EOS

On 19 July 2025, record-breaking rainfall triggered a landslide that destroyed 26 buildings. Plans are now being developed to permanently relocate the community.

On 19 July 2025, parts of South Korea suffered record-breaking rainfall. Flooding and landslides were the inevitable outcome. One location that was particularly severely impacted was a small rural village called Sangneung, which is located in Saengbi-riang-myeon, Sangcheong. It is incredibly difficult to track down village locations in South Korea, but after a lot of work I think it is at [35.38269, 128.05740].

This landslide has attracted considerable attemtion because of the damage it has inflicted. There is a good news report that includes a drone video of the site on Youtube:-

The drone footage starts at 00:33.

This image, released by the local government, also shows the site:-

The aftermath of the 19 July 2025 landslide at Sangneung village. Image released by Sancheong County.

There is a good reflective piece on the plight of the inhabitants of Sancheong, outlining why the village is now longer viable. A decision has now been taken to permanently relocate the village, and detailed plans are being developed.

This is an unusual intervention, but it is hard to argue that it is not the correct one.

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Source: Journal of Geophysical Research: Planets

Orbital imaging has hinted that Mars may have carbon-containing rocks called carbonates on its surface. Carbonates on Mars could offer new insights into how water interacted with rock on the Red Planet, helping scientists learn more about its past. In addition, because carbonates on Earth are primarily produced by living organisms, these rocks are high-value targets in the search for signatures of past life on Mars.

NASA’s Perseverance rover has been traversing Mars since 2021, covering more than 41 kilometers, much of it within Jezero Crater in the Nili Fossae region. Previous orbital data indicated the crater contains carbonates, as well as abundant olivine, which can change to carbonate in the presence of water and carbon dioxide. Now Clavé et al. have analyzed spectroscopic data from Perseverance’s SuperCam instrument suite from multiple locations within Jezero Crater, providing clear evidence of carbonates on Mars, as well as detailed information on how the mineralogy varies between locations.

The authors confirmed the presence of both carbonates and olivine-bearing rocks throughout Jezero Crater and found a generally inverse relationship between the two minerals. By contrast, carbonates were generally positively correlated with the presence of hydrated silica. The researchers hypothesize that an ancient lake in the crater, along with potential hydrothermal activity, played a role in transforming olivine to carbonate. The varying amounts of carbonate and different alteration states seen today may have been caused by changing lake levels on Mars billions of years ago, the researchers suggest.

Amounts of carbonate by weight vary between locations, from 1%–3% in the Séítah unit to 6%–16% in the Eastern Margin Unit. Extrapolating to the entire regional olivine-rich unit, the researchers calculated it could contain as much as 1.1 × 1014 kilograms of carbon, or up to 0.4% of the current total mass of the Martian atmosphere. Overall, Mars’s crust could contain significant amounts of carbon, implying that widespread carbon sequestration may have cooled the planet significantly in the past. (Journal of Geophysical Research: Planets, https://doi.org/10.1029/2025JE009107, 2026)

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2026), Carbon-rich rocks may have cooled the ancient Martian atmosphere, Eos, 107, https://doi.org/10.1029/2026EO260170. Published on 28 May 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

On 31 March 2026, the U.S. Department of Agriculture announced the closure of 57 of its 77 U.S. Forest Service research facilities. The scientific community’s response was warranted: Save the science, restore the funding, protect the researchers.

All of that is correct. But it misses a structural problem inherent in agency governance, one that will recur at every reorganization until the Earth science community builds an instrument to prevent it.

In massive reorganizations like the ones federal agencies are currently experiencing, the threat to long-term research facilities is not primarily a lack of funding. The true threat is an oversight of administrative architecture. There appears to be no general federal requirement to have a successor stewardship plan in place before reducing the output or outreach of a long-term research facility—or closing it entirely.

The Physical Archive Is Not a Digital File

Hubbard Brook Experimental Forest in New Hampshire was among the sites under review during the Forest Service restructuring but has since received a public reprieve. The future of Bartlett Experimental Forest, also in New Hampshire, remains unresolved. The governance problem, however, extends beyond either site.

Hubbard Brook’s physical archive holds more than 60,000 barcoded and cataloged samples: water, soils, plant material, and physical cores spanning 7 decades of continuous collection and stored under active environmental controls in a dedicated building on site.

These samples cannot be digitized. They cannot be migrated to a remote server, backed up to cloud storage, or emailed to a university partner. The samples require a functioning building, active temperature management, and a named human steward responsible for their integrity.

• The physical archive at Hubbard Brook holds more than 60,000 barcoded and cataloged samples stretching back to the founding of the facility in 1955. Credit: Anthony Veltri
• The archive includes core samples of trees dating to long before the experimental forest was established, and the archive maintains each as a managed scientific record with continuity of custody. Credit: Anthony Veltri
• Core samples like these document the watershed at Hubbard Brook and anchor long-term understanding of system processes. Credit: Anthony Veltri

The archive at Hubbard Brook is impressive, but a governed record is defined by continuity, provenance, and stewardship, not by the number of observations it contains: Data volume is not data value. A 70-year unbroken record of watershed chemistry, maintained by named stewards who documented what they were measuring and why, is a governed product. Without that stewardship and physical anchor, volume can become noise.

The failure to maintain archives like this is likely not malicious; it is an example of administrative indifference or perhaps a lack of awareness or understanding. Environmental controls, for example, get zeroed out of a budget line item, and nobody notices until the temperature in the facility drifts. By then, the sample record has degraded in ways that cannot be reversed.

This Is Not a Hubbard Brook Problem

Many physical archives, calibration sites, and long-duration sampling programs operate without a formal requirement for stewardship continuity.

Hubbard Brook is the most visible instance of a pattern—the lack of a successor stewardship plan—that runs across the entire 84-site federal Experimental Forests, Ranges, and Watersheds network. The March order that identified Bartlett Experimental Forest and 56 other research facilities across 31 states for closure was executed without a mandatory requirement to identify successor stewards for what gets left behind.

Nor is the pattern unique to experimental forests. The Long Term Ecological Research network spans 28 core sites. AmeriFlux includes more than 500 monitoring locations across North America.

Throughout all these systems, many physical archives, calibration sites, and long-duration sampling programs operate without a formal requirement for stewardship continuity under agency reorganization.

What We Stand to Lose

Long-term physical archives provide scientists and other stakeholders the ability to ask future questions of past reality. Nobody collecting water samples at Hubbard Brook in 1963 was thinking about PFAS (per- and polyfluoroalkyl substances), for instance, but the baseline its site samples provide is why we can track the chemicals today. The same continuous record was central to the regulatory science behind the Clean Air Act amendments of 1990.

Archival value compounds silently and becomes visible only when someone needs it.

Archival value compounds silently for decades and becomes visible only when someone needs it.

When these archives fail, the loss is not historical. It is operational. Regulatory agencies rely on long-baseline records to determine whether interventions are working. Without a continuous physical reference, observed changes cannot be distinguished from measurement drift, instrumentation bias, or natural variability. The results are policy decisions made without a defensible scientific baseline.

Federal investment in continuous collection at a site like Hubbard Brook runs to tens of millions of dollars over decades. That investment is not recoverable once continuity is broken.

Unlike a paused research grant, a degraded physical archive cannot be restarted. You can photograph a sample, but you cannot rerun its chemistry 40 years from now if the physical sample has degraded.

In 2017, a double mechanical failure at the University of Alberta destroyed 12.8% of the Canadian Ice Core Archive over a single weekend, permanently erasing records dating back 12,000 years. That incident was accidental. A mechanical malfunction is a failure of equipment. Administrative disposal without a named successor steward is a failure of governance. One arrives without warning. The other can be prevented.

The Community Already Knows How to Do This

The Earth observation community has already built the governance model we need. We are not yet applying it to long-term ecological research infrastructure.

GRUAN, the Global Climate Observing System (GCOS) Reference Upper-Air Network, operates under the World Meteorological Organization and GCOS, with explicit named stewardship obligations. Upper-air observations—measurements of temperature, humidity, and wind through the atmosphere—are foundational inputs to weather forecasting and climate monitoring. Each GRUAN station has a designated principal investigator with a documented succession obligation.

ICOS, the Integrated Carbon Observation System operating across Europe, applies the same logic to terrestrial ecosystem observations through formal site-level stewardship agreements and named succession requirements.

In the United States, the National Ecological Observatory Network is funded by the National Science Foundation (NSF) and operated by Battelle, a science and technology nonprofit, under a contract that includes explicit data continuity obligations.

These systems did not emerge by accident. They were explicitly designed to solve a known failure mode: Distributed observational networks cannot maintain their own calibration integrity without a separately governed reference layer. That design decision is documented, enforced, and funded. The absence of an equivalent requirement in long-term ecological research infrastructure is not a technical limitation. It is a governance omission.

The pattern is consistent across every network that has solved this problem: Named continuity obligations must be written into the governance structure before the need becomes acute.

The Governance Instrument

The best outcome is the continued, uninterrupted operation of facilities like Hubbard Brook.

Any federal agency action that would reduce operational support for a long-term research facility should require a formal continuity plan before the action takes effect.

If reductions move forward, however, the proposed fix is specific and not novel: Any federal agency action that would reduce or eliminate operational support for a long-term research facility should require a formal continuity plan before the action takes effect. That plan must name a successor steward for each active long-term dataset and for each physical archive under active environmental control.

In practice this means specificity: the name and institutional affiliation of the successor, a funded maintenance budget sufficient to sustain environmental controls and sample integrity, documented protocols for custody transfer, and a timeline for uninterrupted handoff. The plan must demonstrate that the successor steward has the operational capacity and funded mandate to preserve the archive’s physical integrity and continuity.

This instrument prepares plant samples collected at Hubbard Brook using standardized methods. Consistent preparation is what makes results comparable across time and labs and why continued stewardship is so important. Credit: Anthony Veltri

The default should be continued stewardship by the responsible federal entity. If a change in custody is legally permitted and genuinely unavoidable, any successor steward, whether another federal unit, a university partner, a consortium, or another entity, must have a funded mandate, demonstrated technical capacity, enforceable continuity obligations, and the ability to maintain the archive without interruption.

Protocol demands that if the agency cannot name a viable successor steward, the agency cannot execute the closure. This requirement does not prohibit closure; it prohibits closure without continuity of custody.

The instrument requiring a research facility to have a formal continuity plan should be applied not on a site-by-site basis, but uniformly across networks. A limitation narrowly written to protect a named facility invites the agency to execute the same administrative disposal at adjacent sites while technically complying with the specific requirement. The governance is structurally sound only if it applies across the network.

How This Actually Happens

The pathways that would make such an instrument possible already exist.

Agencies can impose continuity requirements through policy directives, appropriations language, or funding conditions. The federal Office of Science and Technology Policy and the Office of Management and Budget have coordinated interagency data management guidance before, and a directive requiring named successor stewardship before any facility reduction does not require legislation. Sen. Jeanne Shaheen (D-NH) has already secured fiscal year 2026 language directing the Forest Service to prioritize staffing at long-standing experimental forests; attaching successor stewardship language is the logical next step. NSF, the Department of Energy, and NOAA could require stewardship continuity guarantees from partner agencies as a condition of incorporating facility data into federally funded continental-scale products.

Scientists recognize that agencies reorganize and funding for facilities can be downgraded. That is why preserving a continued record of any long-term research facility must be part of the facility’s governance structure from the outset. Credit: Anthony Veltri

What is missing is the requirement itself—and the strategic initiative to establish it. The Earth science community has the standing, the documented models, and the mechanisms to close those gaps.

This is not an argument against reorganization. Agencies reorganize. Budgets shift. Research priorities evolve.

The argument is that reorganization cannot be permitted to destroy multigenerational scientific infrastructure through administrative indifference when a specific, enforceable governance requirement can prevent it. The Earth observation community built GRUAN because it recognized that no federation of climate datasets can be a substitute for a governed anchor point. Long-term ecological research infrastructure needs the same recognition applied to the administrative layer that governs its continuity.

The scientific enterprise already knows how to do this. The governance has not caught up yet.

Author Information

Anthony Veltri (anthony@anthonyveltri.com) is an independent practitioner and former physical scientist and senior policy analyst with the USDA Forest Service Washington Office, where he worked on enterprise architecture and governance in federal programs, including those supporting scientific research.

Citation: Veltri, A. (2026), The governance gap threatening long-term ecological archives, Eos, 107, https://doi.org/10.1029/2026EO260172. Published on 27 May 2026. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 2026. 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’ Vox is a blog from AGU’s Publications Department.

Explosive volcanic eruptions inject gases and ash into the atmosphere, posing major hazards for human health, infrastructure, and aviation. A new article in Reviews of Geophysics examines recent advances in estimating Eruption Source Parameters (ESPs), the key conditions at the volcanic vent that are a necessity for modeling the behavior of volcanic plumes. Here, we asked the authors to explain what ESPs are, what technologies are used to observe eruptions, and which scientific challenges and future research directions remain for improving volcanic plume monitoring and modeling.

In simple terms, what are Eruption Source Parameters?

Eruption Source Parameters (ESPs) describe the key conditions at the volcanic vent during an eruption.

Eruption Source Parameters (ESPs) describe the key conditions at the volcanic vent during an eruption, such as the mass eruption rate, exit velocity, temperature, and particle size distribution. These parameters define how material is injected into the atmosphere and are essential inputs for models that simulate plume rise and subsequent dispersal of volcanic gases and ash in the atmosphere. In simple terms, ESPs represent the boundary conditions that control the behavior of volcanic plumes. Because they cannot usually be measured during an eruption, they must be estimated from indirect observations and models, which introduces significant uncertainty.

Why is it important to understand how volcanic ash and gases disperse after an eruption?

Volcanic ash and gases can travel long distances and affect aviation safety, human health, infrastructure, and even climate. Fine ash particles are particularly hazardous for aircrafts, while ash fallout can disrupt communities and critical services on the ground. Gas emissions may also impact air quality and alter the atmospheric radiative budget. Understanding volcanic dispersion is therefore essential for forecasting the movement of volcanic clouds and issuing timely warnings. Reliable forecasts support risk mitigation strategies and enable more effective responses by civil protection agencies and aviation authorities.

What technologies are used to observe volcanic plumes?

Volcanic plumes are observed using a combination of satellite, ground-based, and, more rarely, airborne measurements. Satellite observations are crucial for tracking ash and gas clouds over large spatial scales and in near real time. Ground-based instruments, such as radar, cameras, and infrasound sensors, provide detailed information on plume dynamics close to the source. Increasingly, these observations are integrated with numerical models to infer eruption conditions. The combination of multiple data streams is essential for constraining ESPs and improving the reliability of plume simulations.

What are some of the recent advances in estimating Eruption Source Parameters?

Recent advances have focused on combining observations with numerical models to better constrain ESPs. Multi-sensor approaches, data inversion techniques, and improved plume models have significantly enhanced our ability to estimate eruption rates and plume dynamics. At the same time, high-resolution computational fluid dynamics (CFD) simulations provide deeper insights into the complex fluid dynamic processes governing plume behavior. However, these models are computationally expensive and unsuitable for real-time applications, highlighting the need for approaches that bridge the gap between physical realism and operational efficiency.

What strategies do you propose in your review to improve Eruption Source Parameters estimation?

A central contribution of this review is the proposal of a new class of operational models for volcanic plumes.

A central contribution of this review is the proposal of a new class of operational models for volcanic plumes. These models integrate the physical realism of high-fidelity CFD simulations with the efficiency of simplified models used in forecasting. In particular, the review highlights the potential of artificial intelligence and machine learning techniques to “learn” from CFD results and optimally calibrate the key variables controlling plume dynamics. This hybrid approach allows complex physical processes to be represented in a computationally efficient framework, making it suitable for real-time applications while retaining improved accuracy.

How does improved volcanic plume monitoring lead to more effective volcanic hazard assessment?

Improved monitoring leads to more accurate estimates of ESPs, which directly translate into better forecasts of plume rise and ash dispersion. This reduces uncertainty in hazard assessments and supports more reliable decision-making. For example, more accurate forecasts can help aviation authorities minimize disruptions while maintaining safety and enable civil protection agencies to issue targeted warnings. Ultimately, better integration of observations and models enhances the capacity to respond effectively during eruptions and to mitigate their societal and economic impacts.

What are the remaining questions or knowledge gaps where additional research is needed?

Further research is needed to improve the coupling between observations, physics-based models, and data-driven approaches.

Despite progress, significant challenges remain. ESPs are still difficult to constrain in real time, and uncertainties in both observations and models propagate into forecasts. The integration of diverse data sources is not yet fully optimized, and different estimation methods can yield inconsistent results. Further research is needed to improve the coupling between observations, physics-based models, and data-driven approaches. In particular, developing robust hybrid frameworks that combine CFD, simplified models, and machine learning represents a key direction for advancing both scientific understanding and operational forecasting.

—Antonio Costa (antonio.costa@ingv.it, 0000-0002-4987-6471), Istituto Nazionale di Geofisica e Vulcanologia, Italy

Editor’s Note: It is the policy of AGU Publications to invite the authors of articles published in Reviews of Geophysics to write a summary for Eos Editors’ Vox.

Citation: Costa, A. (2026), From volcanic vents to safer skies, Eos, 107, https://doi.org/10.1029/2026EO265022. Published on 27 May 2026. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

A new study (Sun et al. 2026) shows that in six earthquakes in China between 2010 and 2022, landslides and rockfalls were responsible for at least half of the total fatalities.

It is well-established that landslides are a major cause of loss of life in earthquakes in mountainous areas. The seismology maxim that “it is not earthquakes that kill people, it’s collapsing buildings” does not apply in its pure form in mountains – landslides also kill large numbers of people.

An earthquake triggered landslide from the 2008 Wenchuan earthquake.

However, the actual number of people killed by landslides in earthquakes is poorly understood. This is largely due to the challenges of collecting reliable information in the aftermath of a major earthquake, when the focus is on rescue and recovery rather than data collection. For this reason, many studies of landslide fatalities do not include seismically-triggered events. This is true of my own work.

However, a study has just been published (Sun et al. 2026) in the journal Natural Hazards Review that starts to address this issue. The paper nominally examines fatalities from all causes from earthquakes in China from 2001 to 2022. However, the authors note that the data has low reliability until 2010, so I’ll focus on the period from 2010 to 2022. I also note that the authors use the term “geological hazards“, which is a little broader than landslides. I should note that the paper isa broad look at fatalities from earthquakes – there is a much richer range of analyses than I will cover here.

In the period from 2010 to 2022, Sun et al. (2026) identified 14 earthquakes in which geological hazards caused loss of life. In some cases, the impacts were substantial. Thus, the M=6.5 3 August 2014 earthquake at Ludian in Yunnan led to 134 fatalities and 40 people missing from geological hazards from a total of 728 fatalities (c.24 % of the total), whilst the 5 September 2022 M=6.8 earthquake at Luding in Sichuan led to 76 geological hazard fatalities and 25 missing from a total of 118 fatalities (c.86% of the total). In six of the 14 examples, geological hazards caused at least 50% of the fatalities.

Sun et al. (2026) highlight that “fatalities from geological hazards concentrate in geologically complex, mountainous provinces, i.e., Sichuan, Yunnan, Gansu, Guangxi, and Guizhou”. They note that even small events can trigger fatal landslides – for example, six people were killed in a rockfall triggered by a M=4.3 earthquake in Guizhou in 2010, whilst a M=2.8 aftershock from the Yanjin earthquake in 2006 triggered a rockfall that killed a person.

This is an incredibly useful study. It starts to shed light on the impact of landslides in large earthquakes. It is not the definitive study, and questions remain – not least, the pattern of landslide losses in very large earthquakes, like the 2010 Wenchuan event, in which landslides were ferocious. But it forms the basis for such investigations, starting to fill a major gaps in our understanding.

Reference

Sun, B. et al. 2026. Causes Analysis of Earthquake-Related Deaths in Mainland China 2001–2022. Natural Hazards Review, 27 [2]. https://doi-org.ntu.idm.oclc.org/10.1061/NHREFO.NHENG-2458

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Magma on the move can cause the ground around a volcano to heave in measurable ways. But surface deformation doesn’t always point to an impending eruption—new results show that the terrain around a volcano can also shift during episodes of heavy rainfall. Researchers studying Japan’s Mount Fuji spotted instances of centimeter-level ground deformation tied to intense precipitation. Fortunately, such events can be readily differentiated from deformation caused by magmatic activity, the team reported in Geology.

Keeping an Eye on Volcanoes

Volcanoes around the world, from Kīlauea in the United States to Calbuco in Chile, are outfitted with arrays of sensors. Mount Fuji is no exception—the region around the edifice is equipped with dozens of instruments to detect ground movement, infrasound, and other signs of potential volcanic unrest. All that monitoring is warranted: Shin-Fuji (“Younger Fuji”)—the youngest of Mount Fuji’s three overlapping volcanoes—is currently active.

Shuo Zheng, a hydrological geodesist at Hong Kong Polytechnic University in China, and his colleagues recently mined some of those Mount Fuji data. The team focused on Global Navigation Satellite System (GNSS) observations—otherwise known as GPS data—collected daily from 2017 to 2023.

Rain and Rise

Zheng and his collaborators found several instances in which the two GNSS stations located within 10 kilometers of the summit of Mount Fuji recorded clear signs of uplift. Those signals, reflecting changes of roughly 1–2 centimeters, far exceeded the sensors’ millimeter-level precision. And when the team correlated the timing of that uplift with rain gauge records, they found that the ground often tended to rise almost immediately during periods of heavy precipitation (defined as several tens of millimeters of rain falling per day).

“They can store and transmit groundwater, acting like aquifers.”

There’s likely a physical link behind that correlation, the researchers surmised. The explanation involves the so-called clinkers that cap each of Mount Fuji’s subterranean layers of lava. Clinkers are layers of small rocks that form when the surface of a lava flow rapidly cools, and these structures persist in the shallow subsurface of Mount Fuji. “They can store and transmit groundwater, acting like aquifers,” Zheng said.

Clinkers, or layers of small rocks that form from cooling lava, can store and transmit water. They may be responsible for the way Mount Fuji’s surface uplifts in response to heavy rainfall. Credit: U.S. Geological Survey

When water fills up the pore space within a clinker, there’s no place for the overlying ground to go but up. It therefore makes sense that GNSS stations located atop old lava layers would exhibit uplift in response to intense rainfall, the team concluded.

When Zheng and his collaborators analyzed data from the nine GNSS stations located between 25 and 40 kilometers from the summit, however, they found that the ground actually tended to subside during periods of heavy precipitation. “There are two different responses,” said Kosuke Heki, a geophysicist and geodesist at Hokkaido University in Japan and a member of the research team. That subsidence is a known effect, and it’s been observed in a variety of locales. The subsidence doesn’t dominate closer to the summit of Mount Fuji because of the presence of the clinker layers there, the team reasoned.

Long-Lasting Magma

“Uplift by rain easily terminates when it stops raining.”

The uplift that the team recorded close to the summit of Mount Fuji tended to last just a day or two; it disappeared when the rainfall ceased. That timing is key for differentiating precipitation-induced uplift from magma-induced uplift. “Uplift by rain easily terminates when it stops raining,” said Heki. “But magma has a much longer timescale. It continues for weeks or months.”

That difference is critical, said Luca Caricchi, a volcanologist at the Université de Genève who was not involved in the research. There’s long been the mindset that ground deformation means that an eruption is imminent, but these new findings show that a heaving volcano doesn’t always mean that magma is on the move, said Caricchi. If the deformation is short-lived, the explanation might just be precipitation, he said. “You don’t need to worry.”

Zheng and his colleagues have looked for a similar effect for other volcanoes in Japan. They didn’t find any conclusive trends when they analyzed a chain of island volcanoes south of Tokyo, however. Perhaps that’s because the clinker layers beneath those edifices are so close to the sea that water efficiently drains out of them, the team hypothesized.

—Katherine Kornei (@KatherineKornei), Science Writer

Citation: Kornei, K. (2026), Heavy rainfall inflates Mount Fuji, Eos, 107, https://doi.org/10.1029/2026EO260169. Published on 26 May 2026. Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: AGU Advances

As meltwater drains through and beneath a glacier, it can alter how the ice flows and whether it breaks apart. Meltwater can also cause feedbacks that lead to more ice loss. Understanding when and how glacial meltwater drains is therefore critical to predicting how fast glaciers will lose ice and how that loss will affect sea level.

Chudley et al. modeled how the rate of water flowing into a glacier relates to seasonal changes in the forces that squeeze and stretch ice—forces caused by gravity pulling the glacier downhill, by the ice sliding over subglacial water, and by how portions of the ice interact with the ocean.

The researchers focused on the Sermeq Kujalleq glacier (also known as Store Gletsjer or Store Glacier) in Greenland. In spring, meltwater can fill cracks, or crevasses, that run through the surface of this glacier. These crevasses sometimes go on to drain as the year progresses.

The researchers used satellite imagery from the Sentinel-2 mission to see how much water was present in crevasses between 2016 and 2022, focusing especially on 2019, when the Sentinel-2 satellites provided the best coverage of the glacier. They fed those data into a convolutional neural network to map water cover through the season and looked for a relationship between the mechanical forces acting on the ice and the formation and drainage of crevasse ponds.

The researchers found that the mechanical forces acting on ice are the dominant factor in determining when crevasse meltwater drains into a glacier. When seasonal changes cause ice to stretch, crevasses can drain suddenly, releasing the water they held.

The Greenland Ice Sheet sheds trillions of gallons of water each year, and knowing when to expect that water to drain through the ice sheet is key to understanding processes such as how the glacier slides across the bed and when meltwater emerges in the ocean. The study’s results likely also shed light on dynamic processes in other glaciers and ice sheets, the authors say, and should help inform representations of ice behavior in numerical models. (AGU Advances, https://doi.org/10.1029/2025AV002150, 2026)

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

Citation: Sidik, S. M. (2026), Stretching and squeezing release glacial meltwater, Eos, 107, https://doi.org/10.1029/2026EO260152. Published on 26 May 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

Highly porous rocks, such as sandstones, often deform in a surprising way: instead of breaking apart or sliding, they develop thin zones called deformation bands. In these bands, the grains are squeezed closer together, making the rock denser, and reducing how easily fluids such as water or oil can move through it. This behavior is important because it affects both the strength of rocks and their ability to store and transport fluids underground. However, these bands are difficult to model because they form suddenly from an initially uniform material and concentrate deformation into very narrow zones.

Wang et al. [2026] developed a computer modeling approach called a “phase‑field model” to study this process. Instead of drawing the bands in the initially homogeneous rock, the model allows them to appear naturally as the system evolves and minimizes its energy. The study shows how grain crushing and rearrangement allows the formation of localized deformation zones. The results also demonstrate that natural spatial variations in the rock, such as differences in grain size or porosity, strongly influence where bands initiate and how they grow. Additionally, the model captures how deformation changes from sliding (shear bands) to pure compaction as pressure increases. Overall, this work provides a realistic way to understand how localized deformation develops in rocks, with important implications for geology, engineering, and energy applications.

Citation: Wang, Y., Zhang, C., Braun, P., Kang, X., & Wu, W. (2026). How does heterogeneity control strain localization patterns in high-porosity rocks? Journal of Geophysical Research: Solid Earth, 131, e2025JB032494. https://doi.org/10.1029/2025JB032494

—François Renard, Associate Editor, JGR: Solid Earth

Text © 2026. The authors. CC BY-NC-ND 3.0
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Editors’ Vox is a blog from AGU’s Publications Department.

After 18 years of data collection, quality control, processing, and archiving, the United States Magnetotelluric Array (USMTArray) data set was completed in 2024. A new article in Reviews of Geophysics introduces this unprecedented data set and a new high-resolution model of the Earth’s crust and upper mantle that was made possible because of it. Here, we asked the authors to give an overview of magnetotellurics, how the USMTArray was developed, and future directions for research.

In simple terms for a non-specialist, what is the science of magnetotellurics?

Magnetotellurics (MT) is a passive geophysical technique capable of imaging the subsurface from hundreds of meters to hundreds of kilometers depth using the Sun and global lightning as sources. The science behind MT is largely based on Faraday’s law of induction, where external magnetic field variations induce telluric (from the Latin word ‘tellus’ meaning Earth) currents in the conducting Earth. These magnetic field variations are constantly occurring and happen over a wide range of time scales ranging from milliseconds to hours. And they are tiny – typically on the order of 0.1% of Earth’s magnetic field amplitude and even during intense magnetic storms rarely exceed 1%. 

By measuring these magnetic variations, and the induced electric field variations at Earth’s surface, we can constrain the 3D distribution of conductivity in the Earth. MT is an elegant method – we exploit powerful and distant energy sources which we have no control over and can mathematically remove the stochastic source spectrum to recover reliable estimates of Earth impedance. Impedance can be thought of as the Earth filter – a complex, frequency dependent set of functions that encapsulates all the information about the 3D conductivity structure beneath our feet. Through numerical inversion of impedance data at an array of sites, we build up 3D models of electrical conductivity.

What are some of the applications of the magnetotelluric method?

MT is applied across a broad spectrum of the Earth and space sciences ranging from mineral and geothermal resource investigations, to fundamental geologic and tectonic studies, to imaging the magmatic plumbing systems of active volcanoes, and to hazard mapping centered upon geomagnetically induced currents and the risk they pose to power grids.

Studies using MT are performed on every continent and in all tectonic settings, on land and on the ocean floor, on the Antarctic ice sheet, and even on the Moon. Because of its ability to image the entire lithospheric column, MT studies have made important contributions to our understanding of continental assembly by revealing ancient orogens and rifts. Moreover, MT is uniquely able to constrain the stability of cratonic roots by mapping hydration of the mantle lithosphere. MT studies are key to understanding active tectonic processes, including constraining the water budget in subduction zones, imaging melt zones beneath orogenic plateaus, and mapping the extent of crustal extension – for example beneath the western U.S.

Installation of a USMTArray site in the arid southwestern United States. Sites are installed in remote areas far from infrastructure (powerlines and pipelines) which can interfere with magnetotelluric measurements. Credit: Lena Tokmakoff

With the rise of computational power and 3D modeling and inversion codes, MT is now routinely used to study complex 3D systems, such as active volcanoes, geothermal systems, and mineral deposits. The sensitivity of MT to minor conductive phases – be it partial melt, clay, or conductive minerals such as graphite and metallic sulfides – make it ideal for studying these types of systems. As a result, MT is commonly employed within the resource sector at both the district and deposit scale. Many of the world’s iconic volcanoes have also been imaged with MT, where they constrain the geometry of crustal melt reservoirs – especially their volume and melt fraction which is in turn linked to the eruptibility of a subsurface magma. These analyses are especially powerful because they are sensitive to a distinct physical parameter – resistivity – of Earth materials. MT therefore provides unique and complementary information about the subsurface across a wide range of scales and is a particularly invaluable tool when other methods yield non-unique interpretations. 

One somewhat unexpected application of MT has been to space weather hazards. It was recognized a little over a decade ago that MT impedances are key to estimating surface electric fields generated during intense geomagnetic storms that can impact electric power grids. Past storms have knocked out power to vast areas and damaged critical infrastructure such as transformers. The importance of MT data to scenario analysis, in which power grid components are ‘stress tested’ against past geomagnetic storms, cannot be overstated. Regional to national-scale geoelectric hazard maps, both in the U.S. and internationally, are also informed by MT data, as are real-time geoelectric hazard estimates.

What is the United States Magnetotelluric Array (USMTArray)?

The USMTArray was an ambitious program begun in 2006 under the NSF-funded EarthScope program and completed in June of 2024 under USGS funding. The USMTArray collected long-period MT soundings on a 70-km grid across the contiguous U.S. – totaling more than 1,800 stations – each collected with uniform instrumentation, acquisition parameters, data processing, archiving, and metadata. Funded throughout its 18-year lifetime by three different federal agencies (the NSF, NASA, and USGS working closely with the Incorporated Research Institutions for Seismology and Oregon State University), the data – time series, response functions and metadata – were released incrementally to the public without data embargo or usage restriction.

Map of USMTArray site locations illustrating how the survey rolled across the country over its nearly two-decade lifetime. Credit: Kelbert et al. [2026], Figure 1

In broad terms, how was the USMTArray developed?

The USMTArray had humble beginnings – being mentioned in early planning documents as having value in understanding subduction zones and characterizing volcanic systems. Funded by NSF in 2003, the MT component of EarthScope was modeled after the much larger seismic component, with a transportable array of instruments to march across the U.S. on a 70-km spaced grid and a backbone array of seven instruments to study deep mantle structure. The USMTArray started off small and before dedicated instruments were even available. In 2006, a pilot study collected the first 30 stations in eastern Oregon using borrowed instruments, while subsequent years expanded what became known as the ‘northwest’ footprint, a 331-sites array completed in 2011 encompassing the Yellowstone-Snake River Plain, the Northern Rocky Mountains, the Cascades magmatic arc, and the northern Basin and Range province. Subsequent footprints in the midcontinent and the eastern U.S. continued to expand coverage.

What were some of the challenges in developing the USMTArray?

The biggest challenge by far was money. Within the EarthScope program, the USMTArray was never funded at the level needed to cover the contiguous U.S. The MT component was instead carried out as a series of footprints in areas deemed most scientifically advantageous. This limitation, however, led to one of the big successes of the USMTArray – active community engagement. Siting workshops held in 2008 and 2013 brought together participants from academia, government, and industry to discuss and prioritize where the array would go next, while a community working group provided scientific and operational guidance throughout the life of the array. The success of the USMTArray was recognized early on by the community governance of the EarthScope facility activities, with the ‘full-48’ concept endorsed in 2009, leading to modest increases in funding and an acceleration of station completions. In 2018, by the end of NSF-sponsored activities, roughly 2/3 of the contiguous U.S. had been covered. Seeing the array to completion, however, required additional funding, a challenge met by NASA (2019-2020) and the USGS (2020-2024), in large part due to recognition of the importance of USMTArray data to space-weather hazards and supported through executive orders in 2016 and 2019.

Another notable challenge that we faced while developing the USMTArray operations was the absence of established data sharing practices within the magnetotelluric community. Indeed, the concept of FAIR data was only introduced in 2016. Back in 2006 when this program commenced, the concepts of open data and systematic data sharing were largely unfamiliar, and no widely adopted, sustainable data formats existed. Available data formats were lacking in flexibility, consistency, and self-descriptive metadata. As the project progressed, our team developed such formats and accompanying databases, which have now reached maturity and are helping to drive more sustainable MT data‑sharing practices internationally.

How has the development of the USMTArray advanced the scientific field?

The USMTArray, along with parallel advances in modeling capabilities and increased computational power, ushered in a jump to 3D MT and to interrogating the Earth at regional to national scales. National-scale conductivity models, such as those developed from the USMTArray, now join the ranks of other data sets like magnetic, gravity, and seismic, and are a new lens with which to view the architecture of the North American continent. Numerous contributions to continental architecture and assembly and to understanding active tectonic processes have come from the USMTArray.

Map of the United States underground electrical structure integrated over mid- to lower crustal depths, illustrating the resistive (dark) and conductive (hot) regions. The latter reflects ancient tectonic scars within the crust. Credit: Kelbert et al. [2026], Figure 17

The USMTArray also serves as a framework for more detailed studies, allowing Principal Investigators (PIs) to derisk future surveys and industry to investigate anomalous or unexpected structure. Studies of the Cascadia subduction zone and the adjacent magmatic arc and geothermal energy prospectivity studies in the Oregon Cascades and Great Basin have been built upon the USMTArray while new MT surveys along the eastern seaboard are collecting high-resolution MT data to improve space-weather hazard maps over areas identified as particularly at risk from the analysis of USMTArray data.

Beyond the data and models derived from them, the USMTArray has motivated methodological advances, led to an investment in MT instrumentation and open-source software for researchers within the NSF-supported National Geophysical Facility, and served as a model for other regional and continental scale MT experiments.

What are some of the future directions for research in continental scale magnetotellurics?

With completion of the USMTArray, and the 3D conductivity models derived from it, there are numerous avenues for future research. Most models of continental evolution, for example, were developed prior to the advent of this rich data set. Critically evaluating such models in light of this new data set is paramount, and initial studies are already forcing a reexamination of certain paradigms.  

Multi-disciplinary studies incorporating geochronology, geochemistry, and rapidly evolving seismic models is another promising area as is the coupling of geophysical models to geodynamic models to examine the evolution of newly imaged model structure. Similarly, advancements in integrated and joint inversion are promising directions to leverage the wealth of public data sets available at regional to continental scales.  

Geology doesn’t stop at national borders or the land-sea interface – additional opportunities exist for cross-border arrays and onshore/offshore MT studies. Investigation of subduction zone processes and rifted continental margins by their very nature demand an amphibious approach.

On the applied front, resource assessments increasingly are applied at national and even global scales and demand data support at these same scales. Mineral resource assessments, for example, in the U.S., Canada, and Australia are exploring machine learning approaches to map prospectivity for various deposit types and incorporate a range of geophysical data layers to do so. Similarly, geothermal assessments can benefit from the consistent and synoptic data coverage offered by USMTArray data and models.

Finally, on the space-weather hazards front, partnering with power-system engineers to investigate data scale and uncertainty shows promise in generating accurate hazard maps and in improving upon operational, near real-time geoelectric field models. For all these future research directions the USMTArray remains both a framework and a benchmark upon which to build.

—Paul A. Bedrosian (pbedrosian@usgs.gov; 0000-0002-6786-1038), U.S. Geological Survey, United States; Anna Kelbert (anna.kelbert@cfa.harvard.edu; 0000-0003-4395-398X), Center for Astrophysics | Harvard & Smithsonian, United States; Adam Schultz (adam.schultz@oregonstate.edu; 0000-0003-1663-1547), Oregon State University, United States; and Gary D. Egbert (gary.egbert@oregonstate.edu; 0000-0003-1276-8538), Oregon State University, United States

Editor’s Note: It is the policy of AGU Publications to invite the authors of articles published in Reviews of Geophysics to write a summary for Eos Editors’ Vox.

Citation: Bedrosian, P. A., A. Kelbert, A. Schultz, and G. D. Egbert (2026), Mapping the hidden electrical anatomy of a continent, Eos, 107, https://doi.org/10.1029/2026EO265021. Published on 26 May 2026. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

Today, NASA announced an agencywide realignment that includes combining related mission directorates to sharpen the agency’s focus on human spaceflight.

“This initiative reflects NASA’s extreme focus on executing the mission in direct support of the National Space Policy,” NASA Administrator Jared Isaacman said in a press release about the realignment.

The National Space Policy refers to Executive Order 14369: Ensuring American Space Superiority, which was released by the Trump administration in December 2025. The order sets national priorities of returning Americans to the Moon, establishing a lunar base, developing a nuclear reactor in space, developing the commercial space economy, and enhancing the United States’ national security space architecture.

NASA’s Artemis II crew captured this image of the Moon eclipsing the Sun during their flyby of the Moon on 6 April 2026. Credit: NASA

NASA’s six existing mission directorates will be slimmed down to four. Exploration Systems Development and Space Operations will be combined into a new Human Spaceflight Mission Directorate and will facilitate human spaceflight in low-Earth and lunar space environments. Aeronautics Research and Space Technology will be folded into a new Research and Technology Mission Directorate, tasked with researching and developing nuclear power and propulsion. The structure of the Science Mission Directorate (SMD) and Mission Support Directorate remain unchanged at the time of publication. All directorate leaders will now report directly to the NASA Administrator (Isaacman) to ensure that each remains focused on their directorate’s new mission.

“There will be no reduction in force, no program cancellations, no closures, but we will achieve cost savings through more efficient execution and taking an active role in delivering the outcomes the world has been waiting for from NASA,” Isaacman said.

More Efficient?

At first glance, it is hard to see how combining four mission directorates into two, refocusing the missions of each, and pushing for increased efficiency and cost reduction will not result in some loss of talent either through positions being eliminated or individuals finding themselves in jobs they do not want to hold.

In a letter to NASA employees, Isaacman went into more detail about the specifics of this realignment and described how it will shift the agency’s internal bureaucratic authority away from directorates and toward NASA’s field centers. Prior to this, centers like Goddard Space Flight Center in Greenbelt, Md., and Johnson Space Center in Houston would need to compete for funding that had been appropriated to directorates based on the programs or missions they were tasked with.

A NASA source based in Houston told Ars Technica that the competition for funding “has been an absolute disaster.”

 
Related

•  NASA Announces Realignment to Accelerate Mission Delivery
•  Isaacman’s Letter to NASA Employees
•  ENSURING AMERICAN SPACE SUPERIORITY
•  AGU Action Center: Tell the Senate to reject House cuts to science funding 

This new realignment “will adjust the funding distribution, so Centers have the financial support needed to sustain the baseline critical capabilities independent of near-term mission assignment,” Isaacman stated. “This shift will allow Center Directors to focus on maintaining the infrastructure, workforce, and capabilities required for current and future missions.”

Isaacman was unclear about when these changes will take effect, and policy analysts are unsure whether the realignment will be recognized by Congress through its appropriations process. The most recent Fiscal Year 2027 appropriations bill for NASA, which advanced out of the House Committee on Commerce, Justice, and Science on 13 May, allocates funding for six mission directorates, not four. The Senate appropriations committee is expected to release its proposed budget for NASA in the coming weeks, and the two bills must still undergo a lengthy reconciliation process.

In fiscal year 2026, Congress broke with the president’s budgetary priorities for NASA and passed a budget that ignored several of the administration’s proposed financial and mission cuts. Whether Congress will do the same this year and maintain the prior breakdown of directorates will become clear in the coming months.

—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 © 2026. AGU. CC BY-NC-ND 3.0
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For many years a source of irritation, a fossil of the Brazilian spinosaurid Irritator challengeri is now bringing some joy to paleontologists in its homeland.

Following a successful public campaign for restitution, the piece is returning to Brazil from the collection of Germany’s State Museum of Natural History Stuttgart (SMNS), where it has been kept for the past 30 years—a situation that Brazilian paleontologists and lawmakers deemed illegal.

Representatives of both countries made the announcement last month during Brazilian President Luiz Inácio Lula da Silva’s visit to Germany. In a joint statement, they announced the German museum’s “willingness” to “hand over” the fossil to Brazil and start a new, more transparent era of international collaboration.

“It is a very expected and cherished move because it represents a huge scientific and social victory for the Global South and for Brazil.”

“Finally, the Irritator will be back to its original place,” said paleontologist Allysson Pontes Pinheiro, director of the Plácido Cidade Nuvens Paleontology Museum.

The museum, located in northeastern Brazil where the fossil was discovered in the 1990s, will host the Irritator when it returns to Brazil. “It is a very expected and cherished move because it represents a huge scientific and social victory for the Global South and for Brazil,” Pinheiro said, highlighting that the return will allow local scientists and the population to have access to a heritage that would be difficult and expensive to access abroad.

The Irritator challengeri fossil is one of many that have been illegally obtained from South America by researchers from the Global North. Considered the most complete spinosaurid skull ever described, the 110-million-year-old specimen was taken from the Araripe Basin in northeastern Brazil and described in 1995 by British paleontologist David Martill and his German colleague Eberhard “Dino” Frey. Martill and Frey worked on at least one other fossil smuggled from Brazil to Germany, an Ubirajara jubatus specimen, which was repatriated in 2023 and is currently housed at Plácido Cidade Nuvens.

Martill and Frey named the newly discovered species in reference to their irritation upon learning that the skull had been manipulated by fossil dealers to get a better price. Little did the researchers know that the fossil would irritate many other scientists, especially those from the animal’s homeland.

Revisiting a Fossil with “Problematic Status”

In 2023, triggered by the publication of a paper that acknowledged the fossil’s “problematic status,” paleontologists in South America published an open letter to the Ministry of Science, Research and Arts of Baden-Württemberg State demanding its return. The document received about 300 signatures from scientists and lawyers and was followed by a viral social media campaign involving influencers and a more recent public petition on Change.org that gathered more than 34,000 signatures.

“This campaign showed us that it is worth continuing to fight for our fossils.”

The restitution request is based on Brazilian legislation passed in 1942 that determined that fossils found in the country are the state’s property and cannot be traded or exported without explicit authorization. In addition, a more recent Brazilian ordinance (dating to 1990) mandates that any holotype (a fossil used to describe a new species, such as the contested Irritator specimen) must remain in the country. Regardless, SMNS maintained the fossil had been legally purchased from a private dealer in Germany in 1991.

“We are very happy the Brazilian law is now being respected,” said Aline Ghilardi, a paleontologist at the Federal University of Rio Grande do Norte who was at the forefront of the repatriation campaign. “This campaign showed us that it is worth continuing to fight for our fossils.”

At the time of publication, SMNS had not responded to requests for comment.

A Long Process of Decolonization

But Ghilardi is not entirely satisfied. She didn’t like the wording of the announcement, which used the expression “hand over” rather than return, repatriate, or restitute.

“The statement was a missed opportunity to demonstrate the German government’s willingness to decide in favor of a restitution process,” she explained. “It seems there is resistance to making these restitutions as actual restitutions. It appears as if it is theirs by right and that they will hand over the fossil to Brazil as part of scientific cooperation.”

Ghilardi expressed that she will believe the repatriation will actually happen only when a specific return date is announced. (As of publication, it has not.) She also hopes that the Irritator case is not an isolated incident, but part of an ongoing trend of restitutions intended to break the pattern of neocolonialism in science.

A 2025 study published by Ghilardi and colleagues in the journal Palaeontologia Electronica showed that of nearly 500 invertebrate species described from fossils found in the Araripe Basin—one of Brazil’s richest and most threatened regions of geodiversity—about half have holotypes stored in institutions across Europe, Asia, and North America, violating Brazilian law.

Most of these smuggled fossils are hosted in Germany. “Some foreign colleagues complained about our campaign, saying that it looked like we were persecuting Germany,” Ghilardi said. “But that is not the case. It is just the numbers.”

It is possible, she noted, that other countries hold even more specimens that were not described in the scientific literature and therefore could not be counted.

The same study also found that more than 200 species were described in publications that did not include any Brazilian scientists as coauthors, despite Brazilian legislation requiring foreign research on Brazilian fossil material to be conducted in partnership with local institutions.

Wave of Repatriation

Paleontologist Serjoscha Evers at the Universität Freiburg, who authored the 2023 study on the Irritator fossil, wrote in an email to Eos that he welcomed the news of the dinosaur’s return.

However, he also wondered whether the decision is just “a diplomatic favor that resulted from the public pressure, or foreshadowing a broader wave of repatriations based on a legal conclusion that the fossils are unlawfully in German custody.”

Paleontologists involved in the Irritator restitution efforts said that since the campaign began, they have been receiving emails from museums and institutions worldwide seeking information on the procedures for returning fossils to Brazil.

Germany recently said it would “hand over” the Irritator challengeri fossil to Brazil. This illustration suggests what the dinosaur would have looked like before it was a fossil, about 110 million years ago. Credit: PaleoGeekSquared/Wikimedia Commons, CC BY-SA 4.0

The Plácido Cidade Nuvens Paleontology Museum, the final destination of the Irritator, has received several restitutions itself, including 45 fossils originally collected from the Araripe Basin and previously held by the University of Zurich in Switzerland, the fossil of a crustacean that was in the possession of the Universidad Nacional del Nordeste in Argentina, and a fish fossil seized in Italy.

According to Pinheiro, the museum’s director, paleontologists and the Brazilian government have listed at least 90 Brazilian holotypes still held in Germany. And the Brazilian Ministry of Foreign Affairs confirmed to Eos that it is currently negotiating the return of nine fossils held in undisclosed countries.

“We have been talking with colleagues from the museums where these materials are hosted, and they seem very favorable to returning them,” Pinheiro observed. “It is a huge advancement and a great change of behavior from important museums that have been holding heritage from the Global South.”

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

Citation: Moutinho, S. (2026), Germany to return contested dinosaur fossil to Brazil, Eos, 107, https://doi.org/10.1029/2026EO260167. Published on 22 May 2026. Text © 2026. 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.

As the Indian and Eurasian continental plates collide, the Tibetan Plateau is slowly deforming. For decades, geoscientists debated how this deformation occurs: Is the plateau like a block of crumbly aged cheddar, deforming mostly at its faults, or is it more like French brie, moving like a very viscous liquid being pushed slowly to the east?

A new study published in Science shows that both theories are at work. The study’s findings provide the most comprehensive picture yet of the Tibetan Plateau’s deformation and offer valuable information for earthquake hazard assessments in the region.

The new model that combines the two theories is a “significant advance,” said Eric Fielding, a geodesist who was not involved in the study. Fielding is a staff member at NASA’s Jet Propulsion Laboratory but did not speak on behalf of the agency. “It’s clearly the result of a very large amount of work,” he said.

A Deformation Investigation

For decades, scientists have held differing views on the Tibetan Plateau’s deformation. One camp modeled the plateau’s deformation with movement occurring mostly at its faults, while the other modeled the movement like a thick fluid deforming areas beyond faults.

“These two communities have carried on modeling deformation in different ways” and have never fully resolved the differences between their models, said Tim Wright, a geodesist at the University of Leeds in the United Kingdom and lead author of the new study.

It’s tricky to measure the plateau’s deformation, though, because it changes so slowly: One of the fastest faults on the plateau, the Kunlun Fault, moves at about just 10 millimeters per year. “These are rates that are less than your fingernails growing,” Wright said.

And because much of the Tibetan Plateau’s terrain is inaccessible, there’s a dearth of ground-based stations to track movement, meaning most geodetic data for the area must come from satellites.

“It’s a boon for science to have that consistent acquisition of the same kind of data for 10 years.”

Tracking such nearly imperceptible movement with satellites hundreds of kilometers above requires enormous amounts of data collected over many years. Wright and his colleagues finally had those data after 10 years of observations from the European Space Agency’s Sentinel-1 satellite mission, which launched in 2014.

“Because the signals are so small, you need to wait for some time before you accrue enough deformation that you can actually measure it,” Wright said. The 2014–2024 data they analyzed are “giving us a really clean signal,” he said.

“It’s a boon for science to have that consistent acquisition of the same kind of data for 10 years,” Fielding said.

Using tens of thousands of satellite images alongside ground-based satellite navigation system stations, Wright and the team constructed comprehensive velocity maps of the deformation of the plateau. Results showed that a mix of theories best describes the mechanism.

“We think what’s really happening is a combination of both,” Wright said.

Wright, who described himself as “formerly of the viscous deformation camp,” was surprised by the prominent role that faults played in the plateau’s deformation. Previously, he said, he would have described the faults as passive markers within the underlying flow of the landmass. But the data show that the faults influence a much broader area of the plateau: “The whole deformation of the plateau is influenced by those faults,” he said.

The study “shows clearly that these major fault systems are responsible for a large part of the strain within the plateau,” Fielding said.

Mapping Seismic Hazards

“We have very little information about the history of earthquakes on these faults in this area.”

Knowing how the plateau deforms can also help scientists create more accurate seismic hazard assessments for the millions of people who may be affected by earthquakes there, particularly at the edges of the plateau. “We have very little information about the history of earthquakes on these faults in this area,” Fielding said.

The research team is working with the Global Earthquake Model Foundation, a nonprofit earthquake research collaboration, and other organizations to incorporate their findings into hazard assessments.

Wright and the research team recently used a similar methodology to map the deformation field of the entire Alpine-Himalayan belt, which stretches from Spain to eastern China. The same methods could be used to map the deformation of the western United States, another area where both viscous and fault-related deformation may affect large population centers, Fielding said.

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

Citation: van Deelen, G. (2026), Weak faults play a strong role in the Tibetan Plateau’s deformation, Eos, 107, https://doi.org/10.1029/2026EO260162. Published on 22 May 2026. Text © 2026. 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.

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Renske Jongen, an ecologist at the University of Sydney, calls seagrass ecosystems the “tropical rainforests” of the ocean. These underwater flowering plants offer habitats to marine life, protect coastlines from damage, and, like rainforests, store enormous amounts of carbon.

They’re also under threat from pollution, development, and warming ocean waters, which stress plants and slow growth rates. Seagrass populations have been declining globally for nearly a century, and recent estimates suggest 7% of seagrasses are lost worldwide each year.

A new study published in New Phytologist shows that warming waters may affect a microscopic aspect of the seagrass ecosystem, too: the microbes that live in their sediments. The new insight can inform efforts to restore seagrasses, the authors write.

Seagrasses are “getting attacked from both sides,” said Jongen, the lead author of the new study. Warming water stresses the plants themselves, while “something changes in the sediment that makes them grow worse.”

Sediments and Seagrass The research team transplanted seagrasses from elsewhere in Lake Macquarie to a preexisting, artificially warmed area to run their experiment. Credit: Renske Jongen

To test how microbial communities affect seagrass growth under warming temperatures, Jongen and the research team transplanted seagrasses and their sediment from both warm and cool areas of Lake Macquarie, a coastal saltwater lake in New South Wales, Australia, into an artificially warmed part of the lake. The artificially warmed part of the lake has received intermittent plumes of heated water from a nearby power plant since 1984, leading to a consistent temperature increase of 1°C–3°C (1.8°F–5.7°F) compared with the rest of the lake.

For half of the seagrasses, the team also used an autoclave, an instrument that uses steam to sterilize materials, to kill most of the microbes in their associated sediment before transplanting them to the experimental garden. “By looking at how plants respond with and without their microbes, you can get an idea for whether [those microbes] help or harm the plant under certain environments,” Jongen said.

The plants were then left to grow for 28 days before the team measured how they’d fared.

The warm-origin seagrasses in their original, warm-origin sediments with microbes intact grew the slowest once they were in the artificially heated waters, producing 35% less aboveground biomass than their counterparts whose sediment microbial communities had been killed. That result suggests that the microbial community in warmed sediment contributes to seagrass stress, the authors wrote.

“These plants, in general, do not like sediments that have been exposed to warmer temperatures.”

“These plants, in general, do not like sediments that have been exposed to warmer temperatures,” Jongen said. She was surprised that the plants that came from the warm areas had the worst outcomes but hypothesizes that perhaps these plants were already too stressed from warm waters to deal with the changes to sediment bacterial communities that occurred after they were transplanted into the even warmer part of the lake.

“It’s just like us, for example: When we don’t sleep or we’ve had a stressful week, then we get sick more easily,” she said.

Jongen said more research is needed to say for sure why warmed sediment seems to change microbial communities in a way that harms seagrasses. But research has shown that some microbes in ocean sediment produce sulfide, which can be toxic to seagrasses if it accumulates, especially if those seagrasses are already stressed. Warmer conditions may allow these sulfide-producing microbes to grow more quickly, harming the plants.

The new research highlights the “context dependency of host-microbe interactions,” said Karolina Zabinski, a marine ecologist at the University of California, Davis, who was not involved in the new study. Previous research by Zabinski and others also showed that seagrass growth depends on their associated sediment microbiome.

Restoration Lessons

The new study “serves as a great springboard” for both academics seeking to understand seagrass-microbe interactions and practitioners working on seagrass restoration in the field, Zabinski said.

For academic researchers, the paper raises exciting questions about how the microbial communities present in the sediment actually function, she said. Though the study identified the types of microbes in the seagrasses’ sediments, it didn’t evaluate the abilities of those microbes, which genes they possess or express, or how those microbes interacted with each other. “What are their actual genes, and what are they doing?” Zabinski asked.

“When plants don’t do well, we can’t just assume it’s inherent to the plants—we have to remember it could be driven by the microbes that they’re interacting with.”

For seagrass restoration practitioners, the study could offer new methods to try to improve restoration success. Some projects, for example, aim to take plants from warmer environments and transplant them to seagrass ecosystems that will face warming stress in the future as the climate changes. “It seems pretty intuitive that maybe those plants will have the traits or the genetics to respond to that warming,” said Randall Hughes, a marine ecologist at Northeastern University in Boston who was not involved in the new study. But the study’s results highlight “that intuition is not always reliable.”

“Certainly, having experimental studies like this helps us think about those restoration efforts in a more informed way,” she said. “When plants don’t do well, we can’t just assume it’s inherent to the plants—we have to remember it could be driven by the microbes that they’re interacting with.”

Jongen hopes to continue studying related questions about how seagrasses respond to warming waters. In particular, she’d like to investigate how long changes to the sediment microbial community last and whether those changes reverse once a marine heat wave subsides.

The research team collected sediments and seagrasses from different sites within Lake Macquarie before transplanting the plants into an artificially warmed area of the lake. Credit: Renske Jongen

Ultimately, the answers to these questions will help scientists better predict where seagrasses are in danger and how they might be helped. “If we lose the seagrasses, we don’t only lose the seagrasses, we lose all the other benefits that they provide,” Jongen said. “I think they deserve a little bit more attention.”

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

Citation: van Deelen, G. (2026), Warm waters disrupt seagrasses’ microbial environment, Eos, 107, https://doi.org/10.1029/2026EO260166. Published on 22 May 2026. Text © 2026. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

A new paper in the journal landslides (Yang et al. 2026) details the 6.8 million cubic metre Huangci Landslide in China, which was a reactivation on a slope that has suffered two other failures in recent decades.

On 10 December 2025, failure occurred in the large Huangci landslide in Gansu Province, China. The event is described in a new paper (Yang et al. 2026) in the journal Landslides (this link should provide access even though the article is paywalled). The paper is fascinating as this is a very complex slope with an interesting history of deformation, and because large failures do not usually occur in the winter months in this part of China.

The location of the Huangci landslide is [36.08983, 103.32412]. This is a Google Earth image of the site, captured in 2004:-

Google Earth image of the Huangci landslide in 2004.

The geology consists of loess overlying mudstones. As the image above shows, the site had previously failed. The houses at the foot of the slope are the homes of people displaced in 1968 during the impoundment of the Liujiaxia Reservoir. Note also the farmland on the terrace behind the landslide. This is an arid area, so this farming requires extensive irrigation.

According to Yang et al. (2026), the failure that can be seen in the image above occurred on 30 January 1995. About 6 million cubic metres of rock and loess were involved, creating a landslide with a width of about 500 metres and a length of about 370 m.

The Huangci landslide failed again on 14 May 2006, this time with a volume of about 4 million cubic metres. The image below, captured in 2013, shows the aftermath:-

Google Earth image of the Huangci landslide in 2012.

In this failure, 10 houses were destroyed.

The most recent failure of the Huangci landslide occurred on 10 December 2025. This time, a larger mass failed, creating a landslide with a volume of about 6.77 million cubic metres, a length of up to about 740 metres and a width of up to about 420 metres. There is a spectacular video on Youtube showing the aftermath of the failure:-

The still below gives an impression of the scale of the failure:-

An image from a drone showing the aftermath of the 10 December 2025 Huangci landslide in China. Still from a video posted to Youtube by 阿龍說牆內事.

According to Yang et al. (2026), this failure destroyed 39 houses plus a range of infrastructure that includes power transmission systems, irrigation systems, water supply systems and transportation facilities. The site had been successfully evacuated as a result of a community-operated early warning system.

As noted above, this is an unusual time of the year for a landslide of this type. However, Yang et al. (2026) conclude that the underlying driver is irrigation on the terrace upslope from the landslide, driving a rise in the groundwater and consequent progressive deformation of the slope. This led to weakening of the mudstones that were buttressing the failure, eventually triggering collapse.

Reference

Yang, Y. et al. 2026. The reactivated Huangci landslide at the Heifangtai terrace, Gansu Province, China, on December 10, 2025. Landslides. https://doi.org/10.1007/s10346-026-02765-2.

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In its annual forecast of the upcoming Atlantic Hurricane season, NOAA suggests the 2026 season has a 55% chance of being below normal, compared with a 35% chance of being near normal and just a 10% chance of being above normal.

The forecast, announced at a press conference at the NOAA Aircraft Operations Center in Lakeland, Fla., includes 8 to 14 named storms (with winds of at least 39 miles per hour), 3 to 6 of which will be hurricanes (with winds of at least 74 miles per hour). One to three of those are forecast to be major hurricanes (category 3 to 5 storms, with winds of at least 111 miles per hour).

NOAA forecasts that a below-average hurricane season is most likely in 2026, largely because of El Niño conditions. Credit: NOAA

A below-average number of hurricanes does not reduce the need for people to be prepared, NOAA representatives emphasized.

“Even though we’re expecting a below-average season in the Atlantic, it’s very important to understand that it only takes one.”

“Even though we’re expecting a below-average season in the Atlantic, it’s very important to understand that it only takes one,” said Under Secretary of Commerce for Oceans and Atmosphere and NOAA Administrator Neil Jacobs. “We have had category 5s make landfall in the past during below-average seasons.”

In contrast, NOAA is forecasting an above-average season in the Pacific, with a 70% likelihood of above-normal activity.

Matthew Rosencrans, lead hurricane forecaster with NOAA’s National Weather Service, noted that the Atlantic forecast does not yet contain information about potential hurricane landfalls, just the likelihood of their formation. National Weather Service Director Ken Graham said the potential for rapid intensification—when wind speed increases by at least 35 miles per hour over the course of 24 hours—makes early preparedness particularly important.

“Every category 5 that’s made landfall in this country was a tropical storm or less 3 days out,” he said. “So they rapidly intensified that quick. You think you might have a week on your timeline. The reality is you may only have days.”

“There will never be a ‘Hurricane Justa,’” he added. “There’s no such thing as just a category 1, just a tropical storm, just a category 2.…Even the smallest storm, if it’s slow enough and big enough, it’s going to be catastrophic flooding and storm surge.”

The Atlantic hurricane season runs from 1 June to 30 November. The NOAA forecast is in line with an Atlantic hurricane forecast issued 9 April by Colorado State University (CSU), which predicted 13 named storms and 6 hurricanes, including 2 major hurricanes. Similarly, a forecast released 22 April by North Carolina State University predicted 12 to 15 named storms, 6 to 9 hurricanes, and 2 to 3 major hurricanes.

All three forecasts are slightly below the average Atlantic hurricane numbers for 1991–2020: 14.4 named storms, 7.2 hurricanes, and 3.2 major hurricanes.

The World Meteorological Organization has released its list of 2026 Atlantic tropical cyclone names. Credit: NOAA El Niño

The forecast for below-average activity levels largely stems from El Niño, a climate pattern that increases vertical wind shear over the tropical Atlantic. Vertical wind shear is how much the speed and direction of wind change with altitude. When wind shear is too high, it can tear a hurricane apart before it forms.

“Wind shear is good for us, bad for the hurricanes,” said Phil Klotzbach, a hurricane forecaster at Colorado State University and lead author of the CSU report.

This year, researchers suggest El Niño could become the strongest in modern history, which could have ripple effects on global temperatures. At the NOAA press conference, Jacobs said that there is a 98% chance of El Niño conditions occurring later this season and an 80% chance that it will be moderate to strong. The forecasted strength of El Niño has only grown since CSU issued its forecast, Klotzbach said.

However, in addition to high wind shear, El Niño is also characterized by unusually warm waters in the Pacific. Klotzbach compared the warm waters of El Niño to loaded dice.

“If the waters are a little bit warmer, that will load the dice for the storm to get stronger.”

“To get to a hurricane, you need to have warm water,” he said. “You need to have a lot of other stuff as well, but if the waters are a little bit warmer, that will load the dice for the storm to get stronger.”

El Niño isn’t the only reason our oceans are warming.

At a press briefing hosted by Covering Climate Now prior to the NOAA press conference, Shel Winkley, a meteorologist at Climate Central, noted that about 90% of the excess heat caused by greenhouse gas emissions has gone into Earth’s oceans, as the planet tries to keep our atmosphere in balance.

“We’re not saying that climate change necessarily creates hurricanes,” Winkley said. “But it is supercharging them: More intense winds, heavier rain, bigger flooding. That’s the connection that we can confidently draw.”

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

Citation: Gardner, E. (2026), NOAA forecasts a below-average hurricane season, Eos, 107, https://doi.org/10.1029/2026EO260171. Published on 21 May 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
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Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Tectonics

At subduction zones, one tectonic plate dives beneath another, dragging rocks tens of kilometers into Earth’s interior where they are transformed by extreme pressures and temperatures. Some of these deeply buried rocks make it back to the surface, carrying a record of conditions along the plate boundary at depth. Geologists have long debated how these high-pressure rocks are exhumed and how they end up mixed into younger, lower-grade surrounding material.

Wang et al. [2026] address this question with detailed geologic mapping, Ar-Ar analyses, and U-Pb geochronology from subduction complex rocks on Cedros Island, offshore Baja California, Mexico. Their data show that high-pressure blocks yield cooling ages between 172 and 144 million years old, yet they are hosted in sedimentary rocks no older than about 92 million years. This age mismatch, combined with field evidence that the blocks are enveloped in sedimentary matrix rather than tectonically sheared into place, leads the authors to propose that the high-pressure rocks were exhumed to the surface, eroded, and recycled back into the subduction trench as sedimentary debris, potentially multiple times. The authors suggest that rapid exhumation was driven by extension within the forearc wedge. When plate convergence rates dropped abruptly, the wedge became gravitationally unstable and stretched along brittle-ductile shear zones, bringing deeply buried rocks to shallow crustal levels.

This polycyclic model is incompatible with alternative interpretations in which exotic blocks were mixed into their host matrix by viscous return flow within the subduction channel, because such models predict that blocks and their surrounding matrix should share similar thermal histories. Instead, the data require that blocks completed their journey to depth and back long before the surrounding sediments even entered the trench. The new understanding of subduction dynamics on Cedros Islands illuminates connections with the broader Franciscan Complex of California, where the origin of similar high-pressure blocks in younger matrix has been debated for decades. Together, these findings offer new perspectives on how subduction zones operate over long timescales and how their fragmentary rock record preserves fundamental evidence of the tectonic history of the continental margin. 

Citation: Wang, J. W., Kapp, P., Holder, R., He, J., Hernández-Uribe, D., & Worthington, J. (2026). Polycyclic metamorphism, exhumation, and recycling of subduction complex rocks, Cedros Island, Baja California. Tectonics, 45, e2025TC009340. https://doi.org/10.1029/2025TC009340

­­—Alexis Ault, Associate Editor, Tectonics

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Wind-driven waves on Earth move sediments and shape shorelines. They transport energy between the atmosphere and planetary surface and also mix bodies of liquid, affecting both chemistry and biology. On other worlds with surface liquids, either now or in the past, wind waves would likely perform the same function and so would play a key role in climate and astrobiological potential.

“They’re basically the interface between how the atmosphere communicates with the landscape, especially at the coast.”

New research went back to the fundamentals and explored the conditions that can generate waves on worlds with different physical properties and different liquids, such as Titan, Mars, and select exoplanets.

“Wind waves are really interesting phenomena,” said Una Schneck, a planetary science doctoral student at the Massachusetts Institute of Technology (MIT) in Cambridge. “They’re basically the interface between how the atmosphere communicates with the landscape, especially at the coast.”

The Physics of Waves

Past models of wind generation on other planets struggled because they tended to start from preexisting models of Earth waves. Those models were developed to describe waves in Earth’s specific combination of gravity, atmosphere, and surface liquid, namely, water, said Schneck, who led the new research. Such models were sometimes tailored to describe a particular location and season. Adapting those models for conditions on other worlds, including other liquids like methane and sulfuric acid, always seems to leave traces of Earth behind.

However, the physics of what creates wind-driven waves should be universal, Schneck said, so the team went back to the basics of wave generation. They developed a wave model that explores the relationship between a world’s bulk properties, like gravity and air density, and liquid properties, like surface tension, to determine the wind strength needed to produce a wave.

The team “created this model that went back to the basic physics of waves, instead of just trying to fit to known wave conditions,” said Taylor Perron, an MIT geomorphologist and planetary scientist and coauthor of the research.

The Curiosity rover landed in Gale Crater on Mars (left) and has since found evidence—wavy bedforms—that this former crater lake had waves. Titan’s northern hemisphere hosts a sprawling lake district (right). The shores of one of the moon’s largest bodies of liquid, Ligeia Mare, shows evidence of wave activity. Credit: Left: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS; right: NASA/JPL-Caltech/ASI/USGS

The model showed that the threshold wind speed to generate a wave is lower for liquids with less surface tension, which makes it easier to change the liquid’s shape. Higher air density provides more force to push against a liquid’s surface, and lower gravity makes it easier for a wave to rise up—both factors allow a weaker wind to create a wave. The team published these results in the Journal of Geophysical Research: Planets in April.

Waves on Other Worlds

The team first tested their model on the only set of wind and wave data we have—Earth. They used 20 years of wave and weather data for Lake Superior. The model found, correctly, that it takes wind speeds of 2.2 meters per second to generate waves on the lake’s surface and accurately predicted the height of waves for different wind speeds.

They then used the model to predict wave conditions on other worlds. They started with Mars, which likely had ancient oceans and lakes. Winds of 1.2 meters per second would have created waves in the lake that filled Gale Crater millions of years ago. A wave in Gale Crater would have been taller than a wave on Earth produced by wind of the same strength owing to Mars’s lower gravity.

The story is similar on Titan, the largest moon of Saturn. Waves in Titan’s hydrocarbon lakes would swell with a mere 0.5 meter per second of wind and would rise higher than an Earth wave under similar wind conditions. But they would travel much more slowly than Earth waves and would be spaced farther apart.

“The paper represents our best theoretical understanding of how we expect for waves to behave in a variety of environments,” said Jason Barnes, a planetary scientist at the University of Idaho in Moscow who was not involved with this research. “The movie of Titan waves is particularly awesome—very slow moving for such large amplitudes! Although I don’t expect waves to get that high ever in Titan’s sluggish atmosphere, it’s fun to be able to visualize what they might look like if they did.”

“In theory, this is something that people could do.”

The team also explored wave-generating conditions on three Earth-sized exoplanets. The possible sulfuric acid lakes of the exo-Venus Kepler-1649 b would grow in winds of 5.3 meters per second but would grow to a height similar to that of Earth waves because of its Earth-like gravity. Water lakes on LHS 1140 b would grow in 2.7 meter winds, similar to those on Earth, but would not grow as high because of its higher gravity. And on 55 Cancri e, a lava world, it would take winds of 37 meters per second—a category 1 hurricane—to move tiny waves of molten rock.

“Would you be able to ever detect this? Is this a useful thing to think about, or is it just a fun thought experiment?” Schneck asked. “If the waves are tall enough, you should be able to detect a change in the polarization [of an exoplanet’s light curve] that would not only suggest that there is a liquid surface on that exoplanet, but that liquid surface has waves.…In theory, this is something that people could do.”

Will We See It? Not Soon

Right now, the only world known to have surface liquid other than Earth is Titan, but we don’t have the right observations of Titan to test the new model. The European Space Agency’s Huygens probe landed on the moon in 2005, but nowhere near the northern lake district. NASA’s Cassini mission (of which Huygens was a part) did not detect any waves but did observe a changing lake shore that hinted at wave activity.

It’s possible that Titan’s waves are seasonal and Cassini just didn’t have the right timing, Perron noted. Temperature changes during Saturn’s year could affect wind speeds and also the composition of Titan’s lakes, changing the conditions of wave generation.

Still, the wind speed needed to make a wave on Titan is so low that “it would be very surprising if waves never formed. It just may be difficult to catch them when they’re there,” he said.

“The best way to test this work would be to send a sea probe to float or motor on one of Titan’s big 3 seas.”

“The best way to test this work would be to send a sea probe to float or motor on one of Titan’s big 3 seas—Kraken Mare, Ligeia Mare, or Punga Mare,” Barnes said. “Such a ‘buoy’ probe would be able to simultaneously measure both the sea conditions and the wind conditions, allowing for a comprehensive test of the model.”

Alas, no such mission is in the works, and the upcoming Dragonfly mission won’t travel near any lakes to test this theory either. A future Titan orbiter might provide that information, while a current or future Mars rover might yet gather evidence showing how lakes worked in that planet’s past.

“The improved understanding of waves from this paper might help to constrain the possibilities for wave erosion at the margins of bodies of water…thereby helping us to probe into the past climates of Mars and Titan,” Barnes said.

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

Citation: Cartier, K. M. S. (2026), What winds whip up otherworldly waves?, Eos, 107, https://doi.org/10.1029/2026EO260165. Published on 21 May 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
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Arsenic-contaminated groundwater affects more than 230 million people living in 108 countries. About 180 million of these people live in the Indian subcontinent (which includes Bangladesh, Nepal, and Pakistan, in addition to India) and Southeast Asia. The Indian state of Bihar, which borders Nepal, has several regions with extremely high levels of naturally occurring arsenic in their groundwater.

In Bihar, silt from the Himalayas containing arsenic and other heavy metals is routinely deposited in floodplains and seeps into the groundwater below. This phenomenon puts up to 21 million residents in Bihar at risk of consuming arsenic-contaminated water each day. Arsenic is a carcinogen that has also been linked to diabetes, pulmonary disease, cardiovascular disease, and infant mortality.

Though Bihar has close to 600 groundwater treatment units designed to filter out arsenic, a recent study of 98 units found that 90% of them were installed in parts of the state where groundwater arsenic levels were within the World Health Organization’s permissible limits (below 10 parts per billion)—which means almost all the communities that need these units the most still do not have access to them. The research was published in Groundwater for Sustainable Development.

“Some of the areas with these units had reported a higher prevalence of gallbladder cancer, which is associated with arsenic poisoning. But we found that it was the food that was the main source of arsenic exposure, not groundwater,” said Arun Kumar, a study author and senior scientist at Mahavir Cancer Sansthan & Research Centre in Patna, the state’s capital city. “In the last decade, we have observed drastic changes in groundwater arsenic levels in Bihar. Along with that, the cancer burden has also reduced in some parts of the state.”

In another city, Buxar, Kumar and his colleagues observed levels of arsenic of up to 1,900 parts per billion in the groundwater in 2015. But when the researchers retested that region’s water samples last year, the arsenic levels had gone down to 100–200 parts per billion.

“We hypothesize that because Bihar is prone to earthquakes, the seismic activity might have changed the properties of sediments and silt in groundwater. And perhaps, at some stage, those regions with the groundwater treatment units had experienced arsenic contamination,” added Kumar. “It is still a mystery to us” why the levels changed so drastically.

Ditching Groundwater for River Water

Kumar acknowledged that in the past few years, there has been a mushrooming of public and private groundwater arsenic treatment units in regions located within 10 kilometers (6.2 miles) of the Ganges River in Bihar. The majority of the 98 units included in the study were installed by the state government from 2016 onward. The researchers observed that privately owned units underwent regular maintenance, unlike many of the government-run units.

“Much of the previous large-scale groundwater testing conducted in Bihar was limited to the 6-mile stretch on either side of the Ganges River.”

The corresponding author of the study, Laura Richards, a professor of water resources and geochemistry at the University of Manchester, explained that regions close to the Ganges River may have been given higher priority mainly because they are situated along major roads and highways, making them easier to access than inland Bihar.

“Much of the previous large-scale groundwater testing conducted in Bihar was limited to the 6-mile stretch on either side of the Ganges River. The issue with that is that the regions selected for arsenic remediation units were likely based on nonrepresentative spatial sampling of the state, and those locations might not have necessarily covered all areas with arsenic contamination in the groundwater,” said Richards. “Arsenic distribution across the state is really quite heterogeneous.”

The researchers further found that in 10% of the locations where groundwater arsenic treatment units were installed by the state government, high levels of fluoride posed a greater public health risk than arsenic, suggesting that governmental policies were rolled out without site-specific water quality monitoring and testing.

“Alluvial or sand-rich aquifers are the main culprits of arsenic-contaminated water in Indian terrains.”

In addition to arsenic and fluoride, the groundwater in different parts of Bihar has high levels of manganese and iron. Currently, the state has more than 3,000 groundwater treatment units for arsenic, fluoride, and iron. However, Kumar said a better solution would be to look to other sources for drinking water and to ensure water treatment centers are properly maintained.

“People would be a lot safer if they stopped consuming groundwater altogether,” Kumar said. “This is why the state government has started treating and supplying water from the Ganges River to villages. They have already started doing it in two districts and plan on expanding the supply of river water.”

“Alluvial or sand-rich aquifers are the main culprits of arsenic-contaminated water in Indian terrains,” said M. Santosh, a professor at the China University of Geosciences in Beijing who was not involved in this study. “This study clearly shows how we can rectify remedial measures on a local level. We should encourage more such studies on how to tackle this problem.”

—Anuradha Varanasi, Science Writer

Citation: Varanasi, A. (2026), In Bihar, groundwater treatment units were installed in regions that didn’t need them, Eos, 107, https://doi.org/10.1029/2026EO260168. Published on 21 May 2026. Text © 2026. The authors. 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

Most auroras appear in the “auroral oval” at high latitudes surrounding the magnetic poles. However, some can appear as a detached auroral arc from the auroral oval, at lower latitudes in mid-afternoon and connected to the oval only at a tip or two. Such a detached arc is believed to be linked to the “plasmaspheric plume,” the tongue-shaped extension of the plasmasphere during the recovery phase of a geomagnetic storm. (The plasmasphere is the torus-shaped region of cold, dense plasma above the low- and mid-latitude ionosphere.) The surface waves at the plume boundary cause it to ripple and modulate the various plasma waves in the plume.

Based on observations from multiple satellites and ground stations, Feng et al. [2026] find sawtooth-like undulations along the equatorward boundary of a detached auroral arc in the ultraviolet that was produced by energetic (>keV) electrons and accompanied by energetic (>10 keV) ions. The authors attribute the undulations to Electromagnetic Ion Cyclotron (EMIC) waves that are modulated by the surface waves and resonating with the energetic ions. The study unravels the fine-scale structures of detached auroral arcs and sheds important light on the dynamics underlying their formation.

Schematic illustration of the formation mechanism for the sawtooth-like undulations of a detached auroral arc. The surface waves modulate the Electromagnetic Ion Cyclotron (EMIC) waves in the plasmaspheric plume, causing the energetic ions to precipitate into the ionosphere and resulting in the formation of an afternoon detached auroral arc with sawtooth-like undulations. Credit: Feng et al. [2026], Figure 4

Citation: Feng, H., Wang, D., Hao, Y., Miyoshi, Y., Fu, H., Jun, C.-W., et al. (2026). First observation of sawtooth-like undulations in afternoon detached auroral arcs modulated by surface waves at the plasmaspheric plume boundary. AGU Advances, 7, e2025AV002234. https://doi.org/10.1029/2025AV002234

—Andrew Yau, Editor, AGU Advances

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Forecasts for the 2026 South Asia monsoon are for below average rainfall, but some of the most landslide prone areas of India may receive totals that are above average.

As usual, we are now starting to see the number of reported global fatal landslides increase as the northern hemisphere rainy season commences. In recent days, there have been fatal floods and landslides across several provinces of mainland China as well as landslides on the pilgrimage route to Kederath in northern India.

The global pattern is dominated by the South Asia (southwest / summer) monsoon, so it is interesting at this point to to consider the prospects for this year. The monsoon itself is expected to start in SW India next week, timing that is normal. It will then build over the following month or so.

The current forecast for the monsoon itself is that the total rainfall is likely to be below average. This is the WMO forecast:-

The WMO 2026 South Asia monsoon forecast from the WMO.

The map shows below average precipitation for much of South Asia. The IMD also forecasts below average rainfall.

Of course, in landslide terms we are interested mainly in SW India (Kerala), which has a below average forecast, and the mountainous areas of Pakistan, India, Nepal, Bhutan and Bangladesh. Much of this is also forecast to receive below average precipitation, but note the above average forecast for parts of northern India (Jammu and Kashmir, Himachal Pradesh) and NE India (Sikkim, Arunachal Pradesh). These are some of the most landslide-prone areas of India, suggesting that we may well see substantial landslide challenges in these areas.

The caveat of course is that monsoon-triggered landslides are sensitive to rainfall intensity as well as rainfall magnitude. A below average monsoon can bring intense rainfall events that trigged catastrophic landslides. Unfortunately, the forecasts cannot resolve this issue.

As an aside, the next few days in the European Alps will be interesting. We are about to see a few days of unusually high temperatures, which are likely to drive a wave of snowmelt and permafrost thawing. Given the time of year, this could well trigger extensive rockfall activity.

Unfortunately, by the time I get to Switzerland in nine days the weather is forecast to have reverted to cool drizzle!

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