untangle this paradox, Reed Maxwell and Harry Stone, environmental engineers at Princeton University's High Meadows Environmental Institute, installed an array of sensors across a 200-acre (81 hectares) area of the East River watershed in Colorado, which feeds into the Colorado River. The sensors measured water movement through the snowmelt-to-streamflow pathway over two years: 2023, which had a high snowpack but a hot, dry summer; and 2024, which had a moderate snowpack followed by a cool, wet summer.

They found that even during hot, dry periods ‪—‬ when soil moisture was at record lows ‪—‬ evapotranspiration remained high. This suggests that plants were tapping into groundwater reserves when soil moisture was low, using water that would otherwise end up in the river.

"Dry summer, wet summer; they're getting their water," Maxwell told Live Science. "But they're finding it from other sources. They're taking it from shallow groundwater."

Historical temperature and streamflow data also showed that summer temperatures affected the streamflow regardless of how much snow had fallen the previous winter. Snowmelt efficiency, the ability for a given amount of snowmelt to produce a certain amount of runoff, has declined over the past century, so the same storm produces less water in the reservoirs as time goes on. It's unclear exactly what is driving this shift, but climate change is a part of it.

"We see that across the Upper Colorado River Basin; a warm summer will actually take a big snowmelt and make it like an average snowmelt because of the additional water demands from plants," Maxwell said. "Plants are still meeting their needs; they're just using other water sources, and those sources are taking away from the water that would end up in our reservoirs."

The work was published as a preprint article, meaning it has not yet undergone peer review or been published in a scientific journal.

Brad Udall, a senior water and climate research scientist at Colorado State University who was not involved in the research, said a major strength of the work was that the researchers directly measured changes in evapotranspiration on an hourly basis, rather than relying solely on computer models.

The findings support a hypothesis that Udall and others are actively investigating: that increased evapotranspiration brought on by higher temperatures is contributing to reduced river flows, he said.

Over the past century, temperatures in the Colorado River Basin have risen by 2.5 degrees Fahrenheit (1.4 degrees Celsius), according to the study. Over the past seven years, water flow in the basin has dropped by 35%, Udall said. He and others have hypothesized that there will be "increased reductions in flow due to these higher temperatures going forward," Udall told Live Science.

That could have major impacts on how much water is available for the people who depend on the Colorado River in the future. "It means there will be a lot less water, and we're already seeing it," Udall said. "We could see a 40% decline by mid-century."

New management rules for how water is shared between the upper and lower basin are supposed to go into effect next year. But so far, there is no agreement on what these rules should look like, Udall said. Rising temperatures, declining river flows, and decreases in precipitation will only complicate those negotiations.

While this study is just one piece of how the water cycle in the Upper Colorado River Basin works, it could have important impacts on decisions about water use in the future, Maxwell said. As summers get drier and warmer, we will have to recalibrate our understanding of how much water might be available in the Colorado River, even in years with big snowfalls.

"A better water budget that takes into account increases in summer transpiration is a really important factor when figuring out how much water there is in the basin, before we start to divide it up," he said.

Editor's note: This article was updated at 8.39 a.m. ET on March 19 to correct the picture caption for the second image to say it shows the East River, a tributary of the Colorado River. It was updated again at 12:50 p.m. ET on March 19 to change the top caption from Colorado to Utah.

A sunken landmass that connected Britain to mainland Europe until a few thousand years ago may have been an excellent refuge for plants and animals, including humans, during the last ice age, a new study finds.

Parts of Doggerland, which is now submerged under the North Sea, hosted temperate forests as early as 16,000 years ago — long before such forests recolonized Britain and northwestern Europe following the final retreat of glaciers about 11,700 years ago.

Doggerland is named after a large sandbank in the North Sea called Dogger Bank, which references a type of medieval Dutch fishing boat called a dogger.

Oaks (Quercus), elms (Ulmus) and hazel trees (Corylus) thrived for millennia in southern Doggerland, where the new study was conducted, before the landmass disappeared. Previous estimates suggest Doggerland was fully inundated by 7,000 years ago, but the new results indicate this may have happened closer to 6,000 years ago. Researchers reconstructed the region's long-lost terrestrial ecosystem using DNA that was preserved in dirt under the sea for thousands of years, known as ancient sedimentary DNA.

"We got evidence of boars, deer, bears, aurochs," study lead author Robin Allaby, an evolutionary geneticist and professor of genomics at the University of Warwick in the U.K., told Live Science. "To my knowledge, it's the largest sedimentary DNA study that's been done."

Allaby and his colleagues analyzed 252 samples from 41 cores that they drilled up from beneath the North Sea off the coast of England. Specifically, the researchers took the cores along the prehistoric, 20-mile-long (30 kilometers) Southern River, situated in what was once southern Doggerland.

Researchers have long known that Doggerland was forested before it was inundated by the North Sea. But the ages of those forests were unclear, so scientists assumed that they appeared around the same time as forests in Britain. The consensus prior to this new research was that 16,000 years ago, southern Doggerland was tundra (a dry, treeless plain), not forest, Allaby said. At that time, ice sheets reached down to what is now the border between Scotland and England, he added.

The researchers analyzed sediments in the cores and separated them into two categories: secure and insecure. Secure sediments were fine silts and clays that contained ancient DNA from species that lived in the area where the core was taken. Insecure sediments were coarser sand and gravel that contained ancient DNA that was shed far from where the core was extracted, meaning this DNA was not useful to reconstruct the local ecosystem.

"That just makes perfect sense," Allaby said, as "DNA doesn't survive long in water." Sediments are usually transported and deposited in fluid, with slow-moving waters picking up only fine sediments and fast-moving, higher-energy waters shifting coarser sediments. Slow-moving waters can transport sediments carrying DNA only short distances before the DNA quickly degrades. Fast-moving waters, on the other hand, can transport sediments with DNA much farther before it disintegrates.

This means that when the researchers found fine sediments with ancient DNA in the cores, that DNA was likely to have been shed locally. DNA in coarse sediments was probably from upstream ecosystems. Therefore, "we could pick out the samples which we would not trust to be telling us about the local environment," Allaby said.

Ancient DNA in secure sediments showed that temperate trees and forest animals lived around the Southern River starting about 16,000 years ago, when much of Northwest Europe and Britain was still covered in tundra. Remarkably, the researchers identified DNA from a walnut relative (Pterocarya) that was thought to have gone extinct from the region 400,000 years ago. The team also found traces of warmth-loving lime trees (Tilia), suggesting that southern Doggerland was milder than the surrounding regions during the last ice age.

"Our knowledge is very imprecise, as it turns out," Allaby said. "This is not pure tundra — there is enough of an environment here to sustain something that looks like a forest."

The results, published March 10 in the journal PNAS, indicate that Stone Age people would have had "plenty to live on" in southern Doggerland after ice sheets retreated from the area about 21,000 years ago, Allaby said. "We can predict where good places for settlement would be, and typically at the mouths of rivers is the place to go, because you're close to resources."

The findings could also help resolve Reid's paradox, which describes the mismatch between seed dispersal rates and how quickly trees like oaks recolonized northern regions from farther south after the last ice age, the researchers said. Southern Doggerland or another nearby region, such as northern France, may have been a glacial "microrefuge" for temperate trees, enabling species to spread north much faster than they could have done if they had survived only on the Iberian Peninsula, for example.

Finally, the study indicated that the North Sea fully submerged southern Doggerland around 6,000 years ago, which is at least 1,000 years earlier than previous estimates of when the landmass was inundated.

"It's another highlight of the imprecision of what our knowledge is of this landscape," Allaby said. "It really is a frontier."

Sørvágsvatn, also called Leitisvatn, is a 1.3-square-mile (3.4 square kilometers) lake in the Faroe Islands that appears to float above the sea.

The optical illusion is visible from a limited number of angles along the lake's southern tip.

The trick functions because the lake sits 105 feet (32 meters) above sea level at the top of a cliff that slopes slightly inland toward the lake. Therefore, from a point a few hundred feet out, it looks like the lakeshore reaches all the way to the edge of the cliff, creating the illusion that the water extends over the sea.

Locals disagree about the name of the lake, hence why there are two. The inhabitants of Sørvágur, a village to the west of the lake on the island of Vágar, prefer the name Sørvágsvatn, which means "the lake by Sørvágur." People living in Miðvágur and Sandavágur to the east of the lake on Vágar call it Leitisvatn, or "the lake by Leiti," in reference to a territory in the east of the Faroe Islands.

The village of Miðvágur is closer to the lake than Sørvágur is, but the latter is thought to have been settled earlier during the ninth century, complicating the picture. Another argument in favor of calling the lake Sørvágsvatn is that the Faroe Islands' first settlers divided Vágar into three equal regions — and the lake is situated in the same region as Sørvágur.

But to avoid this debate, locals mostly refer to the lake as Vatnið, meaning simply "the lake."

The lake is surrounded by cliffs, which creates the impression that it is higher above the waves than it actually is. This is especially the case on either side of the lake's primary outlet, a 100-feet-high (30 m) waterfall called Bøsdalafossur, meaning "the waterfall at Bøsdal," referring to the area near the settlement of Bøur.

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

Blackwater lakes and rivers in the Congo Basin are releasing ancient carbon into the atmosphere, a new study shows. Previously, scientists thought this carbon was safely stored in the surrounding peatlands, but the research reveals that's not the case.

The finding contradicts the long-held assumption that old peat carbon remains trapped underground, suggesting that some tropical peatlands could switch from being carbon sinks to major carbon sources.

"We are now faced with a 30-million-tonne question: we need to determine if this is just a small, natural leakage of ancient carbon, or the onset of broadscale destabilization," study lead author Travis Drake, a carbon biogeochemist at the Swiss Federal Institute of Technology Zurich (ETH Zurich), told Live Science in an email.

Drake and his colleagues have conducted three research trips to the Congo Basin over the past four years. Specifically, the team traveled to the Cuvette Centrale, a 56,000-square-mile (145,000 square kilometers) region of forests and swamps in the Democratic Republic of the Congo that holds Earth's largest known tropical peatland complex. Situated in the heart and to the south of the Cuvette Centrale are two large blackwater lakes — Lake Mai Ndombe and Lake Tumba — while a major blackwater river, the Ruki River, flows west-northwest across it to meet the Congo River.

Blackwater lakes and rivers contain high levels of decaying plant debris, or dissolved organic carbon, which gives them their black color. This dissolved organic matter, together with direct inputs of carbon dioxide (CO2) from the surrounding swamps and forests, creates supersaturated concentrations of CO2 in lakes Mai Ndombe and Tumba and in the Ruki River. As a result, these waters emit enormous amounts of CO2 into the atmosphere.

Crucially, however, none of the CO2 was previously thought to originate from the Cuvette Centrale's ancient peat, as these deposits, protected from decomposition by their oxygen-depleted, waterlogged environment, were believed to be highly stable.

But in a paper published Feb. 23 in the journal Nature Geoscience, Drake and his colleagues found otherwise. Their results showed that a significant proportion of the CO2 escaping the Cuvette Centrale's blackwater bodies is from peat carbon that is between 2,170 and 3,500 years old.

"We were very surprised because we fully expected the carbon dioxide to be modern," Drake said.

The researchers drew their conclusions from measurements they took at Lake Mai Ndombe in 2022 and 2024, and at Lake Tumba and the Ruki River in 2025. They accessed Lake Mai Ndombe with small boats, which was difficult due to strong winds that almost capsized them, Drake said.

"The ecosystems remain in relatively pristine condition," he said. "There are some small settlements and villages scattered around Lake Mai Ndombe, but they are far and few between."

The team measured sediments, greenhouse gases, dissolved organic carbon and dissolved inorganic carbon, which includes dissolved CO2, bicarbonate ions (HCO3–) and carbonate ions (CO32-). Later, in the lab, the researchers analyzed their samples with high-precision spectrometry to separate modern carbon from plants and older carbon from soils.

"Because the organic carbon in the lake was modern, we assumed the inorganic carbon would be too, so we initially just analyzed a single sample to confirm," Drake said. But when about 40% of the inorganic carbon in that sample turned out to be millennia old, the team decided to test the remaining samples.

The results were consistent across Lake Mai Ndombe, so the researchers returned to the Cuvette Centrale to sample Lake Tumba and the Ruki River. Both contained high levels of inorganic carbon derived from ancient peat, suggesting that microbes in the region are breaking down peat carbon into CO2 and methane, which then seep into lakes and rivers before wafting into the atmosphere.

The Cuvette Centrale is estimated to hold one-third of the carbon stored in tropical peatlands globally, equivalent to about 33 billion tons (30 billion metric tons). It's possible that recent losses of ancient peat carbon are linked to the formation of new peat deposits, in which case the phenomenon might be nature returning to a state of equilibrium, according to the study. But it's also possible that climate change is destabilizing long-buried deposits and that the Congo Basin's peatlands are nearing a tipping point.

"This pathway highlights a critical vulnerability," Drake said. "If the region experiences future drought, this export mechanism could accelerate, potentially tipping these massive carbon reservoirs from a sink into a major source to the atmosphere."

Next, the researchers will analyze water trapped in the Congo Basin's peat to explore if and how microbes are releasing ancient carbon.

"Ultimately, we aim to confirm whether this process is happening across the entire Cuvette Centrale and quantify oxidation rates to determine if this leakage is a natural baseline or a sign of instability in this large carbon reservoir," Drake said.

The Gulf Stream holds tantalizing clues about when other key Atlantic Ocean currents could collapse due to climate change, a new study finds.

Originating in the Gulf of Mexico and leaving the U.S. East Coast near Cape Hatteras in North Carolina, the Gulf Stream is a branch of the Atlantic Meridional Overturning Circulation (AMOC) — a giant system of ocean currents that brings heat to the Northern Hemisphere and Europe, in particular.

A growing body of evidence suggests that the AMOC is weakening and speeding toward a "tipping point," which could completely transform the climate in many parts of the world, including Northwest Europe and tropical monsoon regions. When the AMOC might collapse is uncertain, but an early warning signal hidden within the Gulf Stream could help scientists predict the event years before it happens, the new research shows.

"First, you have this very gradual northward drift [of the Gulf Stream], which is related to some AMOC weakening, but apparently there is also this jump when the AMOC is getting too weak, which is this early warning indicator," study lead author René van Westen, a postdoctoral researcher in climate physics at Utrecht University in the Netherlands, told Live Science.

Unlike other currents that form the AMOC, the Gulf Stream is wind-driven. After passing by Florida, it follows the U.S. East Coast northward to Cape Hatteras and then veers east into the North Atlantic Ocean. Although the Gulf Stream is a surface current, its position is controlled by much deeper currents that also belong to the AMOC and create tight vortices when they interact with the layers above. These spirals push the Gulf Stream as a whole southward — but as the AMOC weakens and the vortices loosen, the Gulf Stream may start to drift northward.

To explore these effects further, van Westen and Henk Dijkstra, a professor of physical oceanography at Utrecht University, simulated an AMOC collapse in an ocean model with a very high resolution over the Gulf Stream. In the climate models typically used to study the AMOC, the Gulf Stream "is smoothed out, so you hardly see any features and the dynamics are not well captured," van Westen said.

The researchers triggered an AMOC collapse in the model that was much more gradual than the collapse humans may be causing by heating Earth and accelerating Arctic ice melt, which prevents the formation of deep ocean currents. They observed the Gulf Stream's response in unprecedented detail, revealing for the first time an extremely abrupt, northward shift of the current 25 years before the start of the collapse.

The results were published Feb. 26 in the journal Communications Earth & Environment.

The researchers found two stages in the Gulf Stream's response, both measured off Cape Hatteras at 71.5 degrees west longitude. First, as the AMOC gradually weakened over 392 simulated years, the Gulf Stream inched northward by 83 miles (133 kilometers). Second, as the AMOC continued to weaken over two more simulated years, the Gulf Stream suddenly jumped north by 136 miles (219 km). This abrupt shift happened just 25 years before the start of the AMOC collapse, suggesting it could be used as an early warning signal to predict the collapse.

While the two stages may be realistic, it's unlikely that the time lag between the abrupt Gulf Stream shift and an AMOC collapse would actually be 25 years in real life, van Westen said. That's because the model didn't account for global temperature rise, which is accelerating the collapse of the AMOC; the model only simulated an increase in fresh water in the North Atlantic.

A northward drift of the Gulf Stream has implications for ocean ecosystems that are presently north of the current in colder waters but may soon end up south of the current in warmer waters. The drift may also exacerbate sea level rise along the East Coast, van Westen said.

Already underway

Next, the researchers analyzed satellite data to determine whether the Gulf Stream has already begun shifting northward. "We found this relationship within our climate model, and now the next step was to look whether those results appear in observations," van Westen said. "What we found in observations is that, yes, indeed, the Gulf Stream has shifted northward over the past three decades."

This finding is more evidence that the AMOC is weakening and means we are in the first stage of the Gulf Stream's response, van Westen said. Natural climate and atmospheric variability may have contributed to the slow drift, but those contributions are small relative to the AMOC's weakening, he added.

It is unclear when the transition to the second stage of the Gulf Stream's response will occur, but satellites are in place to detect this switch if and when it happens. The next task for researchers is to work out the true lag time between this second stage and the AMOC collapse so that the second stage can serve as a robust warning indicator, van Westen said.

The study is the most in-depth analysis of the potential impacts of an AMOC collapse on the Gulf Stream to date, but there are some caveats, said Maya Ben-Yami, a climate tipping point researcher at the Technical University of Munich and the Potsdam Institute for Climate Impact Research in Germany who was not involved in the research.

"This paper definitely points at Gulf Stream changes as a possible warning signal, but a lot more work would need to be done to confirm that, for example by looking across different models," Ben-Yami told Live Science in an email.

It's possible that the abrupt northward shift could happen without the AMOC collapsing down the line, in which case it may not be an early warning indicator but rather a response to the weakening, she said.

Additionally, the rate of AMOC weakening in the study was likely slower than what can be expected under future warming conditions, meaning that the 25-year lag time could shrink to "almost nothing" and come too late to be an actionable warning signal, Ben-Yami said.

"Personally I think that it's also useful to have a signal that just tells you 'the tipping point has been crossed' without earlier warning, but I'd say we still don't know if Gulf Stream changes could be either type of signal," she said.

This striking satellite photo shows off the contrasting colors at the point where three rivers converge in Guyana. The multicolor waterways result from the country's unique geology, as well as an increasingly disruptive human-caused factor.

In the Indigenous Arawak language, Guyana means "land of many waters," which is an apt name, given that the country is home to 10 major rivers and dozens of smaller waterways, despite being around the size of South Carolina, according to NASA's Earth Observatory.

This unique hydrology is linked to the Guiana Shield, a 1.7 billion-year-old geologic feature that covers Guyana as well as parts of Venezuela, Brazil, Suriname and French Guiana. The shield contains hard crystalline bedrock made up of rocks such as gneiss and granite, meaning it does not easily erode except from flowing water, which has carved out many routes through the region.

In this photo, two smaller rivers — the Cuyuni River (left) and the Mazaruni River (center left) — come together shortly before merging with the Essequibo River (center right) to form one of Guyana's largest waterways.

The town of Bartica, which is home to around 15,000 people, is located on the piece of land that juts into the water at the point of the secondary merger. From there, the enlarged Essequibo River flows northward for around 30 miles (50 kilometers), before draining into the Atlantic Ocean.

Prior to merging, the Mazaruni and Essequibo are dark brown, which is likely the result of tannins — chemicals released by rotting vegetation that stain waterways via a process similar to tea brewing. The Cuyuni is light brown due to high levels of suspended sediment in its water, according to the Earth Observatory.

When the rivers meet, the lighter and darker waters do not readily mix because of the differences in density caused by varying levels of sediment.

While the presence of tannins is a natural phenomenon triggered by flooding, the high levels of sediment are the result of mining waste that is dumped in the Mazaruni.

"This image is from a wet time of year when all three rivers were running high and carrying a lot of sediment," Evan Dethier, a hydrologist at Colby College in Maine, told the Earth Observatory. "But the Cuyuni is the clear outlier, which we can attribute to the intensity of mining upstream."

Guyana is a hotspot for mining, largely because of its vast deposits of gold, diamonds and bauxite, as well as lithium, copper and nickel, which are also linked to the Guiana Shield, according to the U.S. Department of Commerce.

The country's mining industry began in ernest in the mid-2000s, and since then, the concentration of sediment in the Cuyuni has likely increased tenfold, Dethier said. Similar changes have been documented in rivers across the planet.

A 2022 study led by Dethier revealed that sediment concendrations in rivers in the Southern Hemisphere has risen by around 40%, largely due to mining and deforestation. However, the opposite is true in the Northern Hemisphere due to the construction of large-scale dams, which have blocked sediment flow by around half.

The changes in global sediment flow also may be affecting the marine environment, because the sediment input in most of the world's oceans has changed drastically, the study warned ‪—‬ but it is still too soon to see what sort of long-term effect this may have.

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China's Yangtze River is showing signs of recovery following the introduction of a 10-year ban on commercial fishing in 2021. The number of large fish has increased, and there has been recovery among endangered animals, including the Yangtze sturgeon (Sinosturia dabryanus) and the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), new research finds.

"These results show that strong political decisions are required to restore biodiversity," Sébastien Brosse, an ecologist at the University of Toulouse in France and co-author of the new study, told Live Science via email. "This is an encouraging message because biodiversity loss is often seen as irreversible." The Yangtze is the longest and largest river in China. About 30% of the country's population lives within its drainage basin, and the 11 provinces and municipalities that make up the Yangtze River Economic Belt generate about 47% of China's total gross domestic product.

But rapid urban development since the 1950s, dam building, decades of overfishing, pollution and habitat degradation had all led to a decline in water quality and a biodiversity crisis. The Yangtze River dolphin (Lipotes vexillifer) and the Chinese paddlefish (Psephurus gladius) went extinct, and 135 fish species found in historical surveys disappeared.

This decline continued despite the establishment of a network of protected areas and an investment of more than $300 billion in water-quality management and improvement. In response, China took drastic measures: The country instituted a 10-year fishing ban across the entire Yangtze basin in 2021, used river police to enforce strict penalties, and continued broad environmental management.

To assess the effects of the fishing ban, Yushun Chen, a hydrobiologist at the Chinese Academy of Sciences in Wuhan, China, and his colleagues used data from between 2018 and 2023 to evaluate the health of fish communities in the Yangtze before and after the ban went into effect.

They found that overall, the total mass of fish collected in samples more than doubled between those dates, and there was a 13% boost in the number of species in the samples.

The overall number of fish stayed about the same, but larger-bodied species that are higher up in the food web, including the economically valuable black Amur bream (Megalobrama terminalis) and the white Amur bream (Parabramis pekinensis), grew, and they contributed a larger amount of the biomass. However, the total mass of smaller species sampled decreased by 18%.

The team's findings, published on Thursday (Feb. 12) in the journal Science, also included positive signs for migratory and endangered species. For example, populations of slender tongue sole (Cynoglossus gracilis) increased after the ban, and its freshwater migration extended farther upstream. Endangered fish species — such as the Yangtze sturgeon, Chinese sucker (Myxocyprinus asiaticus) and tube fish (Ochetobius elongatus) — also showed signs of recovery.

Another notable positive was the boost in numbers of the only freshwater mammal remaining in the Yangtze River, the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), whose population rose by a third from 445 in 2017 to 595 in 2022. This gain may have resulted from a greater availability of bigger fish to eat; fewer deaths related to vessel strikes or fishing bycatch; and a reduction in other stressors, such as underwater noise from vessel propellers, the researchers suggested.

"In an era of unprecedented biodiversity losses and declines, especially in freshwater systems, this study offers a glimpse of hope regarding the future of biodiversity," said Lise Comte, a conservation ecologist at California-based Conservation Science Partners who wasn't involved in the research.

"It demonstrates that bold protection and restoration strategies can be efficient in slowing down and even reverting human impacts on ecological communities," she told Live Science via email.

Chen and his colleagues are still monitoring Yangtze River biodiversity, and they said the recovery is continuing. But they warned that the progress could easily be reversed if commercial fishing were to restart and that lasting biodiversity recovery will depend on sustained management that addresses all human pressures on river systems.

They also suggested that similar conservation measures might be useful on rivers such as the Mekong and the Amazon.

However, the Yangtze fishing ban had huge human and financial costs, as it involved the recall of 111,000 fishing boats, the resettlement of 231,000 fishers, and an investment of more than $2.74 billion in the Yangtze River Economic Belt.

"The promising findings demonstrate the resilience of these systems but are also a case study of an approach that I hope we don't have to emulate elsewhere," co-author Steven Cooke, a professor of biology at Carleton University in Ottawa, Canada, told Live Science via email. "Closing all fisheries in a river basin has significant socio-economic consequences. Fishers, and those in related industries, often move on, forever changing those communities. Managing fisheries in ways that do not require such a 'nuclear' option is always preferred."

A better approach would involve the ongoing assessment of fish populations; science-based fisheries management; and the study of watersheds as integrated systems that connect people, water and fish, he added.

A giant reservoir of "secret" fresh water off the East Coast that could potentially supply a city the size of New York City for 800 years may have formed during the last ice age, when the region was covered in glaciers, researchers say.

Preliminary analyses suggest the reservoir, which sits beneath the seafloor and appears to stretch from offshore New Jersey as far north as Maine, was locked in place under frigid conditions around 20,000 years ago, hinting that it formed in the last glacial period due, partly, to thick ice sheets.

Last summer, researchers went on an expedition to follow up on reports from the late 1960s and early 1970s of fresh water beneath the seafloor off the East Coast. "It was quite the project and sort of a lifelong dream," Brandon Dugan, the expedition's co-chief scientist and a professor of geophysics at the Colorado School of Mines, told Live Science.

The research voyage, known as Expedition 501, lasted three months and dredged up 13,200 gallons (50,000 liters) of water from beneath the seafloor in three locations off the islands of Nantucket and Martha's Vineyard. The results aren't finalized yet, but so far it looks as if the reservoir might stretch farther underground than early reports suggested, meaning it might be even bigger than previously thought.

Dugan and his colleagues also think they know what created the reservoir thanks to preliminary radiocarbon, noble gas and isotope analyses, he said.

Fresh water in the region was first reported 60 years ago by the U.S. Geological Survey (USGS), during offshore mineral and energy resource assessments between Florida and Maine. "In a very peculiar way, they found fresh water in the sediment beneath the ocean," Dugan said. "In the 1980s, some of the USGS people came up with ideas of how that fresh water could get there. Then it went quiet for a while — no one was talking about it."

In 2003, Dugan and Mark Person, a professor of hydrology at the New Mexico Institute of Mining and Technology, rediscovered these records and came up with three ideas of how fresh water can end up beneath the ocean. One way that a submarine freshwater reservoir can form is if sea levels are very low for a long time and rainfall seeps into the ground. Then, when sea levels rise again over hundreds of thousands of years, that fresh water gets trapped in the underlying sediment, Dugan said.

A second possibility is that tall mountains close to the ocean funnel rainwater directly down into the seabed from their high elevation point, he said. And thirdly — related to the first hypothesis — a freshwater reservoir can form under the ocean if ice sheets expand, causing sea levels to drop. Meltwater collects at the bottom of ice sheets because they grind against the bedrock, producing heat. The huge weight of the ice sheet then pushes that water into the ground, trapping it beneath layers of sediment.

More than two decades later, the researchers are finally close to getting an answer, with preliminary data indicating that most of the fresh water came from glaciers some time during the last ice age (2.6 million to 11,700 years ago). "We kind of ruled out the large topography for New England, because we don't have big mountains next to the coast," Dugan said. However, "there might be a rainfall component" blended in the glacier water, he said. "You can imagine that in front of a glacier you have rainfall, so it's probably a mixed system."

Expedition 501 extracted water samples from sites 20 to 30 miles (30 to 50 kilometers) off the coast of Massachusetts. The researchers drilled down to 1,300 feet (400 meters) below the seafloor, which was deep enough to reveal a thick layer of sediment engorged with fresh water sitting beneath a layer of salty sediment and an impermeable "seal" of clay and silt.

"We have a seal at the top [of the fresh water] that keeps the seawater above from the fresh water below," Dugan said. This seal is strong enough to separate the two layers now, but it wasn't robust enough to stop a glacier from forcing water down through it — if that is what happened. "Whatever emplaced that water didn't care if there was a seal. There was enough energy to flush it with fresh water," he said.

Salinity measurements showed that water freshness in the reservoir drops with distance from the shore, but it stays well below ocean salinity in the areas studied last summer. The drill site closest to Nantucket and Martha's Vineyard had a salt content of 1 part per 1,000, which is the maximum safe limit for drinking water. Farther offshore, salt content was 4 to 5 parts per 1,000, and at the farthest site, the researchers recorded 17 to 18 parts per 1,000 — or about half of the ocean's average salt content.

"The important part was we collected all the samples we need to address our primary questions," Dugan said. "When we're done drilling and we pull our equipment out, the holes collapse back in and seal themselves up."

Now, scientists are studying the reservoir in finer detail, including any microbes, rare earth elements, pore space — which can help researchers better estimate the reservoir's size — and the age of the sediments, which will help narrow down when it formed. More definitive results about how and when the reservoir formed are expected in about one month's time, Dugan said.

"Our goal is to provide an understanding of the system so if and when somebody needs to use it, they have information to start from, rather than recreating information or making an ill-informed choice," he said.

This striking satellite snap highlights the immense power of 7-story waves crashing along the Portuguese coast and ejecting massive sediment plumes under the sea. The same day this photo was taken, a local 18-year-old surfer set a new world record by riding one of the colossal crests.

The Landsat 8 satellite captured this epic scene near the town of Nazaré in western Portugal, a region famous for having some of the tallest waves on Earth. Nazaré is home to around 15,000 people and regularly hosts "big-wave" surfing competitions, which attract surfers from around the world. The swells there are so big that surfers often have to be towed into the breaking waves with a jet ski.

The monster waves in the image likely reached heights of around 80 feet (24 meters), which is roughly equivalent to a 7-story building. This is exceptionally tall — even for Nazaré, where waves usually peak up to 50 feet (15m) at this time of year — and would usually be considered too dangerous to surf.

As these waves broke along the shore, their powerful undercurrents ripped up sand and other sediments from the seafloor and spat them out in the opposite direction to the waves, creating murky underwater clouds that could be seen from space.

The plumes in this photo extend up to 6 miles (10 kilometers) from the coastline, according to NASA's Earth Observatory.

Later the same day, local surfer António Laureano rode an even loftier wave, estimated to be approximately 101.4 feet (30.9 m) tall — the largest wave ever surfed by a human.

This record is not officially recognized by the World Surf League (WSL) because the organization's representatives did not calculate the wave's height. Instead, the height was determined by oceanographers at the University of Lisbon, who analyzed a video of the wave sent to them by Laureano, surfing news site Surfer Today reported at the time.

The current WSL record for the tallest wave ever surfed belongs to German surfer Sebastian Steudtner, who rode a 93.7-foot (28.6 m) wave, also at Nazaré, on Feb. 24, 2024, according to Surfer.com.

In total, seven of the official top 10 largest waves ever surfed have occurred at Nazaré, according to Red Bull.

"Big-wave" hotspot

The secret behind Nazaré's giant waves is the Nazaré Canyon just southwest of the town. It is the largest submarine canyon in Europe, stretching 130 miles (210 kilometers) long and roughly 3 miles (4.8 km) deep into the Atlantic Ocean.

Water inside the canyon travels faster than shallower water, forming large waves at depth that are "bent" in the direction of Nazaré. As they approach the coast, these large waves collide with other waves coming from the northwest, which further amplifies their speed and allows them to quickly rise when they approach the shore.

Occasionally, the waves can be further amplified by strong offshore winds. This was the case with the supercharged swells in the satellite photo, which were partially fueled by the remnants of Hurricane Epsilon, according to the Earth Observatory.

Nazaré's big wave phenomenon is highly seasonal, with the largest waves typically occuring between November and February. In the summer months, the waves almost completely disappear, allowing tourists to flock back to the beaches and swim in the sea. However, even then, disaster can still strike.

In August 2012, for example, a five-year-old girl and her 66-year-old grandfather, both British nationals, were killed after being dragged out to sea by a massive "rogue wave" as they were walking on a nearby beach, according to the BBC.

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

The ocean soaked up more heat last year than in any year since modern measurements began around 1960, according to a new analysis published in Advances in Atmospheric Science.

The world's oceans absorb more than 90% of excess heat trapped in Earth's atmosphere by greenhouse gas emissions. As heat in the atmosphere accumulates, heat stored in the ocean increases, too, making ocean heat a reliable indicator of long-term climate change.

Ocean temperatures influence the frequency and intensity of marine heatwaves, change atmospheric circulation, and govern global precipitation patterns.

Scientists measure the ocean's heat in different ways. One common metric is global annual mean sea surface temperature, the average temperature in the top few meters of ocean waters. Global sea surface temperature in 2025 was the third warmest ever recorded, at about 0.5°C (0.9°F) above the 1981-2010 average.

Another metric is ocean heat content, which measures the total heat energy stored in the world's oceans. It's measured in zettajoules: One zettajoule is equivalent to 1,000,000,000,000,000,000,000 joules. To measure heat content in 2025, the study's authors assessed ocean observational data from the upper 2,000 meters of the ocean, where most of the heat is absorbed, from NOAA's National Centers for Environmental Information, the European Union's Copernicus Climate Change Service, and the Chinese Academy of Sciences.

They found that in total, the ocean absorbed an additional 23 zettajoules of heat energy in 2025, breaking the ocean heat content record for the ninth consecutive year and marking the longest sequence of consecutive ocean heat content records ever recorded.

"Last year was a bonkers, crazy warming year," John Abraham, a mechanical engineer at the University of St. Thomas and a co-author of the new study, told Wired.

Twenty-three zettajoules in one year is equivalent to the energy of 12 Hiroshima bombs exploding in the ocean every second. It's also a large increase over the 16 zettajoules of heat the ocean absorbed in 2024. The hottest areas of the ocean observed in 2025 were the tropical and South Atlantic, Mediterranean Sea, North Indian Ocean, and Southern Ocean.

The results provide "direct evidence that the climate system is out of thermal equilibrium and accumulating heat," the authors write.

A hotter ocean favors increased global precipitation and fuels more extreme tropical storms. In the past year, warmer global temperatures were likely partly responsible for the damaging effects of Hurricane Melissa in Jamaica and Cuba, heavy monsoon rains in Pakistan, severe flooding in the Central Mississippi Valley, and more.

"Ocean warming continues to exert profound impacts on the Earth system," the authors wrote.

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

Many of the world's biggest river deltas — including the Nile, Amazon and Ganges — are sinking faster than global sea levels are rising, a new study shows.

This means subsidence is becoming the main driver of land loss, coastal flooding and saltwater intrusion at river deltas — surpassing the impacts of sea-level rise from climate change. Researchers also found that groundwater extraction is the biggest cause of subsidence at deltas globally, with urban expansion and declines in rivers' sediment loads contributing to the overall sinking trend.

Deltas are facing a "double burden" of sea-level rise and sinking land that increases the risk of catastrophic flooding and displacement for millions of people in some of the world's biggest cities, the study's authors warn.

"To our knowledge, this is the most comprehensive, high-resolution, delta-wide assessment of contemporary land subsidence ever conducted at the global scale," co-author Manoochehr Shirzaei, an associate professor of geophysics and remote sensing at Virginia Tech, told Live Science in an email. "Across the deltas we analyzed, groundwater storage change emerged as the single most influential anthropogenic factor explaining subsidence patterns in many systems."

Shirzaei and his colleagues used data from the Sentinel-1 satellite to examine subsidence at 40 of the world's largest river deltas between 2014 and 2023. Sentinel-1 captures changes in ground elevation resulting from subsidence, as well as sediment deposition and erosion, according to the study, which was published Wednesday (Jan. 14) in the journal Nature.

Of the 40 deltas, 18 had average annual subsidence rates greater than the current rate of global sea-level rise, which is about 0.16 inches (4 millimeters) per year.

Zooming in, the researchers found that every studied river delta except the Rio Grande Delta was in some places sinking faster than global sea levels are rising. In 38 deltas, more than 50% of the delta area sank during the study period, and in 19 of them — including the Mississippi Delta, the Nile Delta and the Ganges-Brahmaputra Delta — more than 90% of the delta area had subsided.

The worst-affected deltas in the study were the Chao Phraya Delta in Thailand, the Brantas Delta in Indonesia and the Yellow River Delta in China. These showed average sinking rates of about 0.3 inches (8 mm) per year — double the rate of global sea level rise.

Two main points arose from the study, Shirzaei said. "First, land subsidence often exceeds sea-level rise as the dominant driver of relative sea-level rise in river deltas today, meaning that many coastal risks are increasing faster than climate-only projections suggest. Second, there is a profound mismatch between risk and capacity: the deltas sinking fastest are often in regions with the least resources to respond."

River deltas are home to between 350 million and 500 million people around the world. They host 10 of the world's 34 megacities, along with vital infrastructure such as ports, meaning the impacts of subsidence and sea-level rise — such as shoreline retreat and more frequent floods — are immense.

And these huge populations are themselves a driver of subsidence, because cities pile enormous weight onto the land, compressing the soil. Huge populations typically also require massive amounts of water, which exacerbates groundwater pumping. This causes further compaction of the soil.

"In rapidly urbanizing deltas, urban growth can substantially exacerbate land sinking," Shirzaei said. However, groundwater extraction for all purposes, including agriculture and industry, remains the biggest cause of subsidence at deltas, he said. "Groundwater pumping is a well-known local driver of subsidence, but what stood out was how consistently dominant it appears at the global scale, even when compared alongside other major anthropogenic pressures."

Another cause of subsidence is a reduction in the amount of sediment that rivers flush into the ocean due to dams and other river-control strategies. Sediment delivery can offset subsidence and sea-level rise to some extent, but human modifications to natural river flow have disturbed this balance. For example, about 1,900 square miles (5,000 square kilometers) of land has been lost in the Mississippi River Delta since 1932 due to the combined effects of dams, levees and erosion.

The main drivers of subsidence at river deltas are human-made, which presents an opportunity for intervention, Shirzaei said. "One of the most important messages of the study is that subsidence is often manageable," he said.

Alongside efforts to limit climate change, countries should consider reducing groundwater extraction and replenishing aquifers with floodwater or treated wastewater, Shirzaei said. Controlled flooding and sediment diversions can help increase sediment deposition. And restricting heavy infrastructure in the areas most prone to subsidence could also help slow subsidence, he said.

"When combined with flood protection and climate adaptation, these measures can significantly reduce long-term risk," he said.

​​Rivers may seem as old as the hills, but they have life cycles just like other natural features do. Many grow and make their meandering mark on the landscape, before ultimately drying up. Some rivers last longer than others, however. So which river is the oldest in the world today?

The winner is older than the dinosaurs: The Finke River in Australia, or Larapinta in the Indigenous Arrernte language, is between 300 million and 400 million years old.

This network of streams and channels extends more than 400 miles (640 kilometers) across Northern Territory and South Australia. The arid conditions in the center of the continent mean the river flows only intermittently; most of the year, it exists as a string of isolated water holes. However, a combination of geological records, weathering profiles and radionuclide measurements in the surrounding sediments and rocks has enabled scientists to date this river system to the Devonian (419 million to 359 million) or Carboniferous (359 million to 299 million) period.

One of the strongest pieces of evidence for its ancient age is a geological anomaly called cross-axial drainage, said Victor Baker, a geomorphologist at the University of Arizona. Rather than flowing parallel to resistant rock structures, such as quartzite, the Finke River cuts across these tough mineral formations as it passes through the MacDonnell Ranges in central Australia.

Flowing water always takes the easiest path, making it counterintuitive that a river would flow against these hard rocks rather than alongside them. Consequently, the presence and origin of this cross-axial drainage reveal crucial details about the historic course of the Finke.

"There is some suggestion that there was a preexisting drainage that was flowing as this range was building up," Baker told Live Science. "It's called antecedence — basically, the river is there before the mountains form and as the crust is being thrust up, the river is cutting down."

The MacDonnell Ranges (or Tjoritja in Arrernte) formed as part of the Alice Springs Orogeny — a tectonic mountain-building event that occurred 300 million to 400 million years ago — making the Finke at least as old as these mountains.

Later evidence comes from erosion and weathering, which generate specific chemical profiles. This information indicates how and where the surface interacted with the atmosphere and water flow through time. Using the radioactive signatures of certain isotopes (elements with different numbers of neutrons in their nuclei), scientists can also infer the ages of these rocks. Because radioactive isotopes decay at a fixed rate, it's possible to estimate when rocks formed by working backward from the relative proportions of different isotopes. Together these data points create a roadmap for piecing together the history and evolution of the Finke River.

But rivers are constantly in flux, with some growing bigger from year to year and others drying up completely. So why has the Finke system lasted so long?

"Rivers can disappear if a massive influx of sediment overwhelms them (e.g., volcanic eruptions) or if topography changes so dramatically that the flowing water takes a new course across the landscape (e.g., glacial advance and retreat)," Ellen Wohl, a geologist at Colorado State University, told Live Science in an email.

Additionally, "rivers can cease to flow because of climate change and/or human consumptive use of water," Wohl said. "Long duration is promoted by tectonic stability and lack of glaciation during the Pleistocene" (2.6 million to 11,700 years ago).

In the case of the Finke, Australia has been an unusually stable landscape for a very long time. Resting in the middle of the Australian Plate, the continent has experienced virtually no significant tectonic activity for the past several 100 million years, Baker explained. Consequently, the Finke River system has been able to develop and expand almost uninterrupted for most of its history.

As for the future, it's difficult to say how much longer the Finke will last.

"Long-persisting [rivers] will probably continue to persist," Wohl said. However, "many rivers in dry lands" — such as the Finke — "are highly altered by human consumptive water use."

This, she added, "is likely to increase in future as global water consumption continues to rise and global warming makes many dry regions even drier."

If the Finke ever dries up, the runner up may be the New River, which today is about 300 million years old, Baker said, and runs through Virginia, West Virginia and North Carolina.

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

This intriguing astronaut photo shows off a series of rippling sandbanks surrounding a pair of small islands in the Bahamas. The submerged swirls were partly carved out by a coral reef lurking on the edge of a hidden ocean "drop-off."

The Bahamas is made up of more than 3,000 islands and smaller cays interspersed with coral reefs, fast-flowing tidal channels and shallow underwater structures, known as sand banks. These features collectively make the islands "one of the most recognizable places on Earth for astronauts," according to NASA's Earth Observatory.

This photo shows a series of intricate sandbanks and a shallow barrier-like coral reef in the waters surrounding two diminutive islands — Carter's Cays (lower left) and Strangers Cay (upper right). The islands are two of the northernmost landmasses in the Bahamas, located around 125 miles (200 kilometers) east of Florida. (For context, Strangers Cay is around 2.2 miles (3.6 km) across at its widest point.)

The sand banks, which can be seen winding in and around the two cays like ribbons, have been sculpted by decades of unchanged ocean currents, causing sand to pile up in the same place over time.

But the coral reef — which cuts across the bottom right corner of the image and has waves breaking across its far edge — is much older, having likely built up over several millennia.

The largest and most prominent sandbank, which looks like a giant U-shape in the center of the image, lies directly opposite a large gap in the coral reef. This is no coincidence: The break in the reef has created a strong and sustained tidal flow that has pushed the sand much further backward, according to the Earth Observatory.

These sand swirls are fairly small compared with some of the larger sandbanks in the region. The biggest is the Great Bahama Bank, which covers an area of around 80,000 square miles (210,000 square kilometers) off the Exuma Islands in the central Bahamas and supports a massive seagrass ecosystem.

These features frequently draw comparisons to abstract paintings or the Northern Lights, due to their shape and captivating glow, when viewed from above. However, their supposed luminosity is actually just an optical illusion caused by their proximity to the ocean's surface. In some areas, the sand is likely only around 6.5 feet (2 meters) below the waves, according to the Earth Observatory.

If you look closely at the ocean's surface in the image, you will also notice that the water to the upper left of the islands is very light and covered with shimmering streaks, while the bottom right corner of the image — beyond the reef — is darker and exhibits traditional wave patterns.

This is the result of a steep drop-off in the deep ocean just beyond the coral reef, similar to the one depicted in the film "Finding Nemo." Beyond this point, ocean currents create the swells that many people see from the window of an airplane. But behind the reef, the wind sculpts the ocean's surface into subtle streaks instead.

This drop-off is also why there are no sandbanks visible beyond the reef.

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

This incredible astronaut photo shows the unusual point where a hefty non-retreating glacier, a pristine turquoise lake and a murky green "river" perfectly converge at the intersection of three valleys in Argentina.

The trio of hydrological features — the Perito Moreno Glacier, Lago Argentino and Brazo Rico — lie at the heart of Los Glaciares National Park, which covers an area of around 2,300 square miles (6,000 square kilometers) in the Santa Cruz province of southern Argentina, near the country's border with Chile.

The aerial photo doesn’t just show off these three aqueous entities in a single frame; if you look closely, it also reveals the point where the trio touch in a slim channel along the western edge of the Magallanes Peninsula — the rocky outcrop that lies between the lake and the river, according to NASA's Earth Observatory.

In this photo, the waters of Lago Argentino and Brazo Rico are likely in direct contact with each other (as in the photo below). But their waters do not readily mix because they have different densities, due to their respective concentrations of suspended particulate matter, according to a 2022 study.

But every four to five years, the glacier's tongue juts forward, colliding with the Magallanes Peninsula and temporarily damming the Brazo Rico. When this happens, the surface of the murky body of water rises by up to 100 feet (30 meters) until a pressure build-up causes the icy dam to spectacularly "rupture," the Earth Observatory previously reported.

Perito Moreno is the largest glacier in Patagonia, which includes parts of Argentina and Chile. It is approximately 19 miles (30 km) long with ice up to 200 feet (60 m) thick. In total, the glacier holds roughly the same amount of water as 360,000 Olympic swimming pools, according to back-of-the-envelope calculations.

The glacier is "non-retreating," meaning that it is not shrinking despite rising atmospheric temperatures triggered by human-caused climate change. This is extremely rare nowadays, and Perito Moreno is frequently cited as one of the "world's last major non-retreating glaciers." However, a recent study hints that it may finally be starting to shrink.

Lago Argentino is the largest freshwater lake in Argentina, covering a total area of around 550 square miles (1,425 square km). The section visible in the astronaut photo is the lake's southernmost arm. It contains glacial meltwater filled with rocky particles released by the glaciers' constant movements, collectively known as "glacier milk," which gives the water its striking turquoise color.

The lake's northernmost arm also connects to the Upsala Glacier, which is currently in full retreat.

Brazo Rico, meaning "rich arm" in Spanish, is also technically part of Lago Argentino. However, it has become increasingly isolated from the rest of the lake due to repeated damming by the Perito Moreno glacier, making it behave more like a river than part of a lake.

The frequent icy obstruction is also responsible for Brazo Rico's insipid color, which is the result of sediment dislodged by its movements. The continued rising and falling of the river's surface has also carved out a border around its edges where no trees can grow.

Eagle-eyed viewers may have also spotted the narrow road winding across the Magallanes Peninsula and along the Brazo Rico's northern edge (just above the tree line): One can only imagine the extraordinary views you'd get to experience driving along there.

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

This incredible astronaut photo captured a unique glimpse of Alabama's eponymous river cosplaying as a golden Chinese dragon. The metallic hue of the serpentine waterway is the result of a rare optical phenomenon that is only visible from space.

The Alabama River is a 318-mile-long (512 kilometers) waterway that stretches from the state's capital, Montgomery, past cities like Birmingham and Selma, and into Mobile Bay, where it drains into the Gulf of Mexico.

The section of the river in the photo features a large U-shaped bend, known as Gee's Bend, that surrounds the small town of Boykin, which is renowned for its "vibrant folk art" that is displayed across the country, according to NASA's Earth Observatory.

The river's unusual glow is the result of a rare phenomenon, known as a sunglint, which occurs when sunlight perfectly reflects off a still body of water toward an observer in space, like a massive liquid mirror. This is similar to how the surface of an ocean or lake sparkles when light bounces off it during a sunset — except the only people who can see it are astronauts.

The golden color of the sunglint helps provide greater contrast between water and land, highlighting a series of flooded zones. When combined with the river's larger bends, this makes the waterway look surprisingly like a dragon from Chinese mythology, netizens pointed out at the time.

The head of the dragon (located on the left of the image) is represented by the flooded zones of the artificial William "Bill" Dannelly Reservoir, which was created in the 1960s by partially damming the river. This 27-square-mile (70 square kilometers) reservoir generates hydroelectric power via a dam and has also become a popular fishing spot for people looking to catch crappie, bass and catfish.

The river's water levels rose higher than initially expected following the dam's construction, causing the waterway to permanently spill over into surrounding floodplains, such as at Chilatchee Creek (towards the bend in the dragon's tail) and around Gee's Bend, according to Earth Observatory.

Most bodies of water usually take on a silvery, mirror-like appearance when illuminated by sunglints, making the Alabama River's golden glow particularly noteworthy.

The unusual golden color is likely the result of atmospheric scattering of the reflected light by aerosols, dust and haze. This scatters blue wavelengths of light, giving the remaining light a more yellow hue.

Astronauts are always on the lookout for sunglints, especially over the ocean, because they can reveal hidden natural phenomena, such as gyres and internal waves, as well as human activities, such as ship wakes and oil slicks, according to the National Environmental Satellite, Data, and Information Service.

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

Southern Europe's already scorching dry summers could get even worse over the next 1,000 years if a key ocean current system collapses — with a rise in extreme droughts and longer dry seasons, a new study suggests.

This is the first time that researchers have compared what would happen to Europe's summer precipitation under different climate scenarios if the Atlantic Meridional Overturning Circulation (AMOC) were to collapse.

The AMOC is a major ocean current system in the Atlantic Ocean that brings heat from the Southern Hemisphere to the Northern Hemisphere and helps regulate the climate globally. Scientists have previously warned that human-linked climate change is weakening the massive current system and could be pushing it to a tipping point. (Tipping points are thresholds in Earth's climate system.)

"The AMOC actually shapes our global climate system," René van Westen, lead author on the new paper and a postdoctoral researcher in marine and atmospheric science at Utrecht University in the Netherlands, told Live Science.

These currents are why northwestern Europe has a relatively mild climate compared with southern Canada, which is at the same latitude, he said. An AMOC collapse is expected to result in much colder winter temperatures across Europe. But the AMOC also brings a lot of moisture to the continent. "The climate over Europe is both influenced by temperature, but also precipitation," van Westen said.

In the new study, the researchers ran eight simulations that extended over more than 1,000 years. Four simulations mimicked pre-industrial greenhouse gas levels, but these were theoretical because the world has already surpassed these atmospheric carbon levels.

Of the remaining four, two simulations looked at what would happen to precipitation if humanity's carbon emissions peaked in the middle of this century and then started to decline (known as RCP4.5) and small or large amounts of fresh water flooded the Atlantic Ocean.

When large quantities of fresh water flood the ocean (from melting icecaps, for example), it changes the water's salinity, density and how the water transports energy. In the RCP4.5 models, a large quantity of fresh water ultimately collapsed the AMOC, while it recovered if there was a smaller amount of fresh water.

The final two simulations modeled a high-emissions scenario, in which carbon emissions are three times higher than they are now (known as RCP8.5). The AMOC collapsed in both freshwater scenarios.

Van Westen said that two RCP4.5 options are the most realistic of the eight scenarios. "Under climate change, you're getting more evaporation and your dry season becomes drier," which is already widely known, he said. "If you add AMOC collapse on top of that, you're going to get more drought extremes."

Over the whole of Europe, dry season intensity, or the difference between how much water evaporates off the land and how much precipitation there is), increases by 8% in an RCP4.5 scenario with the AMOC still intact. But if it collapses, that intensity increases by 28%.

There is also a significant contrast between northern and southern Europe. For example, in Sweden, the dry season increases by 54% with the AMOC and 72% without the AMOC. Spain, which is already struggling with extreme drought, will see its dry season increase by 40% with AMOC and 60% without it.

These different scenarios reflect stable climates, rather than the current situation in which global temperatures are rapidly warming. "We're interested in what the mean responses are with different kinds of AMOC states in the background," van Westen said.

Karsten Haustein, a climate scientist at the University of Leipzig in Germany, welcomed the analysis of the stable state of future climates. "The beauty of these simulations is that they look at hundreds of years after everything has changed," he told Live Science.

"The transient scenario where we plan for the next 100 years is different to an equilibrium scenario. Just because we get much drier conditions in the next 50 or 100 years doesn't mean it's going to stay like this forever, depending on the scenario," he said.

The long-term view of stable conditions makes this paper "very exciting and interesting, because it gives us so much more to work with," he added.

However, Jon Robson, a professor of climate science with National Centre for Atmospheric Science at the University of Reading, U.K. who was not involved in the research, warned against using the study's theoretical results to predict future climates. "To get the AMOC to 'collapse' in this particular model, the authors need to add huge amounts of additional freshwater into the North Atlantic [and] that is not realistic," he told Live Science. "But it could be taken as a warning about what might be possible under the rather extreme scenario of an AMOC 'collapse'."

The overall message is clear, Stefan Rahmstorf, co-head of the research department on Earth system analysis at Potsdam Institute for Climate Impact Research in Germany, told Live Science.

"The increasing drought problems expected in any case due to global warming would be made even worse by a major AMOC weakening, and the latter looks increasingly likely," said Rahmstorf, who was not involved in the study.

"If the AMOC shuts down, this would have consequences for at least a thousand years to come — a huge responsibility for the decision makers of today."

Consider your morning cup of coffee. Your kettle's heating element — or flame on a stove — warms up water that you infuse with beans and pour into a mug. Maybe you get busy and the cup of joe sits there for a while, releasing its heat into the atmosphere of the room, until it reaches equilibrium with the indoor temperature. In other words: It got cold.

Now consider that the expansive Southern Ocean, which wraps around Antarctica, could one day do much the same thing. Since the Industrial Revolution kicked off, humans have dialed up the kettle to its max, adding extraordinary amounts of heat into the atmosphere, more than 90 percent of which has been absorbed by the sea. (It's also taken up a quarter of our CO₂ emissions.) Under climate change, the Southern Ocean has been storing warmth which, like your morning jolt, can't stay there forever, and will someday return to the atmosphere.

New modeling suggests that this "burp" of heat — the scientists called it that, by the way — could be abrupt. In a scenario where humanity eventually reduces its greenhouse gas emissions and then goes "net negative," finding ways to remove those planet-warming pollutants from the atmosphere, global temperatures fall. But suddenly the Southern Ocean belches its accumulated heat, leading to a rate of planetary warming similar to what humanity is causing right now. And the thermal burping would continue for at least a century.

Put another way: According to this modeling, at least, humans figure out a way to reverse climate change, only to see the Southern Ocean essentially restart it. While there would be nothing our descendants could do to stop this — since the warming would be driven by already stored heat — the calculations are yet another urgent call to reduce that pollution as quickly and dramatically as possible.

This sudden eructation is not a sure thing, however — it's the prediction of a model. But it's a step toward understanding how the planet could respond as humans continue to manipulate the climate, both warming and cooling it. "The question is: How will the climate system, and specifically the ocean, react to scenarios where we remove CO₂ from the atmosphere, and when we have a net global cooling effect?" said Svenja Frey, an oceanography PhD student at Germany's GEOMAR Helmholtz Centre for Ocean Research Kiel and coauthor of the paper.

The Southern Ocean may encircle the frozen continent of Antarctica, but it's very effective at storing heat: It alone holds around 80 percent of the warmth that's taken up by all the oceans. Some of this comes from currents that transport relatively toasty waters south, but also lots of upwelling in the Southern Ocean brings cold water to the surface to be warmed up.

The skies above the Southern Ocean are also somewhat less reflective than elsewhere around the globe. Cargo ships and industries in the Northern Hemisphere spew air pollution in the form of aerosols, which themselves bounce solar energy back into the cosmos and help brighten clouds, which reflect still more. That cooling phenomenon has vied, in a sense, with the warming that's come from the burning of fossil fuels. "That competition hasn't been as prevalent over the Southern Hemisphere, because it's this slightly more pristine atmosphere," said Ric Williams, an ocean and climate scientist at the University of Liverpool, who studies the Southern Ocean but wasn't involved in the paper.

In the scenario the researchers modeled, the atmospheric concentration of CO₂ increases by 1 percent every year until the total amount is double what the planet had before the Industrial Revolution. Then negative emissions technologies reduce the carbon concentration by 0.1 percent annually. (The study didn't look a specific techniques, but one option is direct air capture of CO₂, though this remains expensive and limited in scale.) In response, the atmosphere, land, and oceans cool.

But something starts brewing in the Southern Ocean. Its surface becomes colder, but also saltier due to the formation of new sea ice: When sea water freezes, it rejects its salt, which is then absorbed into the surrounding waters and makes the surface layer heavier. "At the same time, we have these warm, deeper waters," Frey said. "At some point, the water column becomes unstable, and that's when we have the deep convection event."

In other words, a burp. It's just one way that our planet's extraordinarily complex and intertwining systems might respond to rising and falling emissions in the centuries ahead. "There's very large uncertainty in the Earth system response to net-negative emissions — we don't understand that very well," said Simon Fraser University climate scientist Kirsten Zickfeld, who studies these dynamics but wasn't involved in the new paper. "We may well encounter surprises along the way, as this paper shows."

To be clear, in this scenario, removing atmospheric carbon significantly reduces global temperatures, even factoring in the burp. And the faster we move away from fossil fuels, the less CO₂ we'll have to remove down the line. "Doing negative emissions and reducing our carbon load in the atmosphere is a good thing," Williams said. "I would just add that, rather than do negative emissions, it's better not to do the positive emissions in the first place."

This story was originally published by Grist. Sign up for Grist’s weekly newsletter here.

This striking satellite photo shows a particularly convoluted section of a record-breaking "braided river" in China, which drastically changes shape every year and could become more unstable over the coming decades due to climate change.

The Yarlung Zangbo River is a roughly 1,250-mile-long (2,000 kilometers) waterway that stretches from its origin at a glacier in the eastern Tibetan Plateau all the way into India. It is the longest river in Tibet, as well as the fifth longest in China, and holds the record for being the highest major river on Earth, flowing at an average elevation of 4,000 meters (13,000 feet) above sea level, according to NASA's Earth Observatory.

The photographed section of the river is located in Zhanang County, just before it passes through the world's deepest land-based canyon and its namesake, the Yarlung Tsangpo Grand Canyon, which is more than 6,000 meters (20,000 feet) deep — or three times deeper than Arizona's Grand Canyon.

Yarlung Zangbo is a classic example of a braided river — a waterway with "multi-threaded channels that branch and merge to create the characteristic braided pattern," with mid-channel sandbars that are "formed, consumed, and re-formed continuously," according to the National Park Service.

This section is where the most braiding occurs anywhere along the river, with up to 20 channels across at certain points in the image.

Related: See all the best images of Earth from space

Yarlang Zangbo's extreme braiding is caused by heavy sediment deposits from the steep slopes of the adjacent Himalayas, which are washed into the river and help carve new channels into the ground, Zoltán Sylvester, a geologist at the University of Texas at Austin, told the Earth Observatory. The river changes shape so often that no vegetation can fully grow on the sandbars that sporadically appear between the river's braids, he added.

You can see how quickly the river changes shape for yourself in a 37-year timelapse animation, which shows annual satellite images of this spot taken between 1988 to 2025 by Landsat 5, Landsat 8 and Landsat 9 (see below).

Eagle-eyed viewers may also be able to spot a narrow bridge, which was constructed over the shapeshifting waterway in 2014. (It's visible as a thin line near the far right-hand side of the animation).

The river starts at the Angsi Glacier, emerging from a stream of meltwater that flows from the ice mass. However, this was only officially confirmed in 2011, according to Chinese state media. Before this, there was confusion among scientists about whether the river actually originated from a meltwater stream coming from the nearby Chemayungdung Glacier.

Like many other Himalayan ice masses, the Angsi Glacier has lost a significant amount of water in recent decades due to human-caused climate change. The resulting meltwater has caused more sediment to be deposited into the river, which can increase erosion and make it more likely for its banks to collapse. According to a 2024 study that analyzed satellite photos of the 13 major rivers in the Tibetan Plateau, this poses a risk to local ecosystems, infrastructure and landscape stability.

When the river eventually reaches India, it becomes part of the Brahmaputra River and continues for another 1,800 miles (2,900 km) until it reaches the Ganges River Delta, where it drains into the Indian Ocean, according to the Earth Observatory.

A landslide into a river in Canada's Yukon territory last December sent a tsunami of ice slabs flying over two football fields away, severing trees in the process.

Now, new research suggests that the damage from this "ice tsunami" was worsened by the destructive force of the river ice. However, it was also restricted to a smaller area than if the landslide had hit in summer and created an ice-free wave.

"This effect is an important consideration for future landslide and tsunami hazard assessments in cold regions," study author Derek Cronmiller, a permafrost geologist with the Yukon Geological Survey, wrote in a new paper. Cronmiller visited the remote disaster site 24 days after the landslide and published his findings Sept. 25 in the journal Landslides.

The ice tsunami hit on Dec. 17, 2024, when a steep slope above the Takhini River failed without warning. About 4.1 million cubic feet (118,000 cubic meters) of dirt and rock tumbled into the river, which was covered in ice at the time. The impact created an ice-studded tsunami that washed over 17.8 acres (7.2 hectares) of the river and its banks. River ice cracked up to 820 feet (250 m) away, and chunks of ice over 43 square feet (4 square m) were found 656 feet (200 m) from the landslide.

The icy wave scoured vegetation from the river's banks, stripping all but the four largest trees from the bank opposite the landslide. On that slope, only trees with trunks of diameters over 11.8 inches (30 centimeters) survived.

Some slabs of river ice were flipped over, with about 4 inches to a foot (10 to 30 cm) of sand stuck to them. These slabs had been frozen solid to the bottom of the river, Cronmiller wrote, and the force of the tsunami ripped the riverbed up with them.

Landslides are typically triggered by snowmelt, rainfall or human activity, but Cronmiller found no evidence of an external trigger for the Dec. 17 event. Instead, the slope underwent a "brittle failure," meaning it cracked without any signs of warping or deformation.

Fortunately, no one was hurt in the incident, which happened 15.5 miles (25 km) northwest of Whitehorse, Yukon, in a rural area. The river is a destination for outdoor activities, however. Dogsledders and snowmobilers use it as a thoroughfare in winter, while river rafters traverse the Takhini in the summer.

The landslide narrowed the river by 50% and clogged it with debris, which could be hazardous to paddlers for years to come, Cronmiller wrote. The new study found that it will likely take the Takhini River more than a decade to carve its way back through the landslide debris.

The Coral Triangle is a tropical marine region between the Pacific and Indian oceans where 76% of Earth's coral species are found. It encompasses 2.3 million square miles (6 million square kilometers) of ocean around the Philippines, Indonesia and Papua New Guinea, and stretches south to Timor-Leste and as far east as the Solomon Islands.

Biodiversity in the Coral Triangle is much higher than in other regions with coral reefs, such as the Caribbean Sea and the southwest Pacific Ocean. Around 605 reef-building coral species inhabit the Coral Triangle — 10 times the number in the Caribbean Sea, according to an article from the U.K.'s Natural History Museum (NHM).

These corals provide a home for six of the world's seven sea turtle species and 37% of the world's coral reef fish species, as well as marine mammals like dolphins, dugongs, blue whales and sperm whales, according to the NHM article. This incredible array of species has earned the Coral Triangle the nickname the "Amazon of the sea."

"This part of the world contains the highest diversity of marine species," Nadia Santodomingo, a coral expert and marine biologist at the NHM, said in the article. "Scientists have been trying to understand why it's so diverse for a very long time." In fact, British naturalist and explorer Alfred Russel Wallace was working there when Charles Darwin was alive, trying to solve the same problem, she added.

Wallace traveled through the Malay Archipelago between mainland Southeast Asia and Australia, collecting specimens and developing theories regarding the region's staggering biodiversity. He came up with what scientists call the "Wallace Line" — a gigantic biological boundary that separates the Oriental and Australian faunal regions — and proposed the theory of evolution by natural selection around the same time as Darwin.

Scientists today have more tools at their disposal to understand the region, with evidence suggesting that murkier conditions in the Coral Triangle compared with other shallow tropical waters may provide a haven for different species. The Coral Triangle has been a biodiversity hotspot for at least the past 20 million years, and this is partly thanks to a huge variety of habitat types and optimal conditions for larvae that ride on ocean currents, according to the nongovernmental organization Blue Corner Marine Research.

Research also suggests that the Coral Triangle has a plethora of species simply because diversity built up over time. Unlike temperate and polar marine regions that have undergone glaciations, tropical regions like the Coral Triangle have remained relatively stable. And what sets this region apart from other tropical seas is its unique, platform-like geology and location at the intersection between two oceans, researchers say.

Like other coral reef regions, the Coral Triangle is vulnerable to overfishing, pollution from coastal development, and ocean acidification linked to climate change — although scientists think its murky conditions may shield it somewhat.

"Corals living under continuous sediment stress seem to be more resilient, as the mud may block light, which in turn alleviates bleaching stress induced by high temperatures," Kenneth Johnson, a paleobiologist and principal researcher at the NHM, said in the article.

Nevertheless, it's important to protect this patch of ocean, Johnson said. "Nobody really thinks about these reefs," he said, "but they might be the ones we really want to protect."

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

The Book of Exodus tells of a miraculous parting of the Red Sea that allowed Moses and the Israelites to escape Egypt. Now, science has an older and more extreme tale to tell: About 6.2 million years ago, the Red Sea dried up completely.

Some millennia later, the dried seabed filled back up in a cataclysmic flood that may have carved a deep, nearly 200-mile-long (320 kilometers) submarine canyon into the Red Sea's floor.

"Our findings show that the Red Sea basin records one of the most extreme environmental events on Earth, when it dried out completely and was then suddenly reflooded about 6.2 million years ago," study lead author Tihana Pensa, a researcher at King Abdullah University of Science and Technology in Saudi Arabia, said in a statement. "The flood transformed the basin, restored marine conditions, and established the Red Sea's lasting connection to the Indian Ocean."

The Red Sea began to form 30 million years ago as the African and Arabian tectonic plates pulled apart, or rifted. It was a deep valley dotted with lakes until the Mediterranean Sea flooded it 23 million years ago. But just before 6 million years ago, the Red Sea underwent a 640,000-year "salinity crisis." Sea levels dropped and salt levels skyrocketed, leading to deposits of salt up to 1.2 miles (2 km) deep in some places. Marine life died out.

Now, a new study of the seafloor reveals that the Red Sea entirely dried up during this crisis, becoming a dry, salty desert. This barren period ended with a flood from the Indian Ocean, which breached a volcanic ridge that separated the Red Sea from the Gulf of Aden, Pensa and her colleagues reported in their study, published Aug. 9 in the journal Communications Earth & Environment.

The researchers combined data on the rock layers beneath the Red Sea with seismic data that can demarcate the layers of sediment and salt laid down during the sea's history. They found an unconformity throughout the seabed — a place where older, tilted sedimentary layers were suddenly overlain by a horizontal layer of rock. The consistency of this layer indicates that the whole sea desiccated during this time period.

To date the events, the researchers tracked changes in radioactive strontium that varies at a known rate in the oceans. They also studied microfossils, which were largely absent between 14 million and 6.2 million years ago, when the Red Sea was either extraordinarily salty or completely dry. After 6.2 million years ago, fossils of marine creatures such as sea snails and bivalves return.

The researchers argue that the water — and life — returned because the Indian Ocean broke through a ridge of volcanoes and seamounts in the Gulf of Aden known as the Hanish Sill.

This would have happened quickly, in less than 100,000 years, and may have been forceful enough to scour a 200-mile-long, 5-mile-wide (8 km) submarine canyon that still runs from the Gulf of Aden to the Red Sea today.

This amazing astronaut photo shows the bizarre whale-like shape of a Belizean tropical island. The coral-reef-covered structure is home to the Great Blue Hole, one of the deepest marine sinkholes on the planet, which appears to double as the whale's "blowhole" when viewed from space.

The cetacean-shaped landmass, known as Lighthouse Reef, is located around 50 miles (80 kilometers) off Belize's eastern coast in the Caribbean Sea, and is around 26 miles (42 km) long from its "head" to its "tail." It has no permanent human population, but it's visited by more than 10,000 tourists, including many scuba divers, every year.

The island is an atoll, meaning it is mostly underwater and covered by shallow coral reefs, with only a few sandy patches, known as cays, poking above the ocean's surface. The atoll's turquoise waters are only between 6 and 20 feet (2 and 6 meters) deep, but near the island's center lies a dark circle that goes far, far deeper.

The Great Blue Hole is an underwater sinkhole with a near-circular opening that spans 1,043 feet (318 m). It has a maximum depth of 407 feet (124 m) — making it one of the deepest sinkholes on Earth — and it has only recently been properly explored.

Related: See all the best images of Earth from space

Lighthouse Reef is part of the wider Belize Barrier Reef, which is listed as a UNESCO World Heritage Site, and is home to a range of marine life, including a variety of fish, such as wrasses, snappers and gobies, as well as larger animals, such as crocodiles and sea turtles.

One of the island's most notable above-water spots, Half Moon Caye (located on the tip of the hump on the whale's back), is also home to a variety of birds that nest within its coconut trees, as well as endangered species of gecko and anole.

Great Blue Hole

The Great Blue Hole is believed to have initially formed as an above-water cave system, as evidenced by the stalagmites and stalactites found in submerged caves that branch off from the main sinkhole. However, it was flooded around 10,000 years ago as the end of the last ice age caused sea levels to rise.

The hole was made famous in the 1970s when the renowned ocean explorer Jacques Cousteau visited the island and started charting its depths from his famous ship, the Calypso. Cousteau later described the sinkhole as one of his "top five scuba diving sites" in the world.

In 2018, the explorer's grandson Fabien Cousteau and British billionaire Richard Branson led a submarine expedition to explore the Great Blue Hole and created the first 3D map of the structure. One of the standout findings from this expedition was the discovery of a layer of hydrogen sulfide, around 107 feet (33 m) thick, toward the bottom of the hole. This layer is anoxic, meaning it contains no dissolved oxygen, which makes it deadly for most marine animals that venture into it.

The expedition team also discovered the bodies of two scuba divers who had previously gone missing while exploring the Great Blue Hole; their bodies had been perfectly preserved by the hydrogen sulfide layer, according to Newsweek. The expedition team decided to leave the bodies where they were, out of respect. At least one other diver is known to have gone missing in the sinkhole.

More recently, earlier this year, scientists used sediment cores collected from the sinkhole's floor to analyze historic tropical cyclones in the area and found that these storms have become more frequent over the past 6,000 years.

A massive system of rotating ocean currents in the North Atlantic is behaving extremely strangely, possibly because it is approaching a tipping point, a new analysis of clam shells shows.

The North Atlantic subpolar gyre plays a key role in transporting heat to the Northern Hemisphere, and it is a part of a much larger network of ocean currents called the Atlantic Meridional Overturning Circulation (AMOC). But new evidence suggests the subpolar gyre has been losing stability since the 1950s, meaning the gyre's circulation could weaken substantially in the coming decades, researchers report in a study published today (Oct. 3) in the journal Science Advances.

"It's highly worrying," study lead author Beatriz Arellano Nava, a postdoctoral research fellow in physical geography at the University of Exeter in the U.K., told Live Science. "The subpolar gyre was recently acknowledged as a tipping element. We still need to understand more of the impacts of a subpolar gyre abrupt weakening. But what we know so far with the few studies that have been published is that it would bring more extreme weather events, particularly in Europe ... and also changes in global precipitation patterns."

The North Atlantic subpolar gyre is a limb of the AMOC, but it can cross a tipping point independently from the giant network of currents. The climate outcomes for Europe, in particular, would be similar to those that would be triggered by a collapse of the AMOC, although they may be less intense because the AMOC is so much bigger, Arellano Nava said. However, "even if the consequences are not as catastrophic as for an AMOC collapse, a subpolar gyre weakening can bring substantial climate impacts," she warned.

Previous research suggests the AMOC could collapse in the near future because its main engine — a cascade of dense water from the surface of the North Atlantic and Arctic oceans to the seabed — is failing. This cascade, which until now was made of extremely cold and salty water, is being diluted by meltwater and warmed by rising global temperatures, meaning the water in some places is no longer dense enough to sink properly. (Cold, salty water is denser than warmer, less-salty water.)

A similar fate is expected for the North Atlantic subpolar gyre, which also relies on surface water sinking to the ocean floor. A cascade of dense water at the core of the gyre keeps the rotating currents moving, Arellano Nava said. But the system is also partly driven by wind, so a complete collapse is unlikely, she said.

The North Atlantic subpolar gyre is a branch of the AMOC, so an AMOC collapse necessarily involves a dramatic weakening of the gyre. Conversely, a weakening of the subpolar gyre doesn't automatically mean that the AMOC has collapsed, Arellano Nava said.

"The subpolar gyre can weaken abruptly without the AMOC collapsing," she explained. "That's what happened during the transition into the Little Ice Age, which happened in the 13th and 14th centuries."

The Little Ice Age, which lasted from about 1250 to the late 1800s, is one of the coldest periods on record in the Northern Hemisphere since the end of the last ice age. Average temperatures dropped by about 3.6 degrees Fahrenheit (2 degrees Celsius), freezing rivers and harbors across Europe and North America solid in the winter, triggering agricultural crises and broadly throwing medieval society into chaos, according to The New Yorker. Although factors like volcanic eruptions and reduced solar activity contributed to the initiation of the Little Ice Age, the North Atlantic subpolar gyre is thought to have played a major role in strengthening it.

With climate change, conditions are dramatically different now than they were in the 13th century, so scientists don't know if another Little Ice Age is possible, Arellano Nava said. Nonetheless, it illustrates some of the climate impacts that could be coming our way.

Clues in clams

For the new study, Arellano Nava and her colleagues analyzed existing datasets derived from the shells of two clam species living in the North Atlantic: Arctica islandica and Glycymeris glycymeris. Clams record information about the ocean in their shells as they grow; for example, they absorb different forms of elements like oxygen that can give researchers clues about oceanic processes over time.

"With clam records, we have that nice dating for each of the layers," Arellano Nava said. "They are like the tree rings of the ocean."

The researchers compiled 25 datasets to build a high-resolution picture of the North Atlantic subpolar gyre over the past 150 years. They found two strong signals of instability. The most recent is ongoing and suggests the subpolar gyre is approaching a tipping point as a result of global warming, which supports previous observations and research, Arellano Nava said.

But the other signal was a total surprise, she said. The clam data revealed that the subpolar gyre was unstable for a few years in the run-up to the 1920s North Atlantic regime shift. This previously described event was characterized by the strengthening of currents in the gyre. Instability in the subpolar gyre likely caused the 1920s regime shift, and the timeline suggests the period of instability may have reflected the subpolar gyre's recovery from its Little Ice Age collapse, Arellano Nava said.

"It had to restrengthen at some point, but that's not something we have full evidence for because we didn't dive into those mechanisms," she said.

Regardless of whether instability in the early 20th century was actually a signal that the subpolar gyre was returning to its full strength, the overlap between the signal in the clam data and the 1920s North Atlantic regime shift shows that the results are robust, Arellano Nava said.

"If you observe a loss of stability followed by a rapid change, then you are confident that these are early warning signals for an abrupt change," she said.

However, another expert was less convinced. "The datasets are very useful because they are very well dated and allow insights into climate changes on a year-by-year basis," David Thornalley, a professor of ocean and climate science at University College London who was not involved in the study, told Live Science in an email.

But the analysis did not link the patterns observed in the clam data directly to physical features in the ocean, nor provide strong support for a shift in the subpolar gyre's mode of operation, Thornalley said. "I am sceptical about the interpretation," he said.

Regarding the ongoing destabilization of the North Atlantic subpolar gyre, Arellano Nava said she and her team have moved on to map potential climate trajectories that this could unlock.

"We don't know exactly what the tipping point is," she said. "It could be the AMOC, … but we may be observing a subpolar gyre weakening first, and that's worrying, definitely."

Chinese researchers have discovered a giant, previously unknown hydrothermal system at the bottom of the Pacific Ocean that could shed light on the origins of life.

The Kunlun system, northeast of Papua New Guinea, is made up of 20 large craters, the largest of which is around 5,900 feet (1,800 meters) wide and 430 feet (130 m) deep. These craters are clustered together in what the researchers called a "pipe swarm," and they release copious amounts of hydrogen, which may feed the life that thrives throughout the system.

Kunlun is similar to an Atlantic hydrothermal field known as the Lost City, which is located on the Atlantis Massif underwater mountain range. However, Kunlun has several features that make it unique, including its extraordinary size. Kunlun covers an area of about 4 square miles (11 square kilometers), making it hundreds of times larger than the Lost City, according to the study published Aug. 8 in the journal Science Advances.

The Kunlun system offers scientists a new window into deep-sea serpentinization, which is the process by which seawater chemically reacts with mantle rocks beneath the seafloor to create serpentine minerals (a group of minerals known for their greenish color) and release hydrogen.

Researchers think they can study the potential links between these hydrogen emissions and the emergence of life at Kunlun. The system is thought to have hydrogen-rich fluids that are similar to early Earth's chemical environment, according to a statement released by the Chinese Academy of Sciences.

"What's particularly intriguing is its ecological potential," study co-author Weidong Sun, a professor at the Chinese Academy of Sciences' Institute of Oceanology, said in the statement. "We observed diverse deep-sea life thriving here — shrimp, squat lobsters, anemones, and tubeworms — species that may depend on hydrogen-fueled chemosynthesis."

Related: 'Dragon' and 'tree of life' hydrothermal vents discovered in Arctic region scientists thought was geologically dead

Sunlight doesn't reach the deep ocean, so life at the seafloor can't use photosynthesis — the process by which plants, algae and certain bacteria closer to the surface convert sunlight into energy. Some life in the deep ocean therefore relies on chemosynthesis, which involves using chemicals like hydrogen as an energy source to make food.

A separate Chinese-led research team recently used a crewed submersible to film chemosynthesis-based communities at the bottom of the northwest Pacific, at depths of around 31,000 feet (9,500 m). Such communities are rarely documented, with the vast majority of the ocean floor unexplored and unstudied.

In the new study, researchers used the same submersible to map Kunlun and explore four of its largest craters. By measuring the hydrogen concentrations in Kunlun's hydrothermal fluids, the researchers estimated that the field produced more than 5% of the world's non-living submarine hydrogen output — not bad for just one system.

The team proposed that the pipe swarm they documented formed in stages. First, hydrogen accumulated beneath the surface and burst out in major explosions. Fractures then formed along the edges and bottom of the resulting structures, triggering further intense eruptions of hydrogen-rich hydrothermal fluids. These fractures would then slowly become blocked by forming minerals, enabling hydrogen to accumulate again and potentially fuel additional smaller-scale explosions.

Kunlun is different from the more common volcano-powered hydrothermal seafloor systems found at plate boundaries. These systems often feature chimney-like structures, such as black smokers, that are extremely hot, running at about 750 degrees Fahrenheit (400 degrees Celsius). The serpentinization systems like Kunlun and the Lost City are cooler, with temperatures below 194 F (90 C).

Kunlun is not only bigger than the Lost City, it's also in a more unusual location. The Lost City is close to a mid-ocean ridge, which form along diverging plate boundaries and expose mantle rock, while Kunlun is in the interior of its plate, far from any ridge.

"The Kunlun system stands out for its exceptionally high hydrogen flux, scale, and unique geological setting," Sun said. "It shows that serpentinization-driven hydrogen generation can occur far from mid-ocean ridges, challenging long-held assumptions."

This stunning astronaut photo shows a series of milky swirls that appeared in the waters of Turkey's Lake Van, the largest "soda lake" on Earth. While the swirls look like a common natural phenomenon, they're actually something much rarer.

Lake Van is the largest lake in Turkey with a surface area of around 1,200 square miles (3,100 square kilometers), which is slightly smaller than Rhode Island. Its surface is located at an altitude of 5,380 feet (1,640 meters) above sea level and has a pH of around 10, which is highly alkaline.

The photo above shows a section of Lake Van around the city of Erciş, which is located along the lake's north shore. The swirls in the image look very similar to shapes that appear during algal blooms, when rapidly multiplying plankton species get caught up in wind-driven currents. However, this was not the cause of these swirls.

Instead, the milky material in the lake is mostly made up of calcium carbonate, as well as smaller concentrations of detritus — waste organic material left over from living and dead animals, according to NASA's Earth Observatory.

This milky swirls are known as "turbidity plumes," clouds of suspended material that are triggered by natural or human-caused disturbances to the lake floor. These plumes are more likely to appear in this part of the lake because the water level is shallower than the rest of the lake, which reaches a maximum depth of around 1,450 feet (450 m).

Related: See all the best images of Earth from space

Lake Van also has one of Earth's highest concentrations of "microbialite," a collection of free-floating organo-sedimentary structures formed by the trapping, binding and precipitation of minerals by various microbes. Microbialite production peaks in the spring and fall, when microbial communities multiply. However, this is not thought to be the cause of these particular swirls, according to the Earth Observatory.

The lake's high pH levels are caused by high concentrations of carbonate salts, which have built up over time because the lake is "endorheic," meaning it does not have an outlet. Therefore, as water evaporates from the lake, the concentration of salts increases.

The salt concentration in the lake is so high that the water rarely freezes, even though its temperature frequently drops below 32 degrees Fahrenheit (0 degrees Celsius) during the winter months.

Lake Van's water levels have changed significantly over the last 600,000 years as changes in Earth's climate have altered the rates of water input and evaporation. A 2014 study estimated that its depth has fluctuated by around 2,000 feet (600 m) during this time.

While the large milky swirls in the photo are not caused by algal blooms, you can see small concentrations of phytoplankton that have accumulated along Erciş' coastline, as well as within a smaller lake located near the top of the image.

A rocket-like jellyfish, a majestic Komodo dragon and a dangerous surfing encounter are just a few of the stunning photographs captured by the finalists for the Ocean Photographer of the Year 2025 competition. The competition includes categories such as Impact and Hope, which have solicited breathtaking photographs that capture diverse forms of marine life and human interaction with the ocean.

The overall and category winners of the contest, hosted by Oceanographic Magazine and watch company Blancpain, will be announced in September. But all of the finalists' photos emphasize the need to protect the planet.

"In the midst of a deepening climate and biodiversity crisis on our blue planet, ocean photography has never been more important," Will Harrison, director of Ocean Photographer of the Year, said in a statement from the organization. "These images are far more than just beautiful; they are powerful visual testaments to what we stand to lose, and they remind us of the urgent need for protection."

Here are some of the gorgeous photos.

Synchronized swimmers

Photographer Yuka Takahashi, a finalist in the "Young" category of the competition, captured a pair of synchronized humpback whales in French Polynesia swimming through rays of sun. "These two humpback whales are always seen together, and I was fortunate to capture this rare moment of synchronicity," Takahashi said. "To me, this photo reflects the strong bond between them while also revealing their playful and curious personalities."

Warm bath

In this image, snapped by "Wildlife" category finalist and photographer Suliman Alatiqi, a Komodo dragon (Varanus komodoensis) looms over an Indonesian shore. Because Komodo dragons are cold-blooded, they rely on cold water or mud to regulate their body temperature in the summer. They also travel across seabeds to search for food and mates.

Related: Ocean Photographer of the Year 2024: See stunning photos of hungry whale, surfing seagull, freaky fish babies, land-loving eel and adorable toxic octopus

Collateral damage

Photographer Natnattcha Chaturapitamorn snapped this image of fishers unloading their catches at a Bangladeshi harbor during sunrise, which is a finalist in the "Impact" category.

"Amidst this industrious energy, the presence of an endangered species serves as a reminder of the urgent need to protect marine biodiversity," Chaturapitamorn said. "As global fish stocks decline, safeguarding threatened species like this is vital, not only for ecological balance but for the long-term sustainability of fishing communities that depend on the ocean’s bounty."

Stranded

On July 1, wildlife veterinarians received a call about a humpback whale stranded on an Australian beach, and photographer Craig Parry documented the harrowing scene from above. For 15 hours, rescue teams and other members of the community worked to save the whale but were unsuccessful.

"While the outcome was heartbreaking, witnessing the collaboration and compassion shown by multiple agencies and volunteers was incredibly moving — a powerful reminder of what can be achieved when people come together with a shared purpose," said Parry, whose photo is a finalist in the "Human Connection" category.

School of fish

This mesmerizing image, taken in Indonesia by photographer Kim Hyeon Min, captures a school of juvenile fish circling around a tower of coral and is a finalist in the "Hope" category. The vibrancy of the coral suggests it has been unaffected by bleaching and is still able to host a miniature ecosystem for surrounding creatures. "In a time when marine ecosystems are rapidly disappearing, this image is a reminder of what we still have — and a hopeful glimpse of what we must protect for the future," Hyeon Min said.

Otherworldly jellyfish

Jellyfish are often described as alien-like, and this ethereal image captured in Spain by photographer Toni Bertran Regàs takes that comparison to new heights with this finalist in the "Fine Art" category.

"I've always been fascinated by the resemblance between jellyfish and space rockets," Bertran Regàs said. "I was looking for a photograph that conveyed that connection: a rocket leaving Earth. To do this, I used a fisheye lens and took the photo just as the sun was rising. Snell's Window" — an underwater optical phenomenon — "helped me create the Earth, the particles were the stars, and the sun luckily appeared behind it."

Monster waves

Photographer Ben Thouard, a finalist in the "Adventure" category, captured a day of rough seas in Nazaré, Portugal. Though the water was too dangerous for many surfers, two gave it a go. Despite the difficulty of photographing between huge waves and through salt water in the air, Thouard eventually shot this moment.

Rogue waves have captivated the attention of both seafarers and scientists for decades. These are giant, isolated waves that appear suddenly in the open ocean.

These puzzling giants are brief, typically lasting less than a minute before disappearing. They can reach heights of 65 feet (20 meters) or greater and often more than twice the height of surrounding waves. Once a nautical myth, rogue waves have now been observed around the world. Because they're so tall and powerful, they can pose a danger to ships and offshore structures.

To rethink what rogue waves are and what causes them, I gathered an international team of researchers. Our study, published in Nature Scientific Reports, sheds light on these oceanic giants using the most comprehensive dataset of its kind.

By analyzing 18 years of high-frequency laser measurements from the Ekofisk oil platform in the central North Sea, we reached the surprising conclusion that rogue waves aren't just freak occurrences. They arise under the natural laws of the sea. They are not mysterious, but somewhat simple.

27,500 sea states

We analyzed nearly 27,500 half-hour wave records, or sea states, collected between 2003 and 2020 in the central North Sea. These records, taken every 30 minutes, describe how elevated the sea surface was compared to the average sea level. They include major storms, such as the Andrea wave event in 2007.

Under normal conditions, waves arise from wind blowing over the sea surface. It's like when you blow over your cup of coffee and form small ripples on the surface. At sea, with enough time and space, those ripples can turn into large waves.

We focused on understanding what causes waves to suddenly go rogue and rise far above their neighboring waves. One proposed theory is based on modulational instability, a phenomenon described by complex mathematical models. I've revised these models in the past, as my work suggests that this theory doesn't fully explain what causes rogue waves in the open ocean.

Related: 4-story rogue wave that randomly appeared in the Pacific Ocean is the 'most extreme' ever detected

When waves are trapped within a narrow channel, the modulational instability theory describes their rippling movement well. However, it starts to fall apart when you look at the real ocean. In open environments such as the North Sea, waves are free to propagate from multiple directions.

To understand the difference, imagine a crowd of spectators leaving a stadium after a football game. If the exit is a long, narrow hallway with tall walls, people are forced to move in a single direction. Those at the back push forward, and some may even climb over others, piling up between the confining walls. This catastrophic pileup would resemble a rogue wave, caused by their confinement.

In contrast, if the stadium's exit opens onto a wide field, spectators can disperse freely in all directions. They don't push on each other, and they avoid pileups.

Similarly, researchers can generate rogue waves in a confined channel in the lab, where they obey modulational instability. But without the confinement of a channel, rogue waves usually won't follow those physics or form the same way in the open sea.

Our team knew we had to study the open sea directly to figure out what was really going on. The real-world data my team examined from the North Sea doesn't line up with modulational instability — it tells a different story.

It's just a bad day at sea

We analyzed the sea state records using statistical techniques to uncover patterns behind these rare events. Our findings show that instead of modulational instability, the extreme waves observed more likely formed through a process called constructive interference.

Constructive interference happens when two or more waves line up and combine into one big wave. This effect is amplified by the natural asymmetry of sea waves — their crests are typically sharper and steeper than their flatter troughs.

Rogue waves form when lots of smaller waves line up and their steeper crests begin to stack, building up into a single, massive wave that briefly rises far above its surroundings. All it takes for a peaceful boat ride to turn into a bad day at sea is a moment when many ordinary waves converge and stack.

These rogue waves rise and fall in less than a minute, following what's called a quasi-deterministic pattern in space and time. This type of pattern is recognizable and repeatable, but with touches of randomness. In an idealized ocean, that randomness would almost vanish, allowing rogue waves to grow to nearly infinite heights. But it would also take an eternity to witness one of these waves, since so many would have to line up perfectly. Like waiting for Fortuna, the goddess of chance, to roll a trillion dice and have nearly all of them land on the same number.

In the real ocean, nature limits how large a rogue wave can grow thanks to wave breaking. As the wave rises in height and energy, it can't hold itself beyond a certain point of no return. The tip of the wave spills over and breaks into foam, or whitecap, releasing the excess energy.

The quasi-deterministic pattern behind rogue waves

Rogue waves aren't limited to the sea. Constructive interference can happen to many types of waves. A general theory called the quasi-determinism of waves, developed by oceanographer Paolo Boccotti, explains how rogue waves form, both in the ocean and in other wave systems.

For example, for turbulent water flowing through a confined channel, a rogue wave manifests in the form of an intense, short-lived spike in vortices — patterns of spinning swirls in the water that momentarily grow larger as they move downstream.

While ocean waves seem unpredictable, Boccotti's theory shows that extreme waves are not completely random. When a really big wave forms, the waves in the sea around it follow a recognizable pattern formed through constructive interference.

We applied Boccotti's theory to identify and characterize these patterns in the measured North Sea wave records.

The giant waves observed in these records carry a kind of signature or fingerprint, in the form of a wave group, which can reveal how the rogue wave came to life. Think of a wave group like a small package of waves moving together. They rise, peak and then fade away through constructive interference. Tracking these wave groups allows researchers to understand the bigger picture of a rogue event as it unfolds.

As one example, a powerful storm hit the North Sea on Nov. 24, 2023. A camera at the Ekofisk platform captured a massive 55 foot (17 meter) rogue wave. I applied the theory of quasi-determinism and an AI model to investigate the origin of this extreme wave. My analysis revealed that the rogue event followed these theories — quasi-determinism and constructive interference — and came from multiple smaller waves repeatedly stacking together.

Recognizing how rogue waves form can help engineers and designers build safer ships and offshore platforms — and better predict risks.

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

Even a small slowdown to one of Earth's major ocean currents could nearly halve the rainfall over parts of the planet's rainforests, fueling droughts that could accelerate climate change, a new study warns.

The Atlantic Meridional Overturning Circulation (AMOC), which includes the Gulf Stream, plays a key stabilizing role in climates around the planet. Yet a number of studies indicate that the current is slowing, with some even suggesting its heading toward a disastrous collapse.

Now, a new study has analyzed 17,000-year-old climate records to connect the current's weakening with its effects on the planet's tropics. Published Wednesday (July 30) in the journal Nature, the research suggests that the possible impact presents "a stunning risk" that could send swathes of usually humid regions, in the Amazon rainforest and elsewhere, into drought.

"This is bad news, because we have these very important ecosystems in the Amazon," study lead author Pedro DiNezio, an atmospheric and ocean scientist at the University of Colorado Boulder, said in a statement. "The Amazon rainforest contains almost two years of global carbon emissions, making it a major carbon sink on Earth. Drought in this region could release vast amounts of carbon back into the atmosphere, forming a vicious loop that could make climate change worse."

The AMOC acts as a planetary conveyor belt, bringing nutrients, oxygen and heat north from tropical waters while moving colder water south — a balancing act that keeps both sides of the Atlantic 9 degrees Fahrenheit (5 degrees Celsius) warmer than it would otherwise be.

But research into Earth's climate history shows that the current has switched off in the past, and some studies have hinted that glacial meltwater released by climate change is causing the AMOC to slow. The worst-case scenarios predicted by some models suggest that the current may outright collapse sometime this century, leading to devastating and irreversible impacts felt across the globe.

Related: Atlantic ocean currents are weakening — and it could make the climate in some regions unrecognizable

These predictions remain controversial, yet the risks are large enough for scientists to have called for urgent investigation. The effects of a diminished AMOC would include plummeting temperatures in Europe and storms proliferating around the equator — but scientists have also pointed to other, less foreseeable, impacts in Earth's tropical regions.

To investigate these possible outcomes, the researchers behind the new study pooled data of ancient rainfall patterns preserved in cave formations and lake and ocean sediments. They then plugged them into climate models to simulate the shifts in the past and how they may change in the future.

These models predict that a weakening AMOC would cool the northern Atlantic, causing temperatures to drop in the tropical Atlantic and Caribbean. This change, accompanied by rising global temperatures due to climate change, would lead to a drop in precipitation over regions in the rainforest belt, with rainfall dropping by up to 40% over parts of the Amazon rainforest.

Yet despite this alarming prediction, the researchers stress that the situation isn't hopeless: Though the tropics may remain sensitive to small shifts in the AMOC's strength, they say it is unlikely to collapse completely.

The fate of the current, and how severely it slows, depends on tackling climate change now.

"We still have time, but we need to rapidly decarbonize the economy and make green technologies widely available to everyone in the world," DiNezio said. "The best way to get out of a hole is to stop digging."

In 2023, global marine heatwaves were the biggest, most intense and most persistent on record, a new study reveals. The researchers suggest that these heat waves were driven by climate change and may signal a climate tipping point.

Global marine heatwaves (MHWs) are prolonged periods of unexpectedly warm ocean temperatures. These warm periods can critically threaten marine ecosystems, for instance by leading to coral bleaching and mass marine die offs, and can cause economic challenges by disrupting fisheries and aquaculture. While it's widely accepted that human-driven climate change is making MHWs more destructive, little is known about the ocean dynamics behind the phenomenon.

"Marine heatwaves have emerged globally as one of the most severe threats to marine ecosystems," Ryan Walter, a marine scientist at the California Polytechnic State University who was not involved in the study, told Live Science.

A climate tipping point?

In a study published Thursday (July 24) in the journal Science, the researchers used satellite observations and ocean circulation data to evaluate the MHWs of 2023. They found that the year set new records for MHW temperatures, duration and geographic range — some of which have been measured since the 1950s — with these events lasting four times longer than the historical average and covering 96% of oceans worldwide.

The most intense warming, which occurred in the North Atlantic, tropical Pacific, South Pacific and North Pacific, accounted for 90% of unexpected oceanic heating during 2023. The North Atlantic MHW lasted for 525 days, and the Southwest Pacific MHW broke records for geographic extent and duration.

Related: A Hot Blob in the Pacific Ocean Caused 1 Million Seabirds to Die

The scientists identified several drivers behind the extreme MHWs, including rising solar radiation due to reduced cloud cover, weakened winds and changes in ocean currents.

They suggest that the 2023 MHWs may indicate a fundamental shift in ocean dynamics — which could be early warnings of a climate tipping point. Though there's not a singular definition of a tipping point, most researchers use it to mean the threshold at which certain effects of climate change are irreversible.

It's still uncertain whether or not oceans have reached a crucial tipping point just yet. "Tipping points are difficult to quantify," Walter said. Because the ocean and atmosphere contain many feedback loops, "if you change one thing, it changes another," so making exact predictions of where climate tipping points occur is tricky.

Other factors may also have influenced 2023's record-breaking ocean heat waves. A large El Niño event — a climate cycle in which waters off the eastern Pacific are warmer than usual — in the summer of that year meant "a lot of heat was released from the deeper waters of the ocean into the atmosphere, helping to fuel a lot of these heat waves that the authors write about," Michael McPhaden, a senior scientist at the National Oceanic and Atmospheric Administration who was not involved with the study, told Live Science. For example, in the Tropical Eastern Pacific, temperature anomalies peaked at 34.9 degrees Fahrenheit (1.6 degrees Celsius) during the onset of El Niño, the new paper found.

McPhaden agreed that 2023 was a remarkable year for MHWs and other climate extremes, but said, "I don't consider 2023 to be a tipping point." Though extreme temperature events are on the rise due to climate change, the natural variability that comes with El Niños also affects year-to-year oceanic measurements.

"There are going to be years when things go off the charts, and those are going to be the years when we have big El Niños," McPhaden said.

Marine ecosystems and human livelihoods

Regardless of whether or not 2023 represented a tipping point, extreme MHWs across the globe emphasized the vulnerability of marine ecosystems and human livelihoods that depend on them. MHWs "not only have impacts on foundational ecosystems like kelp forests, seagrasses and coral reefs, all of which provide many valuable ecosystem services and support other species, but they also impact many economies," Walter said.

These extreme events can also lead to the expansion of certain species' habitats — potentially further destabilizing battered ecosystems. Warmer waters off the coast of California, for example, drew equatorial venomous sea snakes to the state. "These sea snakes that typically live in the equatorial Pacific can follow warm waters as far north as Southern and even parts of central California," Walter said.

These extreme MHWs won't be the last. "What you're seeing is a consequence of climate change," McPhaden said. "We're just going to see more temperature extremes in the ocean and in the atmosphere."

Key Atlantic Ocean currents that appear to be slowing down due to climate change may be more resilient to global warming than scientists previously thought — thanks to a secret back-up system, a new study shows.

The Atlantic Meridional Overturning Circulation (AMOC) is a web of currents that loops around the Atlantic like a giant conveyor belt. Cold, salty waters sink near Greenland then travel south along the ocean floor. Eventually these waters rise to the surface again near Antarctica and return north, bringing balmier waters to the Northern Hemisphere. This system is crucial to warming Europe, in particular.

In recent years, experts have repeatedly sounded the alarm bell, suggesting the step in which waters sink could cease completely, which could lead to a massive drop in temperatures in Northern Europe and exacerbate sea level rise along the U.S. East Coast, among other impacts.

Researchers think this crucial stage of the AMOC is in trouble due to changes to dense water formation — the process by which the top layer of the ocean cascades to the bottom. Cold, salty water is more dense than warmer, less salty water. Under normal conditions, surface waters lose a lot of heat as they travel through the North Atlantic, which causes them to sink when they reach the end of their northward journey.

This typically takes place in the Nordic Seas — the Greenland, Norwegian and Iceland seas — Marius Årthun, a physical oceanographer at the University of Bergen in Norway and the lead author of the new study, told Live Science in an email.

But with climate change cooking the planet, surface waters in this region aren't transferring as much heat to the air anymore, while rivers of meltwater are also gushing from the Arctic and Greenland Ice Sheet into the ocean, diluting the salt content of surface waters and preventing them from sinking.

Related: Key Atlantic current is weakening much faster than scientists had predicted

Dense water formation in the Nordic Seas has decreased since 1993, which spells trouble for the entire Atlantic circulation system — were it not for a newly found back-up system, Årthun said. The researchers published their findings Friday (July 11) in the journal Science Advances.

Arctic "Atlantification"

For the study, Årthun and his colleagues fed density measurements from the subpolar North Atlantic, Nordic Seas and Arctic Ocean into a computer model. They compared the results with available observations to check that the simulation accurately mirrored processes in this region.

The simulation confirmed that the Arctic Ocean is undergoing a process called "Atlantification."

"Atlantification refers to the transition of the Arctic Ocean from a cold, ice-covered state to a warm, more ice-free state," Årthun said.

Recent decades have seen sea ice in the Barents Sea — a region of the Arctic Ocean that is situated between Scandinavia and Svalbard — retreat farther and farther north, Årthun said. "We expect the Barents Sea to be the first Arctic region to become ice-free," he said, adding that Atlantic waters are now also spreading into the Eurasian Basin, north of the Barents Sea.

Atlantification of the Arctic Ocean means the region is creating more dense water than it was previously, Årthun said.

"We find that this decrease [in dense water formation] in the Nordic Seas has been compensated for by more dense water formation in the Barents Sea and north of Svalbard," he said. "These two regions have experienced a retreating sea ice edge [...], hence increasing the area over which dense waters can be produced."

The authors think this back-up system could help to sustain the AMOC. "There are processes that add resilience to the AMOC, perhaps making a serious weakening or collapse less likely," Årthun said.

More research is needed to figure out whether this back-up system will last in a warming world. There is also a question mark over how well the Arctic Ocean can really replace the Nordic Seas by forming extremely dense water, said Nicholas Foukal, a physical oceanographer and assistant professor at the University of Georgia who was not involved in the study.

It would be interesting to explore whether the densest waters are still being formed, Foukal told Live Science in an email, because "the water masses that were formed historically in the Greenland Sea were incredibly dense."

The Greenland Sea is a very deep ocean basin that is exposed to frigid gusts from the Greenland Ice Sheet. "The Arctic does not have this type of setting," Foukal said. "I doubt that these really dense waters are being formed in the Arctic."

This striking astronaut photo shows a unique chain of three atolls lined up side-by-side off the coast of Australia. The oval islands were once part of a colossal coral system that rivaled the Great Barrier Reef.

The trio of islands makes up Rowley Shoals, an uninhabited Australian territory located in the Timor Sea around 180 miles (290 kilometers) off the coast of Western Australia. From southwest to northeast (left to right), the islands are named Imperieuse Reef, Clerke Reef and Mermaid Reef.

The egg-shaped structures are all atolls — rings of land built from fringing coral reefs that once circled an island that has subsequently sunk beneath the waves. These atolls are evenly spaced out into a near-perfect straight line spanning roughly 60 miles (100 km) from end to end, according to NASA's Earth Observatory.

Each island has a surface area of around 30 square miles (80 square km). Only Imperieuse Reef and Clerke Reef have white sandy islets, or cays, that remain above water. Imperieuse Reef also has the only permanent human-made structure in Rowley Shoals — a lighthouse.

The atolls sit on one of the largest continental shelves on Earth. Around 10 million years ago, this area was home to a massive barrier reef system spanning more than 1,250 miles (2,000 km), which later fell into the sea due to tectonic subduction.

The atolls are believed to be some of the last remnants of this lost ecosystem, along with Ningaloo Reef, the Ashmore and Cartier Islands and the Scott and Seringapatam Reefs, according to a study published in February 2025.

Related: See all the best images of Earth from space

The collective ecosystems of Rowley Shoals experienced a massive decline in the 1970s when the islands became popular with tourists and started hosting deep-sea fishing expeditions.

As a result, the area is now protected by two marine reserves: Rowley Shoals Marine Park, which contains Imperieuse Reef and Clerke Reef; and Mermaid Reef Marine Park, which protects Mermaid Reef and its surrounding waters. This has helped the respective ecosystems to recover to pre-tourism levels.

Today, the atolls are home to a wide variety of marine life, including sea turtles, reef sharks and giant clams, as well as around 900 other species of fish, mollusks and corals, according to the Atlas of Living Australia.

Rowley Shoals is currently listed as one of the best places to go scuba diving in Australia, outside of the Great Barrier Reef, according to the Professional Association of Diving Instructors (PADI). However, the atolls' diving season is limited to between September and December to help minimize the impacts of these visitors.

Researchers have finally answered a longstanding question about a giant patch of cold water in the Atlantic Ocean, blaming a change in ocean currents for the unexpected cooling.

The anomaly, located just south of Greenland, is — perhaps counterintuitively — called the North Atlantic Warming Hole, and it has been stumping scientists for years. Despite the steady warming of ocean waters around the world, this one area got colder by up to 0.5 degrees Fahrenheit (0.3 degrees Celsius) over the past century.

By analyzing ocean temperatures and salinity patterns, scientists linked this mysterious cooling to the slowing of a system of ocean currents called the Atlantic Meridional Overturning Circulation (AMOC).

The changing AMOC is "a weakening of a major part of the climate system," David Thornalley, a paleoceanographer at University College London who was not involved in the new research, told Live Science in an email.

Finding the cause

The cold blob has long been a point of disagreement among oceanographers. Some believed that ocean dynamics were responsible, while others suggested atmospheric influences like aerosol pollution were the cause, according to a statement from the University of California, Riverside.

These findings, published May 28 in the journal Communications Earth and Environment, could help settle the disagreement, providing evidence that ocean dynamics are responsible.

Related story: Key Atlantic current is weakening much faster than scientists had predicted

There are only about 20 years of direct AMOC observations, so the research team relied on other data to track older ocean movements. They used temperature and salinity data, which are correlated to current speed, to uncover the AMOC's patterns from the last century, and used 94 different ocean models to assess the changes.

With a clear timeline of the AMOC's behavior in hand, the researchers found that only the models that included slowed Atlantic currents matched the real-world cooling.

"It's a very robust correlation," study co-author Kai-Yuan Li, a climate scientist at the University of California, Riverside, said in the statement.

Broad implications

Better understanding of how the AMOC is slowing will not only explain the cold blob but will also contribute to climate forecasting, the statement noted. The AMOC and the anomaly it created both influence European weather patterns, including rainfall and wind.

Marine ecosystems may also be negatively affected by the changing currents, as water temperature and salinity can determine local habitability for some species.

There's also concern that the AMOC will collapse. Scientists believe that it will weaken by at least 20% by 2100, but it's unclear whether a collapse is imminent, said Nicholas Foukal, an oceanographer at the University of Georgia’s Skidaway Institute of Oceanography who was not involved in the new study.

"In some sense, the debate is over how bad the effects will be and whether we will have time to adapt to the changes, not whether it will happen," Foukal told Live Science in an email.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Mariana Trench quiz: How deep is your knowledge?