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Author(s): Jiandong Chen and Yangyang Fu

We develop theoretical models for microscale breakdown under extremely high electric field conditions, by incorporating physical mechanisms associated with extremely strong electric fields, such as field emission, electron runaway, ion impact ionization, and the dynamics of fast atoms, which allows …

[Phys. Rev. E 111, 065214] Published Tue Jun 24, 2025

Author(s): Ravi Kumar, Saikat C. Thakur, Edward Thomas, Jr., and Ranganathan Gopalakrishnan

We investigate static and dynamic behaviors of experimentally realized strongly coupled two-dimensional finite clusters in a complex (dusty) plasma. Clusters, ranging in size from N (number of grains) = 1 to 50 are obtained using a highly precise control arm assembly BECAA (bidirectional electrode c…

[Phys. Rev. E 111, 065215] Published Tue Jun 24, 2025

From sugar plantations in Brazil to tea estates in India, crushed rock is being sprinkled across large stretches of farmland globally in a novel bid to combat climate change.

SummarySoutheast Asia, bordered by significant tectonic plates such as the Indo-Australian, Pacific, and Philippine Sea Plates, is distinguished by its frequent tectonic activity and complex geological structures, making it one of the most dynamically evolving regions worldwide. In this study, we introduce a novel 3D P-wave velocity model of the upper mantle and transition zone in Southeast Asia using regional seismic traveltime tomography based on first-arrival data from the International Seismological Center. We employ an adjoint-state tomography method with normal-vectors independence to accurately invert for 3D velocities using a 1D reference model. Synthetic tests confirm the reliability of our model in delineating features of the subduction zone and the surrounding region. Our inversion results highlight distinct subducted slabs within the subduction zone and a pervasive low-velocity zone beneath Sundaland, which may be associated with lithospheric thermal weakening. Additionally, a mushroom-shaped low-velocity anomaly attributed to the Hainan mantle plume is identified beneath Hainan Island. The low-velocity anomaly observed beneath the western part of the Java Sea may be attributed to the combined effects of Sunda-Java slab subduction, lower-mantle flow through the Sunda Strait, and the influence of the Hainan mantle plume. Notably, beneath the Andaman Sea, we observe an east-west elongation of the northern Sumatra slab, potentially linked to the clockwise rotational opening of the Andaman Sea. Additionally, three potential rifts are identified beneath the subducting Sumatra-Java slab: beneath the Toba Volcano, the Sunda Strait, and the eastern segment of Java Island. Extensive high-velocity anomalies beneath the Philippine Islands and the South China Sea suggest a double-sided subduction process involving the Proto-South China Sea slab.

SummaryInversion of a given geophysical dataset cannot be complete without assessing the resolution and uncertainties associated with the model obtained. However, model appraisal may still be a challenging task from both a theoretical and a computational point of view. To tackle the problems of model estimation and appraisal, we introduce the Subtractive Optimally Localized Averages (SOLA) method to the geophysical electromagnetic community, through the example of linear inversion of induced polarization (IP) data. SOLA is a variant of the Backus-Gilbert method: it is computationally more efficient but also allows one to specify directly the target local averages of the Earth’s properties to be estimated, including their uncertainties. SOLA offers great flexibility in the construction of averaging kernels, via the design of target kernels, and direct control over the propagation of data errors into the local-average estimates. With SOLA we obtain a collection of i) local averages of the ‘true’ Earth model, accompanied with their ii) averaging kernels and iii) uncertainties. We investigated the performance of SOLA for the 2–D tomographic inversion of a field IP data set. The obtained chargeability model compares well with previous studies, and, most importantly, its resolution (the spatial extent of the averaging kernels) and uncertainties can be interrogated. We conclude that SOLA is a promising approach for geophysical-electromagnetic linear(ised) tomographies. In the case of IP inversion, to construct chargeability models and evaluate their robustness.

SummaryFault systems have geometrically complex structures in nature, such as stepovers, bends, branches, and roughness. Many geological and geophysical studies have shown that the geometrical complexity of fault systems in nature decisively influences the initiation, arrest, and recurrence of seismic and aseismic events. However, a vast majority of models of slip dynamics are conducted on planar faults due to algorithmic limitations. We develop a 3D quasi-dynamic slip dynamics model to overcome this restriction. The calculation of the elastic response due to slip is a matrix-vector multiplication in boundary element method, which can be accelerated by using Hierarchical Matrices. The computational complexity is reduced from O(N2) to O(Nlog N), where N is the number of degrees of freedom used. We validate our code with a static crack analytical solution and the SEAS benchmark/validation exercise from Southern California Earthquake Center. We further employ this method on a realistic fault system with complex geometry that was reactivated during the 2023 Kahramanmaraş–Türkiye doublet earthquakes, generating slip sequences that closely match real observations.

Researchers have revealed the declining health of coastal marshes several years before visible signs of decline, providing an early warning and an opportunity to protect an ecosystem that serves as the first line of defense against coastal flooding.

New research from the University of California, Davis, the Chinese Academy of Sciences and Texas A&M University reveals that massive emissions, or burps, of carbon dioxide from natural Earth systems led to significant decreases in ocean oxygen concentrations some 300 million years ago.

The Korea Institute of Ocean Science & Technology (KIOST) has revealed that marine microalgae are responsible for ocean aggregates of buoyant microplastics (MPs), increasing the density of MP aggregates and causing them to sink.

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.

Astronomy is a field of temporal extremes. Some phenomena—the birth of stars, the ballet of galaxies within clusters, the growth of the Universe—take place over millions or billions of years, timescales too vast for the human mind to easily comprehend. Other events can happen in quick bursts that take you by surprise: Asteroids and comets flash by, a star goes supernova, pulsar beams sweep past at dizzying speeds, an exoplanet whips around a star in just a few hours.

The Vera C. Rubin Observatory is designed to watch it all.

The telescope, funded by the National Science Foundation and U.S. Department of Energy, has been 3 decades in the making, and it just released its first science images. Taken by a digital camera the size of a car in just over 10 hours of test observations, these images captured millions of galaxies and Milky Way stars and thousands of solar system asteroids.

The first look is…wow. Just wow. Take a look:

• This image of the Trifid and Lagoon Nebulas combines 678 separate images taken in just over 7 hours of observing time. Combining many images in this way clearly reveals otherwise faint or invisible details, such as the clouds of gas and dust that comprise the Trifid nebula (top right) and the Lagoon nebula (center), which are several thousand light-years away from Earth. Credit: NSF-DOE Vera C. Rubin Observatory
• This image shows a small section of Rubin’s total view of the Virgo galaxy cluster. Bright stars in the Milky Way galaxy shine in the foreground, and many distant galaxies are in the background. Credit: NSF-DOE Vera C. Rubin Observatory
• This image shows a small section of the Virgo galaxy cluster. Visible are two prominent spiral galaxies (lower right), three merging galaxies (upper right), several groups of distant galaxies, many stars in the Milky Way galaxy and more. Credit: NSF-DOE Vera C. Rubin Observatory

Named after pioneering dark matter astronomer Vera C. Rubin, the telescope has a 10-year primary mission during which it will create a wide-frame, ultra-high definition time-lapse record of the Universe.

 
Related

•  Vera C. Rubin Observatory
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•  Vera Rubin’s Legacy Lives On in a Troubled Scientific Landscape
 

From its perch atop Cerro Pachón in Chile, it will take thousands of images of the Southern Hemisphere sky every night and map the trajectories of millions of asteroids, comets, and interstellar objects in the solar system, enhancing planetary defense efforts. It will record the locations, distances, and brightness changes in distant supernovae, allowing for more precise calculations of the expansion rate of the Universe and deepening our understanding of mysterious dark matter and dark energy. And it might even help conclusively determine whether, and where, a large planet lurks in the far reaches of our own solar system.

And that’s just what we expect to see. Most scientists would say that the most exciting discoveries are the ones that they never even thought of before, the “unknown unknowns.” Humanity has never had a telescope quite like this one, and gosh, we just can’t wait to see what amazing discoveries are just around the corner!

The telescope sits inside the closed dome of the NSF-DOE Vera C. Rubin Observatory. NSF-DOE Vera C. Rubin Observatory, CC BY 4.0 International

—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 idea about science or scientists? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Unexpected severe turbulence injured crew and passengers on a Qantas Boeing 737 during descent at Brisbane on May 4, 2024. The subsequent Australian Transport Safety Bureau investigation suggested the severity of the turbulence caught the captain by surprise.

At any given time, about two-thirds of Earth's surface is covered by clouds. Overall, they make the planet much cooler than it would be without them.

In the last few decades, Arctic sea ice has receded ever further, including increasingly in winter when the extent of sea ice is at its most prominent. One of the main drivers of this development is thought to be the warming of Atlantic water that flows from Europe's Norwegian Sea into the Arctic Ocean, passing through the Barents Sea and the Fram Strait in the process.

Boots On the Ground .wp-block-newspack-blocks-homepage-articles article .entry-title { font-size: 1.2em; } .wp-block-newspack-blocks-homepage-articles .entry-meta { display: flex; flex-wrap: wrap; align-items: center; margin-top: 0.5em; } .wp-block-newspack-blocks-homepage-articles article .entry-meta { font-size: 0.8em; } .wp-block-newspack-blocks-homepage-articles article .avatar { height: 25px; width: 25px; } .wp-block-newspack-blocks-homepage-articles .post-thumbnail{ margin: 0; margin-bottom: 0.25em; } .wp-block-newspack-blocks-homepage-articles .post-thumbnail img { height: auto; width: 100%; } .wp-block-newspack-blocks-homepage-articles .post-thumbnail figcaption { margin-bottom: 0.5em; } .wp-block-newspack-blocks-homepage-articles p { margin: 0.5em 0; } Volcanic Anatomy, Mapped as It Erupts The Valuable, Vulnerable, Long Tail of Earth Science Databases Thriving Antarctic Ecosystem Revealed by a Departing Iceberg A New 3D Map Shows Precipitous Decline of Ugandan Glaciers Tracking Some of the World’s Fiercest Ocean Currents Worldwide Fieldwork

“There’s no roads, there’s no helicopters, there’s not even a donkey.”

It’s just another day in the field.

The spartan accommodations available to scientists tracking Uganda’s dwindling glaciers is not universal to geoscience fieldwork, but they’re a good indication of the lengths to which scientists will go—enthusiastically—to discover and document our planet’s particularities. Read all about it in “A New 3D Map Shows Precipitous Decline of Ugandan Glaciers.”

Volcanologists on La Palma, the largest of the Canary Islands, faced a different challenge during their work in the field: an actively erupting volcano. In “Volcanic Anatomy, Mapped as It Erupts,” Vittorio Zanon and Luca D’Auria share how near-real-time petrological analyses can help support the safety of surrounding communities as well as associated scientific efforts.

Scientists on an Antarctic research cruise found themselves stymied by sea ice. But when a Chicago-sized ice shelf unexpectedly calved, the crew quickly pivoted and discovered a surprisingly “Thriving Antarctic Ecosystem Revealed by a Departing Iceberg.”

Far from being stranded, scientists “Tracking Some of the World’s Fiercest Ocean Currents” around the Mozambique Channel found that the eddy-ring dipoles there transport nutrients and biota at a rate of 1.3 meters per second.

Hazards like volcanoes, ice shelves, and ocean currents may ultimately be no match for the “looming catastrophes—funding cuts, software obsolescence, and loss of community support,” however. To this end, the data scientist–authors of “The Valuable, Vulnerable, Long Tail of Earth Science Databases” share research-based recommendations for supporting expert community-curated data resources.

Geoscience fieldwork is globe-spanning and mind-bending, and we hope you enjoy the ride.

—Caryl-Sue Micalizio, Editor in Chief

Citation: Micalizio, C.-S. (2025), Worldwide fieldwork, Eos, 106, https://doi.org/10.1029/2025EO250220. Published on 23 June 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Space Weather

The impacts of space weather such as extreme solar winds and magnetic waves are not limited to outer space. Bursts of plasma emanating from the Sun, for instance, can temporarily intensify electric and magnetic fields on the ground when they arrive at Earth, causing geomagnetically induced currents (GICs) to flow into infrastructure such as powerlines, pipelines, and railways. GICs can cause widespread equipment failures, leading to blackouts and safety concerns.

To improve monitoring, modeling, and forecasting of GICs in the United Kingdom, Beggan et al. developed a set of 14 models that better predicts space weather hazards and tracks them in real time, allowing scientists and forecasters to warn operators of critical infrastructure. They also installed three new variometers to measure magnetic field changes at locations across the country. The work was part of the United Kingdom’s Space Weather Instrumentation, Measurement, Modelling and Risk (SWIMMR) program called SWIMMR Activities in Ground Effects, or SAGE.

The SAGE system can estimate changes in the subsurface electric field during geomagnetic storms, then calculate the size of GICs flowing into grounded infrastructure networks—which have known electrical resistance properties—in real time. SAGE also uses real-time data from satellites to predict the probability of magnetic substorms occurring and the magnitude of the storm at different U.K. ground observatory sites.

A major test of the new system occurred in early May 2024, when significant solar activity triggered the largest geomagnetic storm to hit Earth in the past 30 years. SAGE successfully provided real-time information on how the storm was affecting infrastructure. The system also provided two forecasts of GIC magnitude 30 minutes ahead of time; the real-time magnitude that SAGE later identified was between those two predictions.

More work must be done to continue improving SAGE, the authors write. For example, better monitoring of space weather conditions in space and on the ground would provide the system with more robust data on impacts, further improving its prediction capability. (Space Weather, https://doi.org/10.1029/2025SW004364, 2025)

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

Citation: Sidik, S. M. (2025), U.K. space weather prediction system goes operational, Eos, 106, https://doi.org/10.1029/2025EO250229. Published on 23 June 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

When visiting Godrevy beach on the north Cornish coast, most people look out to sea at the lighthouse, surfers and seals rather than the cliffs behind. But these cliffs hold a history of past climate and sea levels that is incredibly valuable to scientists like me, who are trying to determine how quickly sea level is going to rise in the future.

Years after wildfires burn forests and watersheds, the contaminants left behind continue to poison rivers and streams across the Western U.S.—much longer than scientists estimated.

27 people were killed by a massive channelised debris flow in China last year.

On 3 August 2024, a large debris flow occurred in the Ridi valley, Kangding, Sichuan Province, China. This event is described in a paper (Cheng et al. 2025) just published in the journal Landslides. Whilst the paper itself is behind a paywall, this link should provide access to it.

This event is a really good example of a phenomenon that keeps cropping up, namely multiple shallow landslides that transition into a highly destructive channelised debris flow, generated by extremely intense rainfall. The value of the Ridi valley example is that Cheng et al.(2025) have forensically investigated this particular event.

The outlet of the Ridi valley is located at [30.069422, 102.105085]. This is a Google Earth image of the site from September 2022:-

Google Earth image of the Ridi valley from September 2022.

This is quite remarkable terrain – the linear distance from the top of the catchment to the main channel is about 9.5 km, but the elevation difference is over 4,000 metres. Thus, the catchment is exceptionally steep. Debris flows have been recorded in the Ridi valley in 1952, 1963, 1966, and 1982. Note the large fan at the junction with the maion channel, which is populated and is crossed by a key road (China National Expressway G4218).

I have downloaded a Planet Labs image of the site from 1 August 2024 and draped it onto the Google Earth DEM:-

Satellite image of the Ridi valley before the 3 August 2024 landslides ad debris flow. Image copyright Planet Labs draped onto the Google Earth DEM, used with permission. Image dated 1 August 2024

And here is a Planet Labs image from 5 August of the site, showing the aftermath of the landslides and debris flow:-

Satellite image of the Ridi valley after the 3 August 2024 landslides ad debris flow. Image copyright Planet Labs, draped onto the Google Earth DEM, used with permission. Image dated 5 August 2024.

And here is an image compare:-

Images copyright Planet Labs.

The Planet Labs images show multiple shallow landslides in the catchment and also the track of the debris flow. Cheng et al.( 2025) have mapped 28 shallow landslides and four rock slope collapses in the catchment. These had a total volume of about 12,000 cubic metres. It is fascinating to note that the local rain gauges did not record any substantial rainfall at the time of the event, suggesting that the trigger was a highly localised rainstorm.

The initial 12,000 m3 of landslide material combined to form a debris flow that eroded a further 31,000 m3 from the slopes below, and 337,000 m3 from the channel to form a debris flow with a total volume of 380,000 m3. Thus, the initial slope failures constituted just 3.2% of the total debris flow volume. This is the epitome of a cascading event.

Cheng et al.( 2025) do not document the detailed impact of the 2024 Ridi valley debris flow, saying just that “the disaster had severe impacts on local residents and infrastructure.” The Planet Labs image suggests that this might have been very severe:-

Satellite image of the Ridi valley after the 3 August 2024 landslides ad debris flow. Image copyright Planet, draped onto the Google Earth DEM, used with permission. Image dated 5 August 2024.

A news report at the time indicated that up to 27 people were killed. Xinhua published this image of the impact on Ridi:-

The aftermath of the 3 August 2025 debris flow in the Ridi valley. Image published by Xinhua.

Reference

Cheng, Q., Liu, T., Lei, H. et al. 2025. Investigation of a shallow high-locality landslide-induced debris flow in an alpine valley: A case study of the Ridi debris flow, Kangding, Sichuan Province, China (August 3, 2024). Landslides. https://doi.org/10.1007/s10346-025-02559-y

Planet Team, 2025. Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/

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

SUMMARYThe spherical harmonic coefficient Level-2 products of the Gravity Recovery and Climate Experiment (GRACE) mission are affected by north-south stripe noise. Toward this end, we have developed a new filter named Variational Mode Decomposition spatial (VMDS) filter that transforms the Equivalent Water Height (EWH) map derived from GRACE level-2 product into a one-dimensional sequence, which is then filtered by using variational mode decomposition. This approach overcomes the limitations of the singular spectrum analysis spatial (SSAS) filter, which well performs in the medium-frequency band but omits the high-frequency NSS noise. We thus put the VMDS filter behind the SSAS filter to utilize the good performance of SSAS in the medium-frequency band and thus propose a combined filter termed SV. A closed-loop simulation demonstrates the better ability of SV to suppress NSS noise and preserve signal at the grid scale compared to the SSAS filter. In the real-world scenario, the SV solution achieves a noise level (46.68 mm of EWH) below that for SSAS and DDK7 solutions (53.52 and 53.68 mm of EWH, respectively) over the ocean at low latitudes. Moreover, the well-documented water level of Lake Victoria and the well-modeled coseismic gravity change of the Mw9.2 2004 Sumatra-Andaman earthquake demonstrate that the SV filter efficiently preserves localized mass evolutions while suppressing north-south stripe noise. Such short-wavelength signals usually miss in highly filtered spherical harmonics (e.g. DDK5 and DDK6) solutions or are significantly inconsistent for various mass concentration solutions.

SUMMARYWe propose a stable and efficient method for high-degree regional lithospheric magnetic field modeling based on spherical Slepian functions, achieving significant improvements in the computational efficiency of solving large linear systems by reducing both complexity and memory requirements. This method leverages the orthogonality of Slepian basis functions on regional domains R to improve the stability of regional modeling. The block-diagonal structure of the normal equation matrix and the sparse representation by Slepian functions are simultaneously exploited to achieve a two-stage matrix compression. Additionally, a Bayesian Information Criterion (BIC)-based strategy is introduced to determine the optimal truncation number for the Slepian basis functions, ensuring a balance between computational efficiency and data fidelity. Our method was validated by directly inverting synthetic regional lithospheric magnetic field data generated from a spherical harmonic model up to degree 1050. The modeling process showed a reduced memory requirement of approximately eight orders of magnitude. The high-degree model successfully reconstructed the desirable magnetic field at different heights, and the residual statistical analysis results showed that the spatial variation of the lithospheric magnetic field was accurately captured. In addition, the proposed method can be readily extended to gravity modeling and other applications that utilize spherical harmonic analysis. The matrix compression techniques adopted provide an ideal framework for parallel computing, showing a wide range of application potential.