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Author(s): Nadine Wetta and Jean-Christophe Pain

This work investigates how locally persistent crystal-like ordering in liquids influences the Debye-Waller factor. We have developed a theoretical framework based on liquid-phonon theory which introduces a phonon relaxation time, expressed as the ratio of shear viscosity to infinite-frequency shear …

[Phys. Rev. E 114, 015220] Published Fri Jul 24, 2026

SummaryIn near-surface porous media containing aligned fractures and fluids, the propagation of Rayleigh waves is influenced by both fracture geometry and wave-induced fluid flow. These processes introduce frequency-dependent dispersion and azimuthal anisotropy in both phase velocity and attenuation. To investigate these effects, this study applies Chapman-type fracture–pore effective medium theory to describe fluid-saturated fractured media as horizontally transversely isotropic (HTI) media with frequency-dependent complex stiffness. The complex dispersion relation of Rayleigh waves is obtained by combining this model with the Stroh formalism for HTI half-spaces. Numerical results show that Rayleigh-wave phase velocity exhibits clear frequency-dependent dispersion together with azimuthal anisotropy. The fast and slow propagation directions remain consistent with the orientation of the fracture strike. Rayleigh-wave attenuation exhibits a clear relaxation peak within the frequency band associated with wave-induced fluid flow and shows strong azimuthal variation. Parameter analysis further indicates that fracture density primarily controls the strength of azimuthal anisotropy, whereas porosity mainly affects the overall level of dispersion and attenuation. The relaxation time governs the frequency range over which dispersion and attenuation become significant. The combined frequency–azimuth variations of phase velocity and attenuation therefore provide potential constraints for estimating fracture–pore structures in fractured reservoirs using multi-frequency and multi-azimuth Rayleigh-wave observations.

For more than 20 years, about 4,000 autonomous profiling floats have been drifting through the ocean. They form part of the international Argo program (Argo—global array of profiling floats). At regular intervals, they descend to a depth of 2,000 meters (6,600 feet) and, as they rise, measure parameters such as temperature, salinity and pressure. Once they reach the sea surface again, they transmit these data via satellite to the Argo network, which is available to researchers worldwide. Hardly any other observation system has transformed ocean research so profoundly in recent decades.

A new study led by Japanese researchers from Tohoku University and the National Institute for Environmental Studies (NIES) reveals that some of the minerals most essential for green technologies may have a significant negative impact on biodiversity. Using remote sensing and machine learning, the scientists produced an unprecedented global map of mined commodities.

If the Colorado River Basin is the lifeblood of the American Southwest, keeping the region's agricultural, ecological and economic systems thriving, Colorado's West Slope River basins could be considered the heart. Together, they contribute about 70% of the water delivered to Lake Powell, the second-largest reservoir in the nation.

A heat wave lasting four months, followed by water shortages and crop failures. This is England in the 13th century, not the 21st. What is often called the Medieval Warm Period saw elevated temperatures in many parts of the world between the 10th and 13th centuries.

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.

23 July: This article was updated to include comments from Jennifer Jones and Colette Delawalla.

A report released this week directs the U.S. government to spark a “new golden age” of science by ushering funds toward artificial intelligence, fostering closer relationships with private industry, and dismantling and rebuilding the federal science funding process.

The report was written by Michael Kratsios, director of the White House Office of Science and Technology Policy. He outlined his recommendations to Congress at a hearing of the House Committee on Science, Space, and Technology on 22 July. 

Kratsios intended the report to emulate a letter written to President Franklin D. Roosevelt by Vannevar Bush in 1945, called Science, the Endless Frontier, which set the foundation for the current U.S. federal science process in which federal funds support university research. “As we celebrate the United States’ 250th anniversary, we have the responsibility to renew our foundations once more,” he wrote.

Kratsios listed four goals to guide this approach to U.S. science: to “prioritize the individual scientist over legacy institutions,” to “fundamentally change how research dollars are allocated, distributed, and assessed,” to “set clear scientific goals and build the industrial muscle to translate scientific discovery into technological strength,” and to “prepare our research enterprise for the AI revolution.”

“If you think about this report in the context of everything else this administration has done, it really is about weakening independence, weakening accountability, [and removing] scientific integrity protections in favor of empowering political appointees,” said Jennifer Jones, director of the Center for Science and Democracy at the Union of Concerned Scientists.

Science-A-New-Golden-Age_EosDownload

The report recommends a handful of federal priorities to achieve these goals, including the Genesis Mission, a “national effort to harness AI for scientific discovery at a scale no other nation can match” led by the Department of Energy (DOE).

At the 22 July hearing, Kratsios said the Genesis Mission “is the crown jewel of American AI for science” and announced that federal agencies have committed more than $5 billion to the project. So far, 278 awards have been made, the largest being a three-year, $60 million grant for a project that will “help deliver nuclear facilities faster and safer” with the use of AI, according to the DOE. 

“There’s no mention of scientific integrity, no mention of protections for independence, it’s just the opposite.”

“There are some examples in STEM where AI is valuable,” such as increasing power in computational modeling or identifying new Earth-like planets at scale, for example, wrote Colette Delawalla, founder of science advocacy group Stand Up for Science, in an email. “But AI will never replace curiosity-driven scientific advancement,” she wrote. 

Some scientists viewed the report as a way for the government to justify steering research funds toward private industry and increasing political interference in science. “I think they’re trying to turn it into a venture capital model,” Jeremy M. Berg, a computational biologist and former director of the National Institute of General Medical Sciences at the National Institutes of Health, told The New York Times. 

“Under the hood,” the report is a “vision for faster technology development and commercialization while underinvesting in the fundamental research, expert peer review, and scientific workforce that make those advances possible,” Keivan Stassun, an astrophysicist and member of the National Science Board prior to its dissolution by the Trump administration, told Science.

What’s interesting about the report, Jones said, is what it doesn’t mention. “There’s no mention of scientific integrity, no mention of protections for independence, it’s just the opposite,” she said. “There are no clear systems of accountability” explained in the report, and its suggestion to funnel funds to individual researchers rather than institutions such as universities also means more research could occur outside of universities’ established and robust systems of accountability, she added.

The recommendations in the document largely align with recommendations made by former National Academy of Sciences president Marcia McNutt in June. In the annual president’s address, McNutt encouraged the scientific community to “better understand the needs of industry” and embrace the use of AI to increase research efficiency. 

At the hearing, however, Kratsios agreed with Rep. Brian Babin (R-TX), chair of the committee, that the National Academies of Science, Engineering, and Medicine required more federal oversight, especially in light of its recent report on climate attribution science that Babin said raised “transparency concerns.” Kratsios said he looked forward to working with Congress to codify the recommendations made in the “new golden age” report.

Funding the Golden Age

The vision the report presents is accompanied by recommendations from Kratsios and Russell Vought, director of the Office of Management and Budget, for the FY 2028 budget. These recommendations include prioritizing funding for physical sciences, including quantum physics, chemistry and materials sciences, mathematics and computer sciences, engineering, and biological sciences. 

For FY 2028, “agencies should align their R&D investments, where appropriate, with the Administration’s national missions,” the report states, listing those “national missions” as AI, quantum computing, fusion power, the construction of a lunar base and return of humans to the Moon, autonomous robotics, and semiconductor technology. 

 
Related

•  Read the Report: “Science: A New Golden Age”
•  Watch the Hearing: “Examining the Priorities of the FY2027 Research and Technology Enterprise”
•  Trump’s Plan for Science: More Money for A.I., Less for Universities
•  Trump Administration Steers $5B Toward AI Research
•  Get Involved: AGU Science Policy Action Center
 

At the 22 July hearing, Democrats argued that the Trump administration’s actions have worked against the stated goals of Kratsios’s report. “Big new initiatives and promises mean nothing when agencies act capriciously, canceling grants midway, delaying awards for months, even after they’ve been selected through the rigorous merit review process, and blacklisting educational and research institutions,” said Rep. Zoe Lofgren (D-CA).

The report did not mention the Trump administration’s proposed FY 2027 budget, which, if finalized, would reduce the National Science Foundation’s budget by 53%, the U.S. Geological Survey’s budget by 37%, the NASA science budget by 42%, and NOAA’s budget by 28%.

“I anticipate the report will be used as the rationale for making further cuts in the budgets and staffing of federal research agencies while limiting their authority and accountability to the American people,” Neal Lane, former director of the NSF, told Science. 

The report also did not mention recent sweeping cuts to the NSF’s FY 2026 budget, the fact that the NSF currently has no director, or a June proposal from the Office of Management and Budget that, if finalized, would give political appointees final approval power for scientific grants.

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

In recent summers, wildfire smoke has been inescapable across Wisconsin, drifting south from Canada and leading to long stretches of poor air quality. Whether that smoke clears or lingers is often influenced in part by the atmospheric boundary layer—the lowest part of the atmosphere, where airborne particles mix and move.

The winter earthquake of 923 or early 924 CE remains the benchmark event in the Seattle Fault Zone. It lifted shorelines around Puget Sound and gave geologists one of the most decisive records of the fault’s power.

But that shoreline-lifting earthquake is only part of the zone’s history. A recent Geological Society of America Bulletin study led by Stephen J. Angster, a geologist with the U.S. Geological Survey, looks past the most famous Seattle fault earthquake to examine evidence of earthquakes on lesser-known secondary faults.

At Lytle Beach on Bainbridge Island and at Vasa Park near Bellevue, subtle landforms and trench records suggest evidence of smaller ruptures has been preserved in the landscape but not fully recognized.

At Lytle Beach, the first clue was a small, raised surface. Angster described the “localized uplifted terrace” as “the first feature we saw that drew our eye to that area.” Similar features had already helped geologists read other secondary faults in the Seattle Fault Zone.

For instance, Angster said the Toe Jam Hill fault became one of the better-known examples when lidar helped reveal its scarp through dense vegetation. Later work found smaller uplifted terraces near similar secondary structures, which Angster said may indicate separate earthquake events focused on smaller faults rather than the larger regional rupture.

However, Lytle Beach stood out in a different way, as its fault dips south, in contrast to the zone’s better-known secondary faults, which dip north.

Faults Hidden in the Fold

Finding the localized uplifted terrace was only the beginning for Angster, who used lidar to uncover scarps and lineaments through the region’s forest cover.

His team also utilized ground-based magnetic transects across the Lytle Beach fault to look for changes that may reveal displacement beneath the surface. In addition, they gained a more direct view of disturbed sediments by excavating the Rose Hip trench across the newly identified Lytle Beach scarp and analyzing evidence from the earlier Vasa Park trench.

In the Rose Hip trench at Lytle Beach, Angster said the team found glacial deposits dating to roughly 15,000 years ago. Above them were lake sediments left behind as ice retreated. The trench also preserved an old layer of soil that formed after the lake dried. “That whole package was folded,” he said. “The only way you could fold those is mostly by a tectonic fault.”

A regional map of the Seattle Fault Zone shows the Lytle Beach and Vasa Park fault scarps, along with the uplifted shore platform associated with the 923 CE earthquake. A new study used mapping, geophysics, trenching, and dating methods to investigate secondary faults within the broader fault zone. Credit: Angster et al., 2026, https://doi.org/10.1130/B38333.1, CC-BY-4.0

The trench record showed evidence of two surface-rupturing earthquakes on the Lytle Beach fault. The older event occurred between 11,240 and 10,430 calibrated years before present, whereas the younger event occurred after 1663 CE, likely in the early nineteenth century. (“Calibrated years before present” refers to dates arrived at via radiocarbon dating, relative to the year 1950 as the “present.”)

“I thought the trenching on Lytle Beach was surprising, that we found two events, because it was such a relatively subtle feature that wasn’t really identified before,” Angster said.

At Vasa Park, the team found evidence of one past earthquake that occurred sometime between 11,380 and 7,400 calibrated years before present. That range overlaps with the older Lytle Beach event and raises the possibility of a longer rupture along the Blakely Harbor fault. However, the evidence in Angster’s study better supports separate ruptures on the two secondary faults.

A Longer Record of Smaller Ruptures

Harold Tobin, an earthquake scientist at the University of Washington who was not involved in the study, called the work “exciting new research.”

He said the study shows there is “room to accommodate smaller earthquakes” that do not reshape shorelines like the 923 or 924 event but are “still big enough to be damaging earthquakes.” The Angster paper, he said, examines “additional earthquakes not accounted for in the shoreline uplift record centered on the 923 or 924 event. These smaller earthquakes may have happened more recently or more often.”

“Subtle features, relatively small or fault traces that we might have ignored before, can be an important part of the story.”

For Tobin, the value also extends beyond Puget Sound. The study “shines a light for other people working in cities and urbanized settings,” he said, because it shows that “subtle features, relatively small or fault traces that we might have ignored before, can be an important part of the story.”

By comparing the dated events at Lytle Beach, Vasa Park, and other secondary faults, the authors estimated that these faults may have ruptured roughly every few hundred years during the late Holocene. Angster cautioned that it’s not quite clockwork. “The secondary faults appear, especially within the last 2,500 years, to rupture more frequently, and that’s where that 350-year interval comes from,” he said. But the estimate rests on a limited record.

Though the work doesn’t forecast the next earthquake, it gives scientists more of the past to weigh as they assess the Puget Lowland. Tobin said the paper “certainly beg[s] more research” because the Seattle Fault Zone contains many strands that still need to be studied. Earthquake hazards should remain “something real” for the public and civil planners.

“We don’t know when they are going to come,” Tobin said. “Obviously, we can go decades without any significant earthquakes, as we have since 2001. But when we least expect it, one will happen, and we just have to be prepared.”

Angster framed the findings more conservatively: “This study doesn’t really change the hazard with the Seattle Fault. It just provides more insight into how it behaves.”

—Jason Collins, Science Writer

Citation: Collins, J. (2026), Small faults add to Seattle’s quake story, Eos, 107, https://doi.org/10.1029/2026EO260238. Published on 23 July 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.

Author(s): S. A. Khrapak and A. G. Khrapak

The excess energy, entropy, and pressure of a strongly coupled Yukawa fluid are calculated from the variational approach using the fluid of hard spheres as a reference system. As in the case of the one-component plasma, the Percus-Yevick virial entropy is appropriate for such calculations and delive…

[Phys. Rev. E 114, 015216] Published Thu Jul 23, 2026

Author(s): S. A. Khrapak and A. G. Khrapak

The variational approach based on the Bogoliubov inequality using the fluid of hard spheres as a reference system is implemented to evaluate instantaneous shear, bulk, and longitudinal elastic moduli, as well as related sound velocities of Yukawa fluids. The remarkable accuracy of this method is doc…

[Phys. Rev. E 114, 015217] Published Thu Jul 23, 2026

Author(s): Yue Dong, Zhigang Yuan, Shiyong Huang, Xiongdong Yu, Zuxiang Xue, Honghong Wu, Dedong Wang, C. J. Pollock, R. B. Torbert, and J. L. Burch

Electron holes are Debye-scale kinetic structures that mediate particle trapping, field-aligned electric fields, and energy conversion in collisionless plasmas. How such coherent structures interact with one another, however, has remained difficult to resolve in situ. Using four-spacecraft Magnetosp…

[Phys. Rev. E 114, 015218] Published Thu Jul 23, 2026

Author(s): De-Hua Shi, Xiao-Kun Wang, De-Qi Wen, and Yong-Xin Liu

While investigating radio-frequency gas breakdown, the authors experimentally observed and simulated a novel, time-dependent striated optical emission structure. The study reveals that these striking patterns are driven by differing electron-ion mobilities and locally amplified ionization, which are ultimately suppressed as the electric field becomes screened.

#AdvancingField

[Phys. Rev. E 114, L013201] Published Thu Jul 23, 2026

SummaryAutonomous underwater vehicles (AUVs) provide high-resolution magnetic measurements essential for investigating crustal accretion, tectonic segmentation, and hydrothermal processes at mid-ocean ridges. However, raw magnetometer measurements are strongly influenced by platform-induced magnetic fields, attitude-dependent biases, and navigation uncertainties that must be corrected to recover geophysically meaningful anomaly fields. We apply a procedure to measurements from AUVs which includes platform independent scalar calibration, transformation into geographic reference frames, spin-based removal of permanent and induced vehicle magnetization, and computation of magnetic anomalies relative to the International Geomagnetic Reference Field. The framework also incorporates a two-dimensional spectral upward continuation to reconcile altitude variations, thereby recovering anomalies at a uniform reference level. Application of this system to AUV datasets from the East Pacific Rise and Mid-Atlantic Ridge demonstrates effective suppression of platform biases, improved crossover consistency, and the generation of internally coherent geomagnetic anomaly fields suitable for subsequent analysis and mapping.

SummaryThe Southwest Subbasin (SWSB) of the South China Sea represents a young oceanic basin formed by continental rifting and subsequent seafloor spreading between ∼23.6 and 16 Ma. Yet the deep crustal structures of its continental margins and the oceanic crustal accretion processes remain poorly understood. This study presents integrated two-dimensional seismic and density models along the OBS2020-3 profile, which traverses the continental margins and oceanic basin, using seismic refraction, multichannel seismic reflection, and free-air gravity data. Our results reveal prominent intra-crustal reflectors at ∼11.5 km depth beneath the northwestern continental margin, which we interpret as the brittle-ductile transition marking depth-dependent extension during rifting, without any evidence of high-velocity lower crust layers. Within the oceanic basin, the thin magmatic crust overlying serpentinized mantle suggests reduced magmatic supply during its opening. Combined with published seismic profiles crossing the ridge axis to the northeast and southwest, our results reveal a systematic southwestward decrease in crustal thickness in the ridge-parallel direction, suggesting a progressive reduction in melt supply toward the southwestern termination of the SWSB. The ridge axis (Longmen Seamount) is characterized by pronounced crustal low-velocity anomalies accompanied by apparent crustal thickening. We interpret that these features resulted from enhanced porosity and mantle serpentinization, both facilitated by extensive faulting during the final, tectonically dominated spreading stage. Together, these findings provide new constraints on continental extension along the northwestern margin of the SWSB and oceanic crustal accretion within the basin, and highlight comparable fault-controlled processes in other marginal seas.

Anyone who has boiled a pot of water understands that it takes both time and energy to raise the temperature, so it may come as a surprise to learn that scientists have long treated marine heat waves (MHWs) as isolated events. New research led by William & Mary's VIMS & Batten School is challenging that narrative by providing a framework to characterize an ecosystem's cumulative heat exposure from MHWs and the extended periods of warm water that precede and follow them.

In a new study, researchers at Leipzig University have identified a major cause of the unusually severe summer soil drying and rising temperatures across Europe. They found that much of the trend can be attributed to changes in atmospheric circulation patterns—that is, shifts in the weather regimes that typically occur over Europe. These changes account for around 55% of the observed summer drought trend. Specifically, more frequent and persistent high-pressure systems have brought drier conditions and reduced rainfall.

The seafloor plays an important ecological and societal role. Understanding the processes that shape this environment will help guide conservation policy and decision-making about underwater infrastructure and geohazards.

New research from the University of St Andrews has found that metal production carbon footprints could be more than 10 times higher than previously estimated, with serious implications for the ambition to reach net zero.

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

What exactly is a moon? It’s an existential question lunar researchers found themselves pondering when they discovered an exosatellite at least 90% the size of Jupiter, orbiting a brown dwarf in a system about 73 light-years away from Earth.

 
Related

•  Read the Paper: Satellite Discovered Around a Star’s Substellar Companion
•  What Makes a Moon?
•  Very Large Telescope
 

Depending on how exactly one defines “moon,” the object could be the first moon definitively discovered outside our solar system.

If a moon is a body orbiting another body that is orbiting a star, then yes, we’ve got a moon on our hands. But this exosatellite is orbiting a brown dwarf, a body far larger than most planets but too small to sustain hydrogen fusion as stars do, instead of a planet. And it’s enormous in a way our local moons aren’t.

The whole system is really weird, explained lead author Kevin Hoy in an email to Eos. Hoy is a European Southern Observatory astrophysics Ph.D. student who is also affiliated with the Instituto de Estudios Astrofísicos at the Universidad Diego Portales in Chile and its Millennium Nucleus of Young Exoplanets and their Moons research center.

“The host star is much smaller than the Sun, the brown dwarf is much heavier than our most massive planet, and the satellite is much heavier than any of the moons in our system,” Hoy said. “No part of this system has an obvious comparison to any object in the Solar System.”

The researchers published their findings today in Nature.

When Words Fail

The scientists detected the maybe-moon in the CD-35 2722 system using the radial velocity method, which is often used to detect exoplanets. The brown dwarf moves slightly in response to the exosatellite’s orbit, as the exosatellite exerts a slight gravitational pull. These movements can be seen from Earth as small changes in the brown dwarf’s light spectrum. Scientists observed 26 of these changes from the European Southern Observatory’s Very Large Telescope (VLT) in Chile between October 2023 and February 2026.

The scientists ran several models to see what could explain the periodic changes, including a model in which the brown dwarf actually had two exosatellites. The best explanation to fit the data, they found, was one satellite at least 90% as massive as Jupiter orbiting the brown dwarf approximately every 170 days. (The brown dwarf itself is about 37 times as massive as Jupiter, meaning that although the proposed exomoon is huge, it could be proportionally much less massive compared to its primary than the Moon is to Earth.)

The combination of techniques the researchers used were first proposed for detecting exomoons in 2018, in a paper coauthored by Andrew Vanderburg, now an astronomer at Harvard University.

“I never would have imagined that this technique would reveal such an unusual object!” Vandenburg said in an email to Eos. He added that he wondered what exactly the exosatellite was, how it formed, and how big it was. “Regardless, it’s an amazing discovery and I’m super excited to see what else we can find by observing planets like this!”

Researchers have discovered more than 6,200 confirmed exoplanets so far, but only a few candidates for exomoons have been detected, and none have been confirmed. Such a discovery could help us learn more about how various parts of the universe were formed, and how they function today, the paper suggests.

Though it’s possible some unknown variable in the brown dwarf itself could be responsible for the periodic changes in radial velocity the team observed, “we can’t think of any physical mechanism that could reproduce the signal we see,” said Hoy, the lead author of the study. “That’s why we think a satellite is the most likely explanation.”

In this case, the scientists are confident about what they’ve found. They’re just not sure exactly what to call it.

“Perhaps we are approaching the limit of language invented to describe the Solar System, which is entirely unlike CD-35 2722,” the paper reads.

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

These updates are made possible through information from the scientific community. Do you have a story about science or scientists? 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.