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SummaryThe Alpine-Himalayan orogen preserves geological remnants of subducted lithosphere from the Paleotethys and Neotethys oceans and intervening microcontinents. This orogenic belt displays distinct segments separated by discontinuities aligned with paleo-transform faults, reflecting laterally varying ocean opening and closure histories. We investigate how upper and lower mantle slab remnants imaged by seismic tomography may correlate with Paleo- and Neotethyan subduction zones, focusing on the Anatolian, Aegean, and Iranian segments. Using plate tectonic reconstructions in a mantle reference frame, we predict slab subduction timing, amount, and location and make a semi-quantitative dimensional comparison with seismic tomographic images beneath the Eastern Mediterranean and Middle East. We identify three major Neotethyan slabs: the Pontides and Egypt slabs detached in the Late Cretaceous and now occupy the upper lower mantle. The Cyprus slab remains mainly in the upper mantle in which it overturns. To account for subducted lithosphere that reconstructions predict, we interpret that the Cyprus slab lies overturned in the lower mantle down to ∼1000 km. We interpret a large lower mantle anomaly volume between 2200-1500 km (the Herodotus anomaly) as representing Paleotethyan lithosphere that subducted between ∼240-180 Ma. Our reconstruction-tomography comparison suggests that current slab positions likely reflect past detachment locations, while geometries indicate paleo-trench absolute motions, including a Late Cretaceous same-dip, double subduction configuration. Slabs associated with Aegean, Anatolian, Iranian, and Tibetan segments define stable mantle provinces with boundaries aligned with transform-related orogenic segmentation, implying minimal paleo-longitudinal mantle flow since the Early Mesozoic. Our findings indicate upper and lower mantle structure primarily results from near-vertical slab sinking after detachment since the Triassic, without evidence for deflection by lateral components of mantle convection.

SummaryAs the demand for European domestic mineral resources increases, exploration is increasingly focused on deeper and covered targets, often located in populated regions. In such environments, the application of electromagnetic (EM) techniques is severely challenged by anthropogenic infrastructure. Metal-bearing structures, including power lines, pipelines, railway tracks, and mine shafts, can strongly distort the EM fields, producing significant artefacts in both the measured data and the resulting inversion models, thereby biasing or hindering geological interpretation. These effects currently limit EM investigations in inhabited areas, despite their potential for non-invasive and efficient exploration of challenging subsurface targets. Focusing on semi-airborne electromagnetic (sAEM) data, we develop a data-driven approach to address infrastructure-related effects. By inverting affected data for the distribution of infrastructure currents, we account for the full coupling between the EM transmitter, the conducting Earth, and the metal infrastructure. In sAEM field experiments, involving a grounded dipole transmitter and an airborne receiver system, we study the distortion by self-built infrastructure and investigate both measured currents in infrastructure as well as its EM coupling. We validate the functionality of our current inversion approach by reproducing the measured currents in a simplified 1D scenario. With a synthetic 3D study, mimicking a sAEM campaign in the presence of infrastructure, we find that the current inversion approach is capable of separating and correcting for infrastructure effects even if the true resistivity distribution of the subsurface is unknown. In particular, other conductive subsurface structures can be resolved well, even directly below infrastructure. On a small sAEM field data example, affected by the impact of a metal-built conveyor belt and pipeline, we demonstrate the applicability of this framework for real-world scenarios.

SummaryPermeability is a critical parameter for reservoir characterization and hydrocarbon development, yet its accurate prediction remains a challenge. Pore structure, as the intrinsic factor governing both the elastic and hydraulic transport properties of rocks, serves as a bridge between these properties and facilitates permeability prediction from well logs and seismic data. To accurately describe the variation in the physical properties of tight sandstone reservoirs with pressure, our study aims to construct a physical model that relates rock elastic properties with permeability. We developed a dual-porosity rock physics model by coupling David & Zimmerman’s pore-structure inversion method with Dienes’s percolation theory. Our model divides the pore space into pressure-insensitive stiff pores and pressure-sensitive compliant microcracks. By inverting the microcrack density and aspect ratio distribution-which evolve with pressure-from elastic wave velocities, we quantitatively predict permeability variations using Dienes statistical percolation model. To validate this model, we measured porosity, permeability, and P- and S-wave velocities on four tight sandstone samples under effective pressures of 5 to 50 MPa. The results show that the proposed model accurately captures the evolution of both elastic parameters and permeability with effective pressure, demonstrating strong predictive capability for the experimental data. The significance of this study lies in achieving a quantitative relation between elastic and transport properties by explicitly characterizing the pore structure and integrating percolation theory, which is then calibrated with real experiment data, thereby providing solid physical basis for better prediction of reservoir permeability using acoustic logs and seismic data.

Scientists have found evidence that a colossal cliff stretching thousands of kilometers across ancient North America may have exposed the heart of the Grand Canyon nearly a billion years before it was carved by the Colorado River.

For all that day-to-day weather forecasts have improved, it remains a challenge to forecast events that might happen once in 1,000 years—like the deadliest heat waves.

The Kakhovka Dam in southern Ukraine was destroyed on June 6, 2023. The event unleashed a catastrophic flood that forced thousands of residents to evacuate their communities as water levels rose 10 feet (3 meters) above normal.

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

The Arctic Report Card, an annual, peer-reviewed evaluation of the state of our warming Arctic, will still be published this year despite a lack of financial or logistical support from NOAA. 

On 10 August, editors of the Arctic Report Card were informed that NOAA will no longer support its publication, meaning the agency will not provide the report with coordinating editors, coordinate its external peer review, or fund the report’s web presence, publicity, graphics, or summary video. 

After a meeting of non-NOAA editors and chapter authors, however, the Arctic Report Card team has decided to move forward with publishing the 2026 report. Many of the report’s authors had been well into their work on their chapters when they learned that NOAA would no longer support that work.

“While many of the details are not final, we will be producing an ARC sans NOAA this year,” Rick Thoman, an Arctic scientist at the University of Alaska Fairbanks and an editor of the 2026 report, wrote in a message to Eos. Thoman said the team is not yet sharing which organization will host the 2026 Arctic Report Card, but that there has been a “tremendous outpouring of support for the Arctic Report Card, from individuals to large organizations.”

 
Related

•  Government Pulls Funding for the Arctic Report Card
•  Amid the Arctic’s Hottest Year, Arctic Science Faces a Data Deficiency
•  Get Involved: AGU Science Policy Action Center
 

He said the team plans to move forward with the original plan to present the report’s findings in a press conference at the 2026 AGU Annual Meeting in San Francisco, Calif. this December. Thoman also said the group of editors and authors is “pursuing multiple avenues” to produce the report’s graphics and summary video, and that they are planning to establish a non-NOAA website to serve as a long-term home for the Arctic Report Card in future years. 

“A lot of what we’re doing right now is, ‘How do we get this year’s report card out?’” he said. “But we are looking at the longer term, [also].”

The Arctic Monitoring and Assessment Programme (AMAP), part of the Arctic Council (an international Arctic policy and research collaboration), previously found reviewers and carried out the review process for the report. According to Thoman, AMAP has committed to providing that service for the 2026 report card. 

Science for Stakeholders

Having support from NOAA gave the report a heightened credibility for stakeholders, said Walter Meier, a sea ice scientist at the National Snow and Ice Data Center and a longtime author of the report’s sea ice chapter. “NOAA has had a strong reputation for providing high quality data, high quality observations, analysis, and research,” he said. “When you have that NOAA stamp of approval, people trust in that.” 

“I’m confident that the science will be of the same high quality.”

Still, he said not much would change about the scientific content of the report once it is hosted by a new organization. “I’m confident that the science will be of the same high quality,” he said. “I don’t feel there will be any loss [of quality], which is really the most important part.”

The report being outside of NOAA’s purview also “allows much more flexibility in language,” for the authors, Thoman said. He added that creating an Arctic Report Card without NOAA may allow the report to be more internationally focused than it has been previously.

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

These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2026. AGU. CC BY-NC-ND 3.0
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Growing up in New Jersey, Emily Wilson regularly passed tidal marshes without giving them much thought. They were part of the coastal landscape—stretches of green and blue she saw from the road.

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

The U.S. Forest Service has moved forward with a rule to withdraw protections from 45 million acres of pristine national forests by rescinding the 2001 Roadless Area Conservation Rule. The U.S. Department of Agriculture (USDA) first announced its intent to rescind the Roadless Rule in June 2025 and it has now taken the next step to do so.

In today’s announcement, Secretary of Agriculture Brooke Rollins claimed that the Roadless Rule increases wildfire risk by preventing land managers from maintaining national forests.

“For too long, outdated restrictions have kept tens of millions of forested acres off-limits to the very treatments that improve forest health and reduce wildfire risk to our communities,” Rollins said in a statement. “Today, we filed a proposal to restore authority to local forest managers who know the land best, removing the barriers that have kept them from doing the work the land demands. It’s time to turn the page on the failed roadless rule and return our forests to health and productivity.”

However, this justification is not backed up by data. Research has shown that nearly 85% of wildland fires begin with human activity, either accidentally or deliberately. What’s more, human-caused fires are much more destructive than naturally-caused fires from, for example, lighting strikes. Building roads would bring more people into former wildlands, thereby increasing wildfire risk despite the increased access for maintenance, several forest experts told the New York Times.

The Trump Administration “is trying to walk away from the most successful land conservation policy in modern U.S. history.”

“The truth is that roadless forests are our greatest defense against wildfire,” David Jenkins, president of the nonprofit Conservatives for Responsible Stewardship, said in a media statement. “Not only are old growth forests naturally resistant to fire, but 90% of all wildfires in the U.S. occur within a half mile of a road. Any claims to the contrary are demonstrably false.”

Most of the inventoried roadless areas are in western states, with more than 95% located in Alaska, Arizona, California, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. However, the proposed rule does not apply to Colorado and Idaho, which have state-specific roadless regulations.

Some suspect that the administration’s true intent is not to reduce wildfire risk but to drastically increase logging production.

“The Trump administration is moving to gut our most iconic national forests by giving loggers and drillers free rein to turn them into industrial wastelands. It is trying to walk away from the most successful land conservation policy in modern U.S. history,” Andrew Wetzler, senior vice president for nature at the nonprofit Natural Resources Defense Council, said in a statement.

Jenkins added, “This is one of the most boneheaded and fiscally irresponsible actions this administration could take. The agency doesn’t have the budget to take care of the 368,000 miles of roads already riddling our national forests. In fact, there is currently a $10.8 billion maintenance backlog.”

 
Related

•  Trump Administration Moves to Allow Logging in Pristine National Forests
•  Read the Forest Service’s Proposal
•  Context from Eos: USDA Moves to Rescind Roadless Rule Protecting 45 Million Acres of Wild Area
•  Get Involved: AGU Science Policy Action Center
 

The Roadless Rule was enacted by the Clinton administration in 2001 to prevent logging and development on millions of acres of pristine forest across the country. For 25 years, this rule has protected crucial habitats for migratory species, headwaters for municipal water supplies, and old-growth forests which act as significant carbon sinks. If the rule was rescinded, those forests and the ecosystem services they provide would be at risk.

“Once we cut a road through these forests, we don’t get their values back,” Wetzler said. “The forest fragments. The streams and rivers are degraded by runoff. Iconic wildlife struggles to find suitable habitat. And we get stuck with even more roads in a vast network the agency already can’t maintain.”

The Roadless Rule itself is hugely popular, garnering around 75% public support. Nearly 626,000 public comments were submitted on the USDA’s 2025 draft proposal to eliminate the rule, with more than 99% of comments calling for the rule to stand. Former U.S. Forest Service chiefs, lawmakers, Tribal leaders, scientists, and wildland firefighters have also defended the rule.

The Forest Service’s proposal will be published in the Federal Register on 20 August, after which it will accept public comments before finalizing the rule change.

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

A study led by a Montana State University research professor reveals how climate and hydrothermal activity have shaped the vegetation, wildfire and aquatic ecosystem histories of the Yellowstone Plateau over the past 15,000 years. The results of the project were published in the journal Proceedings of the National Academy of Sciences.

A team of researchers reports that they may have found rock containing some of the earliest forms of microbial life on Earth. Their study, published in the Proceedings of the National Academy of Sciences, describes the biosignatures found in this 3.5-billion-year-old, carbon-rich, layered rock, called chert.

In recent years, the Alps have experienced devastating glacier collapses: In September 2023, a section of the Marmolada glacier in the Dolomites collapsed, resulting in the deaths of seven mountaineers. Just over a year and a half later, in May 2025, the Birch Glacier above Blatten collapsed, keeping Switzerland and the entire world in suspense.

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

Droughts are becoming an increasing global concern as their impacts intensify. Understanding how climate change affects drought frequency and severity is essential for projecting future drought risk. In this context, the question raised by Helpap et al. [2026]—”are modern droughts unprecedented?”—has a high scientific relevance. Here, 20 ensemble members from a 600-year climate simulation and reanalysis data from the period 1950-2024 are analyzed to place recent droughts in a multi-century context. It is concluded that drought extremes are intensifying more rapidly beyond the range experienced in the past than moderate droughts. Therefore, an increasing likelihood of droughts reaching unprecedented magnitudes is expected in the near future, thus highlighting the urgency for adaptation measures in water resources and environmental management.

Citation: Helpap, P., Brönnimann, S., Hand, R., Franke, J., Raible, C. C., & Stocker, B. D. (2026). Are modern droughts unprecedented? AGU Advances, 7, e2026AV002536. https://doi.org/10.1029/2026AV002536

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

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.

The mantle, a rocky layer accounting for more than 80% of Earth's volume, circulates at rates of only a few centimeters per year. This circulation drives plate tectonics and influences major geological phenomena such as earthquakes and volcanic activity. Despite its fundamental importance, the history of mantle circulation remains poorly understood because direct observations of the deep Earth are extremely limited. Currently, scientists rely on geological records of past surface movements and geophysical imaging methods, including seismic observations, to infer the mantle's structure and behavior. However, reconstructing historical mantle flow remains a major challenge.

The summers of recent years have been hot, but not unusual from a meteorological perspective. According to researchers at Leipzig University, though, the next extreme summer would far exceed anything we have experienced so far.

Massive storms like Hurricane Katrina in 2005, which caused more than $100 billion in damage, were once considered lifetime events. Increasingly, however, they are becoming the norm: a direct result of climate change, which has made large storms more frequent, intense and slower-moving, deepening their impact.

Author(s): E. S. Uchava and A. G. Tevzadze

We investigate linear perturbations of an incompressible, weakly collisional, anisotropic plasma in the low frequency limit using an extended 16-moment fluid description that retains parallel and perpendicular heat fluxes. We identify a class of linear perturbations associated with a conserved therm…

[Phys. Rev. E 114, 025206] Published Tue Aug 18, 2026

Author(s): Runze Li, Wenchao Yan, and Longqing Yi

When a high-power, femtosecond, circularly polarized (CP) laser pulse impinges on a micrometer-scale aperture in a solid foil target, it drives surface plasma oscillation on the boundary, and generates high-order harmonic vortices in the diffracted light [L. Yi, Phys. Rev. Lett. 126, 134801 (2021).]…

[Phys. Rev. E 114, 025207] Published Tue Aug 18, 2026

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

On social media, the Department of Mineral and Petroleum Resources, Republic of South Africa has released two aerial images of the aftermath of the 13 August 2026 tailings storage facility failure at the Semancor Dikwena Chrome Mine in South Africa.

The first shows the tailings storage facility (TSF) itself, including the loss of slimes:-

The aftermath of the TSF failure at the Samancor Dikwena Chrome Mine tailings storage facility near Brits. Image released by the Department of Mineral and Petroleum Resources on social media.

It is interesting to note the small-scale slope failures on the tailings wall in the foreground (I’d be interested to know if this was expected as part of the design), but also the fact that this TSF has been raised above those on either side.

The second shows the breach itself:-

The aftermath of the TSF failure at the Samancor Dikwena Chrome Mine tailings storage facility near Brits. Image released by the Department of Mineral and Petroleum Resources on social media.

I’m no expert on TSF construction, but this one has a complex history. There is a very detailed archive of images on Google Earth. So for example, this was the facility in August 2015:-

Google Earth image of the TSF that failed at the Samancor Dikwena tailings storage facility near Brits. Image from 2015.

Note that this was a single facility at that stage.

This is the same site in June 2022:-

Google Earth image of the TSF that failed at the Samancor Dikwena tailings storage facility near Brits. Image from 2022.

The eastern end of the facility (which failed) had become vegetated with little sign of human activity. There was some work going on at the western end.

If we jump to July 2025, we see the facility had been raised and subdivided, and that active deposition was occurring in both sections. The one that failed (known as 1b) was notably higher than the one to the west.

Google Earth image of the TSF that failed at the Samancor Dikwena tailings storage facility near Brits. Image from 2025.

It is good to see that Semancor has taken full responsibility for “the repair of any infrastructure and the rehabilitation of the affected area“, noting of course that the global mining industry does not have a good track record of actually delivering against such commitments.

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SummarySatellite formation configuration plays a crucial role in formulating the next generation gravity mission aiming at improving the accuracy and spatiotemporal resolution of Earth’s gravity field modeling. For the proposed GRACE-Pendulum (GRACE-P) formation, technical challenges and limited accuracy gains from the third observation link led to the adoption of only two baselines, without incorporating the third link perpendicular to the GRACE-type baseline, resulting in potential limitations in modeling accuracy. With future technological advancements overcoming these constraints, this study first proposes a complete triangular GRACE-Pendulum-full (GRACE-PF) formation, which includes the omitted third link, to explore the upper limit of accuracy achievable with this formation geometry. Building on this, we further introduce a novel satellite formation, namely the Three-Observation-Link (Three-OL) formation, inspired by the Chinese TianQin gravitational wave detection project. While geometrically similar to GRACE-PF, Three-OL does not include a GRACE-type baseline. To systematically evaluate the performance of these formations, a closed-loop simulation experiment was conducted, followed by a comparative analysis of GRACE-P, GRACE-PF, and Three-OL formations in the spectral-spatial domain. Specifically, spatial-domain results show that GRACE-PF outperforms GRACE-P by 28.7 per cent globally, confirming the accuracy contribution of the third link. Three-OL exhibits superior performance to GRACE-PF, with higher accuracy for mid-high degree signals in the spectral domain, and an 11.3 per cent accuracy improvement over land areas in the spatial domain. Furthermore, compared with the mainstream Bender and GRACE formations, Three-OL reduces the residual RMS over land areas by 28.4 per cent and 75.9 per cent, respectively, while also demonstrating improved capability for recovering sub-monthly gravity signals. In summary, this study reveals the accuracy potential of the complete GRACE-P configuration and proposes a novel formation capable of supporting high-precision temporal gravity field modeling. This work provides a feasible and efficient formation design for gravity satellite missions dedicated to Earth’s gravity field detection.