EOS

Past lunar missions have detected evidence of large ice deposits in permanently shadowed regions near the Moon’s south pole. Such ice could provide astronauts with drinking water, oxygen, and rocket propellants, reducing the cost of lunar operations.

But new research has found that astronauts might not have to dig very deep or journey especially close to the Moon’s poles to find water ice. A recent study published in Communications Earth and Environment says the critical resource for future lunar explorers might lurk tantalizingly close to the surface on pole-facing slopes at lower latitudes. The Sun shines at a low angle on such regions, which may allow ice to accumulate just centimeters below the surface, where it would be insulated by lunar regolith.

The Moon’s low axial tilt means that craters and low-lying areas near the south pole never see direct sunlight. This lack of sunlight would allow even surface ice deposits to remain frozen for a long time—perhaps billions of years. Because of the likely presence of ice, both NASA and China’s space agency have announced plans to land astronauts near the south pole and eventually establish permanent outposts there.

The Chandrayaan-2 orbiter photographed the Vikram lander from orbit. Credit: Indian Space Research Organisation

Locations farther from the poles “can also become potential locations for future human habitats, with better illumination and smoother topography than the poles. These regions pose less technical challenges for landing and operations.”

“Our study reveals that the poles are not the only options for future exploration,” said K. Durga Prasad, lead author of the report and a planetary scientist at the Physical Research Laboratory in Ahmedabad, India. Locations farther from the poles “can also become potential locations for future human habitats, with better illumination and smoother topography than the poles. These regions pose less technical challenges for landing and operations.”

“This result is very much consistent with both theoretical modeling studies and observations made by Lunar Reconnaissance Orbiter,” said Timothy McClanahan, an emeritus planetary scientist at NASA’s Goddard Space Flight Center who was not involved with the study.

First Measurements Since Apollo

The new lunar temperature data come from Chandra’s Surface Thermophysical Experiment (ChaSTE), an instrument aboard the Vikram lander, which itself was part of India’s Chandrayaan-3 mission. Vikram touched down on 23 August 2023 at 69° south latitude, the most southerly landing site at that time. (Two subsequent landers, both built by the American company Intuitive Machines, landed farther south, but both tipped over on landing and were unable to achieve all of their science goals.)

ChaSTE collected data continuously from 24 August to 2 September, shortly before the Sun set on the solar-powered lander (a lunar day lasts about 29.5 Earth days). The probe penetrated 10 centimeters into the regolith, with temperature sensors spaced at 1-centimeter intervals. The instrument also heated the regolith to measure its thermal conductivity.

ChaSTE provided the first direct subsurface lunar temperature measurements since the Apollo 15 and 17 missions of the early 1970s. The Apollo heat probes drilled deeper than ChaSTE did but provided fewer measurements of the top 10 centimeters. The Apollo sites also were close to the equator, where temperatures are likely to remain too warm for water ice even well below the surface, Prasad said.

An enlarged version of the Pragyan image of Vikram indicates the location of the ChaSTE instrument, which measured thermal conductivity and temperatures, and the Instrument for Lunar Seismic Activity (ILSA). Credit: Indian Space Research Organisation

Vikram landed on the rim of a shallow crater in a Sun-facing area with a 6° slope. ChaSTE and other instruments aboard the lander recorded a peak daytime surface temperature of 355 K (81.85°C). That was higher than expected on the basis of both models and observations by Diviner, an infrared instrument aboard the Lunar Reconnaissance Orbiter that has compiled temperature maps of much of the lunar surface. (Temperatures at the probe’s maximum depth ranged from 55 K to 85 K colder than surface temperatures, depending on the time of day.)

However, the temperature on a flat area just 1 meter from the ChaSTE site peaked at only 332 K (58.85°C), suggesting that a location’s slope could play a significant role in its subsurface temperatures.

The findings “validated the idea that topographic variation, even toward meter scales, has an important impact on locations where we might expect water ice to occur,” McClanahan said.

Taking the Right Angle

Modeling showed that at high latitudes, poleward-angled slopes of 14° or greater could remain cold enough to preserve ice at depths of just a few centimeters. The Sun would hit such tilted regions at a low angle, minimizing heating, and the fine-grained top layer of the regolith would be an efficient thermal blanket, effectively insulating the shallow subsurface.

“Depending on the slope, you can have a lot of temperature variation even in craters as small as a meter. One side might be quite warm, but…you could have conditions that are suitable for water ice on the poleward-facing slope.”

“Depending on the slope, you can have a lot of temperature variation even in craters as small as a meter,” McClanahan said. “One side might be quite warm, but given the low thermal conductivity of the regolith, you could have conditions that are suitable for water ice on the poleward-facing slope.” The slope angle suitable for hosting ice increases as you move farther from the pole, he added.

The Vikram team is continuing to analyze the ChaSTE observations to learn more about the thermal characteristics of the landing site and of high lunar latitudes in general, Prasad said. In addition, because temperatures are important for any lunar lander, “future missions will definitely carry similar instruments that will also help substantiate our results,” he said.

—Damond Benningfield, Science Writer

Citation: Benningfield, D. (2025), Lunar ice might be easier to reach than we thought, Eos, 106, https://doi.org/10.1029/2025EO250136. Published on 11 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: AGU Advances

Magma transport involves interactions of rocks and volatiles in their solid, fluid, and gas phases that must be captured by physical models across a vast range of scales. What complicates matters further is that eruptions respond to heterogeneous and time-variable source conditions modulated by a crust that experiences hysteresis due to its volcano-tectonic history. Any efforts of interpreting signals such as the multi-decadal unrest at the Campi Flegrei, Italy volcanic fields thus must find the balance between honoring the regional specifics and fundamental volcano dynamics.

Numerical scenario computation illustrating how dike populations may respond to the large-scale caldera stress field. Credit: Buono et al. [2025], Figure 7l

Buono et al. [2025] present a sweeping review that seeks to integrate rock physics, seismic tomography, and mechanical modeling into a systems-level understanding of the Campi Flegrei setting. It appears that the combination of caldera geometry and lithology leads to a crustal stress state that affects volcanic dike ascent which in turn may feed back into crustal deformation behavior. This suggests the importance of a resulting weak crustal layer for subsequent magma and gas pathways and perhaps an evolutionary scenario for similar volcanic centers. While the modeling is suggestive, there are a range of interactions and features left to be explored. However, the range of geophysical and geological constraints that are accessible in well instrumented volcanic systems points toward the potential of future, fully integrated models that might be capable of assimilating time dependent observations for improved, physics-based forecasting of volcanic hazards.

Citation: Buono, G., Maccaferri, F., Pappalardo, L., Tramelli, A., Caliro, S., Chiodini, G., et al. (2025). Weak crust owing past magmatic intrusions beneath Campi Flegrei identified: The engine for bradyseismic movements? AGU Advances, 6, e2024AV001611. https://doi.org/10.1029/2024AV001611

—Thorsten Becker, Editor, AGU Advances

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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.

Rail Advent has a very nice article that describes the now completed repair of the Browney Curve landslide on the East Coast Mainline railway line in England. This is a site that is dear to my heart as, for 14 years, I drove across the landslide on my way to work.

There is a Google Earth image from 2020, taken from a low sun angle, that beautifully illustrates the issues at this site:-

Google Earth image from 2020 showing the Browney Curve landslide site. Note the East Coast mainline railway running across the landslide.

The East Coast Mainline is one the most important long distance line the country. Built two centuries ago, the line links London and Edinburgh, via York and Newcastle. The Browney Curve landslide has caused issues for many years. The image below, from Network Rail, shows the scale of the problems:-

The Browney Curve landslide site. Image from Network Rail.

The hummocky terrain seen in the image is characteristic of land that is undergoing movement. The underlying surface geology consists primarily of glacial till, which causes stability issues in many locations in the UK. The embankment supporting the railway line runs below the very clear back scarp of a natural landslide, and there are clear signs of ground deformation on the slopes above and below the track.

The landslide has regularly caused damage to the track and the road, and there were concerns that a major movement could close the line for a protracted period. Prior to the works, the line was being intensely monitored at this location to ensure that the alignment was safe.

Network Rail has a good page detailing the remediation works, which primarily consist of the installation of 529 piles extending up to 25 metres into the ground to anchor the slope, plus extensive drainage works to lower pore water pressures. The gradient of the embankment has also been reduced, and there will be a tree planting programme as well.

Pell Frischmann has a good web page detailing the ground investigation and design works at the site. There is also a very good, very detailed review of the problems and the repairs on Youtube, presented by Pell Frischmann and Network Rail. This is a fantastic resource:-

The works have cost £33 million (US$43 million), representing a significant investment in the safety and resilience of the East Coast Mainline.

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A warm cup of tea could offer some unexpected health benefits.

While steeping, tea leaves soak up lead ions from water, researchers reported in ACS Food Science and Technology. Though the process doesn’t completely purify the water and is not intended for large-scale water remediation, the passive benefit could help explain the correlation between regular tea consumption and lower incidences of heart disease and stroke.

“This idea that the tea bag, or tea within the bag, would absorb something was something nobody thought about.”

Tea is known to release various compounds such as tannins and caffeine into water. But “this idea that the tea bag, or tea within the bag, would absorb something was something nobody thought about,” said Vinayak Dravid, a coauthor of the study and a materials scientist at Northwestern University.

In the lab, Dravid and his research group regularly develop spongelike materials that absorb pollutants. The composition of one of these sponges reminded study coauthor Benjamin Shindel of tea bags, Dravid said. Shindel, at the time a Ph.D. candidate and now a materials scientist contracting with the U.S. Department of Energy, suspected that conditions inside a cup of tea would encourage metals to stick to the tea leaves.

To test the hypothesis, Shindel and his colleagues prepared solutions made of water with different concentrations of lead, ranging from 10 parts per billion—EPA’s trigger level for lead—to highly toxic levels of 10 parts per million. Then they heated the solutions to 85°C (185°F, just below the boiling point of water) and prepared different kinds of teas, including traditional black, green, oolong, and white teas brewed from the Camellia sinensis plant as well as the herbal teas rooibos and chamomile. After steeping the tea leaves for a range of times—anywhere from a few seconds to 4 hours—the researchers measured how much lead was left in each cup.

Spilling the Tea

Black and green teas were the most effective at removing lead, the team found, although the type of tea had less efficacy than the time it steeped. Finely grinding the leaves before steeping slightly improved their performance, likely because the increased surface area left more space for lead atoms to attach to the leaves. Steeping leaves in a cup of black tea for 5 minutes removed about 15% of the lead from the laboratory solutions. White and herbal teas, whose leaves remain smooth as they steep, were less effective.

The wrinkled surface of black tea leaves, seen here under a scanning electron microscope, may contribute to an increased surface area onto which lead and other metal ions adsorb. Credit: Vinayak P. Dravid Group/Northwestern University

The longer the leaves steeped, researchers found, the more lead adsorbed onto them. The longer leaves steep, however, the more bitter the tea becomes.

Tea’s metal-remediating benefits weren’t limited to lead. The team also prepared separate solutions of cadmium, chromium, copper, and zinc. Ions of each adsorbed onto the leaves.

In addition to the leaves themselves, the team also experimented with whether the type of tea bag influenced the amount of metal removed. Though nylon and cotton tea bags didn’t remove any lead, the metal did bind to cellulose (or “wood pulp”) tea bags.

Previous research has shown that C. sinensis can absorb metals from soil and store them in its leaves, so “there is always a risk, and obviously a concern, that you are actually then contributing those heavy elements and heavy toxins into water again when you make tea,” Dravid said.

But the new study suggests that metals will stick with the plant and not be released into the surrounding environment. “What our work showed,” Dravid explained, is that C. sinensis “has an affinity for heavy metals—that even if they exist in the leaf, they actually will remain. And that’s so reassuring.”

Brewing with Perspective

Tea leaves are not a substitute for existing methods of water purification, the authors emphasized. Most of the lead that enters drinking water does so through lead pipes connecting water mains and homes, and many domestic faucets or under-sink filters can remove more than 90% of lead ions.

Instead, tea leaves are “a way of reducing the lead exposure that occurs naturally,” explained Marc Edwards, an environmental engineer at Virginia Tech who was not involved in the study. Tea leaves could help mitigate—though not completely remove—the presence of other metals that enter drinking water either through corrosion (e.g., of copper or zinc pipes) or through erosion of mineral deposits like chromium.

“It’s not going to remove all the metal in the water.…But it is removing a fraction that may be meaningful from a public health perspective.”

“It’s not going to remove all the metal in the water, 99.9% or something like this,” Shindel agreed. “But it is removing a fraction that may be meaningful from a public health perspective.” If brewing tea removes 15% of lead and a person drinks enough tea to account for one fifth of their daily liquid consumption, that consumption could lower their lead intake by 3% compared with someone who drinks no tea.

This passive removal may help explain the observed relationship between tea consumption and a lower incidence of certain health issues such as heart disease, high blood pressure, and stroke, the researchers suggest. All three conditions have been associated with lead intake. But more research is needed to determine whether a direct link exists between tea consumption and metal intake, they said.

Though tea leaves can’t eliminate lead in water completely, their widespread use may help reduce an individual’s lead exposure over time.

Still, there’s no need to oversteep your morning cup, Shindel said. “I don’t think people should be changing their tea consumption patterns, or brewing really bitter tea…so they can get more metals out.”

—Skyler Ware (@skylerdware), Science Writer

Citation: Ware, S. (2025), Tea leaves remove lead from water, Eos, 106, https://doi.org/10.1029/2025EO250134. Published on 10 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.

After decades of nondetections and tantalizing maybes, astronomers have definitively detected an aurora on Neptune. Using the James Webb Space Telescope (JWST), researchers detected an infrared auroral glow and the spectral signature of a key tracer of aurorae in Neptune’s upper atmosphere for the first time. The spectrum of this ionized molecule also suggests that Neptune’s upper atmosphere has cooled significantly since Voyager 2’s flyby 34 years ago.

Aurorae have been seen on planets and moons throughout the solar system. Theories predicted that Neptune should have aurorae, too, but previous attempts to detect them failed, said Henrik Melin, a planetary aurora researcher at Northumbria University in Newcastle upon Tyne, United Kingdom (U.K.).

“I’ve spent many, many nights up a mountain trying to detect this stuff using ground-based telescopes. You spend four nights staring at Neptune, and you see nothing,” Melin said.

This auroral detection is “completing the set” of giant planet aurorae, he added. “We have Jupiter, we have Saturn, we have Uranus. We now have Neptune.”

Chilly Aurora

Aurorae occur when charged particles from the solar wind or a nearby volcanic moon, for example, interact with a body’s magnetosphere and upper atmosphere. Some aurorae glow in visible light, like on Earth and some of Jupiter’s moons. Mercury’s aurorae shine in X-ray light.

On planets with hydrogen-dominated atmospheres like Jupiter, Saturn, and Uranus, aurorae typically glow in the infrared or ultraviolet and are traced by the presence of the trihydrogen cation (H3+). Anywhere they occur, aurorae can help scientists understand the inner workings of a planet’s magnetosphere.

“Auroral emissions provide important insight into the space environment of a planet.”

“Auroral emissions provide important insight into the space environment of a planet, and this is particularly important for Neptune, which has a very bizarre magnetic field,” said Jonathan Nichols, a planetary aurora researcher at the University of Leicester in the U.K. who was not involved with the new discovery.

Voyager 2’s brief 1989 flyby suggested that Neptune’s magnetic field is both tilted from its axis of rotation and offset from the center of the planet. The flyby also detected some hints of a possible aurora that astronomers have been hoping to confirm ever since. Models of Neptune’s atmosphere and magnetic field have suggested that Neptune’s aurorae should also be traceable by H3+ and have even predicted the longitudes at which they should appear. But detecting the aurorae proved elusive.

In June 2023, Melin and his colleagues obtained near-infrared JWST spectra of Neptune, originally intending to explore the circulation of Neptune’s middle atmosphere. The observations unexpectedly revealed an infrared auroral glow as well as a shockingly clear infrared spectrum of H3+ emitted by the planet’s upper atmosphere.

The intensity of the H3+ spectrum suggests that the upper atmosphere generating the aurora is 85°C (358 K), a significant cooldown from the 477°C (750 K) temperature measured by Voyager 2.

“It’s great to see this addition to the family portrait of solar system auroras.”

“That was quite a surprise,” Melin said.

Neptune’s seasons are roughly 41 Earth years long, so this dramatic cooling took place faster than the seasonal timescale. The researchers don’t yet understand what might be driving the cooldown, Melin said, though it is likely unrelated to the unseasonably cool summer observed elsewhere in Neptune’s atmosphere.

“The consequence of these really cold temperatures means that the auroral emissions are extremely faint,” Melin said. That explains why Neptune’s aurorae eluded the gazes of ground- and space-based telescopes before. “It was just really, really cold.”

“It’s great to see this addition to the family portrait of solar system auroras,” Nichols said. “Now we know how bright the infrared emission is, we can work out the intensity in other wavelengths such as ultraviolet, and we can run models to see what the upper atmosphere is like.”

The researchers published this discovery in Nature Astronomy.

A Neptunian Day

These JWST data were clear enough to trace aurorae to specific latitudes and longitudes, “producing the first map of the aurora at Neptune,” Melin said.

What’s more, the aurorae appeared at the exact longitudes in the southern hemisphere predicted by long-standing theories.

“This is the tantalizing starting point of really getting to understand Neptune.”

“This was not a given,” Nichols explained, “since the length of the planet’s day was determined more than 3 decades ago, and the uncertainty was such that we were supposed to have lost track of what the time is at any point on Neptune.” (Uncertainty in planetary day lengths is pretty common.)

“But it appears as if it is more accurate than we thought!” Nichols added.

Later this year, the team will point JWST at Neptune several times over the course of a month to learn more about what drives its aurorae and how the planet’s magnetosphere responds to different levels of solar activity.

“By studying the morphology of the aurorae and its changes over time, we can figure out what drives it,” Melin said. The team needs more data to do that, “but this is the tantalizing starting point of really getting to understand Neptune.”

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

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

Citation: Cartier, K. M. S. (2025), After 30-year search, scientists finally find an aurora on Neptune, Eos, 106, https://doi.org/10.1029/2025EO250130. Published on 10 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.

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

The longer a magma chamber resides in the upper crust, the more likely it will evolve to silica-rich compositions. Volcanism has been active on Mars throughout its history, but there is an apparent lack of widespread evolved magmatism, and the development of magma storage systems has been poorly constrained.

To better understand how crustal depth and temperature profile affect the evolution and growth of magma chambers on Mars, Chatterjee et al. [2025] utilize numerical modeling and compare with recent results from the InSight lander mission. Their models suggest that Mars’ crust is divided into three zones that are consistent with InSight seismic data: (1) the upper crust where small intrusions, such as dikes, dominate the upper crust; (2) the lower crust where larger magma chambers can develop and grow; and (3) a middle zone where magma chambers can occasionally grow and produce dikes that erupt at the surface.

The depths where the three magma storage zones are located depend on the crust’s temperature gradient and this study is the first to model the longevity of magma chambers on Mars as it has gradually cooled over geological time. A higher temperature gradient during Mars’ early history (the Noachian and Hesperian time periods) would have allowed larger, more long-lived upper crustal chambers to develop with the potential to feed eruptions at the surface. Seismic activity in Cerberus Fossae detected by InSight is consistent with magmatism and suggests its continued influence on the structure and make-up of the crust of Mars.

Citation: Chatterjee, A. P., Huber, C., Head, J. W., III, & Bachmann, O. (2025). Magma chamber longevity on Mars and its controls on crustal structure and composition. Journal of Geophysical Research: Planets, 130, e2024JE008798. https://doi.org/10.1029/2024JE008798

—Mariek E. Schmidt, Associate Editor, JGR: Planets

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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.

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

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

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

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

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

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

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

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

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

Reference

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

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

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

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

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

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

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

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

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

 
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•  Trump Moves to Hobble Major U.S. Climate Change Study
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•  Trump Administration Fires Staff for Flagship U.S. Climate Assessment
•  Get Involved: AGU Science Policy Action Center
 

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

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

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

These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2024. The authors. CC BY-NC-ND 3.0
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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.

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

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

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

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

 
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• Reinvigorating America’s Beautiful Clean Coal Industry
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•  Immediate Measures to Increase American Mineral Production
•  Layoffs threaten US firefighter cancer registry, mine research and mask lab (AP)
•  Get Involved: AGU Science Policy Action Center
 

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

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

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

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

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

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

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

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

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

— The White House (@WhiteHouse) April 9, 2025 These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2024. The authors. CC BY-NC-ND 3.0
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Valentina Rossi first saw the 30,000-year-old griffon vulture as a master’s student in Rome in 2014. The fossil, which had been found by a local landowner near Rome in 1889, was remarkably well-preserved. She couldn’t look away as her future collaborator, Dawid Iurino, presented about the fossilized imprint of the bird’s head.

“I was mind-blown,” Rossi said. 

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

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

“We finally did it.”

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

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

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

Matching Minerals

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

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

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

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

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

A Vulture’s Final Moments

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

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

The findings “open up another window for fossilization.”

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Exploration of Microbial Life

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

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

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

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

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

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

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

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

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

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

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

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

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

—Mary Hudson, Editor, AGU Advances

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Guest post by Giuseppe Esposito and Stefano Gariano

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

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

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

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

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

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

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

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

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

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

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

References

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

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

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

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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

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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.

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
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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.