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Science News by AGU

Updated: 18 hours 26 min ago

The 8 May 2022 Baiyan rock avalanche in Guizhou, China

Thu, 04/10/2025 - 07:52

The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.

On 8 May 2022, the catastrophic Baiyan rock avalanche occurred in Zhijin County, which is located in Guizhou Province, China. The digital lat/long is [26.63771, 105.69200]. I described this event at the time (on the old AGU blogsite). It destroyed 53 houses, killing three people.

Intriguingly, many of the reports of this event seem to have been removed, such as the 163.com news item and the Youtube video. This is the image of the failure that I posted at the time:-

The 8 May 2022 Baiyan rock avalanche in Bijie, Guizhou. Image from 163.com.

There is a very interesting new paper (He et al. 2025) about this event in the journal Landslides. The aim of the paper is to examine the behaviour of the particles that formed the rock avalanche using a very impressive combination of a drone survey and articial intelligence driven analysis of individual particles. This is fascinating work, which demonstrates that underlying topography plays a large role in determining the runout characteristics of individual blocks.

But along the way, the paper also provides some very interesting information about the Baiyan rock avalanche itself. First, the slope from which this failure occurred had suffered an astonishing total of seven other rock avalanches in the period between 2019 and 2022. The Google Earth image below, from March 2022 (i.e. before the Baiyan rock avalanche) shows the problems that were occurring on the slope:-

Google Earth image of the site of the 8 May 2022 Baiyan rock avalanche in China.

According to He et al. (2025), the Baiyan rock avalanche itself had a volume of 36,000 cubic metres. It had a runout distance of about 560 metres and a vertical height difference of about 455 m. Significant, but not exceptional, rainfall occurred in the days leading up to the collapse.

Tucked away towards the end of the article is a fascinating consideration of the causes of this event, and of the extraordinary cluster of failures that occurred in this area at the time. Underground coal mining was being undertaken directly below this slope – He et al. (2025) show that a panel advanced from the SW to the NE directly below the ridgeline, starting in the southwest in October 2021. In May 2022, the mining activities were occurring directly below the source area of the Baiyan rock avalanche. The implication is clearly that disturbance / subsidence caused fracturing of the rock mass, triggering the failure.

That comparatively shallow coal mining was occurring directly below such a sensitive location is perhaps surprising. This should be a classic case study of the impacts of poorly controlled mining on slope stability. I also wonder why the village was not evacuated before the landslide given the multiple failures that were occurring on the slope directly behind. It would be interesting to know more about the analyses and discussions that were occurring at this location in the early months of 2022.

Reference

He, J., Zhang, Y., Sun, P. et al. 2025. Investigation of deposition characteristics using a novel super-resolution method: a case study of Baiyan rock avalanche in Guizhou, China. Landslides. https://doi.org/10.1007/s10346-025-02512-z

Return to The Landslide Blog homepage Text © 2023. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

U.S. National Climate Assessment Likely Dead After Contract Canceled

Wed, 04/09/2025 - 19:26

body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news regarding law and policy changes that impact science and scientists today.

The Trump administration has canceled funding used to coordinate the National Climate Assessment, a major, congressionally mandated U.S. climate change report produced through the U.S. Global Change Research Program (USGCRP).

The National Climate Assessment is published approximately every four years and is the United States’ broadest assessment of current climate change impacts and climate science.

NASA canceled a contract with ICF International, a consulting firm. ICF International was hired by the agency to support USGRCP’s logistical work and help coordinate the expansive assessment, which involves input from 15 federal agencies and hundreds of authors and contributors.

ICF previously supported the development and release of the Fifth National Climate Assessment and the Fourth National Climate Assessment.

The change likely means the Sixth National Climate Assessment, planned for publication by early 2028, won’t be completed.

I can't say this was unexpected, but it is deeply, deeply disappointing nonetheless. The #NCA6 is now up in the air – at best.Some problems go away on their own. This is not one of them.It is coming. It's already here. You can either be prepared or unprepared.

— Cullen Hendrix (@cullenhendrix.bsky.social) 2025-04-09T16:15:43.477Z

Congress requires the Sixth National Climate Assessment to move forward, but federal officials involved in USGCRP work told Politico that the assessment is likely dead without the support of ICF International staff. Two dozen staff at the USGCRP will lose the funding to support their roles, Science reported.

The move is not a surprise to those who have been following Trump’s actions on climate change. Russell Vought, the current director of the Office of Management and Budget for the Trump administration, has previously recommended ditching the National Climate Assessment and firing scientists who worked on previous editions of the report.

The cuts come alongside other efforts from the Trump Administration to undermine climate change research including cutting funding to cooperative agreements between U.S. universities and federal agencies to study Earth systems and climate change.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2024. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Executive Order Seeks to Revive “America’s Beautiful, Clean Coal Industry”

Wed, 04/09/2025 - 14:47

President Trump signed an executive order on 8 April to drastically reduce restrictions on domestic coal production . It lays out plans to enable coal mining on federal lands, identify and revise existing regulations and policies that seek to transition the country away from coal production, and identify regions where “coal-powered infrastructure” can be used to support artificial intelligence data centers.

In a separate order, Trump said he would instruct the Justice Department to identify and fight any state and local laws “purporting to address ‘climate change’ or involving ‘environmental, social, and governance’ initiatives, ‘environmental justice,’ carbon or ‘greenhouse gas’ emissions, and funds to collect carbon penalties or carbon taxes.” Such climate policies, he said, were “putting our coal miners out of business.”

In March, the president signed a different executive order demanding immediate action to increase production of minerals in the United States. The order defined “mineral” as critical minerals, uranium, copper, potash, gold “and any other element, compound, or material as determined by the Chair of the National Energy Dominance Council (NEDC).”

The new executive order designates coal as a mineral as well. Several days before Trump signed the order, the U.S. Department of Agriculture removed regulations that protected 264,000 acres of land in Nevada from oil, gas, and geothermal energy development and 165,000 acres of land in New Mexico from mining and geothermal leasing.

According to the 2024 global carbon budget, coal is responsible for 41% of global fossil carbon dioxide emissions. Burning coal also emits sulfur dioxide, nitrogen oxides, particulates, mercury, and other heavy metals, all of which can contribute to health problems such as respiratory illness and some of which contribute to smog and acid rain.

In the United States, reliance on coal has been falling for decades as it has been replaced with other sources of electricity, primarily natural gas. Though natural gas is not a clean energy source, it produces fewer emissions than coal does, and natural gas plants are cheaper than coal plants to build and operate. Solar and wind power have also risen in popularity. In 2001, about 51% of the country’s net electricity generation came from coal. By 2023, the figure had dropped to just 16.2%.

Trump signed the executive orders while standing in front of a group of coal miners wearing hard hats, and spoke about “bringing back an industry that was abandoned, despite the fact that it was just about the best, certainly the best, in terms of power, real power.”

“I told my people ‘Never use the word “coal” unless you put “beautiful, clean” before it,’” he said. “Today, we’re taking historic action to help American workers, miners, families and consumers.”

The executive order comes in the wake of the General Services Administration closing dozens of Mine Safety and Health Administration (MSHA) offices across the country, laying off an estimated 85% of employees at the National Institute for Occupational Safety and Health, and imposing tariffs on Chinese-made ships entering U.S. ports to pick up materials, including coal.

In a 9 April statement, Cecil E. Roberts, international president of the United Mine Workers of America (UMWA), said the union appreciated the new executive order. In an earlier statement, he had called the downsizing of MSHA offices “devastating to the coal industry” and said the Trump administration owes American miners an explanation for the slew of new policies that put “a target on their back.”

The White House posted a video on X of several of the people who stood behind Trump while he signed the executive order. None were identified by name, but one was Jeff Crowe, a miner from West Virginia who also spoke briefly at the podium during the announcement of the executive order. All praised the president’s decision, as well as his new tariff policies.

President Trump signed major energy executive orders today—surrounded by REAL AMERICANS.

The fake news media's latest orchestrated attack—this time over tariffs—falls flat with coal miners, who told us: "it's actually gonna help our industry out [&] bring jobs back to America." pic.twitter.com/yQsxAJxIxm

— The White House (@WhiteHouse) April 9, 2025 These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2024. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

A 30,000-Year-Old Feather Is a First-of-Its-Kind Fossil

Wed, 04/09/2025 - 13:29

Valentina Rossi first saw the 30,000-year-old griffon vulture as a master’s student in Rome in 2014. The fossil, which had been found by a local landowner near Rome in 1889, was remarkably well-preserved. She couldn’t look away as her future collaborator, Dawid Iurino, presented about the fossilized imprint of the bird’s head.

“I was mind-blown,” Rossi said.

The presentation by Iurino, now an associate professor at Universita degli Studi di Milano Statale, ended with a discussion of the bird’s feathers. Rossi remembers him saying that determining what exactly the feather fossils were made of was a topic for future research because analyzing such well-preserved structures was outside of the expertise of the team of paleontologists at the time.

Now, a new study by Rossi, Iurino, and others, published in Geology, has finally revealed the answer: The feather fossils are made of zeolites—minerals made of aluminum and silicon compounds. This study is the first time scientists have reported soft-tissue mineralization by zeolites.

“We finally did it.”

“We finally did it,” said Rossi, lead author of the paper and a paleontologist at University College Cork in Ireland.

It’s extremely rare to find feathers preserved in three dimensions and even rarer to find mineralized feathers, Rossi said. The knowledge that the feathers were fossilized by zeolites, minerals that form naturally by reactions between volcanic rock and water, could guide paleontologists to target volcanic settings when searching for fossils.

“The more people look, the more people are going to find the preservation of materials that we previously thought was impossible,” said Mary Schweitzer, a paleontologist and emeritus professor at North Carolina State University who was not involved in the new study.

Matching Minerals

Rossi and the team of scientists used a powerful electron microscope to study the shape and texture of the preserved structures, confirming that the tissue was mineralized. Then, they analyzed the chemical structure of the fossil using multiple spectroscopy methods. “We recognized certain chemical bonds that are similar to those found in zeolites,” Rossi said.

Valentina Rossi and the research team used a variety of methods, including electron microscopy and multiple forms of spectroscopy, to determine the feather fossils were made of zeolites. Credit: Dirleane Ottonelli

Certain soft tissues lend themselves to fossilization. Muscle tissues, for example, are commonly mineralized by the calcium phosphate mineral apatite. That’s because muscle tissue already contains calcium and phosphorus, which jump-start the mineralization process.

Laboratory studies have shown that zeolites will form on biological materials in solutions of silicon and aluminum. But feathers do not contain these elements, making the zeolite fossil puzzling, Rossi said.

Schweitzer said that parts of certain molecules that make up decaying feather tissue may have an affinity for aluminum or silica but that more research would be needed to determine the exact chemistry behind the mineralization. Another explanation for the mineralization, Rossi suggested, may involve the pH of the soft tissue, especially as the tissue decays.

A Vulture’s Final Moments

The findings helped Rossi and her colleagues create a taphonomic model—a likely story line of how the bird went from a living animal to a hunk of rock. Previous studies of the whole fossil had not indicated that the bird was injured; Rossi suspects toxic gases from a nearby volcanic eruption may have killed it.

Dead but intact, the bird lay in the path of a lava flow. Rossi thinks the vulture was probably quite far from the actual eruption and may have been covered by a cooler, slow-moving volcanic flow, as its tissues weren’t destroyed by heat or turbulence.

The findings “open up another window for fossilization.”

The volcanic flow hardened and cooled with the griffon vulture beneath it. Eventually, rains soaked the rock, creating a fluid rich in minerals. The chemical composition of the bird’s feathers spurred a reaction with the silicon- and aluminum-rich fluids, and zeolites began to form and replace the tissue. The feathers turned to stone faster than they decayed.

Something similar may have happened to many more specimens over Earth’s history, which could mean that paleontologists are overlooking entire categories of rock in which highly preserved soft-tissue fossils may be found, the authors write. Volcanic settings are typically disregarded as likely spots to find fossils because volcanic flows are turbulent and hot and usually destroy soft biological material that might otherwise be fossilized. But the new paper’s results mean there are likely some exceptions.

The findings “open up another window for fossilization,” Schweitzer said.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

This news article is included in our ENGAGE resource for educators seeking science news for their classroom lessons. Browse all ENGAGE articles, and share with your fellow educators how you integrated the article into an activity in the comments section below.

Citation: van Deelen, G. (2025), A 30,000-year-old feather is a first-of-its-kind fossil, Eos, 106, https://doi.org/10.1029/2025EO250131. Published on 9 April 2024. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Salt May Be Key to Martian Mudflows

Wed, 04/09/2025 - 13:27

On Earth, mud flows because water, a major ingredient, often exists in its liquid state.

On Mars, however, the thin atmosphere causes liquid water to sublimate or freeze. This general lack of liquid makes it difficult to explain mounds that dot parts of the Red Planet—mounds that some scientists think are mud volcanoes.

A study published in Communications Earth and Environment suggests that a key to understanding how these features form is simple: add salt. By lowering the freezing point of water, salt allows mud to flow for longer periods of time and form structures that more closely resemble flows on Earth.

On Earth, mud volcanoes form when pressurized mud and gases bubble to the surface, often forming a cone with a crater. Here, one of the smaller cones of the Dashgil mud volcano in Azerbaijan erupts. Credit: Petr Brož/Wikimedia Commons, CC BY-SA 4.0

Because salt has been detected on Mars, it is likely that Martian mudflows are also salty, much like Earth’s mud volcanoes, which form when pressurized mud and gases are pushed to the surface, often forming a cone with a crater.

Terrestrial “mudflows are similar to lava flows, but they’re made of water, clay, and other materials,” explained geophysicist Ondřej Krýza of the Institute of Geophysics of the Czech Academy of Sciences and first author of the study.

In the laboratory, Krýza and his colleagues tested how different salts affect mud behavior under Mars-like conditions. They prepared separate mud samples containing magnesium sulfate, sodium chloride, sodium sulfate, or calcium sulfate. Inside the Large Mars Chamber, a mechanism poured 500 milliliters of mud onto an aluminum tray cooled to around −25°C (−5.8°F), mimicking temperatures that might be found on the Martian surface. The chamber itself simulated the planet’s low atmospheric pressure.

The experiments showed that a solution of 10% magnesium sulfate or 2.5% sodium chloride maximized mud propagation. Both salts have been identified on the Red Planet.

Exploration of Microbial Life

“The study presents a unique and fascinating approach that I have not encountered before,” Ryodo Hemmi, a planetary geologist at the Japan Aerospace Exploration Agency who was not involved in the research, said in an email.

Hemmi pointed out that though some Martian mounds resemble mud volcanoes on Earth, how they formed remains unclear. He emphasized that the new study is valuable for examining mound shapes but that more research is needed before drawing definitive conclusions. Current models, he said, don’t explain how material composition affects the size and form of Martian mounds, especially given their large scale compared to mud volcanoes on Earth.

“These salts are important because they can…affect the flow of water and other fluids, which is crucial for understanding the potential for microbial life.”

“I believe their study provides a valuable new perspective on the morphological analysis of both terrestrial and Martian mud volcanoes,” Hemmi said.

“Mud volcanoes on Earth act like natural exploration wells because they bring up sediments from many different layers beneath the surface,” explained Adriano Mazzini, a geologist at the University of Oslo in Norway and a coauthor of the study.

If the volcano-like structures on Mars are, indeed, made of salty mud, studying them could provide insights into Mars’s subsurface geology and could potentially reveal areas where liquid water once existed or may still be hidden.

“These salts are important because they can…affect the flow of water and other fluids, which is crucial for understanding the potential for microbial life,” Krýza said.

—Larissa G. Capella (@CapellaLarissa), Science Writer

Citation: Capella, L. G. (2025), Salt may be key to Martian mudflows, Eos, 106, https://doi.org/10.1029/2025EO250133. Published on 9 April 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Fast Flows in Earth’s Magnetotail Surveyed by NASA Satellites

Wed, 04/09/2025 - 12:00

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: AGU Advances

Magnetotail high-speed electron flows are found to be associated with magnetic field line reconnection in Earth’s magnetotail. They are found to be widely distributed using high-resolution data from NASA’s Magnetospheric Multiscale (MMS) mission.

As described in Liu et al. [2025], our knowledge of the electron physics of magnetic field line reconnection has been greatly enhanced by the in-situ 4-spacecraft NASA MMS measurements in a way that cannot be achieved directly in solar eruptions. A better understanding of these eruptions, both solar flares and coronal mass ejections, when and under what circumstances they occur, has important societal implications for technological systems subject to space weather.

Citation: Liu, H., Li, W., Tang, B., Norgren, C., Liu, K., Khotyaintsev, Y. V., et al. (2025). High-speed electron flows in the Earth magnetotail. AGU Advances, 6, e2024AV001549. https://doi.org/10.1029/2024AV001549

—Mary Hudson, Editor, AGU Advances

Text © 2024. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

The 27 August 2024 post-fire debris flows in San Felice a Cancello, Italy

Wed, 04/09/2025 - 10:49

Guest post by Giuseppe Esposito and Stefano Gariano

The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.

In a recent article published in the journal Landslides, Esposito and Gariano (2025) describe the first post-fire debris flow event with fatal consequences recorded in Italy.

On 27 August 2024, a large part of the Campania region in southern Italy was affected by intense rainfall associated with local storm cells forced by orography. Three watersheds affected by wildfires some weeks before responded to the rainfall with intense runoff and erosion processes supplying extremely rapid debris and hyperconcentrated flows downstream. These hit the urban settlements, causing extensive damage to the main and secondary road network, the ground and basement floors of many buildings.

Post-fire debris flow deposits in the urban centre of San Felice a Cancello. Image from the Italian Fire Brigade: www.vigilfuoco.tv

In the town of San Felice a Cancello, two people lost their lives while they were coming back home with their vehicle. The latter was dragged by the flows within the main drainage channel of the watershed for about 800 m. The two lifeless bodies were found only after long searches 2 km away from the impact point, on 2 and 12 of September 2024, respectively.

The vehicle on which the two people were travelling, found 800 m away from the impact point near San Felice a Cancello. Image from the Italian Fire Brigade: www.vigilfuoco.tv.

This event highlights an emerging cascading hazard in the whole Mediterranean area, where both burned areas and intense rain bursts are expected to increase in the future. The very short timing of hydro-geomorphic responses (e.g., 15-20 min) represents the main challenge in the implemention of an effective early warning system for small-scale, urbanised watersheds.

Incision of a channel bed created by turbulent flows at San Felice a Cancello. Image from the Italian Fire Brigade: www.vigilfuoco.tv

Esposito and Gariano (2025) found many similarities between this and previous post-fire debris flows occurred in the region (Esposito et al., 2023), even if none of them was characterized by a so severe impact on people and properties. According to their analysis, this unprecedented impact may have been due to both natural and human factors, among which the role played by the rainfall inputs is predominant (peak intensity in 30 minutes of 83.6 mm/h; peak intensity in 10 minutes of 106.8 mm/h; both highly ranked among historical events of the same duration in the area, and located well above the triggering threshold for such events previously defined in the area).

The quarry located 2 km away from the impact point where the two lifeless bodies were found near San Felice a Cancello. Image from the Italian Fire Brigade: www.vigilfuoco.tv

The current local warning system for geo-hydrological risk mitigation is based on rainfall thresholds coupled with different risk scenarios. Both this and previous events demonstrated that such system is not suitable to face this type of process, providing insufficient lead time to fully develop an effective emergency response. Therefore, they conclude that focusing on innovative monitoring and predicting tools based on meteorological, geomorphological and hydrological factors may represents a key strategy to face future challenges posed by post-fire debris flows in Italy and similar settings worldwide.

References

Esposito, G., Gariano, S. 2025. Overview of the first fatal post-fire debris flow event recorded in Italy. Landslides. https://doi.org/10.1007/s10346-025-02516-9

Esposito, G., Gariano, S., Masi, R. et al. 2023. Rainfall conditions leading to runoff-initiated post-fire debris flows in Campania Southern Italy. Geomorphology, 423, 108557. https://doi.org/10.1016/j.geomorph.2022.108557

Image credits: www.vigilfuoco.tv (Italian Fire Brigade).

Weather Alert Translations on Hold Until Further Notice

Tue, 04/08/2025 - 20:53

This month, the National Weather Service (NWS) announced that, until further notice, it will no longer be offering automated translation services for its severe weather alerts. These alerts warn U.S. residents about imminent dangers including thunderstorms, tropical cyclones, flooding, and extreme heat. The news was reported by Earth.org, The Washington Post, the Associated Press, and other outlets.

The agency attributed the change to a contract lapse with Lilt, an artificial intelligence company that worked with NWS forecasters to develop software that could accurately translate weather terminology into Spanish, simplified Chinese, Vietnamese, French, and Samoan.

The agency’s short announcement came on 1 April. Credit: NCEP/NWS

The agency’s product translation page states that the NWS “is committed to enhancing the accessibility of vital, life-saving information by making urgent weather updates available in multiple language.” However, it also notes that “changes or discontinuations may occur without advance notice.” A banner atop the page now reads, “The translated text production functionality on this site may be interrupted after 3/31/2025. Further details will be provided when available.”

According to the U.S. Census Bureau, 67.8 million people in the United States speak a language other than English at home, including nearly 42 million Spanish speakers and more than 2 million French (including Patois, Cajun, Creole, and Haitian) speakers. The Census Bureau lists communication barriers, such as those that exist in households with limited English, as a measure of social vulnerability. Previous research has documented that a lack of translated emergency alerts, or poorly translated alerts, can leave communities uninformed, confused, and ultimately more vulnerable to danger.

The NWS is part of NOAA, which has faced drastic cuts under the Trump administration. More than 1,000 employees have been laid off from the agency, though a handful have been rehired. More mass layoffs are expected as the Department of Government Efficiency eliminates thousands of federal positions.

A NOAA employee told PBS that if the contract with Lilt is not reinstated within 30 days of its 1 April expiration, restarting it will be a complex and lengthy process that involves seeking bids from several companies.

—Emily Dieckman (@emfurd.bsky.social), Associate Editor

An Atmospheric River Exacerbated Türkiye’s 2023 Earthquake Crisis

Tue, 04/08/2025 - 13:53

On 6 February 2023, a pair of powerful earthquakes—magnitudes 7.8 and 7.5—struck southern Türkiye and northwestern Syria 9 hours apart, killing 59,000 people and causing catastrophic damage.

While in the area mapping earthquake-triggered landslides the following month, Istanbul Technical University geomorphologist Tolga Görüm and his team noticed an atmospheric river approaching the disaster zone. They found this worrying, because an earthquake can weaken surrounding slopes for months and possibly years, making them vulnerable to heavy rainfall.

In a recent Communications Earth & Environment study, Görüm and colleagues documented the atmospheric river’s characteristics and how it caused flooding, landslides, and, tragically, further loss of life in the already devastated region. According to the team, the case study demonstrates a need for updated hazard models that better integrate various atmospheric and seismic hazards, particularly as climate change is expected to intensify atmospheric rivers in some regions.

A Once-in-20-Year Storm

“This was the heaviest rainfall event in the area in the last 20 years.”

For the study, the scientists analyzed global climate data from the European Centre for Medium-Range Weather Forecasts’ Reanalysis v5 (ERA5). The data revealed that the atmospheric river, originating over the Red Sea, carried more moisture than did 99.99% of all such events recorded in the region. When that moisture hit southern Türkiye’s Taurus Mountains on 14 and 15 March 2023, the resulting upward airflow along the slopes produced extreme rainfall.

“This was the heaviest rainfall event in the area in the last 20 years,” Görüm said. In the Turkish town of Tut, the storm delivered up to 183 millimeters (7.2 inches) of rain within 20 hours. In addition, warm temperatures had caused snowmelt in the mountains just before the atmospheric river arrived, leaving the soil saturated with water and further reducing its stability.

By analyzing the strength of shaking, the steepness of the terrain, and the position of the slopes, the scientists estimated that the shear strength of hillsides—the ability of soil and rock to resist sliding when subjected to a force—in the Tut region was weakened by 52%–77%.

An atmospheric river hit the town of Tut 36 days after two powerful earthquakes, initiating catastrophic landslides. Credit: Tolga Görüm

The consequences were severe. “The atmospheric river hit the area, triggered significant sediment movement, and killed more than 20 people,” Görüm said. Twelve of those deaths were within the study area. The resulting landslides, debris flows, and flooding also disrupted ongoing recovery efforts from the earthquake.

The catastrophe was the result of unfortunate timing. Using a computational model, the scientists ran simulations for earthquakes occurring in different seasons and tracked landslide probability over 5 years. They found that had the earthquakes occurred during summer or fall instead of winter, the recovery period wouldn’t have coincided with peak atmospheric river season, and the landslide hazard would have been significantly reduced.

Ben Leshchinsky, a civil engineer at Oregon State University who has studied cascading hazards but wasn’t involved in the research, said this study “highlights the importance of remembering there is a legacy to hazards. It’s incredibly important to keep following what happens so we can make sure we recover more quickly and plan for recovery in a smarter, more resilient way.”

Anticipating the Worst

Preparing for contemporaneous disasters might become increasingly relevant. Using 40 years of data, the researchers showed that Türkiye has experienced a significant increase in atmospheric river frequency and intensity, likely driven by climate change.

The landslides and flooding that followed the atmospheric river in the earthquake-struck zone damaged roads and bridges, inhibiting recovery efforts. Credit: Tolga Görüm

This trend extends beyond Türkiye to other seismically active regions worldwide. “On the Pacific coast [of the United States], the frequency and magnitude of atmospheric rivers is even higher than our area,” Görüm noted, adding that Southern California is seismically similar to Türkiye. These parallels suggest that lessons learned from Türkiye’s experience could help vulnerable communities around the globe develop more comprehensive disaster preparedness plans.

“This paper…reinforces the argument that we need to be thinking about these coincident hazards.”

Bruce Malamud, a geophysicist at Durham University who wasn’t involved in the study, noted that it can be dangerous when multiple hazards coincide, because government agencies focusing on different hazards work independently, so their disaster responses aren’t coordinated. “What’s important about this paper is that it reinforces the argument that we need to be thinking about these coincident hazards,” he said.

Having spent time in the disaster zone following the 2023 earthquakes, Görüm saw damaged cities and the struggles of response crews to rescue people; he understands more than most the need to warn communities of additional hazards. “It was like a nightmare,” he said.

It’s taxing to work in those conditions, he said, “but at the same time it’s quite important. You have to learn from this type of event.”

—Andrew Chapman (@andrewchapman.bsky.social), Science Writer

Citation: Chapman, A. (2025), An atmospheric river exacerbated Türkiye’s 2023 earthquake crisis, Eos, 106, https://doi.org/10.1029/2025EO250132. Published on 8 April 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Strange Branching of Water Flows Through Rivers and Lakes

Tue, 04/08/2025 - 12:00

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Water Resources Research

Rivers can split into branches, a phenomenon called bifurcation. Typically, the branches return again to the main river or the same floodplain after some distance downstream from the bifurcation, such as around an island, in a braided river, or in a river delta. Some bifurcations, however, are different, branching off and never returning, and seemingly defying conventions of hydrology, the science of Earth’s water and especially its movement in relation to land.

In their new article, Sowby and Siegel [2025] describe such curious bifurcations of rivers and lakes in North and South America. Some rivers diverge rather than converge; some rivers flow in two directions; some lakes have not one but two outlets; and some watersheds have strange boundaries. Some of these irregular water bodies are remote and wild while others are developed and controlled; some are streams small enough to step over and others are lakes over 100 kilometers long; and some are protected in national parks, but others are not. Their irregularities illustrate various aspects and manifestations of the complexity of Earth’s water system on land and how much we have still to learn about it.

These irregularities raise interesting questions: How should the watershed boundaries of such water bodies be defined on maps? Whose water is it before or after it bifurcates? If contaminated, who is responsible? Should flows in a bifurcated river be manually controlled, or left to nature? How can such interesting hydrological features be preserved and studied? The authors explore the natural settings and the societal uses, impacts, and management of these unusual bodies of water on land, along with the implications for our ability to quantitatively model and predict their characteristics and involved water system interactions.

Citation: Sowby, R. B., & Siegel, A. C. (2025). Unusual drainages of the Americas. Water Resources Research, 61, e2024WR039824. https://doi.org/10.1029/2024WR039824

—Georgia Destouni, Editor-in-Chief, Water Resources Research

Text © 2024. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Trump Administration Moves to Weaken PFAS Rules

Mon, 04/07/2025 - 13:56

President Donald Trump’s EPA is considering a rule that would weaken regulations that limit the use of chemicals harmful to human health in consumer goods, The Guardian reports.

Per- and poly-fluoroalkyl substances, or PFAS, are a group of chemicals added to consumer products, oftentimes for their water- and stain-resistant properties. Exposure to PFAS is known to raise the risk of certain cancers, kidney and liver disease, and complications surrounding reproductive health. The chemicals are omnipresent in everyday life and contaminate drinking water across the United States.

The EPA places regulations on PFAS and other toxic chemicals in consumer goods based on the health risks they pose.

Under a set of rules enacted by the Biden administration, if any specific use of a chemical in any consumer goods presented an “unreasonable risk” to human health, the chemical itself could be considered a risk. This regulatory framework was especially helpful to states, which can regulate chemicals categorized as an “unreasonable risk.”

The new rule submitted by the Trump administration would direct the EPA to separately evaluate the risk posed by each use of a chemical, as opposed to the chemical itself. Most individual uses of chemicals such as PFAS would not be considered a “unreasonable risks” because the chemicals are present in small amounts in most consumer goods, The Guardian reports.

“They are going to exclude a huge number of consumer products from being considered for risk management,” an EPA employee told The Guardian.

https://bsky.app/profile/ssteingraber1.bsky.social/post/3lm6swjhxms2o

The new rule could weaken state chemical regulations, including California’s Proposition 65, a highly effective law that has limited consumer exposure to harmful chemicals, including PFAS, in drinking water.

The proposed rule would take time to go into effect, however, as the EPA has limited staff to carry it out. Last month, the Trump administration announced plans to fire more than 1,000 EPA scientists and dissolve its Office of Research and Development, the arm of the agency that would traditionally be responsible for evaluating chemical limits.

The Trump administration has begun to roll back other PFAS protections, too. In January, the EPA withdrew a preexisting plan to limit manufacturers’ ability to release PFAS into wastewater.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

“Thirstwaves” Are Growing More Common Across the United States

Mon, 04/07/2025 - 13:17

Source: Earth’s Future

As the climate warms, the atmosphere is getting thirstier. Scientists define this atmospheric thirst, or evaporative demand, as the amount of water that could potentially evaporate from Earth’s surface in response to weather.

Standardized short-crop evapotranspiration (ETos) is a metric that estimates how much water would evaporate and transpire across a uniform, well-watered grass surface. It is used to measure the evaporative demand experienced by land covered by agricultural crops. Past studies have shown that ETos has increased over time in response to factors such as air temperature, solar radiation, humidity, and wind speed. But that research doesn’t cover patterns and trends over prolonged periods with exceptionally high atmospheric thirst.

Kukal and Hobbins designate a new term for these extreme ETos events: thirstwaves. A thirstwave is a period of extremely high evaporative demand that like its cousin the heat wave, can wreak havoc on a growing season. To be called a thirstwave, the ETos must be above the 90th percentile for at least 3 days.

The researchers studied ETos measurements for the contiguous United States for the 1981–2021 growing seasons, examining the intensity, duration, and frequencies of the thirstwaves they identified at the county level. They then grouped the results into nine regions.

The researchers’ analysis showed that thirstwaves occurred an average of 2.9 times throughout the growing season of April through October and had an average duration of 4 days. The longest duration was 17 days, and the greatest frequency was 20 events per season. Across the nation, the High Plains experienced the most intense thirstwaves; the South, Upper Midwest, Pacific Northwest, and West Coast experienced the longest average duration (approximately 4.5 days), and the West Coast and South experienced the highest frequency (around 3.5 events per season).

Thirstwaves have become more widespread and are affecting regions such as the Southwest, Northern Plains, and Northern Rockies, which might not have experienced them in previous decades. The likelihood that a region won’t experience a thirstwave at all during the year has also decreased. Continuing to measure and track thirstwaves will be crucial for crop and water management in the coming years, especially as the climate continues to warm, the researchers say. (Earth’s Future, https://doi.org/10.1029/2024EF004870, 2025)

—Rebecca Owen (@beccapox.bluesky.social), Science Writer

Citation: Owen, R. (2025), “Thirstwaves” are growing more common across the United States, Eos, 106, https://doi.org/10.1029/2025EO250129. Published on 7 April 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Emissions from Coal-Fired Power Plants May Lower Crop Yields in India

Wed, 04/02/2025 - 13:18

Coal-fired power plants in India—responsible for generating 73.4% of the country’s electricity—are bad for the country’s wheat. A new study shows that nitrogen dioxide (NO2) emitted from the plants can affect agricultural productivity on farms up to 100 kilometers away and reduce crop yields for wheat and rice in particular.

“Our primary finding here is that nitrogen dioxide emissions from the coal electricity generation sector are associated with meaningful crop loss in certain parts of India.”

Farms across the states of Madhya Pradesh, Uttar Pradesh, and West Bengal are especially vulnerable to NO2 emissions. Research indicated that annual crop yield losses in these states exceeded 10% over what was expected between 2011 and 2020.

“Our primary finding here is that nitrogen dioxide emissions from the coal electricity generation sector are associated with meaningful crop loss in certain parts of India,” said Kirat Singh, one of the study authors and a Ph.D. student at the Doerr School of Sustainability at Stanford University.

Making the Model

To understand the relationship between coal plant emissions and crop productivity, Singh and his fellow researchers gathered data on the presence of nitrogen dioxide from the Tropospheric Monitoring Instrument (TROPOMI) on board the European Space Agency’s Copernicus Sentinel-5 Precursor satellite. They integrated other satellite data on vegetation as well as datasets on electricity generation and weather.

The scientists were ultimately confronted with the challenge of teasing apart the source of the gas. “We built a model to determine what portion of total can be linked to emissions from coal power plants,” Singh said. The model uses changes in wind direction to try to isolate pollution that can be linked to emissions from specific sources, he explained.

The results, published in the Proceedings of the National Academy of Sciences of the United States of America, show that in certain regions heavily exposed to coal emissions, yields are more than 10% lower than they would have been in the absence of emissions from coal-fired power plants.

Agricultural Benefits for Improving Air Quality

This is a case of direct toxicity, said Jennifer Burney, a professor of environmental social sciences and Earth system science at Stanford’s Doerr School who was not involved in the study. “The plant might be taking [NO2] in through stomata or protecting itself against it by not respiring,” said Burney, who has conducted several studies assessing the impact of air pollution on agriculture.

In addition to acting as a toxin itself, nitrogen oxide is also one of the precursors of ground-level ozone, a major component of smog, according to Lisa Emberson, an environmental pollution biologist in the Department of Environment and Geography at the University of York. “Ozone is formed as sunlight drives chemical reactions between nitrogen oxides and volatile organic compounds such as methane,” she said. In her own research, Emberson has found that ozone pollution also affects the nutritional content of grains.

The study strengthens the links between air quality and India’s food security and economic progress, its authors conclude. “For Indian policymakers and regulators, these findings mean that there are potentially very substantial, and previously unaccounted-for, agricultural benefits from improving air quality through controlling emissions at coal power plants,” Singh said.

—Pragathi Ravi (@pragathi_r24), Science Writer

Citation: Ravi, P. (2025), Emissions from coal-fired power plants may lower crop yields in India, Eos, 106, https://doi.org/10.1029/2025EO250120. Published on 2 April 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Asteroid Samples Suggest a Solar System of Ancient, Salty Incubators

Wed, 04/02/2025 - 13:18

Researchers have found salts in samples from asteroid Ryugu. Combined with similar salty discoveries from asteroid Bennu, the finding suggests that aqueous incubators of life’s first ingredients may have been relatively common in the early solar system.

Astrochemists have found sugars and nucleotide bases outside of Earth before, but an extraterrestrial environment in which these ingredients could combine—and possibly create life—remained elusive. The salts lifted from the two asteroids are evidence that just such an incubator (salty liquid water) existed in the early solar system.

The results from Ryugu were reported in Nature Astronomy in November 2024, and those from Bennu were reported in January 2025. The parallel discoveries paint a compelling picture of the early solar system.

“We can now say, for the first time, that 4.5 billion years ago—long before most of us thought it could happen—we had both the ingredients and the environment in which the early stages of organic evolution towards life could begin,” said Tim McCoy, a curator of meteorites at the Smithsonian’s National Museum of Natural History who studied the Bennu samples. Such evolution “didn’t happen on a large, icy moon or a large, warm planet like Earth. It was actually happening in asteroids at the birth of the solar system. From day one of the solar system, we were seeing this organic evolution.”

Avoiding the Elements

Meteorites, typically fragments of larger space rocks, are exposed to moisture as they fall to Earth. When this happens, any water-soluble materials they may have had react and disappear. The atmosphere, McCoy said, is “actually removing some of what was there to start with.” That means meteorites themselves are not always reliable for studying whether their parent bodies contained water.

Two recent space missions sought to bring back regolith directly from asteroids. JAXA’s (Japan Aerospace Exploration Agency) Hayabusa2 visited Ryugu in 2019, returning samples in 2020. NASA’s Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) collected samples of Bennu in 2020 and returned to Earth in 2023.

“Meteorites have been studied for about 150 years. But nobody had found such kind of salts, so we are surprised.”

Most researchers think common, carbon-rich asteroids like Ryugu and Bennu, known as C-type asteroids, contain water and organic material left over from the formation of the solar system.

Toru Matsumoto, an astromaterials scientist from Kyoto University, and his colleagues found thin white veins in tiny samples from Ryugu. Using electron microscopy and radiation X-ray analysis, they identified the minerals and their chemical compositions.

The Ryugu sample showed a composition remarkably similar to that of samples from Bennu. Both asteroids contain clays, iron oxides, iron sulfides, and carbonates, suggesting they were altered by water.

The Ryugu samples also contained sodium carbonate salts. “Meteorites have been studied for about 150 years,” Matsumoto said. “But nobody had found such kind of salts, so we are surprised.”

Aqueous Evidence

Salty water provides a unique environment for the development of life. A sodium-rich solution with minimal calcium allows phosphate to stay in the solution, which is important because phosphate combined with sugar forms the backbone of RNA and DNA. Sodium-rich solutions can also catalyze chemical reactions between organics and precipitate minerals that act as templates for those reactions.

Evaporite salts such as sodium carbonate are the last minerals to precipitate out of salty water. Their presence on Ryugu suggests that “there were really large volumes of water on this asteroid, which is kind of weird, because it’s a small rock floating in space, so it’s not going to have [an] actual ocean on it,” said Prajkta Mane, a planetary scientist at the Lunar and Planetary Institute in Texas who was not involved with the research.

“These two sample sets really provide our first glimpse of a portion of the solar system that was previously poorly sampled.”

“In order to get something like these evaporites, you have to have a pocket of water that’s evaporating,” McCoy said. “I don’t think we had any proof of that before, and now we do.”

That samples from both Bennu and Ryugu contain salts suggests that watery environments were common in the outer solar system, where the asteroids’ parent bodies likely formed. “Processes that occurred on one likely occurred on many or most similar asteroids, and likely [on] icy moons,” McCoy said. The salts resemble those recently discovered on the dwarf planet Ceres and on icy moons orbiting Jupiter and Saturn, which likely host subsurface oceans.

“These two sample sets really provide our first glimpse of a portion of the solar system that was previously poorly sampled,” McCoy said.

—Molly Herring (@mollyherring.bsky.social), Science Writer

Citation: Herring, M. (2025), Asteroid samples suggest a solar system of ancient, salty incubators, Eos, 106, https://doi.org/10.1029/2025EO250122. Published on 2 April 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
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Taking Our Paleoceanographic Tools to the Next Level

Wed, 04/02/2025 - 12:00

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Paleoceanography and Paleoclimatology

Climate models predict that the Atlantic Meridional Overturning Circulation (AMOC) – a major conveyor-like system of ocean currents in the Atlantic – will weaken under global warming scenarios, causing major shifts in climate patterns. To build confidence in these projections, it is valuable to test how capable the models are at capturing past AMOC behavior.

One method used for reconstructing the strength of the AMOC over the past 100,000 years has been the measurement of the ratio of protactinium (231Pa) to thorium (230Th) isotopes preserved in seafloor sediments that have built up, layer-upon-layer, over time. Although often simplistically linked to changes in AMOC strength, the 231Pa/230Th ratio preserved in deep-sea sediments is controlled by a vast array of biogeochemical, sedimentological, and oceanographic factors.

Scheen et al. [2025] take an important step forward by modeling the behavior of these isotopes in an Earth system model of intermediate complexity that includes many of the key environmental processes affecting these isotopes. Their results largely support the traditional interpretation of some of the iconic 231Pa/230Th records, but they also reveal the sometimes-counterintuitive behavior of this proxy system, thus cautioning us to recognize its full complexity. The results are also used to suggest optimal locations for developing new 231Pa/230Th reconstructions. The model presented by the authors should not be treated as the final word, since – necessarily – it is still a simplified representation of a very complex system, yet they are to be commended for advancing our interpretation of a proxy system oft viewed as a key tool for constraining past AMOC behavior.

Citation: Scheen, J., Lippold, J., Pöppelmeier, F., Süfke, F., & Stocker, T. F. (2025). Promising regions for detecting the overturning circulation in Atlantic 231Pa/230Th: A model-data comparison. Paleoceanography and Paleoclimatology, 40, e2024PA004869. https://doi.org/10.1029/2024PA004869

—David Thornalley, Associate Editor, Paleoceanography and Paleoclimatology

Text © 2024. The authors. CC BY-NC-ND 3.0
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Fatal landslides in March 2025

Wed, 04/02/2025 - 07:05

The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.

In March 2025, I recorded 37 fatal landslides globally (excluding those triggered by earthquakes), costing 90 lives. The 2004-2016 average number of fatal landslides in March reported by Froude and Petley (2018) was 28.3 landslides, so 2025 is running considerably above the long term mean. However, it is lower that the total recorded for 2024 (49 landslides).

As usual, the best way to present the data is using pentads – five day blocks. Pentad 18 extends to the end of March. This is the cumulative total number of fatal landslides for 2025, with the 2004-2016 average and 2024 plotted for comparison:-

The cumulative total number of fatal landslides for 2025 by pentad, with 2024 and 2004-2016 for comparison. Author’s own data, published under a CC licence.

As the data shows, towards the end of the winter, 2025 was plotting above 2024. However, this has now changed, although the difference is small. 2024 was characterised by a marked increase around at pentad 23 (which starts on 21 April), reflecting the start of the rainy season in the key parts of the Northern Hemisphere, so April 2025 will be very interesting. In general, this acceleration in landslide rate does not start until about pentad 30 (which starts on 26 May).

I also recorded one fatal landslide triggered by an earthquake, which occurred in Hutabarat village, North Sumatra, Indonesia, triggered by a M = 5.6 earthquake. Two people were killed. An unknown number of people may also have been killed by landslides in the earthquake and its aftershocks in Myanmar, but this is very uncertain.

Particularly notable in March 2025 has been a series of landslides, alongside flooding, in Ecuador. This has had a high social cost.

As always, I am happy for others to use this fatal landslide data and the figure, but please attribute to me and cite Froude and Petley (2018). Contact me if you want the data for 2004-2016.

Reference

Froude M.J. and Petley D.N. 2018. Global fatal landslide occurrence from 2004 to 2016. Natural Hazards and Earth System Science 18, 2161-2181. https://doi.org/10.5194/nhess-18-2161-2018

1,900 Scientists Warn Of “Real Danger” In Open Letter

Tue, 04/01/2025 - 19:03

In an open letter to the American people, more than 1,900 scientists sent an “SOS” that the Trump administration’s actions have “decimated” the nation’s scientific enterprise and censored scientific work. “We see real danger in this moment,” the scientists wrote.

Each of the scientists who signed the letter is an elected member of the National Academies of Sciences, Engineering, and Medicine, a congressionally chartered group of nonprofit organizations that provide expertise to the federal government and the public on scientific and technological issues. The letter stated that the signatories hold a range of political beliefs. Signatories represent a range of scientific disciplines, from cell biology to planetary science to economics.

The letter emphasized the need for U.S. scientists to retain their independence and ability to explore scientific questions without the influence of special interests or the limitations of censorship—that ability is now in question due to the administration’s cuts to scientific funding, firings of scientists, removals of public data, and pressure for researchers to abandon certain work.

The Trump administration is “using executive orders and financial threats to manipulate which studies are funded or published, how results are reported, and which data and research findings the public can access. The administration is blocking research on topics it finds objectionable, such as climate change, or that yield results it does not like, on topics ranging from vaccine safety to economic trends,” the letter stated.

Letter from more than 1,900 scientists Download

“We have spent 80 years in this country building up our scientific infrastructure,” Steven Woolf, an author of the letter and professor of family medicine at the Virginia Commonwealth University School of Medicine told PBS. “That’s enabled our country to make remarkable scientific discoveries that have made the United States the envy of the world. In a matter of weeks, the Trump administration has pursued a set of policies that are basically removing the capacity of our country to do this kind of research.”

Woolf also said he was concerned that the attacks on U.S. science, and in particular, cuts to health research and vaccine regulatory work, would affect the health and life expectancy of U.S. residents.

Scientists who haven’t been directly impacted by funding cuts or firings are still facing a “climate of fear,” Woolf said. In the letter, he and other signatories wrote that the Trump administration’s current investigations of more than 50 universities as part of an anti-DEI effort send a “chilling message” to scientists that their research is in danger of being censored on ideological grounds.

Firings of scientists have continued since the letter’s release: Today, the Department of Health and Human Services began sending notices of termination after announcing a plan to cut 10,000 employees from the agency. Federal scientists at other agencies such as NASA, USGS, NOAA, and the EPA have begun similar terminations, though federal judges have ordered some of these firings to be reversed.

“We all benefit from science, and we all stand to lose if the nation’s research enterprise is destroyed,” the letter stated.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

The Rivers That Science Says Shouldn’t Exist

Tue, 04/01/2025 - 13:01

Source: Water Resources Research

Rivers join downstream, flow downhill, and eventually meet an ocean or terminal lake: These are fundamental rules of how waterways and basins are supposed to work. But rules are made to be broken. Sowby and Siegel lay out nine rivers and lakes in the Americas that defy hydrologic expectations.

All exhibit instances of bifurcation, in which a river splits into branches that continue downstream. But unlike typical bifurcations, these examples do not return to the main waterway after branching off.

South America’s Casiquiare River, for example, is a navigable waterway that connects the continent’s two largest watersheds, the Orinoco and Amazon basins, by acting as a distributary of the former and a tributary of the latter. It’s “the hydrologic equivalent of a wormhole between two galaxies,” the authors write. The Casiquiare splits from the Orinoco River and meanders through lush, nearly flat rainforests to join the Rio Negro and, ultimately, the Amazon River. The study’s authors point out that the slight slope (less than 0.009%) is enough to send large volumes of water down the river and that this unusual instance results from an incomplete river capture. They note that understanding of the Casiquiare is still evolving.

Dutch colonists first mapped the remote Wayambo River in Suriname in 1717. This river can flow either east or west, depending on rainfall and human modifications of flow using locks. It is also near gold and bauxite mining as well as oil production sites, and its two-way flow makes predicting the spread of pollutants difficult.

Of all the rivers they reviewed, the researchers described the Echimamish River, high in the Canadian wilderness, as the “most baffling.” Its name means “water that flows both ways” in Cree. The river connects the Hayes River and the Nelson River, and by some accounts, the Echimamish flows outward from its middle toward both larger rivers. However, its course is flat and punctuated by beaver dams, leading to uncertainty, even today, about the direction of its flow and exactly where the direction shifts.

The authors also explored six other strange waterways, including lakes with two outlets and creeks that drain to both the Atlantic and Pacific oceans. In doing so, they highlighted how much there is still to learn about how our world’s waters work. (Water Resources Research, https://doi.org/10.1029/2024WR039824, 2025)

—Rebecca Dzombak, Science Writer

Citation: Dzombak, R. (2025), The rivers that science says shouldn’t exist, Eos, 106, https://doi.org/10.1029/2025EO250123. Published on 1 April 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Impact Spewed Debris Away from the Moon’s South Pole

Tue, 04/01/2025 - 13:00

About 3.81 billion years ago, a giant impactor rocked the Moon’s south pole. It formed the Schrödinger impact basin, which remains clearly visible today.

Astronomers recently found that two extremely deep and long valleys extending away from the crater were formed rapidly by pieces of rock flung outward during the impact.

The debris carved valleys “as big as the Grand Canyon on Earth. But instead of being formed during millions of years, they were formed within 10 minutes.”

“They reimpact the surface—boom, boom, boom, boom—and they form this line of individual craters,” said Danielle Kallenborn, a planetary scientist at Imperial College London and a coauthor of a study outlining the results published in Nature Communications. The debris carved valleys “as big as the Grand Canyon on Earth,” Kallenborn said. “But instead of being formed during millions of years, they were formed within 10 minutes.”

The debris pattern spreads away from sites where NASA’s Artemis mission plans to explore, suggesting that any samples collected there would be less likely to be from the impactor and more likely to be from the Moon itself.

Grand Canyons

The lunar south pole is dominated by the 4.3-billion-year-old South Pole–Aitken basin, among the largest impact craters in the solar system at 2,500 kilometers across. At its edge sits the smaller but still impressive Schrödinger basin, measuring 320 kilometers wide.

The two clearly visible valleys, Vallis Schrödinger and Vallis Planck, extend away from the northwestern edge of the Schrödinger basin. Each appears to be composed of a chain of so-called secondary craters—the result of rocks being thrown from the crater when the main impactor struck. Kallenborn and her colleagues identified 15 secondary craters in Vallis Schrödinger and slightly more in Vallis Planck.

The valleys are 270–280 kilometers long and 2.7–3.5 kilometers deep—about half the length of the Grand Canyon and twice as deep.

A wall of Vallis Planck appears to have partially collapsed following the valley’s formation, whereas Vallis Schrödinger has remained more intact. “The impact events generated rather steep-walled canyons,” said David Kring, a planetary scientist at the Lunar and Planetary Institute in Texas and a study coauthor. “In the case of Vallis Planck, the walls were unable to stay standing.”

“You could look and see them flying through the air.”

In modeling debris patterns from the impact, the researchers estimated the ejecta would have reached speeds of 3,420–4,610 kilometers per hour as the shock wave from the initial impact, millions of times more powerful than the atomic bomb dropped on Hiroshima, expanded outward.

On the bases of the distances of individual craters in each valley from the center of Schrödinger Crater, the team calculated that the pieces of debris took 5–15 minutes to reach their impact sites. “It is quite fast,” Kallenborn said. “You could look and see them flying through the air.”

Kelsi Singer, a planetary scientist at the Southwest Research Institute in Colorado who was not involved in the research, said secondary crater chains like this exist elsewhere in the solar system. One example is Falsaron Crater on Saturn’s moon Iapetus, which has two clear lines extending away from it. “They’re pretty similar,” she said.

Why an impact would produce a straight line of secondary impact craters is unclear, however.

Impactor Angle

The orientation of the two valleys suggests the impactor was headed north-northwest at an angle of less than 45° from the surface when it struck, according to the authors. The majority of secondary debris, including the rocks that formed the valleys, would therefore have been directed away from the Moon’s south pole.

NASA plans to land astronauts back on the Moon this decade, targeting regions south of Schrödinger. “Most of the ejecta was ejected north, which is away from the Artemis exploration zone,” Kallenborn said. “That’s good news” because any rocks collected are more likely to be older lunar rocks, perhaps even fragments of the Moon’s original crust, rather than pieces of the more recent impactor.

The Schrödinger basin was formed relatively late in the evolution of the early solar system. Scientists are more eager to examine rocks that took shape closer to the Moon’s formation 4.5 billion years ago and that might be present in the planned landing zones for Artemis missions.

“They’re more interested in sampling this [early material],” Kallenborn said. “It tells you more about the very early times of the Earth-Moon formation impact event and so on.”

However, there is still interest in sampling the Schrödinger ejecta too. It is “one of the last great basin-forming impact events that shaped the Moon,” Kring said, so examining a sample of it back on Earth could help us more precisely date the impact. “We still debate the magnitude and duration of that period of early solar system bombardment.”

—Jonathan O’Callaghan (@astrojonny.bsky.social), Science Writer

Citation: O’Callaghan, J. (2025), Impact spewed debris away from the Moon’s south pole, Eos, 106, https://doi.org/10.1029/2025EO250121. Published on 1 April 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Come on Feel the Noise: Machine Learning for Seismic-Wind Mapping on Mars

Tue, 04/01/2025 - 12:00

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Journal of Geophysical Research: Planets

Despite providing critical insights into atmospheric dynamics and weather patterns, wind observations on the surface of Mars remain relatively rare. The Temperature and Wind for InSight (TWINS) instrument onboard NASA’s Insight mission was designed to measure wind speed and direction winds. However, due to power constraints caused by increasing dust accumulation on InSight’s solar panels, TWINS primarily operated during the first 750 Martian days (sols) of the mission. In contrast, the Seismic Experiment for Interior Structure (SEIS) instrument operated almost continuously until the mission’s final transmission on Martian day 1440.

Since winds are the dominant source of energy in the seismic data, Stott et al. [2025] developed a machine learning model, WindSightNet, to map seismic data to wind speed and direction, nearly doubling the coverage of TWINS. The authors find an overall good agreement between both datasets during the first 750 sols, increasing confidence in WindSightNet data for the remaining Martian Days. Using this validated dataset, the authors analyze the interannual (one year on Mars is 669 sols) variability of wind speed and direction, as well as large-scale weather patterns and the height of the lower atmosphere throughout the Insight mission.

This dataset delivers a precious long-term and continuous record of Martian winds for the atmospheric community to refine their atmospheric models and better understand how dust is lifted on Mars. While the approach by the authors cannot capture the fastest wind variations or highest wind speeds recorded by TWINS due to a lower sampling rate, nor accurately predict wind speeds near 0 meters per second due to SEIS’s noise level, this study opens new possibilities for planetary instrumentation.

Citation : Stott, A. E., Garcia, R. F., Murdoch, N., Mimoun, D., Drilleau, M., Newman, C., et al. (2025). WindSightNet: The inter-annual variability of martian winds retrieved from InSight’s seismic data with machine learning. Journal of Geophysical Research: Planets, 130, e2024JE008695. https://doi.org/10.1029/2024JE008695

—Germán Martínez, Associate Editor; and Beatriz Sánchez-Cano, Editor, JGR: Planets

Text © 2024. The authors. CC BY-NC-ND 3.0
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