EOS

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

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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

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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

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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

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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/

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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

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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

Text © 2024. The authors. CC BY-NC-ND 3.0
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Source: Journal of Geophysical Research: Biogeosciences

Scientists know that streams and rivers can contribute significant quantities of greenhouse gases to the atmosphere. One way these bodies of water come to contain greenhouse gases is via groundwater, which picks up carbon and nitrogen as it seeps and flows through rock and sediment near rivers. Much research into greenhouse gas emissions from rivers assumes that before being released into the atmosphere, the gases in this groundwater mix with the currents of rivers and streams. But during low-flow conditions, groundwater can seep out along stream banks at or above the river surface, creating a pathway for greenhouse gases to escape directly from groundwater.

Bisson et al. set out to estimate the magnitude of emissions from groundwater rising directly to the surface, known as groundwater discharge. They measured greenhouse gas emissions along riverbanks at three locations in the Farmington River watershed in Connecticut and Massachusetts, concentrating on areas that had groundwater discharge above the waterlines during a typical summer flow season.

At each stream, the team used handheld thermal infrared cameras to identify stream banks with and without areas of exposed groundwater discharge. Once these stream banks were located, the team measured fluxes of the greenhouse gases carbon dioxide (CO2), nitrous oxide (N2O), and methane, as well as groundwater discharge rates along the stream banks. They also collected subsurface groundwater samples and analyzed the samples for concentrations of dissolved organic carbon, oxygen, and nitrogen.

At one site, the researchers found that CO2 concentrations were 1.4–19.2 times higher in groundwater discharge than in surface water and N2O concentrations were 1.1–40.6 times higher. In comparison, stretches of stream with no groundwater seeps acted as N2O sinks. They also found that groundwater emissions of CO2 and N2O were 1.5 and 1.6 times higher than surface water emissions, respectively. On average, 21% of emissions from the groundwater seeps were released into the atmosphere before they could mix with surface waters.

The authors note that their work shows that exposed groundwater discharge along stream banks can be a significant, often unaccounted-for, source of river corridor greenhouse gas emissions. They add that more work should be done to better understand potential emissions from river corridors where groundwater discharge is abundant. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2024JG008395, 2025)

—Sarah Derouin (@sarahderouin.com), Science Writer

Citation: Derouin, S. (2025), Seeping groundwater can be a hidden source of greenhouse gases, Eos, 106, https://doi.org/10.1029/2025EO250118. Published on 28 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.

In 2017, Paulo Tarso Oliveira, a professor of hydrology at the Universidade de São Paulo, came across a news report about a small village along the banks of the São Francisco River, one of the main rivers in northeastern Brazil. The article said villagers were experiencing unusually high rates of high blood pressure, and linked the anomaly with the region’s dry climate and low river flow. As the water table dropped, ocean water began infiltrating the region’s groundwater, raising salt levels in the water supply and making people sick.

“Oftentimes, people don’t realize, but surface and groundwater are connected and must be seen as an entirety.”

Intrigued, Oliveira investigated further. Streamflow was slowing, he later found, because wells were pumping water from the aquifer below. “Oftentimes, people don’t realize, but surface and groundwater are connected and must be seen as an entirety,” Oliveira said.

In places where a water table lies beneath a riverbed, the river can leak water into the aquifer below. This process, known as streamflow leakage, occurs naturally depending on underlying rock formations and groundwater levels, but the construction of wells that overpump water from aquifers may intensify the issue.

The situation in the São Francisco basin is not unique, Oliveira and his colleagues found. In evaluating wells across Brazil, the researchers discovered that water levels in more than half the wells were below the level of nearby streams.

Mapping Wells

In 2023, Oliveira and master’s student José Gescilam Uchôa began mapping Brazilian rivers to identify areas at risk of water loss. They relied on public data on river levels and the locations of wells from the Geological Survey of Brazil. The data, however, were insufficient for most of the registered wells. As a result, they focused on 18,000 wells with comprehensive data spread across thousands of rivers in Brazil.

The researchers compared the water level in each well with the elevation of the nearest stream. In 55% of the wells, water topped out below the elevation of neighboring streams.

José Uchôa takes measurements in a river in São Paulo. Credit: Laboratório de Hidráulica Computacional da Universidade de São Paulo

“Our data suggest that the groundwater use is significantly impacting the rivers’ streamflow,” Uchôa said. “This is and will continue to be a growing worry for water management in the country.”

The study, published in Nature Communications, also identified critical regions, including the São Francisco basin, where more than 60% of rivers may be losing water because of extensive groundwater pumping. Pumping is mainly associated with irrigation activities.

In the Verde Grande basin in eastern Brazil, where irrigation is responsible for 90% of water consumption, 74% of rivers may be losing water to aquifers.

Oliveira thinks the results are conservative and that the situation could actually be worse because the researchers did not account for illegal wells. A 2021 study by geologist Ricardo Hirata at the Universidade de São Paulo estimated that around 88% of Brazil’s 2.5 million wells are illegal, lacking a license or registration for pumping.

Hirata, who was not involved with the new work, warned that the new study was limited to only 5% of existing wells, primarily located in regions where groundwater is more intensely exploited.

“Perhaps this is also happening in other parts of the country with high irrigation demands, and we just don’t know it because we lack data.”

He also stressed that though the researchers identified rivers that are potentially losing water to aquifers, these data alone are insufficient to determine whether the rivers are drying up. To assess that, other factors would need to be considered, such as the amount of water extracted from an aquifer compared to the river’s streamflow, how connected the aquifer is to the river, and how much water is drawn from the aquifer in relation to seasonal variations in streamflow.

“The fact that the water level of a well is lower than that of a nearby river doesn’t necessarily affect the river or the aquifer,” Hirata said.

The areas identified as critical by the study are mostly arid regions where stream leakage was expected to occur naturally, pointed out hydrologist André F. Rodrigues at the Universidade Federal de Minas Gerais in Brazil. Rodrigues was not involved with the research.

The study is important because it highlights a growing issue, he said, but more local analyses are necessary to get a more detailed picture of the problem and consider, for example, the effects of climate and seasonal changes. “Perhaps this is also happening in other parts of the country with high irrigation demands, and we just don’t know it because we lack data,” Rodrigues said.

A Growing Issue

Uncontrolled expansion of wells and excessive pumping not only affect people’s health, water supplies, and agriculture but also can make soil unstable, leading to ground sinking (subsidence). Similar phenomena have been observed in regions of China, the United States, and Iran.

The outlook is not good for Brazil. Wells will likely multiply because irrigated land areas are expected to increase by more than 50% in the coming 20 years, according to the Brazilian water agency.

“We will likely see a vicious cycle of degradation, where a decrease in surface water quality and quantity, coupled with an increase in drought periods, will force farmers to drill more wells for food production, further intensifying groundwater extraction and exacerbating the problem,” Oliveira said.

Overexploitation of groundwater is a global concern. Most aquifers have declined in the 21st century, and modeling studies suggest that stream leakage will become more common in the coming decades. Still, the issue is largely overlooked in tropical places such as Brazil, which holds 12% of the world’s renewable water resources.

This oversight is partly due to a lack of funding and surveillance and partly due to a long-standing belief that rivers in tropical and humid countries mostly gain water from aquifers rather than losing it, Oliveira said. “We must act to avoid having entire regions devastated in the future.”

Researchers are calling for more studies and systematic monitoring of wells to identify critically dry areas and assess the impact of drilling new wells on rivers. Brazil has only 500 observational wells that are constantly monitored by the government, compared with 18,000 in the United States, despite the countries having similar land area. “Surveillance is extremely important and highly undervalued,” Uchôa emphasized.

—Sofia Moutinho (@sofiamoutinho.bsky.social), Science Writer

Citation: Moutinho, S. (2025), Brazil’s rivers are leaking, Eos, 106, https://doi.org/10.1029/2025EO250116. Published on 28 March 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: Machine Learning and Computation

Low-lying clouds over the oceans are of key relevance for understating climate dynamics as they effectively reflect sunlight that otherwise would be absorbed by the ocean. Satellite data are a central pillar of the ongoing quest to better understand such clouds and the physical mechanisms governing their evolution.

In their new study, Tian et a. [2025] utilize a focused exploitation of a complementary source of data—long time series of ground-based radar observations—by means of machine learning. Established, satellite-based cloud categories can be reliably identified in the radar data. This then allows us to contextualize the wealth of additional information contained in the radar data, from cloud height to cloud droplet number concentrations. This study thus expands the observational data on low-level clouds that can be jointly exploited. One application that will potentially benefit from this work is the above-mentioned quest for a better physical understanding of low-level clouds.

Citation: Tian, J., Comstock, J., Geiss, A., Wu, P., Silber, I., Zhang, D., et al. (2025). Mesoscale cellular convection detection and classification using convolutional neural networks: Insights from long-term observations at ARM Eastern North Atlantic site. Journal of Geophysical Research: Machine Learning and Computation, 2, e2024JH000486. https://doi.org/10.1029/2024JH000486

—Doris Folini, Editor, JGR: Machine Learning and Computation

Text © 2024. The authors. CC BY-NC-ND 3.0
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The Landslide Blog is written by Dave Petley, who is widely recognized as a world leader in the study and management of landslides.

There are some reports today that another mining related landslide occurred in the Morowali area of Indonesia yesterday. There are few details in media reports, but videos have been posted that appear to show a significant event. Most notable is this one, from Tiktok, which seems to show two trucks buried in mined material or mine waste.

This is a still from the video:-

The aftermath of a reported mining-related landslide at Morowali in Sulawesi. Still from a video posted to Tiktok.

Reports suggest that there were no fatalities, but I am awaiting further information.

Meanwhile, there remains some uncertainty about the two earlier events. Based on reports online, this is the best that I can determine.

The 16/17 March 2025 tailings landslide

There remains considerable uncertainty about this event, which caused extensive and well-reported flooding downstream. This appears to have been the failure of a tailings facility, although I am unable to pinpoint exactly which one.

This article reportedly shows the aftermath of the embankment breach that led to the 16/17 March 2025 event (even though it is wrongly captioned). It appears to have occurred in a more remote location, but until decent satellite imagery is available I will be unable to pin it down.

The 22 March tailings (?) landslide

A further major landslide occurred on 22 March, killing three excavator operators. This failure has been widely reported to have occurred in tailings. There is speculation about the location of this landslide, with some suggesting that it occurred close to the 16/17 March 2025 event – i.e. upstream from the main industrial IMIP sites.

This video, also on Tiktok, shows the search for one of the victims. There are other, similar videos and images. It includes the following view of the location:-

The aftermath of the 22 March 2025 mining-related landslide at Morowali in Sulawesi. Still from a video posted to Tiktok.

I believe that the most likely location for this landslide is the one that I highlighted in my earlier post:-

Google Maps image of the possible location of the 22 March 2025 tailings landslide at Fatufia in Indonesia.

The configuration of the site shown above matches this location in a way that the other postulated sites do not. In the video, a large cut in a natural slope is shown, and it is clear that a large industrial facility lies on the downslope side. This includes an area under construction on the right side. All of this matches the above location. although I cannot be definitive of course.

Interestingly, also on Tiktok, there is a video of a landslide in the Morowali area, which partially engulfs a backhoe. This is a still from that video:-

A small landslide, reportedly from Morowali, showing a landslide partially engulfing a backhoe. Still from a video posted to Tiktok.

That appears to have been a near-miss event.

Assuming that the video above was not one of the recent landslide events (and I believe that this is the case), it appears that there have been at least four significant landslides at IMIP in Morowali in recent months. This must be a source of very real concern.

However, at this stage there remains very considerable, and frustrating, uncertainty about the events at IMIP.

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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.

After an onslaught of funding cuts, firings, and cancelled programs as a result of Trump administration actions, scientists in the United States are feeling targeted. That’s according to the results of a poll published by Nature. 

In the poll, 75.3% of 1,600 respondents, at least 1,200 of whom were scientists, said they were “considering leaving the country following the disruptions to science prompted by the Trump administration.” 

“This is my home—I really love my country. But a lot of my mentors have been telling me to get out, right now,” one U.S. graduate student who lost her stipend when the Trump administration canceled funding for the U.S. Agency for International Development (USAID) told Nature. “I’ve been looking very diligently for opportunities in Europe, Australia, and Mexico.”

“The ‘brain drain’ is happening,” wrote Brian Romans, a geoscientist at Virginia Tech, on Bluesky.

the 'brain drain' is happening — assuming the U.S. weathers this storm and the current regime is ousted electorally in the near future, I will be listening to candidate's plans for reinvigorating science in the U.S. — the damage being done is significant, the plan to fix will need to be ambitious

— Brian Romans (@clasticdetritus.bsky.social) 2025-03-27T14:34:01.600Z

The trend was especially strong among early-career scientists: 79.4% of postgraduate researchers who responded said they were considering leaving, as well as 75% of Ph.D. students. These groups are also feeling the brunt of funding changes that have affected undergraduate training programs and graduate admissions.

 
Related

•  75% of U.S. Scientists Who Answered Nature Poll Consider Leaving
•  Yale Professor Who Studies Fascism Fleeing U.S.
•  A French University is Offering ‘Scientific Asylum’
•  Get Involved: AGU Science Policy Action Center
 

Losing scientists hinders the country’s ability to remain competitive in science, technology, engineering, and math, or STEM, fields on a global scale, according to a 2024 National Science Board report. The board pointed out that even before the Trump administration took office, the United States was at risk of struggling to retain talented scientists or attract researchers from abroad.

Universities in other countries are taking note: This month, a French university announced the Safe Place for Science, a three-year program meant to bring 15 American scientists to its campus.

I would leave in a heartbeat. But contrary to what most folks might think, there are precious few jobs for someone with specialized expertise.

— Valentin Rodionov (@arbitraryeffect.bsky.social) 2025-03-27T15:21:00.510Z

—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.

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.

Various U.S. federal agencies sent a 36-point survey to researchers abroad who receive U.S. funding, asking questions related to the Trump administration’s priorities. The questions cover topics such as “eradicating anti-Christian bias” and defending against “gender ideology,” and asked researchers to disclose ties to “entities associated with communist, socialist or totalitarian parties.”

The Conversation and The Guardian both published the communication in full. Specific questions include:

• Can you confirm this is not a climate or “environmental justice” project or include such elements?
• Does this project support U.S. energy independence or reduce global reliance on hostile countries for energy resources?
• Can you confirm that your organization has not received ANY funding from the PRC (including Confucius Institutes and/or partnered with Chinese state or non-state actors), Russia, Cuba, or Iran?
• Can you confirm that this is no DEI project or DEI elements of the project?
• Does this project take appropriate measures to protect women and to defend against gender ideology as defined in the below Executive Order?

Versions of the questionnaire were sent out to researchers in Australia, the European Union, the United Kingdom, and Canada beginning 5 March, with deadlines between midnight on 7 March and 5 p.m. on 10 March, according to the New York Times. The survey has come from agencies including the U.S. Geological Survey, the U.S. Department of Agriculture, and the U.S. Department of State, on instruction (according to the email) from the U.S. Office of Management and Budget. Some academics “who conduct joint research with U.S. partners” were sent the questionnaire directly, while others were contacted through national agencies such as Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), with which the U.S. agencies had shared the survey.

 
Resources

• Office of Management and Budget: Outreach to Implementing Partners (survey)
•  Trump team ‘survey’ sent to overseas researchers prompts foreign-interference fears (Nature)
•  Trump Admin Questions Canadian, Australian Researchers (Inside Higher Ed)
•  Trump Administration Sends Politically Charged Survey to Researchers (The New York Times)
•  Get Involved: AGU Science Policy Action Center

Vicki Thomson, chief executive of the Group of Eight (Go8) consortium of Australia’s leading research universities, told Nature that the Australian government has suggested researchers respond to the survey, whereas several European universities told the outlet they are advising researchers not to respond. The president of the Canadian Association of University Teachers said the United States is trying to “impose a certain ideological viewpoint on research.”

Chennupati Jagadish, president of the Australian Academy of Science, told ABC Radio National that some of the primary concerns among researchers are how answering the survey—or not answering it—could affect their research and their ability to travel to the United States.

In a 17 March statement urging the Australian government to resist foreign interference, Chennupati noted that the United States is Australia’s largest research partner, and added, “If responses to the survey lead to reductions or cessation of US–Australian scientific collaborations, it will directly threaten our scientific and technological capability.”

—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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Source: Journal of Geophysical Research: Oceans

The Mozambique Channel, between Mozambique and Madagascar, is home to some of the most turbulent waters in the ocean. Swirling at a rate of more than 1 meter per second, currents in the channel can form structures known as anticyclonic rings that spread up to 350 kilometers across—about the width of Missouri—and extend 2,000 meters below the surface.

The currents carry nutrients and marine life such as shrimp larvae, the basis of a major industry in Mozambique. Information about the movements of shrimp larvae and their food is crucial for managing fisheries. Yet currents in the Mozambique Channel remain poorly understood.

Penven et al. characterized currents in the channel as part of a study called RESILIENCE (Fronts, Eddies, and Marine Life in the Western Indian Ocean). In 2022, the research team set off aboard a vessel towing a Moving Vessel Profiler, which measured water conductivity, temperature, and turbidity in the region with unprecedented spatial resolution. Meanwhile, an instrument on the ship’s hull, called the RDI Ocean Surveyor Acoustic Doppler Current Profiler, measured water velocity.

The movement of ocean chlorophyll (green) in the Mozambique Channel in April 2022 is depicted here. A large anticyclonic ring (dark blue coloration near the top of the image) pulls a chlorophyll-rich water filament into the channel from the coast, while another filament spirals into a smaller cyclonic eddy to the south. Credit: Pierrick Penven

Specifically, the researchers traversed a prominent type of current in the Mozambique Channel known as an eddy-ring dipole. In an eddy-ring dipole, an anticyclonic ring—in which water swirls counterclockwise in the Southern Hemisphere—pairs with a cyclonic eddy—in which water swirls clockwise in the Southern Hemisphere. Using the profiling instruments, the team took high-resolution measurements of several cross sections of the current down to a depth of 300 meters.

The fierce central current formed by the eddy-ring dipole whisked nutrients and sea life away from the continental shelf and the Mozambican coast at speeds of up to 1.3 meters per second, the researchers found. They also found that conditions vary significantly between the current’s two parts. In the cyclonic eddy, patches of either high or low salinity exist and photosynthetic life is abundant. In the anticyclonic ring, on the other hand, conditions are homogeneous and photosynthetic life is largely absent. The study is among the first to characterize these complex currents, and it provides a basis for future research on this turbulent region, the researchers say. (Journal of Geophysical Research: Oceans, https://doi.org/10.1029/2024JC021913, 2025)

—Saima May Sidik (@saimamay.bsky.social), Science Writer

Citation: Sidik, S. M. (2025), Tracking some of the world’s fiercest ocean currents, Eos, 106, https://doi.org/10.1029/2025EO250119. Published on 27 March 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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