EOS

Takao Doi’s dream is to go to the Moon and plant a tree. The former astronaut is inspired by ancient wooden shrines and temples in Kyoto, Japan, that have lasted more than a thousand years.

“If we can use wood in space, we might be able to have sustainable space development forever,” said Doi, a professor at Ryukoku University.

The idea of a wooden space age gained traction last year with the launch of LignoSat, the world’s first wooden satellite to reach orbit. LignoSat, developed by Doi, a group of Kyoto University scientists, and logging company Sumitomo Forestry, is a CubeSat—a type of minisatellite that is relatively inexpensive and easy to construct. LignoSat’s structure is meant to reduce its environmental impact because wood is a renewable material and creates less pollution when it burns up on reentry into Earth’s atmosphere.

“We think wooden satellites orbiting around the Earth are the future.”

LignoSat was deployed from the International Space Station (ISS) last year by the Japan Aerospace Exploration Agency (JAXA) and stayed in space for 116 days.

Doi and his colleagues are using what they learned to develop LignoSat-2, which they expect to launch in 2028. And they’re not alone—at least one other group is also developing a wooden satellite.

“We think wooden satellites orbiting around the Earth are the future,” Doi said.

Raphaela Günther, an aerospace engineering Ph.D. student at Technische Universität Dresden in Germany who is not involved in the LignoSat project, said she considers the work from the Kyoto University team to be a “small breakthrough” in renewable space materials research.

Lessons Learned

The first LignoSat was a 10-centimeter cube made of magnolia wood panels assembled with traditional wooden joinery. An aluminum frame reinforced the structure.

LignoSat used a traditional joinery method called the blind miter dovetail joint. Credit: Kyoto University

The LignoSat mission had five goals: to measure strain on the wooden structure, to measure temperature inside the satellite, to demonstrate how permeable wood is to magnetic fields in space, to analyze the effects of space radiation on wood, and to establish two-way communication with scientists on the ground.

After the satellite was deployed from the ISS on 9 December 2024, though, scientists in Kyoto weren’t able to communicate with it.

Orbital data from the U.S. Department of Defense show the satellite stayed in one piece during its time in space, proving wooden satellites can work, Doi said. But without the ability to communicate with the satellite, the other four missions weren’t able to be completed, either.

“Unfortunately, we didn’t receive any of the information we wanted to know about,” Doi said.

An analysis indicated that the loss of communication could have been caused by two failures: First, any or all of the three switches needed to activate the satellite system and deploy its antenna may not have turned on, and second, the computer program used in the system may not have started up as expected, Doi said. “We are still analyzing what happened, but we now have two reasons to further investigate.”

Despite the lack of communication, Doi recognized two achievements in the LignoSat mission. First, it demonstrated that a wooden satellite can exist in orbit without falling apart. Second, it streamlined the review process for wooden spacecraft. NASA must complete a safety review of all satellites that head to the ISS, he explained, and now that such a review was completed for LignoSat, reviews for subsequent wooden satellites will be simpler.

LignoSat-2 will have both an external antenna and an internal antenna and will be twice the size of the first LignoSat. Credit: Kyoto University

The Kyoto University team plans to build LignoSat-2 to be twice the size of LignoSat, with two communication systems (one inside the structure and another attached to its surface). Installing the antenna inside the satellite body reduces the drag of the structure as it orbits Earth, Doi said.

“Even if the antenna is not deployed, which might have been the cause of LignoSat 1’s communication problems, we may be able to use this second communication system to communicate with [LignoSat-2],” Doi said.

Finnish space technology company Arctic Astronautics is also thinking about wood in space. In 2021, they and Finnish company UPM Plywood developed the WISA Woodsat, a 10-centimeter birch plywood CubeSat. The satellite contains a suite of sensors meant to gather information about how outer space affects wooden spacecraft. It has a deployable camera, a “selfie stick” meant to take photos of itself in space and allow the team on the ground to monitor it visually.

The WISA Woodsat contains a suite of sensors meant to measure how outer space will affect its materials. It also has a selfie stick. Credit: Arctic Astronautics/Flickr, CC BY 2.0

“There is a niche for these kinds of satellites, and the basic research is extremely interesting,” said Jari Mäkinen, cofounder of Arctic Astronautics and initiator of the WISA Woodsat project. “It’s totally possible that when we see these satellites flying, we realize important information [about how plywood acts in space].”

The WISA Woodsat itself is nearly ready for launch, Mäkinen said, but Arctic Astronautics still needs permitting from Finnish space authorities to proceed. He’s hopeful the launch will take place next year. “We will fly as soon as possible,” he said.

A Sustainable Space Industry

For Doi, the wooden CubeSats are just the beginning. “Let’s create a space timber industry” reads the translation of the bio of the research team’s X (formerly Twitter) account. Doi said he imagines a future where wood overtakes aluminum as the primary material for satellites.

Wood is cheaper, easier to use, and lighter than conventional spacecraft materials. Its use as a potential material could both push the space industry toward using more wood and make space development more accessible to countries with fewer resources, Günther said.

A wooden space age could shrink the environmental footprint of the space industry, too. When aluminum satellites fall back into Earth’s atmosphere, they burn, creating aluminum oxide particles. These particles, sometimes smaller than 1 micrometer, may destroy ozone, disrupt atmospheric processes, and even alter Earth’s magnetic field, some scientists suggest. When wood burns, it generates only carbon dioxide, biodegradable ash, and water vapor.

And though scientists don’t fully understand all the possible ways that particles from decomposing metal or wooden spacecraft interact with the upper atmosphere, the decomposition products of wood are easier to assess because they are already major drivers of atmospheric processes, Günther said.

“It’s not a question if we do or if we don’t” begin to use more sustainable spacecraft materials, she said. “I think we have to.”

With a few hundred tracked objects returning to Earth each year, reentering metal spacecraft are not currently a major environmental problem. But as the space industry quickly grows, it’s crucial to look for more ecofriendly materials, Doi said. Replacing even a small portion of parts on future satellites with wood could significantly reduce pollution, Mäkinen said.

Wood poses challenges for spacecraft engineers, too. Because it’s grown naturally, it has defects and doesn’t behave homogeneously, meaning “the behavior of the material in three different directions is not the same,” Günther said. Her own research is working to create spacecraft materials made of wood fibers and binding material that behave more consistently.

“It’s not a question if we do or if we don’t” begin to use more sustainable spacecraft materials, she said. “I think we have to.”

Mäkinen agreed that wood provides many environmental and technical advantages but said large space companies have likely invested enough in their current manufacturing processes that a large-scale shift to wood as a satellite material is unlikely without pressure from space authorities. “I hope that I’m wrong,” he said.

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

Citation: van Deelen, G. (2025), A new satellite material comes out of the woodwork, Eos, 106, https://doi.org/10.1029/2025EO250241. Published on 7 July 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.

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.

On 3 June, the U.S. House of Representatives passed a 940-page spending bill containing President Donald Trump’s domestic policy agenda. After the Senate passed the bill 2 days ago, it cleared the House by a four-vote margin and it will now head to Trump’s desk to be signed into law.

The bill provides trillions of dollars in tax cuts, boosts the fossil fuel industry, and dismantles incentives for clean energy, fulfilling Trump’s campaign promise to remake the U.S. energy economy in favor of oil and gas. 

“Congress has betrayed the working people of this country. This budget bill is the largest-ever transfer of wealth from working families to the ultra-rich and one of the most environmentally destructive pieces of legislation in U.S. history,” said Collin Rees, U.S. campaigns manager at Oil Change International, a clean energy advocacy group, in a statement. 

 
Related

•  How the G.O.P. Bill Will Reshape America’s Energy Landscape
•  A List of Nearly Everything in the G.O.P. Bill, and How Much It Would Cost or Save
•  Chart: ​‘Big, Beautiful Bill’ would cause energy bills to go up in every state
• The Most Perverse Part of the ‘Big, Beautiful Bill’
•  Get Involved: AGU Science Policy Action Center
 

Some of the provisions that most concerned renewable energy and environmental advocates ultimately did not make it into the bill. A tax on future wind and solar projects was removed; the bill no longer mandates the scale of public land sales; and tax credits for companies building nuclear, hydroelectric, and geothermal power plants were not targeted by the bill, according to the New York Times. 

“America, get ready for a safer, stronger, more affordable, and Energy Dominant future,” Doug Burgum, secretary of the U.S. Department of the Interior, wrote on X. According to a 25 February report from the Clean Energy Buyers Association, repealing clean energy tax credits, which the bill calls for, would raise electricity prices for U.S. residents by nearly 7% on average by 2026.

Contained within the bill are provisions related to climate, energy, and Earth science that would: 

• Phase out tax credits that have been in place for decades incentivizing wind and solar power projects. “We’ll continue to build out renewables, but we’ll build out a lot slower,” David Carrol, chief renewables officer for ENGIE North America, a major power plant developer, told the New York Times. 
• Repeal tax credits for consumers who buy new or used electric cars, as well as incentives for businesses to buy electric trucks.
• Postpone fees on methane leaks from oil and gas operations.
• End tax credits for homeowners to upgrade energy efficiency in their homes. In 2023, 3.4 million Americans took advantage of these incentives, according to Rewiring America, an electrification advocacy nonprofit.
• Provide tax breaks for oil and gas producers.
• Rescind unspent funding from President Joe Biden’s Inflation Reduction Act. 
• Mandate that millions of additional acres of federal land be made available for mining. 
• Provide tax breaks for U.S. producers of metallurgical coal (a form of coal used to make steel) and lower royalty rates for coal companies that mine on federal lands.
• Mandate oil and gas lease sales in the Gulf of Mexico, the American West, and Alaska’s Arctic National Wildlife Reserve.

“This bill will be the most transformational legislation that we’ve seen in decades in terms of access to both federal lands and federal waters,” Mike Sommers, chief executive of the American Petroleum Institute, told CNBC. “It includes almost all of our priorities.”

—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 © 2025. AGU. 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.

A group of EPA scientists who signed an open letter voicing their dissent from Trump administration policies have been placed on administrative leave.

The letter, addressed to EPA administrator Lee Zeldin, was published 30 June.

As of Thursday afternoon, all 620 signatories are listed as anonymous. However, initially, more than 300 were identified as EPA staffers, and 170 of those staffers chose to be named, according to the Washington Post. Now, about 140 of them have been placed on administrative leave, according to The Hill, E&E News, The New York Times, and other outlets.

“The Environmental Protection Agency has a zero-tolerance policy for career bureaucrats unlawfully undermining, sabotaging and undercutting the administration’s agenda as voted for by the great people of this country last November,” wrote EPA press secretary, Brigit Hirsch, in a statement.

 
Related

•  Declaration of Dissent
•  EPA places staffers who signed ‘dissent’ letter on leave
•  EPA puts 139 employees on leave who criticized administration
• E.P.A. Suspends 144 Employees After They Signed a Letter Criticizing Trump
• Roughly 140 EPA staffers who signed ‘dissent’ letter are put on leave
•  Get Involved: AGU Science Policy Action Center
 

Marie Owens Powell, president of American Federation of Government Employees Council 238, EPA’s largest union, told E&E News that EPA’s actions were “disgraceful” and an “obvious retaliation for individuals expressing their beliefs. She added that the union is investigating its options for legal recourse.

As of Thursday afternoon, the letter also has 4,597 “supporters and endorsers” who had added their name to a running list. The letter outlines five primary concerns:

• That the EPA is undermining public trust by “promot[ing] misinformation and overtly partisan rhetoric.” The letter calls out the use of politicized terms such as “green slush funds” and “clean coal” in EPA messaging.
• That the EPA is ignoring scientific consensus to benefit polluters. The letter states that the “administration’s actions directly contradict EPA’s own scientific assessments on human health risks” related to mercury, asbestos, greenhouse gases, and PFAS.
• That the EPA is reversing previous progress made to protect vulnerable communities. The letter references environmental justice staffers being placed on leave earlier this year and billions of dollars of cancelled grants.
• That the EPA has dismantled the Office of Research and Development (ORD). The letter suggests that placing ORD scientists in regulatory program offices “will make EPA science more vulnerable to political interference” and that budget cuts will leave the office “unable to meet the science needs of the EPA and its partners and will threaten the health of all Americans.”
• That the EPA has promoted a culture of fear. The letter cites comments from private speeches, reported by ProPublica, in which Office of Management and Budget director Russell Vought stated, “We want their funding to be shut down so that the EPA can’t do all of the rules against our energy industry because they have no bandwidth financially to do so.” And, “We want to put them in trauma.”

—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 © 2025. AGU. CC BY-NC-ND 3.0
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As winter gives way to spring, seasonal snowpack in the American West begins to melt.

Though some of that melt flows over and through shallow alpine soil, new research shows that much of it sinks into bedrock where it percolates for years before resurfacing. Fresh snowmelt makes up less than half of the water in the region’s gushing spring streams, according to the study.

The new finding could improve water resources forecasts. Hydrologic models, which inform the forecasts, largely overlook groundwater contributions and assume the spring’s heavy flows come directly from seasonal snowmelt.

The authors of the study, published in Communications Earth & Environment, used a radioactive isotope of hydrogen known as tritium to measure when the water in 42 western U.S. catchments fell as precipitation.

They found that during late winter, when rain and snowmelt were scarce and streams were fed primarily by groundwater, the water fell as precipitation an average of 10.4 years ago. Even during spring, when the same streams were overflowing with fresh runoff, their chilly waters had an average age of 5.7 years, still indicating significant contributions from groundwater.

A Subterranean Bucket

Hydrologic models typically simulate mountains as impermeable masses covered with a thin sponge of alpine soil, said the study’s first author, Paul Brooks, a hydrologist at the University of Utah. The sponge can absorb some water, but anything extra will quickly drain away.

“Snowmelt is being recharged into groundwater and is mobilizing groundwater that has been stored over much longer [periods].”

However, over the past few decades, scientists have uncovered a steady stream of hints that mountains may store huge volumes of water outside their spongy outer layer. Many high-elevation creeks carry dissolved minerals similar to those found in groundwater, suggesting a subterranean origin. Scientists studying healthy alpine ecosystems in arid conditions have wondered whether plants were tapping into a hidden reservoir of water.

Though snowmelt and rainfall immediately increase streamflow, the relationship is not intuitive. “What appears to be happening is that snowmelt is being recharged into groundwater and is mobilizing groundwater that has been stored over much longer [periods],” said James Kirchner, a hydrologist at Eidgenössische Technische Hochschule Zürich who was not involved in the research.

In areas where the mountains were made of porous sandstone, waters monitored in the new study were much older. In one such stream, the average age of water in winter was 14 years.

Mountains are “more like a bucket with a sponge on top.”

The authors were able to convincingly demonstrate the age of the flows because they used tritium, Kirchner said. Though scientists have previously used tritium to date water from individual streams and large bodies such as oceans and lakes, this study is the first to use tritium to date alpine groundwater and snowmelt across multiple catchments, Brooks said.

On the basis of historic flows, annual precipitation, and the ages of the stream water, the mountains could store an order of magnitude more water than accounted for in current models, Brooks said. As opposed to the impermeable masses in traditional models, he explained, mountains are “more like a bucket with a sponge on top.”

This finding could change how scientists think about the alpine water cycle. “If precipitation takes, on average, years to exit as streamflow, that means that streamflow in any one year is a function of years of climate and weather,” Brooks said. That means forecasters should consider more than just the most recent snowpack when estimating spring flows and potential flooding.

But further research is needed to unearth the role mountains play in water storage. The current study is limited because it covers only snowmelt-driven streams in the arid western United States, Kirchner said. Things might work differently in wetter places, he added.

—Mark DeGraff (@markr4nger.bsky.social), Science Writer

Citation: DeGraff, M. (2025), Years-old groundwater dominates spring mountain streams, Eos, 106, https://doi.org/10.1029/2025EO250238. Published on 3 July 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.

In the face of rising atmospheric carbon dioxide, the Gulf of Maine is thought to be particularly vulnerable to ocean acidification. Its vulnerability has to do with temperature: The waters of the gulf are cold, and cold water dissolves carbon dioxide more easily than warmer water does. Increased carbon dioxide decreases the pH of the ocean (making it more acidic), a concern for the health of the region’s ecosystems as well as its lucrative shellfish industry.

But determining seawater chemistry is complicated. It requires advanced equipment and the assessment of complex physical, chemical, and biological processes. Until now, no long-term data existed to put individual measurements into context, so scientists did not know how acidity in the region’s waters was trending.

Using ocean chemistry recorded in algae, researchers have now constructed a nearly 100-year history of acidity (pH) in the region. The analysis, published in Scientific Reports, shows that ocean acidification, seen around the world, has been delayed in the gulf.

The Gulf of Maine is fed by three offshore water masses: icy, acidic northern waters from the Scotian Shelf and Labrador Current and warm, alkaline Gulf Stream waters. It’s also bordered by thousands of kilometers of shoreline to the west, and its estuaries and inshore waters receive significant riverine runoff.

The group expected to see pH fluctuate in the gulf, given the different factors affecting ocean chemistry and human-driven increases in atmospheric carbon dioxide, said Joseph Stewart, a geochemist from the University of Bristol in the United Kingdom and study coauthor. Data from 2011 to now, collected in Maine’s Casco Bay by a local nonprofit, show an increase in acidity in that coastal area. But that time frame is too short to determine long-term trends, according to the study authors.

Ocean Chemistry Recorded in Algae

Crustose coralline algae live for about 40 years in coastal areas of the Gulf of Maine, the southern limit of their range. These cold-loving algae encrust rocks and grow in seasonal increments, leaving growth bands akin to tree rings in their calcified skeletons. They are highly sensitive to changes in pH and serve as a record for past seawater carbon dioxide concentrations.

Using samples of the algae collected from several locations, the team reconstructed a timeline that spanned from 1920 to 2018.

“We’ve been measuring temperature for a long time, but we have not been measuring seawater pH for very long. It’s a very complicated, hard measurement.”

“We’ve been measuring temperature for a long time, but we have not been measuring seawater pH for very long. It’s a very complicated, hard measurement,” said Branwen Williams, a climate scientist at Claremont McKenna College in California and coauthor of the study. “So records like this are really valuable to get a sense of the variability that exists, particularly in these areas with people,” she said.

To the researchers’ surprise, the algae recorded a historic trend of relatively low pH in surface seawater, about 7.9, with a slight increase of 0.2 pH unit over the past 40 years. (On average, ocean water currently has a pH of around 8.1.) That move toward slightly more basic conditions was counterintuitive.

“We were somewhat surprised by that result, but then it made a lot of sense when we put it in the context of how temperature was changing and how nutrients were changing, and the timing of that change that had been previously documented in other papers,” Stewart said.

Starting around 2010, waters in the Gulf of Maine warmed dramatically. The change was driven by the decreasing influence of frigid northern water masses and the rise of Gulf Stream waters, which are not only warm but also alkaline. These waters seem to act as a buffer and delay the onset of ocean acidification.

Warming Waters

Ocean circulation–driven buffering effects will, at some point, reach their limits, researchers said. The ocean’s uptake of rising amounts of atmospheric carbon will persist, however, and leave the region’s ecosystems and economy vulnerable to the effects of acidification.

Ocean acidification presents one more challenge to the gulf’s coastal economy and its commercial fisheries, which stretch from Cape Cod to Nova Scotia. Ecosystems in the Gulf of Maine already face threats from disease, warming waters, habitat degradation, and invasive species. The added threat of acidification may push individual species past their ability to persist and redefine the biotic and abiotic factors contributing to those species’ ecosystems—a tipping point.

“It’s not just pH on its own that’s going to cause the ecosystem tipping point to occur, but a combination of pH and temperature, and both of those things are changing. The more data we have to understand the systems, all those different factors, the better,” said study coauthor Michèle LaVigne, an ocean scientist at Bowdoin College in Maine.

This and other studies provide insight into acidification trends, but the challenge of understanding and addressing competing factors influencing ocean pH feels intractable, said Damian Brady, an oceanographer at the University of Maine who was not involved in the study. “The dynamics are such that we have these countervailing forces all the time. We have these rises in total alkalinity from offshore source water, increases in temperature, while also, we as a species increase the carbon dioxide that goes in there,” he said. “It’s really complex.”

—Kimberly Hatfield, Science Writer

Citation: Hatfield, K. (2025), Warming Gulf of Maine buffers ocean acidification—for now, Eos, 106, https://doi.org/10.1029/2025EO250239. Published on 3 July 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

Waves in the polar jet stream over eastern North America are often responsible for cold air outbreaks and extreme winter storms. A 1990-2010 increase in jet stream waviness has, controversially, been linked to unusually rapid warming in the Arctic and has been thought to foreshadow a rise in extreme weather as climate change progresses. However, the United States “warming hole” —an enigmatic 1958-1988 cooling trend centered over the eastern U.S.— has also been linked to an increase in jet stream waviness several decades before the 1990s shift in waviness. This timing difference raises questions about whether the jet stream behavior since the 1990s is historically unusual.

Chalif et al. [2025] leverage information from long-term climate reconstructions and find that the jet stream was wavier than it is today during many periods of the 20th century and was the dominant factor driving the winter warming hole. The results highlight the strong relationship between jet stream waviness and eastern U.S. climate, and question whether accelerated Arctic warming is responsible for recent jet stream waviness.

Citation: Chalif, J. I., Osterberg, E. C., & Partridge, T. F. (2025). A wavier polar jet stream contributed to the mid-20th century winter warming hole in the United States. AGU Advances, 6, e2024AV001399. https://doi.org/10.1029/2024AV001399

—Alberto Montanari, Editor-in-Chief, AGU Advances

Text © 2025. The authors. CC BY-NC-ND 3.0
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In April 2025, I recorded 41 fatal landslides that cost 107 lives.

I’m somewhat behind with posting updates on global fatal landslides due to other workload pressures – please accept my apologies. Please be assured that I’m still collecting the data and that I will make a summary available as soon as I can.

Somewhat belatedly, here is a summary for April 2025 (the same report for the previous month is available here). As always, a reminder that this is a dataset on landslides that cause loss of life, following the methodology of Froude and Petley (2018). At this point, the monthly data is provisional.

The headlines are as follows. In April 2025, I recorded 41 fatal landslides that cost 107 lives. The April Average for 2004 to 2016 is 28 fatal landslides, so this is once again substantially above the long term mean. In the exceptional year of 2024, I recorded 40 landslides, so as at 30 April 2025, the cumulative total is proving to be comparable to the prior year. This is a little bit surprising.

Loyal readers will know that my preferred way of displaying these data is using pentads – 73 five day blocks over the course of the year. The end of April takes us to pentad 24:-

The number of fatal landslides to the end of April 2025, displayed in pentads. For comparison, the long term mean (2004 to 2016) and the exceptional year of 2024 are also shown.

As the graph shows, the cumulative total number of fatal landslides to the end of April 2025 has tracked in a very similar way to April 2024. The trend is very substantially higher than for the long term average. But note also that 2024 saw a very early transition to the much higher event rate through the Northern Hemisphere summer (in 2024 this occurred in the latter part of April, the norm is at least a month later). At the end of April 2025, it was too early to tell whether this would be replicated.

I find this continued high rate of global fatal landslides through April 2025 quite surprising, but global temperatures have remained high. As the US Government dismantles its climate infrastructure (an act of pure vandalism), we are increasingly reliant on data being provided elsewhere. Fortunately, the European Copernicus Clime Change Service system remains wonderful and fully available. This shows that:

“April 2025 was the second-warmest April globally, with an average ERA5 surface air temperature of 14.96°C, 0.60°C above the 1991-2020 average for April. April 2025 was 0.07°C cooler than the record April of 2024, and 0.07°C warmer than the third warmest of 2016.”

Thus, the high event rate for fatal landslides may be associated with the continued high global temperatures, and thus high peak rainfall intensities, through the early part of 2025.

Reference

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

Return to The Landslide Blog homepage Text © 2023. The authors. CC BY-NC-ND 3.0
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body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news regarding law and policy changes that impact science and scientists today.

In the latest move in a months-long attack on climate science funding, the Trump administration released a budget document on 30 June that calls for zero funding for climate research and the elimination of a slew of NOAA services, including the agency’s climate laboratories, regional climate data efforts, tornado and severe storm research, and partnerships with other institutions.

The budget, proposed for fiscal year 2026, also calls for a reduction in NOAA’s full-time staff by more than 2,000 people. 

The Office of Oceanic and Atmospheric Research (OAR) would be eliminated under the proposed budget. OAR coordinates and performs NOAA’s climate and weather research.

“With this termination, NOAA will no longer support climate research grants,” the proposal states.

The proposed NOAA budget for 2026 contains the literal line:Total, Climate Research: $0www.commerce.gov/sites/defaul…

— Robert Rohde (@rarohde.bsky.social) 2025-06-30T23:25:38.113Z

“The idea [that] these labs would be completely wiped out is surreal and dangerous,” Dan Powers, executive director of CO-LABS, a science advocacy group, told Colorado Public Radio. 

The proposal would also eliminate funding for all of OAR’s climate and weather cooperative institutes—partnerships between the agency and other research institutions, including universities. One such partnership is the Mauna Loa Observatory in Hawaiʻi, an atmospheric research station best known for its measurements of atmospheric carbon dioxide.

Another is the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder, which houses the National Snow and Ice Data Center. The center tracks critical snow and ice observations used to monitor the impacts of climate change. The center had already halted maintenance for some of its data products after losing support from NOAA in May.

It is difficult to describe just how disastrous it would be if just-released NOAA budget proposal (or even large portions) were to be enacted: It would involve a wholesale dismantling (decimation, really) of entities relevant to weather, climate, & ocean research & prediction.

— Daniel Swain (@weatherwest.bsky.social) 2025-07-01T17:18:29.000Z

Additional programs slated to lose funding include the National Sea Grant College Program, the National Oceanographic Partnership Program, Species Recovery Grants, Climate Competitive Research, and Regional Climate Data and Information. 

The proposal also calls for the elimination of some environmental restoration and research programs, including the Pacific Coastal Salmon Recovery Fund, which had been used to restore 3,624 acres (1,467 hectares) of salmon habitat and enable salmon to travel hundreds of miles to their spawning streams in 2023, according to Oregon Public Radio. 

 
Related

•  NOAA FY26 Proposed Budget
•  New NOAA Document Spells Out Further Deep Trump Cuts
•  Proposed NOAA Budget Would Shutter Boulder’s World-Class Climate Research Laboratories
•  Get Involved: AGU Science Policy Action Center
 

Whether the proposed budget becomes a reality will be decided by Congress.

The future of much of NOAA’s climate and weather research and monitoring has been uncertain for months as the agency has decommissioned datasets, put some of its weather alert services on hold temporarily, and faced layoffs. 

In June, the agency announced that data from three satellites used in monitoring hurricanes would not be available to researchers after 30 June. Then, on the day of the deadline, they reversed course, extending the data availability through 31 July. Scientists expressed concern that extending the data availability still would not mean the data would be available during the peak hurricane months of August, September, and October.

—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 © 2025. AGU. CC BY-NC-ND 3.0
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Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: AGU Advances

Roots play a role in the weathering and breakdown of rocks, but to what extent is largely unknown. Osorio-Leon et al. [2025] use an ingenious field setup to measure gasses and water constituents around deep roots in sandstone bedrock soils. They find that they can only reproduce their measurements with a reactive transport model when they include the CO2 production that is expected from root respiration or microbial respiration around roots.

The authors further show that the export of weathered solutes from the bedrock by water flow is enhanced by more than 40% through this deep root action. These results reveal that deeply rooted trees are important contributors to hardrock breakdown and ultimately stream chemistry. 

Citation: Osorio-Leon, I. D., Rempe, D. M., Golla, J. K., Bouchez, J., & Druhan, J. L. (2025). Deep roots supply reactivity and enhance silicate weathering in the bedrock vadose zone. AGU Advances, 6, e2025AV001692. https://doi.org/10.1029/2025AV001692

—Marc F. P. Bierkens, Editor, AGU Advances

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Source: Journal of Geophysical Research: Earth Surface

Compared to single-channel meandering rivers, multichannel braided rivers are often found in environments with sparse vegetation and coarse, shifting bars of sediment. Past research has called the way in which the paths of braided rivers shift over time “chaotic” because their migration depends on many factors, including river shape and changing water levels.

However, because the migration of individual channel threads can affect the likelihood of hazards like flooding or erosion, understanding this migration is critical to protect the residents, structures, and ecosystems surrounding these complicated waterways.

Li and Limaye examined a 180-kilometer span of the Brahmaputra-Jamuna River, a river in Bangladesh whose channels have been well resolved through satellite imagery.

Scientists—and many of the 600,000 people living in the islands between the river channels—already know that the river’s water levels are high during the summer months’ monsoon season and low but consistent from January to March. But this research team used a statistical method called dynamic time warping to map long-term changes in the river channels’ sizes, shapes, and routes between 2001 and 2021. This technique allowed them to calculate how much and how quickly the centerlines of channel threads shifted. They then applied an existing model developed for meandering rivers to see whether it could also predict the movement of braided channel threads.

They found that the Brahmaputra-Jamuna River’s movements were more predictable than previously realized. About 43% of its channels moved gradually, rather than abruptly, during the study period. On average, these channel threads migrated more quickly than most meandering rivers, at a rate of about 30% of their width per year. In some cases, the rate of this migration was closely related to the curvature of the channel thread, and across the board, it was weakly related to channel thread width.

These findings have important implications for future research on braided river channels, the authors say. Knowing that at least some channel threads migrate coherently might inform erosion and flooding mitigation efforts for braided river regions, especially those in densely populated areas. (Journal of Geophysical Research: Earth Surface, https://doi.org/10.1029/2024JF008196, 2025)

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

Citation: Owen, R. (2025), Coherent, not chaotic, migration in the Brahmaputra-Jamuna River, Eos, 106, https://doi.org/10.1029/2025EO250237. Published on 2 July 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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This is an authorized translation of an Eos article. Esta es una traducción al español autorizada de un artículo de Eos.

Source: Geophysical Research Letters

Hace 56 millones de años, durante el Máximo Térmico del Paleoceno-Eoceno (PETM, por sus siglas en inglés), las temperaturas globales aumentaron más de 5°C durante 100,000 años o más. En ese tiempo, se liberaron entre 3,000 y 20,000 petagramos de carbono a la atmósfera, lo que provocó una grave alteración de los ecosistemas y de la vida marina a nivel global, y dio lugar a un prolongado estado de efecto invernadero.

Se espera que el calentamiento global antropogénico actual también altere el ciclo del carbono terrestre durante miles de años. Entre 1850 y 2019, se liberaron aproximadamente 2,390 petagramos de dióxido de carbono (CO₂) a la atmósfera y con el uso continuo de combustibles fósiles, es posible que en los próximos siglos se liberen otros 5,000 petagramos. Sin embargo, las estimaciones sobre la duración de esta alteración varían considerablemente, desde unos 3,000 hasta 165,000 años.

Comprender cuánto tiempo se vio afectado el ciclo del carbono durante el PETM podría ofrecer pistas clave sobre la gravedad y duración de las alteraciones derivadas del cambio climático antropogénico. Investigaciones previas, basadas en registros de isótopos de carbono, estimaban que el PETM duró entre 120,000 y 230,000 años. Ahora, Piedrahita et al. sugieren que este evento de calentamiento se prolongó por casi 269,000 años.

La evidencia del PETM se encuentra en el registro geológico como una marcada disminución en las proporciones de isótopos estables de carbono. Este descenso se divide en tres fases, cada una representando distintas etapas de alteración y recuperación del ciclo del carbono. Las estimaciones previas sobre el final de esta disminución han variado ampliamente debido al ruido presente en los datos sobre los que se basan.

En esta nueva investigación, los científicos analizaron seis registros sedimentarios con edades bien establecidas en trabajos previos: un registro terrestre de la cuenca Bighorn en Wyoming y cinco registros sedimentarios marinos de diversas localidades. En lugar de basarse únicamente en datos sin procesar, como en trabajos anteriores, aplicaron un enfoque probabilístico que considera las incertidumbres analíticas y cronológicas, lo que permitió restringir con mayor precisión el intervalo temporal del PETM.

En particular, el estudio sugiere que el periodo de recuperación tardó mucho más de lo que indicaban las estimaciones anteriores—más de 145,000 años. Según los autores, este tiempo extendido de recuperación durante el PETM indica que los escenarios futuros de cambio climático podrían afectar el ciclo del carbono por más tiempo del que predicen la mayoría de los modelos actuales. (Geophysical Research Letters, https://doi.org/10.1029/2024GL113117, 2025)

—Rebecca Owen (@beccapox.bsky.social), Escritora 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.

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A new paper (Faral et al. 2025) provides details of a seismically-triggered landslide cascade and tsunami that killed up to 12,000 people.

On 22 November 1815, a very significant landslide disaster occurred in Bali, in what is now Indonesia, killing between 10,000 and 12,000 people. A very interesting new paper (Faral et al. 2025) in the journal Geomorphology has sought to investigate and understand this catastrophe.

The event, which occurred on Buyan-Bratan caldera, was triggered by the Mw=7.3 1815 Bali earthquake offshore. This triggered a translational landslide near the peak of the caldera. To provide a context, this is a Google Earth image of the site:-

Google Earth image of the site of the 22 November 1815 Gejer Bali disaster.

This image shows the steep caldera at the top, with the steep slopes down to the sea.

Faral et al. (2025) have identified the location of the initial failure. This is surprisingly clear on the Google Earth imagery:-

Google Earth image of the source zone of the 22 November 1815 Gejer Bali disaster.

The failure was a translational landslide – the source zone is so clear because it was left steep slopes in the rear scar and the lateral scarps, which now have dense vegetation. These lateral scarps are 30 to 35 m tall, delineating a landslide with a source area of 2.38 km2 and a volume of about 64 million cubic metres. Descriptions of the event highlight that the area had been subject to “intense and prolonged rainfall”, which may have contributed to the instability.

Faral et al. (2025) have undertaken detailed work to understand the characteristics of the landslide as it travelled the c.17 km to the coast. I think the initial path is quite easy to spot on the imagery:-

Google Earth image of the source zone and possible initial track (my own interpretation) of the 22 November 1815 Gejer Bali disaster.

Lower down the path becomes much less clear, but Faral et al. (2025) have used a range of mapping and stratigraphic techniques to try to understand it. In an earlier paper (Faral et al. 2024), the team has also mapped the c.15 villages that historical records indicate were destroyed by the landslide. They conclude that the initial failure transitioned into a debris avalanche and then a debris flow, eroding saturated sediment from the lower slopes and spreading laterally. This huge landslide moved enormous blocks of rock – one of which is 9 metres long for example – that are now scattered on the lower slopes.

Eventually the landslide reached the sea, and there are reports of a local tsunami. Faral et al. (2025) psotualte that this was most likely generated by the landslide rather than by the original earthquake. They note that there are no known deposits from the tsunami, which supports the notion of a smaller, localised event.

The 22 November 1815 Gejer Bali disaster was a very significant event that warrants more attention – I thank the authors of the two papers from highlighting and investigating this most fascinating disaster. I’m left pondering how we could anticipate a similar event. The nature of this type of initial failure seems hard to determine in advance, given its seismic origin, and the behaviour of the flow is also very difficult to forecast. Thus, such events represent a massive challenge in managing landslide risk.

References

Faral, A., Lavigne, F., Sastrawan, W.J. et al. 2024. Deadliest natural disaster in Balinese history in November 1815 revealed by Western and Indonesian written sources. Natural Hazards 120, 12011–12041 (2024). https://doi.org/10.1007/s11069-024-06671-5.

Faral, A. et al. 2025. Field evidence of the greatest disaster in Balinese history: The 1815 Geger Bali multi-hazard event in Buleleng. Geomorphology, https://doi.org/10.1016/j.geomorph.2025.109903.

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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.

Today, President Trump is visiting a new immigration detention facility built on a disused airstrip in the Florida Everglades. On 27 June, environmental groups sued the U.S. Department of Homeland Security (DHS), U.S Immigration and Customs Enforcement (ICE), the Florida Division of Emergency Management, and Miami-Dade County, seeking a temporary restraining order to stop the construction and opening of the facility.

The lawsuit from Friends of the Everglades and the Center for Biological Diversity argues that the facility’s construction did not undergo environmental reviews legally required under the National Environmental Policy Act. The groups assert that constructing the facility, transporting and housing thousands of people on site, and then flying them directly from the facility to other locations, will undermine decades of work spent restoring and protecting the Everglades’ delicate ecosystem.

“The site is more than 96% wetlands, surrounded by Big Cypress National Preserve, and is habitat for the endangered Florida panther and other iconic species. This scheme is not only cruel, it threatens the Everglades ecosystem that state and federal taxpayers have spent billions to protect,” Eve Samples, executive director of Friends of the Everglades, said in a statement.

“The Miccosukee Tribe is opposed to the use of our ancestral lands in Big Cypress as a detention facility.”

A spokesperson for Florida Governor Ron DeSantis said that the facility “will have no impact on the surrounding environment” and that they will oppose the lawsuit in court.

DeSantis and other state officials have claimed emergency powers to commandeer Dade-Collier Training and Transition Airport and build the migrant facility in roughly a week. Given the nickname “Alligator Alcatraz,” the detention facility is made of tents, trailers, and other temporary buildings and is designed to hold up to 5,000 people detained by DHS and ICE.

Immigration and human rights activists have raised additional concerns about housing thousands of people in tents and trailers at the height of a hot and humid Florida summer and during what is likely to be an above-normal hurricane season. Others are concerned about the environmental impact of a crowded detention center near an aquifer that supplies drinking water to the surrounding area.

 
Related

•  The lawsuit
•  Environmental groups sue to block opening of “Alligator Alcatraz” migrant detention center in Florida Everglades
•  Native leaders blast construction of Florida’s ‘Alligator Alcatraz’ on land they call sacred
•  Get Involved: AGU Science Policy Action Center
 

Indigenous tribes also vehemently oppose the construction of the facility on the land, which is sacred to the Miccosukee Tribe of Indians of Florida and the Seminole Tribe of Florida. There are 19 traditional Miccosukee and Seminole villages in Big Cypress, as well as ceremonial and burial grounds and other gathering sites.

Talbert Cypress, Chairman of the Miccosukee Tribe of Indians of Florida, stated, “Rather than Miccosukee homelands being an uninhabited wasteland for alligators and pythons, as some have suggested, the Big Cypress is the Tribe’s traditional homelands….The Miccosukee Tribe is opposed to the use of our ancestral lands in Big Cypress as a detention facility.”

Groups of environmental, Indigenous, immigration, and human rights activists protested outside the facility on 28 June. More protests are expected today as the facility opens and the president visits.

—Kimberly M. S. Cartier (@astrokimcartier.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 © 2025. AGU. CC BY-NC-ND 3.0
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Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Journal of Geophysical Research: Atmospheres

Clouds are a major source of uncertainty in atmospheric predictability and simulating them accurately remains a challenge for large-scale models. Bogenschutz et al. [2025] evaluate a new high-resolution model called the Simple Cloud-Resolving E3SM Atmosphere Model (SCREAM) developed by the United States Department of Energy (DOE), which is designed to better capture cloud and storm processes. The authors use a fast, small-scale version of the model and compare its output to modern real-world observations from the DOE’s Atmospheric Radiation Measurement (ARM) program.

The model performed better at higher resolutions but still struggled with certain cloud types, especially mid-level “congestus” clouds that form between shallow and deep convection. SCREAM also tended to shift too abruptly from shallow clouds to intense storms, and its performance depended on how finely the vertical layers of the atmosphere were represented.

These results help pinpoint key weaknesses in the model’s treatment of clouds and turbulence. The new library of ARM cases added in this work will help guide future improvements to SCREAM and support more accurate simulations of cloud processes.

Citation: Bogenschutz, P. A., Zhang, Y., Zheng, X., Tian, Y., Zhang, M., Lin, L., et al. (2025). Exposing process-level biases in a global cloud permitting model with ARM observations. Journal of Geophysical Research: Atmospheres, 130, e2024JD043059. https://doi.org/10.1029/2024JD043059

—Yun Qian, Editor, JGR: Atmospheres

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On 16 September 2023, a low hum started swaying seismometers around the world. Unlike during the short and jagged frenzy of an earthquake, this signal wobbled every 92 seconds and continued for 9 days. About a month later, while seismologists were still puzzling over the incident, the hum started again and lasted roughly a week.

Researchers traced the confusing signals to East Greenland, where satellite imagery revealed the scars of recent rockslides in Dickson Fjord. They deduced that millions of cubic meters of rock and ice had suddenly fallen into the sea on 16 September, creating a 200-meter (650-foot) tsunami and a long-lasting wave called a seiche. Rather than ricochet out to sea, crooked topography kept the tsunami sloshing back and forth between the fjord’s parallel walls. The later hum was from a second, smaller rockslide and seiche.

The area is unpopulated, meaning no one was threatened by the initial wave but no one observed the event either.

Seiches typically need a continuous energy source such as a windstorm to persist, but the long-lasting waves in Dickson Fjord appeared to be self-sustaining. Two teams independently developed simulations showing Dickson Fjord could support a long-lasting seiche. A new study in Nature Communications builds on that work, using satellite data to provide the first direct observations of the seiche.

“To really robustly be able to say, ‘This is what was shaking the Earth at this time,’ we needed that observational evidence,” said Thomas Monahan, an oceanographer at the University of Oxford and first author of the new paper.

Before (left) and after images show the obvious collapse of a glacier in Greenland’s Dickson Fjord. Credit: Søren Rysgaard As Above, So Below

East Greenland is remote, and the seiche mostly dissipated before the Danish military arrived 3 days after the initial wave to investigate the collapsed mountain face in Dickson Fjord. By then, the amplitude of the wave was already too small to detect from the boat. However, the shift in sea surface was visible from space thanks to the international Surface Water and Ocean Topography (SWOT) satellite, launched in 2022.

“We’ve never had the capability to do things in these regions at this level before.”

SWOT uses two altimeters spaced 10 meters apart to triangulate small changes in water height. Prior to SWOT, satellites had one altimeter and could offer a one-dimensional footprint of the ocean. Now, Monahan said, researchers can obtain precise, high-resolution imagery of the sea surface, even between the deep walls of a distant fjord.

“We’ve never had the capability to do things in these regions at this level before,” he said.

The satellite passed over Dickson Fjord several times during the main event and the smaller rockslide that followed. Monahan and his colleagues examined SWOT data from four transits, tracking the sea surface slope along the same transect each time.

The water was sloshing back and forth between the fjord walls.

The researchers extended their search to rule out other causes. The timing of the waves did not match the timing of winds recorded by a weather station in the fjord or the pattern of tides recorded by SWOT over the next 13 months. The magnitude of the wave did, however, match the seismic signal, further suggesting the fjord’s geometry had trapped a wave.

A sloshing tsunami in Dickson Fjord shimmied seismometers for 9 days starting on 16 September 2023. This data visualization of the fjord on 17 September 2023 shows the sloshing water and adds direct observational evidence to earlier models. Credit: NASA Earth Observatory “Science at Its Best”

The study further confirmed the seiche but also showed the early utility of SWOT, which had finished calibrating just 2 months before the initial rockslide.

“They’re sort of perfect partners, satellite and seismic data.”

“It’s a nice surprise to see the result,” said Yao Yu, a physical oceanographer who works with SWOT data at the Scripps Institution of Oceanography. The satellite is built for oceans, rivers, and lakes, she said, but the new study shows it can also collect good data from high-latitude fjords in areas unreachable by prior satellites. “A lot of things we never expected SWOT can do, it’s actually working very well,” she said.

SWOT’s spatial resolution is especially important in the Arctic, where seismometers are sparse. The satellite provides only intermittent observations, but it can access remote locations. That fills a gap, said Stephen Hicks, a seismologist at University College London and coauthor on one of the original seiche papers.

“They’re sort of perfect partners, satellite and seismic data,” he said. The new study backs up and builds upon the original research, he added, and “that’s sort of science at its best.”

—J. Besl (@J_Besl), Science Writer

Citation: Besl, J. (2025), New satellite adds evidence of an Earth-shaking wave, Eos, 106, https://doi.org/10.1029/2025EO250236. Published on 1 July 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
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A major slope failure killed many people, possibly over 300, in an area of unlicenced mining of the mineral Coltan.

On 19 June 2025, a very significant landslide occurred at the Rubaya mining site in Masisi territory, North Kivu, which is located in the eastern part of the Democratic Republic of the Congo (DRC). The landslide, which reportedly affected a place called Bibatama, killed at least 21 people, but in all probability many more people died. Local news site Mines.cd reports over 300 fatalities.

The Rubaya mining area is a large, unlicenced and unregulated shallow excavation for the extraction of Coltan (known industrially as tantalite), an ore from which niobium and tantalum are extracted. The primary use of tantalum is in mobile phones, but it is also used in computer hard drives and road vehicle electronics.

These types of disastrous mining landslides in less developed countries rarely attract much interest (imagine what would have happened if this event had occurred in Canada or Australia), so I decided to see whether I could find anything out about it. I must note that landslides at this site are common – for example, about 100 people were killed in a landslide in 2013.

The Rubaya mining area is well covered in Google Earth – this is an image from 2021. The marker gives the general location – we’ll come back to this spot below:-

Google Earth image from 2021 showing the Rubaya mining area in the DRC.

Zoom in and you find a landscape scarred by shallow workings and landslides:-

Google Earth image from 2021 showing a part of the Rubaya mining area in the DRC.

The Rubaya mining area has a very challenging history. In recent years, possession has alternated between the military and various militias, who have run the site as a protection racket. Since April 2024, the site has been controlled by the March 23 Movement (M23), a rebel group with a long history of human rights violations.

I have been trying to use Planet Labs images to try to identify the location of the 19 June 2025 landslide. I think the most likely location is in the mining area located at [-1.58203, 28.89378]:-

Google Earth image from 2021 showing the likely location of the 19 June 2025 landslide in the Rubaya mining area in the DRC.

This mining area has expanded rapidly in recent years. The 2021 Google Earth image shows that it has been subject to a number of landslides.

I have downloaded a Planet Labs image from 14 June 2025 – five days before the landslide, and I have draped onto the Google Earth DEM. Of course, the Planet Labs imagery has a lower spatial resolution than the Google Earth imagery:-

Planet Labs image of the likely site of the 19 June 2025 landslide in the Rubaya mining area. Image copyright Planet Labs, used with permission. Image dated 14 June 2025.

The image shows a higher level of mining activity than was the case in 2021, and possibly some further landslides. By comparison, the image below was captured on 25 June 2025, after the landslide:-

Planet Labs image of the aftermath of the 19 June 2025 landslide in the Rubaya mining area. Image copyright Planet Labs, used with permission. Image dated 25 June 2025.

And here is a slider to allow the images to be compared:-

Image copyright Planet Labs, using the Google Earth DEM.

I think the landslide is visible on the left side of the mining area. A series of shallow workings have been destroyed, and the track and runout zone of the landslidecan be seen. The feature that is probably the landslide is about 250 metres long.

These types of landslides in unlicenced and unregulated mining sites are a major contributor to global landslide fatalities, but they are rarely investigated.

Finally, in an interesting twist, the FT reported last week that an ally of Donald Trump, Gentry Beach, is seeking to “snap up” the Rubaya mine site.

Reference

Planet Team 2024. Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/

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

One of the challenges in global hydrology is to simulate water resources globally at a resolution that is fine enough to be of local relevance. However, these hyper-resolution (less than 1 kilometer) simulations are limited by the very high computational demand of routing water through the global river system.

Shrestha et al. [2025] devise a very clever upscaling algorithm for stream directions that allows simulating streamflow at low-resolution, while still being able to locally refine ate points of interest, such as locations where streamflow is measured. This computational breakthrough opens the door to very detailed global hydrological simulations, not only for global hydrology, but for Earth system science at large.

Citation: Shrestha, P. K., Samaniego, L., Rakovec, O., Kumar, R., & Thober, S. (2025). A novel stream network upscaling scheme for accurate local streamflow simulations in gridded global hydrological models. Water Resources Research, 61, e2024WR038183.  https://doi.org/10.1029/2024WR038183  

—Marc F. P. Bierkens, Editor, Water Resources Research

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If astronomers have learned one lesson from 6,000 or so confirmed exoplanets, it’s to expect the unexpected. Even so, a giant planet orbiting a red dwarf star recently caught them by surprise. It is the largest planet relative to its host star yet discovered, and it defies the leading theory of giant-planet formation, according to a new study.

TOI-6894 b orbits an M dwarf star roughly one fifth the size and mass of the Sun—60% the mass of the next-smallest star with a giant planet. TOI-6894 b is the size of Saturn and half its mass. The planet is 40% the diameter of the host star, making it by far the highest planet-star size ratio yet seen.

“Because the star is so low mass, based on what we currently understand about planet formation and protoplanetary disks, we wouldn’t have expected it to be able to form a gas-giant planet,” said Edward Bryant, an astrophysicist at the University of Warwick in the U.K. and first author of the study, published in Nature Astronomy.

The planet was first detected by the Transiting Exoplanet Survey Satellite (TESS) in early 2020 and confirmed with additional observations over the following 3 years. TESS looks for the dip in a star’s brightness that occurs when a planet passes between it and Earth, blocking some of its light.

TESS, a planet-hunting space telescope, stares into space in this illustration. It has discovered more than 600 confirmed exoplanets, with thousands of candidate worlds awaiting confirmation. Credit: NASA Goddard Space Flight Center

Bryant and his colleagues scoured observations of 91,000 stars in the TESS catalog to determine the frequency of giant planets around low-mass red dwarfs, which are the smallest and faintest stars in the galaxy and the most common. They reported the discovery of several such planets in 2023.

The team’s new analysis shows that the transits of TOI-6894 b are record breakers, reducing the star’s brightness by 17% and hinting at how large the planet is relative to its star. The transits also show that it orbits every 3.37 days.

The follow-up observations with ground-based telescopes measured changes in the star’s radial velocity—back-and-forth “wobbles” in its motion caused by the planet’s gravitational pull that revealed the planet’s mass.

A Special Case?

The leading theory of giant planet formation, called core accretion, posits that such worlds form early in a star’s lifetime, when it is still encircled by a protoplanetary disk—a wide disk of gas and dust that comprises the raw building materials for planets. Heavier materials coalesce to form larger and larger bodies, eventually creating a core that can be several times the mass of Earth. When the core grows large enough, it gobbles up the surrounding gas, building a layered giant planet similar to Saturn or Jupiter.

“It’s a surprise to find a giant planet around such a tiny star because we just didn’t think there would be enough material there.”

“The total amount of heavy material in the disk determines how big of a core you can make,” said Joel Hartman, a research astronomer at Princeton University and a member of the study team. “It’s a surprise to find a giant planet around such a tiny star because we just didn’t think there would be enough material there.” Some studies, he added, have suggested that stars less than about one third the mass of the Sun should not be able to form giant planets at all.

“Theorists who model planet formation [with core accretion] are not able to create planets like TOI-6894 b,” said Emily Pass, an astrophysicist at the Massachusetts Institute of Technology who was not involved in the study. “So the question becomes, Are planets like TOI-6894 b special cases that formed in a different way, or does our entire model of giant planet formation need a revision?” Pass explained. “Understanding the occurrence rate of [such] planets will help test the various possibilities.”

Hinting at the Formation Mechanism

One possibility is a modified accretion mechanism, in which the growing planet hoovers up both heavy materials and gas simultaneously, forming a more mixed world.

“None of these theories can really explain this planet.”

Another possibility is direct collapse. “Instead of the core being built from the ground up, the disk fragments under its own self-gravity and directly collapses,” Bryant said. “If the disk becomes unstable in the right way, you can form giant planets around these low-mass stars. The problem is that some of the simulations predict that you would only form planets that are much, much more massive than Jupiter, which would be many times more massive than this planet. So none of these theories can really explain this planet. We’re really limited by our understanding of protoplanetary disks,” he said.

Hints of the planet’s formation mechanism may be found in its atmosphere, which is scheduled for study in the next year by the James Webb Space Telescope (JWST). As the planet passes in front of the star, starlight shining through the atmosphere will reveal its composition.

“We should be able to tell the difference in whether a planet formed from direct collapse versus core accretion by looking at the atmosphere’s metallicity,” which is the makeup of elements heavier than hydrogen and helium, Hartman said. “In the gravitational instability case, all the materials collapsed together, so the elements should all be mixed together. In the core accretion model, all the heavy elements should be in the core, with a gaseous envelope on top of it.”

Two charts compare (a) the mass and (b) size of many exoplanets to their host stars. TOI-6894 b, in purple, clearly stands out from the crowd. Credit: Bryant et al., 2025, https://doi.org/10.1038/s41550-025-02552-4, CC BY 4.0

Because of the large transit signal, TOI-6894 b should be “amenable” to additional ground-based studies, Hartman said, although none are currently planned. “We’ll wait and see what JWST tells us,” Bryant said.

—Damond Benningfield, Science Writer

Citation: Benningfield, D. (2025), A new exoplanet resets the scale, Eos, 106, https://doi.org/10.1029/2025EO250235. Published on 30 June 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.

An excellent new paper (Walden et al. 2025) examines the occurrence of accelerated movement in rock slope landslides in Alaska as adjacent glaciers melt.

The exceptional temperatures in recent days in both North America and Europe has once again highlighted the rate at which the climate is changing in response to anthropogenic increases in greenhouse gases. In most glaciated areas, retreat of the large ice masses is occurring. There has long been discussion of how the slopes adjacent to glaciers will respond to these changes.

There is a very good new open access paper (Walden et al. 2025) in the journal Natural Hazards and Earth System Sciences that examines this issue for eight landslides in southern coastal Alaska. These are large, rock slope failures in areas in which the adjacent glaciers are retreating rapidly. In some cases, the glacier has already retreated beyond the slope, leaving it bordering lakes or fjords. In other cases, the slope is still in contact with the ice, which is in retreat.

On of these landslides is at the actively retreating Barry Glacier – this is a very large rock slope failure, with an estimated volume of between 188 and 500 million cubic metres. This is a Google Earth image of the site in 1996:-

Google Earth image of the landslide at the Barry Glacier in Alaska in 1996.

And this is the same site in 2019:-

Google Earth image of the landslide at the Barry Glacier in Alaska in 2019.

And here is a slider to allow the images to be compared:-

Google Earth images.

The change in the glacier is, of course, startling, but the large rock slope landslide is also notable.

Walden et al. (2025) have used archive datasets extending back to the 1980s to examine these eight slopes as the glaciers below them changed. They found that six of the slopes have experienced a period of substantially increased rates of movement. In four sites, a pronounced acceleration was observed as the terminus of the glacier retreated past the landslide area. Two other sites showed rapid movement during a period of wet weather or as the glacier rapidly thinned. In two cases, the sites did not appear to undergo a change in behaviour.

This is illustrated by data from the Barry Glacier site. This is a part of Figure 4 from Walden et al. (2025), showing the measured landslide velocity (upper graph), the retreat of the terminus of the glacier (middle graph) and the change in thickness of the Barry glacier (lower graph). The pink shading shows onset of rapid movement. The slope underwent a really rapid phase of movement (over 20 metres per year) as the adjacent glacier thinned and the slope started to debuttress.

The behaviour of the rock slope at the Barry Glacier in Alaska. Part of Figure 4 from Walden at al. (2025).
Key parts of the original caption:
“Landslide and glacier evolution at the study sites. Row 1: landslide velocities from ITS-LIVE (black circles, with uncertainty estimates) and manual feature tracking (gray bars). Stars indicate the onset of slope-wide deformation, triangles stand for crack opening, and diamonds mean both deformation and crack opening. Row 2: terminus retreat (dark blue) and location of the landslide along the glacier centerline (light-blue shading). Row 3: glacier thickness change rates (purple) and absolute ice thickness (yellow; right-hand axis) below the landslide. … In all panels, light-red shading indicates the onset of landslide movement.

Large rock slopes are incredibly complex, and the ways in which they interact with their environment (including an adjacent glacier, but also rainfall, seismic forcing and suchlike) is also complex, so we would not expect them all to respond in the same way. But this study is important for two reasons.

First, it provides additional support for the notion that glacial debuttressing is an important element of the geomorphology of areas undergoing glacial retreat.

But second, large rock slope failures can be very hazardous, either through direct impact from the resulting rock avalanche or as a result of the generation of a localised displacement wave. This study once again highlights the need to monitor these types of slope better, to undertake hazard analyses and to ensure that local populations are prepared for the consequences of a rapid collapse event.

Reference

Walden, J., Jacquemart, M., Higman, B., Hugonnet, R., Manconi, A., and Farinotti, D. 2025. Landslide activation during deglaciation in a fjord-dominated landscape: observations from southern Alaska (1984–2022), Natural Hazards and Earth System Sciences, 25, 2045–2073, https://doi.org/10.5194/nhess-25-2045-2025.

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

The morning of 23 July 2024 was like most summer mornings in Yellowstone National Park. Cars vied for parking spaces, bison lounged in meadows, and tourists strolled along boardwalks taking in sights of bubbling springs and spouting plumes of water and steam. All were unaware of the pressure that had built underneath Black Diamond Pool, a thermal spring in Wyoming’s Biscuit Basin about 3.5 kilometers northwest of famed Old Faithful Geyser.

Suddenly, just before 10:00 a.m., jets of muddy, rock-laden water and steam shot from the turbid depths of the pool, building into bursts as high as 400–600 feet (~120–180 meters) that showered the surrounding area and boardwalk with rocks and mud. Water from the pool surged toward the nearby Firehole River, carrying boulders and debris, and a steam plume was visible from kilometers away.

A still image taken from a video shot by a Yellowstone visitor shows the 23 July 2024 hydrothermal explosion at Black Diamond Pool. Credit: Juliet Su

Fifty-five seconds after the explosion began, it was over. Left behind was a roughly 1-square-kilometer debris field, as well as many stunned onlookers, fresh from scrambling away from the unexpected outburst and wondering what had just happened.

Safety was the paramount concern in the immediate aftermath of the event. But scientists also mobilized quickly to monitor for additional activity and to collect timely observations that could help piece together why the explosion happened. On a longer timescale, federal, state, and academic organizations are working together to better understand the dynamics and triggers of hydrothermal explosions to recognize warning signs of future events before they occur.

What Are Hydrothermal Explosions?

Hydrothermal explosions, like the July 2024 event at Black Diamond Pool (Figure 1), occur in many volcanic-hydrothermal areas around the world. When a pressurized hot water reservoir instantaneously decompresses, superheated water violently flashes to steam that has enough energy to break surrounding rock [Muffler et al., 1971; Thiéry and Mercury, 2009; Browne and Lawless, 2001; Montanaro et al., 2022].

Fig. 1. This helicopter image taken 23 July 2024 shows Biscuit Basin, with major hydrothermal features labeled. The debris field from the hydrothermal explosion is the area covered with gray sediment around Black Diamond Pool. The inset map shows the location of Biscuit Basin within Yellowstone National Park. Credit: Photo by Joe Bueter, National Park Service

Such explosions exist on a continuum from large, destructive events to smaller geyser eruptions that routinely spew water and steam into the air. Geysers are caused by constrictions in hydrothermal plumbing systems that temporarily trap boiling water and steam until the pressure is high enough for the water to erupt. Hydrothermal explosions, on the other hand, occur less frequently. They are primed by the gradual pressure increase in a confined system, followed by rapid decompression caused either by rupturing of a hydrothermal seal or by an external event like a landslide or earthquake. Large geyser eruptions can destroy geysers’ plumbing systems and throw rock and mud like hydrothermal explosions, and small, spontaneously reoccurring hydrothermal explosions may arguably be more consistent with geyser activity.

In Yellowstone National Park, at least 18 massive hydrothermal explosions have formed craters ranging from 300 to 2,500 meters across.

In Yellowstone National Park, the occurrence of hydrothermal explosions has been recognized for decades. Since the end of the most recent glaciation roughly 14,000 years ago, at least 18 massive hydrothermal explosions have formed craters ranging from 300 to 2,500 meters across, the largest of which—formed about 13,800 years ago—is the biggest explosion crater on Earth [Muffler et al., 1971; Morgan et al., 2009; Christiansen et al., 2007].

More than 2 dozen hydrothermal explosions have been documented within Yellowstone National Park since its founding in 1872 [Christiansen et al., 2007]. One of the best-observed events prior to 2024 was the explosion of Porkchop Geyser in Norris Geyser Basin on 5 September 1989 [Fournier et al., 1991]. That event—witnessed by nine people, none of whom were injured—threw small rocks and debris 60 meters from the vent and left a crater more than 10 meters wide.

Smaller hydrothermal explosions occur more frequently than larger ones (maybe as often as annually), but they usually go unwitnessed because they occur in the backcountry, at night, or during winter months. Hydrothermally active areas around the world sometimes show signs of instability or increases in temperature prior to an explosion; however, there are no known universal precursory signals upon which forecasts can be based.

Keeping Watch over Yellowstone’s Activity

The lack of knowledge about hydrothermal explosion occurrence rates, precursory signals, and triggers motivated the Yellowstone Volcano Observatory (YVO), a consortium of nine federal, state, and academic organizations, to include hydrothermal processes and hazards in its recently developed hazards monitoring plan [Yellowstone Volcano Observatory, 2022]. The plan includes the installation of broadband seismic, infrasound, thermal, and deformation sensors within geyser basins to better detect anomalous hydrothermal activity and investigate the potential to forecast hazardous events.

A prototype hydrothermal monitoring station, installed in Norris Geyser Basin in 2023, immediately paid dividends. The station clearly detected infrasound signals from nearby geyser eruptions and a small hydrothermal explosion that occurred on 15 April 2024—the first hydrothermal explosion in Yellowstone National Park to be documented by instrumental monitoring [Poland et al., 2025].

Yellowstone Volcano Observatory’s volcano monitoring network barely detected the explosion, even though it was big enough to destroy a section of boardwalk adjacent to Black Diamond Pool.

However, no hydrothermal monitoring station was installed at Biscuit Basin in July 2024, and YVO’s volcano monitoring network barely detected the explosion, even though it was big enough to destroy a section of boardwalk adjacent to Black Diamond Pool. The destructive event—thankfully, no injuries resulted—emphasizes the importance of expanded monitoring in geyser basins of Yellowstone National Park. It also highlights the risk posed by even small explosions that occur when people are nearby.

Much remains unknown about the processes leading to hydrothermal explosions and how best to safeguard the more than 4 million visitors to Yellowstone National Park every year from this underappreciated hazard [e.g., Montanaro et al., 2022]. The goal of postexplosion scientific investigations is to develop understanding that will enable better monitoring, detection, and, potentially, forecasting of future dangerous hydrothermal events.

Black Diamond Pool’s Explosive Past and Present

Explosive activity has recurred sporadically at Black Diamond Pool over its roughly 120-year life. Broken, angular rocks from previous explosions that were cemented back together before being ejected on 23 July 2024 provide evidence of this repeated explosive activity.

According to early geologic maps and photographs, Black Diamond Pool did not exist before 1902. It likely formed dramatically from a hydrothermal explosion sometime between then and 1912. Documents preserved in the Yellowstone National Park archives reference a few short periods of explosive activity that enlarged the new pool and formed two additional springs.

Black Diamond Pool (larger pool at top right) and Black Opal Pool (smaller pool at center left) are seen in this aerial photo taken in 1959 (left). A small hydrothermal explosion occurred at Black Diamond Pool in 2009 (right). Credit: left: Yellowstone Heritage & Research Center photo 35734, Public Domain; right: Wade Johnson, EarthScope

The area was quiet after 1960 until a series of short explosive events of varying intensity (though none approaching the scale of the July 2024 event) reinitiated in 2006. The frequent activity ceased by early 2013, and only three isolated events were reported between then and July 2024.

The 23 July hydrothermal explosion—which occurred during the park’s busiest month—stunned tourists, National Park Service (NPS) officials, and the scientific community. Visitation numbers had peaked a few days earlier, and on the day of the explosion, cameras recorded 209 visitors to Biscuit Basin by 9:00 a.m. Within minutes of the approximately 10:00 a.m. event, law enforcement rangers arrived on the scene and quickly closed the basin to the public to prevent injuries should explosive activity continue.

YVO’s initial response primarily involved communicating to the public and emergency managers about the cause of the event and the potential for additional activity. Observatory scientists also fielded numerous media inquiries.

Coordination of the scientific response began in parallel with these communications activities. YVO scientists and experienced collaborators from other institutions deployed to the field within hours to days to install monitoring equipment and gather time-sensitive data using a variety of approaches.

Fanning Out in Biscuit Basin

Working near an unstable, potentially explosive pool in the immediate aftermath of the explosion was an exercise in situational awareness.

Working near an unstable, potentially explosive pool in the immediate aftermath of the explosion was an exercise in situational awareness, but the extensive training and experience of the scientists involved helped to ensure their safety.

Field teams worked in pairs, with one person keeping an eye out for signs of an ensuing explosion while the other collected data. High-temperature areas surrounding the pool suggested the presence of boiling water or steam underneath a thin crust where the ground could easily collapse or another explosion could break out. Near the pool edge, slippery mud and overhangs that could crumble unexpectedly into the pool also posed particular hazards.

The field teams also knew that newly unsealed hydrothermal systems can emit higher-than-normal amounts of hazardous gases. Thankfully, blowing winds following the explosion diluted potentially dangerous concentrations as well as the strong perfume of acid, sulfur, and hydrocarbons, helping the teams get on with their work.

Geology and Mapping. Hydrothermal explosions leave behind debris fields that can be used to discern many properties of the explosions [Breard et al., 2014]. For example, the size and distribution of ballistic blocks around the vent provide clues about the energy of the explosion. This information also enables calculations of ballistic vulnerability—the probability of a human fatality at any given location around the vent in the event of another explosion of similar size. In addition, rocks excavated from the preexisting subsurface hydrothermal system are useful for understanding the pressure and temperature conditions before the explosion and how sealed the system was.

A field team working near Black Diamond Pool on 28 July 2024 collects location and lithology data for ballistic rocks thrown by the 23 July hydrothermal explosion (left). National Park Service (NPS) employees fly an uncrewed aerial vehicle over the 23 July explosion debris field to image the deposits on 25 July (right). Credit: Photos taken under National Park Service Milestones research permit 1016-9 by Lauren Harrison, Colorado State University

Field teams from Colorado State University, NPS, and the University of California, Berkeley documented the sizes, distribution, and lithology of ballistic blocks thrown by the explosion to begin piecing together what the underlying hydrothermal system looked like before and during the explosion. NPS also used an uncrewed aerial vehicle to collect thermal and structure-from-motion imagery of the deposits and the surrounding area. These images helped identify areas with elevated temperatures and quantify the volume of material ejected by the 23 July explosion.

Dense seismic networks, which can sense the vibrations of bubbles and the brecciation of rock, are powerful tools for resolving subsurface hydrothermal plumbing and detecting small explosions.

Near-Surface Geophysics. Dense seismic networks, which can sense the vibrations of bubbles and the brecciation of rock, are powerful tools for resolving subsurface hydrothermal plumbing, detecting small explosions, and helping scientists assess hazards from ongoing activity.

To record seismic signals in the aftermath of the explosion at Black Diamond Pool, the University of Utah deployed a temporary array of 33 seismometers around the pool by 26 July, and the instruments recorded for about 2 months. Four infrasound microphones were also deployed roughly 300 meters northwest of the pool from 19 August to 18 October. These data will be processed to pinpoint and explore signals from geyser activity and subsequent small hydrothermal explosions in Biscuit Basin.

A temporary seismometer deployed and photographed on 26 July 2024 sits near Black Diamond Pool (left). Another temporary seismometer deployed after the 23 July event—and seen here on 16 October—is partially buried in fine sediment following several small explosions at Black Diamond Pool (right). Credit: Photos taken under National Park Service Milestones research permit 1016-9 by Jamie Farrell, University of Utah

Several weeks after the explosion, field teams from the University of Wyoming and NPS collected nuclear magnetic resonance (NMR), electrical resistivity (ER), and transient electromagnetics (TEM) datasets. NMR data provide estimates of the volume and location of water stored in the subsurface, including in confining, low-permeability zones. ER, which measures resistivity encountered by electrical currents, is ideal for identifying water-saturated subsurface pathways, as hydrothermal waters contain dissolved salts and are electrically conductive. TEM uses pulses of electric current to induce electric and magnetic fields underground. How fast these fields decay is another indication of variations in subsurface resistivity.

Together these techniques paint 3D views of hydrothermal fluids and lithological contrasts in the subsurface—important information for understanding the conditions and characterizing hazard potential in the postexplosion Black Diamond Pool system.

Water and Gas Chemistry. Gas emissions and water chemistry data were collected after the 23 July explosion by the U.S. Geological Survey (USGS), Montana Technological University, and the University of Wyoming to help probe underground processes.

An NPS employee prepares to sample water from Black Diamond Pool on 23 July 2024. The long pole is used for safely dipping sample bottles into the center of the pool, where the hottest water indicates locations of primary thermal water vents. Credit: Photo taken under National Park Service Milestones research permit 1016-9 by Mara Reed, University of California, Berkeley

Gridded measurements of carbon dioxide gas efflux, for example, provide information on spatial variations in diffuse gas fluxes at the surface that can be used to map subsurface gas pathways. Simultaneous measurements of isotopes of the short-lived radioactive gas radon in the same samples used for carbon dioxide measurements can help identify the sources of emissions and timescales of gas movement.

The chemical composition of the water in Black Diamond Pool is important because the solubility of different chemical species depends on the temperature at which water and rocks react. Critically, silica solubility decreases with decreasing temperature, and as hydrothermal waters cool, amorphous (noncrystalline) silica precipitates in subsurface flow paths [Fournier, 1985].

Past analyses of water chemistry at Black Diamond Pool have indicated that water and rocks there react at lower temperatures compared with systems farther south in Upper Geyser Basin, including at Old Faithful [Price et al., 2024]. These lower temperatures are more favorable for silica precipitation and may contribute to sealing flow paths and building pressure for hydrothermal explosions in Biscuit Basin.

Early Insights into the 2024 Explosion

The data collected following the explosion of Black Diamond Pool on 23 July 2024 are still being analyzed to provide a detailed account of the conditions preceding and following the event. However, some preliminary insights are available from the initial observations.

Many indicators point to the explosion being caused by self-sealing in the hydrothermal system.

Many indicators point to the explosion being caused by self-sealing in the hydrothermal system, with the result that increases in subsurface pressure eventually overcame the strength of the sealing rocks—a common mechanism for hydrothermal explosions globally [Morgan et al., 2009; Montanaro et al., 2022]. The lack of a strong earthquake nearby, either before or during the explosion, indicates it was not seismically triggered.

Furthermore, some of the ejected debris—namely, minimally altered, high-porosity, and high-permeability conglomerates and sandstones—likely contained much of the liquid water that flashed to steam and powered the explosion (Figure 2). On the other hand, completely silicified and intensely altered low-permeability rocks also found in the debris field likely constituted the seal that contained the pent-up pressure before the explosion.

Fig. 2. Ballistic rocks thrown by the 23 July 2024 hydrothermal explosion show variation in their degree of alteration, porosity, and permeability. An unaltered, obsidian-rich, cross-bedded sandstone (left) has high porosity and permeability, whereas a gravel lag within a sandstone is highly altered and silicified and has low porosity and permeability (right). These samples were collected under National Park Service Milestones research permit 1016-9. Click image for larger version. Credit: Phillip Kondracki, Colorado State University

The initial analyses of the seismic and infrasound data, as well as observations from scientists and passing visitors, indicate that small explosions at Black Diamond Pool have continued since 23 July 2024 through to the present, posing an ongoing hazard. Some of these explosions have been accompanied by water surges flowing east into the nearby Firehole River and have been large enough to carry seismic instruments several meters downhill and partially bury others in fine sediment. Two witnessed events were observed to throw water, mud, and small rocks 20–30 feet (6–9 meters) into the air. A webcam installed in mid-May 2025 to better document activity at Black Diamond Pool captured a similar small eruption on 31 May 2025.

Better Science for Better Response

New hazard maps and recent geophysical investigations will guide the National Park Service’s response to ensure public safety within Biscuit Basin.

The scientific response to the 23 July 2024 hydrothermal explosion has focused on improving understanding of the event to inform strategies that can be used to detect, and potentially forecast, similar future explosions. New hazard maps and recent geophysical investigations will guide NPS’s response to ensure public safety within Biscuit Basin, helping to address specific questions such as when the basin can be reopened, whether walkways must be relocated, and what the short-term probability of another large explosive event at Black Diamond Pool is. Scientific investigation will also guide YVO’s efforts to deploy targeted monitoring to other hydrothermal areas in Yellowstone National Park.

Hydrothermal explosions in Yellowstone National Park are an underappreciated hazard, and a pressing need exists to better understand where, why, and how often they happen. Filling these knowledge gaps requires multidisciplinary studies that consortia like YVO and its collaborators are well suited to undertake. Ultimately, improved monitoring of hydrothermal hazards will aid risk assessment and mitigation and help park officials and visitors avoid dangerous situations in Biscuit Basin, elsewhere in Yellowstone National Park, and at hydrothermal systems worldwide.

Acknowledgments

We especially thank Jamie Farrell, who assisted with preparation of this article and led the deployment of temporary seismometers and infrasound arrays in Biscuit Basin after the July 2024 explosion. We also acknowledge the many people involved in event response, scientific investigation, and management and policy decisions associated with the 23 July 2024 explosion of Black Diamond Pool. Scientists and personnel from USGS, NPS, Colorado State University, the University of Utah, the University of Wyoming, and Montana Technological University who have contributed include Phillip Kondracki, Alex Hammerstrom, Kiernan Folz-Donahue, Elle Blom, Blaine McCleskey, Sara Peek, Shaul Hurwitz, Steven Rice, Carrie Guiles, Jaclyn Mcllwain, Hillary Robinson, Andy Parkinson, Lexi Peterson, Lisa Morgan, Pat Shanks, Greg Vaughan, Jen Lewicki, Alycia Cox, Michael Loya, Andrew Miller, Katie Copeland, Kallen Snow, and Adaeze Ugwu. We thank Shaul Hurwitz and Patrick Muffler for constructive reviews. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. government.

References

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Browne, P. R. L., and J. V. Lawless (2001), Characteristics of hydrothermal eruptions, with examples from New Zealand and elsewhere, Earth Sci. Rev., 52(4), 299–331, https://doi.org/10.1016/S0012-8252(00)00030-1.

Christiansen, R. L., et al. (2007), Preliminary assessment of volcanic and hydrothermal hazards in Yellowstone National Park and vicinity, U.S. Geol. Surv. Open File Rep., 2007-1071, 94 pp., https://pubs.usgs.gov/of/2007/1071/.

Fournier, R. O. (1985), The behavior of silica in hydrothermal solutions, in Geology and Geochemistry of Epithermal Systems, Rev. Econ. Geol., vol. 2, edited by B. R. Berger, P. M. Bethke, and J. M. Robertson, pp. 45–61, Soc. of Econ. Geol., Littleton, Colo., https://doi.org/10.5382/Rev.02.03.

Fournier, R. O., et al. (1991), Conditions leading to a recent small hydrothermal explosion at Yellowstone National Park, Geol. Soc. Am. Bull., 103(8), 1,114–1,120, https://doi.org/10.1130/0016-7606(1991)103%3C1114:CLTARS%3E2.3.CO;2.

Montanaro, C., et al. (2022), Phreatic and hydrothermal eruptions: From overlooked to looking over, Bull. Volcanol., 84(6), 64, https://doi.org/10.1007/s00445-022-01571-7.

Morgan, L. A., W. C. P. Shanks III, and K. L. Pierce (2009), Hydrothermal processes above the Yellowstone magma chamber: Large hydrothermal systems and large hydrothermal explosions, Spec. Pap. Geol. Soc. Am., 459, https://doi.org/10.1130/2009.2459(01).

Muffler, L. J. P., D. E. White, and A. H. Truesdell (1971), Hydrothermal explosion craters in Yellowstone National Park, Geol. Soc. Am. Bull., 82(3), 723–740, https://doi.org/10.1130/0016-7606(1971)82[723:heciyn]2.0.co;2.

Poland, M. P., et al. (2025), The first instrumentally detected hydrothermal explosion in Yellowstone National Park, Geophys. Res. Lett., 52(11), e2025GL115850, https://doi.org/10.1029/2025GL115850.

Price, M. B., et al. (2024), Historic water chemistry data for thermal features, streams, and rivers in the Yellowstone National Park area, 1883–2021, data release, U.S. Geol. Surv., Reston, Va., https://doi.org/10.5066/P9KSEVI1.

Thiéry, R., and L. Mercury (2009), Explosive properties of water in volcanic and hydrothermal systems, J. Geophys. Res. Solid Earth, 114(B5), B05205, https://doi.org/10.1029/2008JB005742.

Yellowstone Volcano Observatory (2022), Volcano and earthquake monitoring plan for the Yellowstone Caldera system, 2022–2032, U.S. Geol. Surv. Sci. Invest. Rep., 2022-5032, 23 pp., https://doi.org/10.3133/sir20225032.

Author Information

Lauren Harrison (lauren.n.harrison@colostate.edu), Colorado State University, Fort Collins; Michael Poland, Yellowstone Volcano Observatory, U.S. Geological Survey, Vancouver, Wash.; Mara Reed, University of California, Berkeley; Ken Sims, University of Wyoming, Laramie; and Jefferson D. G. Hungerford, National Park Service, Mammoth, Wyo.

Citation: Harrison, L., M. Poland, M. Reed, K. Sims, and J. D. G. Hungerford (2025), Hydrothermal hazards on display in Yellowstone National Park, Eos, 106, https://doi.org/10.1029/2025EO250233. Published on 27 June 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.