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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.”

 
Related

•  US Weather Service Set to Halt Foreign-Language Forecasts As Contract With AI Translation Firm Expires (Earth.org)
•  National Weather Service pauses severe weather alerts in Spanish and other languages (PBS)
•  National Weather Service halts automated translation for alerts (The Washington Post)
• Language Use in the United States (U.S. Census Bureau)
•  Get Involved: AGU Science Policy Action Center
 

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

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.

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.

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.

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.

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.

 
Related

•  Trump Officials Quietly Move to Reverse Bans on Toxic ‘Forever Chemicals’
•  Trump’s EPA Moves to Loosen Chemical Rules
•  How Deregulation Fuels the Spread of Forever Chemicals
•  Get Involved: AGU Science Policy Action Center
 

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

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.

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.

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.

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
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

Return to The Landslide Blog homepage Text © 2023. The authors. CC BY-NC-ND 3.0
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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.

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 scientistsDownload

“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.”

 
Related

•  Get Involved: AGU Science Policy Action Center
•  More Than 1,900 Scientists Write Letter in ‘SOS’ Over Trump’s Attacks on Science
•  Scientists Sound the Alarm on Trump’s Dismantling of Research Funding
•  Over 50 Universities Are Under Investigation as Part of Trump’s Anti-DEI Crackdown
 

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

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.

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.

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.

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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Editors’ Vox is a blog from AGU’s Publications Department.

Geophysics is a powerful tool for understanding how our planet works. It enables us to connect complex real-world phenomena with fundamental physical laws, deduce the nature of otherwise inaccessible regions of the Earth, frame natural processes and events in terms of cause and effect, and mathematically model and predict the future behavior of components of the Earth.

Earth System geophysics recognizes the critical importance of interactions between the components of the Earth System—the solid earth, oceans, atmosphere, and even the biosphere—in achieving that understanding. An Earth System perspective also recognizes convection as a universal process and a unifying theme for studying the Earth.

A new book in AGU’s Advanced Textbook Series, Earth System Geophysics, helps upper-level students learn how to apply math and physics to understand the operation of the Earth System. Here, we asked the book’s author to explain how an Earth Systems approach bolsters the study of geophysics and how to make these topics engaging and accessible to students.

Why take an Earth Systems approach to studying geophysics?

There was a time when geophysics was mainly devoted to the study of the ‘solid earth’—the crust we stand on and the mantle and core below. With that focus, it made sense to treat plate tectonics as the unifying theme. But why limit our view to the solid earth? The oceans and atmosphere also behave geophysically and are ultimately driven by the same kind of process—convection—behind plate tectonics. Furthermore, studying the solid earth alone would be incomplete if interactions with the rest of the Earth System were ignored.

Idealized conception of mantle convection, including descending lithospheric slabs, upwelling plumes, and broad background flow. These components of mantle convection can interact with the core, oceans, atmosphere, and biosphere in different ways. Credit: Jellinek and Manga [2004], Figure 17

How did you come up with the idea for the Earth System Geophysics textbook?

When I first started teaching at SUNY-Binghamton, I was given free rein to teach the ‘rest’ of geophysics, in other words, anything non-seismological. My research has always been ‘global’—involving the various ways Earth’s rotation can be affected by plate motions, ocean tides, and the oceans’ response to atmospheric pressure variations—so it seemed natural to take a global approach in teaching. And, that global approach apparently increased students’ interest (even to the point where they didn’t mind complex math being introduced)! However, I could find no existing geophysics textbook with an Earth System Science approach at the level I wanted to teach this material.

How is the textbook organized?

The textbook comprises two parts: (I) An Earth System Science Framework and (II) A Planet Driven by Convection. The first part includes chapters on Earth’s origin, the evolution of its atmosphere, and the climate system. The second part covers gravity, seismology, heat flow, and geomagnetism, with frequent application to the Earth System.

How could instructors use this textbook in their teaching, and who is the intended audience?

The textbook is fairly lengthy—an unavoidable consequence of trying to explain how the Earth works! Instructors using the entire book to teach about geophysics in the Earth System should plan on a two-semester course. However, as outlined in the textbook’s preface, combinations of different portions of the book can serve as the basis for a variety of one-semester courses, including traditional solid-earth geophysics, climate change, and seminar classes exploring geophysical research.

This book’s primary audience is geology students at the senior undergraduate or beginning graduate level, whose exposure to basic physical geology has been supplemented by at least one semester each of calculus and college physics but who may be somewhat unconfident about using math and physics to understand the Earth. Undergraduate and graduate students majoring in geophysics, physics, and engineering, as well as students working toward a master’s in Earth science teaching, can benefit from this textbook too.

How does your textbook make geophysics accessible to students?

Geophysics is intrinsically a mathematically intensive field, and—on several levels—many students find that daunting. My textbook introduces mathematical concepts gently and builds gradually; where possible, qualitative interpretations are also presented. 

For example, the concept of gradient is first discussed qualitatively in early chapters. Then, it is expressed mathematically using simple calculus. The relevant mathematical and qualitative concepts build throughout the book, until (in the final two chapters) students are able to fully appreciate and employ the gradient as a three-dimensional vector.

What special features appear in your textbook?

Perhaps my most notable feature is the use of ‘stop and think’ questions—moments where I pause the narrative and directly address the reader, in effect encouraging the reader to connect the subject being discussed with previous material (or, sometimes, to anticipate impending material). Additionally, I use specific formatting to highlight definitions of essential terms, explanations of key concepts, and important formulas and equations. Also, a companion website includes homework exercises for each chapter and brief guidance for instructors on the mathematical level of each chapter.

Another feature I’m very proud of is the extensive reference list and abundant in-text citations. In an era when the honesty and validity of science are repeatedly questioned, those citations emphasize that science is not just a story created out of thin air to make some conclusion believable; it is a synthesis of independent results obtained by a great number of peer-reviewed researchers.

Finally, numerous color figures throughout enhance what is already interesting subject matter.

Earth System Geophysics, 2024. ISBN: 978-1-119-62797-5. List price: $169.95 (hardcover), $136 (e-book).

The preface is freely available. Visit the book’s page on Wiley.com and click on “Read an Excerpt” below the cover image.

Editor’s Note: It is the policy of AGU Publications to invite the authors or editors of newly published books to write a summary for Eos Editors’ Vox.

—Steven R. Dickman (dickman@binghamton.edu, 0000-0001-5909-453X), Binghamton University, United States

Citation: Dickman, S. R. (2025), An Earth System Science approach to geophysics, Eos, 106, https://doi.org/10.1029/2025EO255013. Published on 1 April 2025. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). 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 Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.

Back in February I highlighted a Sixth Tone article about the extraordinary landslide cluster that was triggered by Typhoon Gaemi in Hunan Province in China between 26 and 28 July 2024. A paper (Zhao et al. 2025) has now been published in the journal Landslides that provides a more detailed documentation of the event.

As a reminder, this is a Planet satellite image of the aftermath of Typhoon Gaemi in Zixing County, the worst affected area:-

A part of the area of Zixing in Hunan Province after being impacted by the July 2024 rainstorm. Image copyright Planet, used with permission, collected on 5 August 2024.

Zhao et al. (2025) have recorded 19,764 landslides from this single event, an extraordinary number. It is worth looking in a little more detail at the density of landslides in this area. The marker in the centre of this image is located at [23.13507, 95.78573]:-

A part of the area of Zixing in Hunan Province after being impacted by the July 2024 rainstorm. Image copyright Planet, used with permission, collected on 20 March 2025.

Zhao et al. (2025) note that 128,000 people were affected, with 1,714 houses being destroyed and 65 people killed.

A key issue in an event such as this is the rainfall conditions that can cause such an impact. During Typhoon Gaemi, Zixing County averaged 412.7 mm of rainfall, but one weather station recorded 673.9 mm. The maximum 24 hour rainfall was 642.5 mm; the previous record 24 hour rainfall in Hunan Province was 365.4 mm. Thus, this event broke the record to an extraordinary degree. In a landscape with many slopes, multiple landslides were inevitable. I would however be very interested in the peak hourly rainfall, which is likely to have been a key factor, if this data is available.

The failures were mostly small, shallow landslides. The landslide rate was higher in areas in which there had been excavation of the slope for roads or houses.

These types of intense landslide clusters are not in any way unprecedented, but the number of events globally in 2024 was unusually high. This is driven by extreme rainfall associated with the exceptionally high atmospheric temperatures last year.

It is a sign of what is to come in the years ahead.

Reference

Zhao, J., Feng, W., Yi, X. et al. 2025. Clustered shallow landslides caused by extreme typhoon rainstorms in Zixing County, Hunan Province, China, from July 26 to 28, 2024. Landslides. https://doi.org/10.1007/s10346-025-02508-9

Planet Team. 2025. Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/

Return to The Landslide Blog homepage Text © 2023. The authors. CC BY-NC-ND 3.0
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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.

In late February, delegates from more than 190 countries met in Hangzhou, China to make preliminary decisions about the timing and content of the seventh assessment report from the Intergovernmental Panel on Climate Change (IPCC). The Trump administration barred U.S. delegates from attending the February meeting, one step among many the president has taken to abandon America’s global leadership on climate change.

The IPCC is a United Nations body that reviews the science behind climate change. Since 1990, the group has produced assessment reports that evaluate the latest developments in climate science, impacts, adaptation, and mitigation. The reports also assess whether counties are doing enough to combat the climate crisis (spoiler: not nearly enough) and play an important role in influencing climate policy around the world. Those reports depend on the contributions of scientific experts nominated by IPCC member countries and Observer Organizations.

 
Resources

•  Get Involved: U.S. Academic Alliance for the IPCC (USAA-IPCC)
•  New US Academic Alliance for the IPCC opens critical nomination access (AGU)
•  Scientists Form Academic Alliance to Support U.S. Climate Researchers (Rutgers)
 

To supplement nominations by the federal government, the U.S. Academic Alliance for the IPCC (USAA-IPCC) is facilitating nominations to the seventh assessment cycle for the IPCC. The alliance is a network of U.S. universities that are registered observers with the IPCC and is hosted by AGU, which publishes Eos. U.S. researchers can submit materials to self-nominate as experts, authors, and review editors for the next IPCC assessment report.

“This new alliance will help the U.S. maintain a preeminent position in global science-policy assessments,” Pamela McElwee, professor of human ecology at Rutgers University and chair of the USAA-IPCC steering committee, said in a statement. “The benefits to U.S. researchers from involvement in the IPCC are tremendous, and we want to ensure that our scientists continue to play an important leadership role internationally.”

Nominations are open through Friday, 4 April. U.S.-based experts in climate research or practice who are U.S. citizens are eligible. Learn more about the nomination process here and at the video below:

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

Correction 1 April 2025: An earlier version of this article mistakenly listed AGU as an IPCC Official Observer and has been edited to clarify.

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
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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 Mine Safety and Health Administration (MSHA), which works to protect U.S. miners from injury, illness, and death on the job, is among the latest federal agencies targeted for cuts by the Department of Government Efficiency (DOGE).

In collaboration with the General Services Administration, or GSA, DOGE has begun terminating leases for hundreds of offices and buildings for groups such as NOAA, the Natural Resources Conservation Service, geological surveys in several states, and the National Park Service. According to coverage by the Pittsburgh Post-Gazette, Grist, and others, the list includes at least 34 centers run by MSHA, which conduct regular inspections of quarries and mines to ensure worker safety.

It is unclear whether the lease terminations will involve layoffs or relocating workers to other MSHA office locations.

Related

•  DOGE lease cancellations list (AP)
•  DOGE cuts put region’s miners and families on edge (Pittsburgh Post Gazette)
•  Trump brings back a first-term mine safety official to lead MSHA (WKMS)
•  Trump administration moves to shutter mine safety offices in coal country (Grist)
•  Get Involved: AGU Science Policy Action Center
 

When MSHA first began operation under the Mine Act of 1977, 242 U.S. miners died in mining accidents. In 2025, there were 31, according to the MSHA website.

Federal regulators at MSHA also created a rule, set to take effect in April, which cuts in half the amount of silica allowed in air, in an effort to reduce a new form of black lung disease.

Wayne Palmer, tapped by President Trump to be the next leader of MSHA and who held the position during Trump’s first term, recently served as an executive at the Essential Minerals Association, which filed a legal brief challenging the new rule.

In a statement provided to several news outlets, a GSA spokesperson said: “A component of our space consolidation plan will be the termination of many soft term leases. To the extent these terminations affect public facing facilities and/or existing tenants, we are working with our agency partners to secure suitable alternative space.”

In a statement, United Mine Workers of America International President Cecil E. Roberts said the organization was “troubled” by the news. To keep workers safe, she added, both unions representing workers’ best interests and government agencies enforcing laws are necessary.

In their absence, “workers’ safety will be left solely in the hands of employers. History has shown us time and time again that doing so is a recipe for disaster, especially in the mining industry.”

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

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
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This is an authorized translation of an Eos article. Esta es una traducción al español autorizada de un artículo de Eos.

Los cinturones polvorientos de escombros provenientes del nacimiento de estrellas son extensos y dinámicos, alimentados por colisiones frecuentes entre exocometas y agitados por la gravedad de planetas cercanos, según un estudio reciente publicado en Astronomy & Astrophysics. Los hallazgos ofrecen nuevas perspectivas sobre el proceso de formación planetaria.

Estos cinturones son análogos al Cinturón de Kuiper del sistema solar, una zona con forma de rosquilla más allá de la órbita de Neptuno que alberga cientos de millones de cuerpos helados. Los cinturones de exocometas analizados en el nuevo estudio presentan una amplia variedad de características, incluyendo diferencias en anchura, masa y brillo. Según los autores, estos cinturones probablemente fueron esculpidos por exoplanetas aún no detectados.

“Lo que encuentro más emocionante es que este estudio demuestra, una vez más, que los planetas están en todas partes. Incluso si no podemos verlos directamente, detectamos sus huellas en estos discos”.

“Encontramos que cada cinturón es único, por lo que cada sistema planetario es diferente”, dijo el miembro del estudio, Steve Ertel, un astrónomo del Observatorio Steward y científico principal del Observatorio del Gran Telescopio Binocular, ambos en la Universidad de Arizona. “Pero lo que encuentro más emocionante es que este estudio demuestra, una vez más, que los planetas están en todas partes. Incluso si no podemos verlos directamente, detectamos sus huellas en estos discos.”

Investigadores del proyecto REASONS (Observaciones resueltas de ALMA y SMA de estrellas cercanas) produjeron imágenes de alta resolución de los sistemas de cinturones alrededor de 74 estrellas situadas a aproximadamente 500 años luz de la Tierra, constituyendo la muestra más grande hasta la fecha.

El equipo realizó nuevas observaciones de algunos de estos sistemas utilizando el Gran Conjunto Milimétrico/submilimétrico de Atacama (ALMA) en Chile y el Conjunto submilimétrico (SMA) en Hawái, los cuales son instrumentos sensibles al resplandor del polvo y los pequeños guijarros que conforman los cinturones. Los investigadores combinaron estos resultados con observaciones previas de otros sistemas realizadas con ALMA para completar el conjunto de muestras.

Los investigadores utilizaron el Atacama Large Millimeter/submillimeter Array (ALMA) en Chile (en la imagen), junto con el Submillimeter Array (SMA) en Hawái, para observar los cinturones de exocometas. Crédito: ESO/B. Tafreshi (twanight.org) Fragmentación de exocometas

Los cinturones se encuentran a distancias de entre 10 y 100 unidades astronómicas (1 UA equivale a la distancia promedio de la Tierra al Sol) de sus estrellas centrales, una escala comparable a las 30 UA que separan al Sol del borde interno del Cinturón de Kuiper. Estos cinturones se forman a partir de objetos de hasta aproximadamente 1 kilómetro de diámetro, similares a los cuerpos del Cinturón de Kuiper y a los cometas que ocasionalmente visitan el sistema solar interior, razón por la cual se les denomina “exocometas”.

Dichos cuerpos podrían ser restos de los bloques a partir de los cualesnacieron planetas y lunas. En el caso del Cinturón de Kuiper, muchos fueron lanzados lejos del Sol por la gravedad de esos planetas recién formados.

“En las regiones donde observamos estos anillos fríos, se cree que los cuerpos están compuestos por grandes cantidades de hielo, además de material rocoso o polvo”, explicó Ertel. “Cuando estos cuerpos colisionan, se fragmentan en piezas cada vez más pequeñas, y eso es lo que observamos como polvo”.

Este polvo proporciona “perspectivas importantes sobre los sistemas planetarios subyacentes”, señaló Ertel, ya que, al igual que en el Cinturón de Kuiper y el cinturón de asteroides de nuestro propio sistema solar, las propiedades de estos cinturones están estrechamente relacionadas con las órbitas y masas de los planetas.

Los cinturones de exocometas estudiados por REASONS pueden parecerse al Cinturón de Kuiper de nuestro propio sistema solar, como se muestra en este concepto artístico. Crédito: ESO/M. Kornmesser

Algunos sistemas presentan más de un anillo o banda, sugiriendo la posible presencia de múltiples planetas, mientras que el grosor de ciertos anillos indica que podrían contener cuerpos con diámetros de entre aproximadamente 140 kilómetros y el tamaño de la Luna (cuyo diámetro es de unos 3,500 kilómetros). Aunque estos cuerpos son demasiado pequeños para ser detectados en las observaciones de REASONS, su influencia en la dinámica interna de los anillos es significativa.

“La principal sorpresa probablemente fue el hecho de que los cinturones anchos parecen ser más comunes que los anillos estrechos”, mencionó Luca Matrà, físico del Trinity College de Dublín y autor principal del estudio. “Muchos de nosotros apreciamos la imagen del hermoso anillo de Fomalhaut, probablemente el cinturón de exocometas más famoso. Sin embargo, nos sorprendió mucho descubrir que estos anillos son raros”.

Según Matrà, varios factores pueden influir en la forma y el tamaño de los anillos, incluidos los choques entre objetos dentro de los cinturones, las condiciones iniciales en las que se formaron y las interacciones entre el material de los cinturones y los planetas cercanos, posiblemente como resultado de migraciones planetarias.

Las condiciones iniciales incluyen la cantidad de material disponible para formar los cinturones, la luminosidad de la estrella y el entorno estelar circundante. Una estrella más brillante y caliente debería evaporar hielos a mayores distancias dentro del disco de material a partir del cual se forman los bloques de construcción planetarios, conocidos como planetesimales. Una mayor cantidad de material en el disco primordial podría dispersarse más y protegerse mejor de la radiación estelar, evitando la pérdida de polvo hacia el espacio interestelar. En contraste, si una estrella se formó en un cúmulo compacto, las interacciones con otras estrellas podrían haber limitado el crecimiento de los discos formadores de planetas.

Provocando un poco de entusiasmo

Las migraciones planetarias, en las que las interacciones gravitacionales hacen que los planetas se desplacen hacia o lejos de su estrella, podrían provocar que los objetos se agiten en anillos estrechos, los cuales son comunes en sistemas estelares jóvenes donde se están formando nuevos planetas, como pedacitos de hielo en una licuadora. Este movimiento de agitación podría hacer que los anillos se expandan hasta formar los cinturones más anchos que se observan en la actualidad.

“Hubo mucha actividad en el sistema solar temprano, y ahora estamos viendo que ocurren cosas similares en otros lugares. Me parece realmente fascinante”.

“En nuestro propio sistema solar, es probable que Urano y Neptuno no estuvieran originalmente tan lejos del Sol como lo están hoy, sino que fueron empujados hacia el exterior por Júpiter y Saturno”, explicó Sharon Montgomery, profesora de física en la Pennsylvania Western University en Clarion, quien no participó en el nuevo estudio. “Eventualmente, Neptuno provocó todo tipo de agitaciones en el Cinturón de Kuiper. Así que hubo mucha actividad en el sistema solar temprano, y ahora estamos viendo que ocurren procesos similares en otros lugares. Me parece realmente fascinante”.

El nuevo estudio también indica que las estructuras de polvo pierden tanto masa como superficie a medida que envejecen, y que los anillos y cinturones más pequeños se desgastan más rápidamente que los más amplios. Según los investigadores, ambos hallazgos concuerdan con los modelos de formación planetaria y evolución de discos.

Matrà señaló que el equipo ampliará su investigación mediante un estudio más detallado de algunos de los objetivos del proyecto REASONS. “Tomamos 18 de estos cinturones y llevamos al límite la resolución de ALMA, utilizando la máxima resolución posible para abordar nuevas preguntas cruciales”, afirmó Matrà. Las respuestas deberían proporcionar una comprensión aún más profunda de estas intrigantes bandas de exocometas.

—Damond Benningfield, Escritor de ciencia

This translation by Saúl A. Villafañe-Barajas (@villafanne) was made possible by a partnership with Planeteando and GeoLatinas. Esta traducción fue posible gracias a una asociación con Planeteando y GeoLatinas.

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.

In mid-January, a team of scientists were sailing aboard a research vessel in frigid Antarctic waters. They planned to investigate an unexplored section of the Bellingshausen Sea and the creatures that live there, but were stymied by more sea ice than they expected.

“We found ourselves restricted to a smaller area,” said Patricia Esquete, a marine biologist at the Universidade de Aveiro in Portugal and expedition co–chief scientist. “Instead of Bellingshausen Sea, we were restricted to the Ronne Entrance.” The team made the most of the situation, and their research vessel, Schmidt Ocean Institute’s R/V Falkor (too), settled in to conduct science operations in front of the ice shelf.

“We immediately decided to go there and see [what] the seafloor looks like under the ice.”

While checking satellite images of sea ice extent, they noticed that a crack had formed along the edge of the George VI ice shelf about 30 kilometers from their location. They jotted it down but didn’t worry about any dangers it posed. Such cracks can take weeks or months to fully force a break from the shelf and form an iceberg, Esquete explained.

But when the next batch of satellite images came through a few days later, the team was surprised to see that a 510-square-kilometer (209-square-mile) iceberg had broken off and was drifting along (and occasionally bumping against) the coast of the Antarctic Peninsula. The departure of the Chicago-sized iceberg, A-84, revealed a patch of polar seafloor that had been covered by ice for years, and possibly centuries.

“As soon as we realized that the iceberg had moved on and left that space for us to sample, we immediately decided to go there and see [what] the seafloor looks like under the ice,” Esquete said. When they arrived, they found a thriving ecosystem rivaling those in nutrient-rich open waters.

Luck and Daring

Before A-84 calved, the team was poised to document the biodiversity of a nearby deep-sea ecosystem, collect sediment samples, study underwater ocean dynamics, and create seafloor maps.

“A holy grail for oceanography is not only mapping the entirety of the deep seabed in high resolution in terms of its shape and structure, but also in terms of specifically what lives there and how,” said Dawn Wright, an oceanographer and chief scientist at Environmental Systems Research Institute (Esri) in Redlands, Calif., who was not involved with this expedition.

Sea ice impedes that goal: Research vessels can’t get too close to the ice shelf, and remotely operated vehicles (ROVs) and autonomous underwater vehicles can travel only so far from the ship to explore under the ice.

As creatures of interest are spotted on video screens, Maritza Castro of Chile’s Universidad Católica del Norte and other researchers react with excitement in the remotely operated vehicle mission control room on board R/V Falkor (too). Credit: Alex Ingle/Schmidt Ocean Institute, CC BY-NC-SA 4.0

The procedures involved in securing funding and scheduling a ship can make seagoing research in the Antarctic a slow process, explained Joan Bernhard, a biological oceanographer at Woods Hole Oceanographic Institution in Massachusetts. Planning an expedition like the one in January can take years or even decades, with few exceptions.

Some expeditions have been able to mobilize when seafloor is newly exposed. After Larsen C calved in 2017, for example, research vessels arrived in the area about a year later—much faster than average. Changes at the surface take time to affect the seafloor, but even with such a quick response time, researchers still missed the opportunity to establish a precalving baseline.

After most calvings, “any newly exposed seafloor will have been subject to open-water conditions for years; currents could import alien species potentially impactful to indigenous taxa,” said Bernhard, who was not involved with the Falkor (too) expedition.

Iceberg A-84 calved on 13 January. Falkor (too) reached the newly exposed seafloor just 12 days later.

“Good luck played a huge role. We cannot deny that. But there’s also value in daring to explore the unexplored.”

After relocating, the researchers conducted the same suite of science observations they had originally planned, just in the newly exposed location. Thanks to the quick pivot, the team was able to observe the area as if it were still covered by the ice—an “incredibly rare” opportunity, Bernhard said.

“In my view, nowhere has serendipity in ocean science proved more critical,” Wright said of the expedition. Operating in those conditions is hard enough, and it’s even tougher to be in the right place at the right time, she added.

Esquete acknowledged the expedition’s fortune. “Good luck played a huge role. We cannot deny that,” she said. “But there’s also value in daring to explore the unexplored.” The team would have missed the opportunity had they not already been exploring one of the most remote parts of the world.

Thriving Beneath the Ice

The researchers collected sediment samples, used lidar to create bathymetric maps, and studied the water column and ocean currents. They are still analyzing those data. They also deployed the ROV SuBastian to document the biodiversity of the deep sea and found a thriving ecosystem spanning the trophic web: corals, sponges, invertebrates, cephalopods, king crabs, and krill, as well as a few unknown species.

“I was excited to see what appeared to be meter-tall sponges, ‘giant’ pycnogonids (sea spiders), and large ophiuroids (brittle stars), all similar to those known from the McMurdo Sound region,” Bernhard said.

“What surprised me was the sheer variety of organisms that were found, as well as the huge sizes of some of the deep-sea sponges that had apparently been growing for hundreds of years under such harsh Antarctic conditions,” Wright said.

What’s more, the team found several species that filled discrete ecological niches, which suggested that the ice-covered ecosystem received a steady, high-level influx of nutrients and may have been there for a while, Esquete said.

“Basically, we found the same type of ecosystems that you can expect in that area of the Bellingshausen Sea,” Esquete said. But unlike the other areas the team studied, this ecosystem thrived “in an area that’s been permanently covered by ice for probably centuries.”

That in itself was surprising, she said. Most deep-sea ecosystems that aren’t covered by thick ice receive nutrients that trickle down from photosynthetic organisms near the surface. Scientists think that nutrients carried on deep-sea currents supply nutrients to benthic ecosystems where ice prevents top-down nutrient delivery.

“I was mildly surprised by the plethora of sea anemones on a boulder adjacent to a barrel sponge because all are filter feeders,” Bernhard said. “Such abundance implies currents are strong enough to transport sufficient organic matter to this area.”

A Future Without Ice

The Falkor (too) researchers returned to the mainland after weeks studying the newly discovered Bellingshausen habitat. They already hope for a return trip to investigate how that patch of seafloor changes now that its icy cover has drifted off. Nutrients trickling down from photosynthetic algae might now be available, but the ecosystem has already adapted to and thrived on a lower nutrient supply.

As climate change melts Antarctic ice, this ecosystem could be a bellwether for changes across polar ecosystems.

“Open-water conditions may imperil these ecosystems,” Bernhard said. “More settlement of organics to the seafloor…could cause an ecological imbalance.”

As climate change melts Antarctic ice, this ecosystem could be a bellwether for changes across polar ecosystems.

“The accelerating loss of polar ice that protects these ecosystems, including channeling of nutrient-rich currents to them, does not bode well for their vitality,” Wright said. “But there is so much that we just don’t know. The oceanographic community will be watching the results of this expedition as they become available with intense interest. It has direct bearing on the overall health of the planet.”

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

Citation: Cartier, K. M. S. (2025), Thriving Antarctic ecosystem revealed by a departing iceberg, Eos, 106, https://doi.org/10.1029/2025EO250124. Published on 31 March 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.

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

During the late Ediacaran period (about 550–540 million years ago), Earth experienced significant biological, geochemical, and geomagnetic changes, leading to widespread remagnetization particularly in the carbonate rocks of West Gondwanaland.

Pescarini et al. [2025] present detailed paleomagnetic records focusing on remanence carriers to better constrain remagnetization mechanisms. These records were obtained from deeper drill core samples and fully oriented outcrop samples adjacent to the International Continental Drilling Program boreholes, part of the “Geological Research through Integrated Neoproterozoic Drilling: The Ediacaran-Cambrian Transition” project.

Magnetic mineralogy and paleomagnetic data revealed two magnetic components. C1 is a recent viscous remanent magnetization used to reorient the drill core samples, while C2 is a stable, large-scale remagnetization component carried by very small pyrrhotite (Fe7S8) and magnetite (Fe3O4). The remagnetization mechanism is best explained by thermoviscous and thermal remanent magnetization, indicating prolonged heating above 300°C during the tectonic consolidation (collision and subsequent cooling) of the West Gondwanaland megacontinent. The quasi-synchronous remagnetization across the Gondwana craton around 490-480 million years ago challenges the earlier fluid percolation hypothesis, as it cannot account for the tightly clustered remagnetization poles and the predominance of a single reverse polarity.

Citation: Pescarini, T., Trindade, R. I. F., Evans, D. A. D., Kirschvink, J. L., Pierce, J., & Fernandes, H. A. (2025). Magnetic mineralogy and paleomagnetic record of the Nama Group, Namibia: Implications for the large-scale remagnetization of West Gondwanaland and its tectonic evolution. Journal of Geophysical Research: Solid Earth, 130, e2024JB030612. https://doi.org/10.1029/2024JB030612

—Agnes Kontny, Associate Editor, JGR: Solid Earth

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