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A series of more than 100 earthquakes has hit Northern California, shaking up the Geysers geothermal steam field in Sonoma and Lake counties.

Author(s): Zachary A. Johnson, Nathaniel R. Shaffer, and Michael S. Murillo

Laboratory plasma production almost always preferentially heats either the ions or electrons, leading to a two-temperature state. In this state, density functional theory molecular dynamic simulation is the state of the art for modeling bulk material properties. We construct a statistical mechanics …

[Phys. Rev. E 112, 025207] Published Mon Aug 18, 2025

Heat waves are becoming more common, severe and long-lasting. These prolonged periods of hot weather are especially dangerous in already hot places like Texas. In 2023, more than 300 people in Texas died from heat, according to the Texas Department of State Health Services, the most since the state began tracking such deaths in 1989. Researchers found it may not only be temperatures that make heat waves unsafe but also the heat-related increase in airborne pollutants.

At least 43 people were killed in devastating landslides and debris flows in northern China. Planet Labs images provide an insight into this disaster.

It is extremely challenging to keep up with the landslides occurring around the world at the moment. There has been a lot of attention paid to the remarkable rock slope failure and tsunami in Alaska. I feel that others are better placed to write about that (although I will probably continue to highlight updates via my BlueSky account), but if you get a chance please take a look at the images on the Alaska News Source website.

There have also been a devastating set of debris flows in northern Pakistan and parts of India and Nepal. At this stage, it is a little unclear to me as to the full extent of these events (especially in Pakistan) – I am likely to return to this theme.

Often the best way to understand an event is to piece together the news reports with satellite images when they become available. And so, let’s take a look at reported “floods” or “flash floods” (actually landslides and channelised debris flows) that occurred in Yuzhong County in Gansu Province in China on 7 August 2025. The BBC has a good report of the aftermath, whilst Al Jazeera reports 10 dead and 33 missing from this event. We must take reports of losses in China with a large pinch of salt.

The location of the source of this event is [35.71498, 104.02436]. So here is a Planet Labs image, dated 30 July 2025, showing the area affected. The marker is at the location highlighted above:-

Planet Labs image of the source of the 7 August 2025 landslides and debris flows in Yuzhong County, Gansu Province. Image copyright Planet Labs, used with permission. Image dated 30 July 2025.

And here is the same location after the event:-

Planet Labs image of the aftermath of the 7 August 2025 landslides and debris flows in Yuzhong County, Gansu Province. Image copyright Planet Labs, used with permission. Image dated 13 August 2025.

And here is a slider to allow you to compare the images:-

Images copyright Planet Labs.

This is a closer look at this area of intense landslides:-

Planet Labs image of the aftermath of the 7 August 2025 landslides and debris flows in Yuzhong County, Gansu Province. Image copyright Planet Labs, used with permission. Image dated 13 August 2025.

What we see here is literally hundreds of shallow failures that will have occurred almost simultaneously, and then combined to form devastating channelised debris flows. There are many failures on the slopes to the southwest, but the greatest concentration is to the northwest is an area that is densely vegetated.

This is indicative of extremely high rainfall intensities, but this storm was highly localised. The area of intense landslides is only about 9 km x 5 km.

The downstream impacts were terrible. These are the settlements immediately to the east of the landslides:-

Planet Labs image of the downstream area affected by the 7 August 2025 landslides and debris flows in Yuzhong County, Gansu Province. Image copyright Planet Labs, used with permission. Image dated 30 July 2025.

And here is the same area after the landslides:-

Planet Labs image of the downstream area affected by the 7 August 2025 landslides and debris flows in Yuzhong County, Gansu Province. Image copyright Planet Labs, used with permission. Image dated 13 August 2025.

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

Images copyright Planet Labs.

There is a large number of destroyed buildings in this imagery. The devastation extended for a considerable distance.

Reference

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.

AbstractSeismology has entered the petabyte era, driven by decades of continuous recordings of broadband networks, the increase in nodal seismic experiments, and the recent emergence of Distributed Acoustic Sensing (DAS). This review explains how cloud platforms, by providing object storage, elastic compute, and managed databases, enable researchers to “bring the code to the data,” thereby providing a scalable option to overcome traditional HPC solutions’ bandwidth and capacity limitations. After literature reviews of cloud concepts and their research applications in seismology, we illustrate the capacities of cloud-native workflows using two canonical end-to-end demonstrations: 1) ambient noise seismology that calculates cross-correlation functions at scale, and 2) earthquake detection and phase picking. Both workflows utilize Amazon Web Services, a commercial cloud platform for streaming I/O and provenance, demonstrating that cloud throughput can rival on-premises HPC at comparable costs, scanning 100 TBs to 1.3 PBs of seismic data in a few hours or days of processing. The review also discusses research and education initiatives, the reproducibility benefits of containers, and cost pitfalls (e.g., egress, I/O fees) of energy-intensive seismological research computing. While designing cloud pipelines remains non-trivial, partnerships with research software engineers enable converting domain code into scalable, automated, and environmentally conscious solutions for next-generation seismology. We also outline where cloud resources fall short of specialised HPC-most notably for tightly coupled petascale simulations and long-term, PB-scale archives-so that practitioners can make informed, cost-effective choices.

SummaryThe 1985 Mw 6.9 Wuqia earthquake, one of the strongest instrumentally recorded seismic events in the Pamir foreland thrust system, caused significant surface ruptures. The Pre-earthquake KH-9 and post-earthquake WorldView-3 and SPOT-6 satellite images are used to investigate the fault rupture and slip behavior of this earthquake. We revealed a more detailed ∼22 km long displacement belt beyond the previously documented ∼15 km rupture, using optical image correlation with sophisticated error post-processing. Several new fractures in western segment are identified which are confirmed in the displacement map. A comprehensive analysis of the strike change, near-surface dip and cross-fault offsets shows a ∼1.6 km dextral strike-slip tearing fault resulted from the heterogeneous strain release. Based on the empirical scaling relationship, a down-dip rupture width of 10.55 km is estimated using the observed rupture length and inverted slip. Combined with the previously published 3D fault geometry based on seismic imaging, we suggest that the 1985 Wuqia earthquake ruptured only the upper ramp. This study provides precise constraints on surface rupture characteristics, and new insights into the complex rupture pattern of a thrust-type earthquake within the tectonically active Pamir foreland region.

SummaryUnderstanding the geophysical drivers of seasonal geocenter motion (GCM) variations remains challenging due to the complexity of Earth system interactions, limited data on individual mass redistribution components, and model uncertainties. This study presents a comprehensive investigation of seasonal GCM signals from April 2002 to January 2024 using the Fingerprint Approach (FPA), which enables direct quantification of contributions from distinct Earth system components. Additionally, Multichannel Singular Spectrum Analysis (MSSA) is applied to quantify the influence of terrestrial water storage (TWS), atmosphere (ATM), and ocean (OCN) variability on seasonal GCM fluctuations. Correlation and lag analyses are employed to explore their temporal relationships and underlying geophysical linkages. The results reveal that TWS, ATM, and OCN jointly explain 97.9 per cent, 98.1 per cent, and 90.8 per cent of the seasonal variance in the X, Y, and Z components of GCM, respectively. TWS exerts as the dominant contributor in the Y (66.4 per cent) and Z (67.9 per cent) components, while ATM and OCN each contribute less than 49 per cent in all components. Further analysis indicates that ATM, OCN, and TWS exhibit varying lag relationships with GCM in the X and Z components, while TWS demonstrates a notably stronger correlation with GCM in the Y component. Importantly, an approximately 120-day periodic signal identified in GCM is, for the first time, linked to global precipitation variability, providing a novel geophysical interpretation. These findings enhance our understanding of climate-driven geophysical mass redistribution and offer new insights into the processes governing seasonal GCM variations.

Humans adapt to floods through private measures, early warning systems, emergency preparedness and other solutions. A new attribution study by the Potsdam Institute for Climate Impact Research (PIK) shows that such adaptation other than structural flood defenses has reduced economic losses from flooding by 63% and fatalities by 52% since 1950.

The magnitude 7.7 earthquake in Myanmar on 28 March 2025 caused widespread damage and over 3,800 fatalities, and also resulted in strong shaking and a building collapse in Bangkok, more than 1,000 km away. Preliminary analysis soon after the earthquake pointed to the unusually fast rupture velocity, which is known as a supershear rupture.

Apatite. Rhymes with appetite, and fittingly, plays a vital role in the very act of eating. Found in teeth and bones, apatite provides the structural strength behind every bite and step we take.

A new study maps the planetary boundary of "functional biosphere integrity" in spatial detail and over centuries. It finds that 60% of global land areas are now already outside the locally defined safe zone, and 38% are even in the high-risk zone.

A research team at Los Alamos National Laboratory recently found that the strength difference between two very high-frequency radio pulses in lightning is closely related to the altitude of the lightning in the cloud—a finding that sheds light on how the power in lightning radiates. This, in turn, gives insight into lightning initiation in a particularly powerful type of in-cloud lightning.

An interdisciplinary research team led by scientists from Freie Universität Berlin and the Max Planck Institute for Meteorology has shown how deep lakes formed more than 9,500 years ago in the craters of the Tibesti Mountains and existed there for more than 5,000 years.

Regions known as large low shear velocity provinces—more memorably known as “big lower-mantle basal structures,” or BLOBs—have long been known to seismologists because seismic waves generated by earthquakes slow down when they pass through them.

One BLOB is under Africa, and the other sits below the Pacific Ocean. They are thousands of kilometers wide and may be more than a thousand kilometers high, containing up to 8% of Earth’s total volume.

The origin of the BLOBs is not certain, nor is it clear what they are made of. Many researchers think the BLOBs formed from subducting oceanic crust at ancient plate boundaries, while another hypothesis suggests they are remnants of the asteroid impact that threw up the material that became the Moon.

BLOBs are hotter than the surrounding mantle and perhaps compositionally distinct. While some research predicts they are denser than the mantle rock that houses them, other models have found the opposite.

Plume Factories

In the early 2000s, a group of scientists led by Trond Torsvik of the University of Oslo suspected a link between the BLOBs and volcanic activity at Earth’s surface. To test this theory, they mapped the location of large igneous provinces (LIPs) and kimberlites—diamond-bearing volcanic rocks that originate deep in Earth’s interior. The researchers then rewound the clock on these emplacements, restoring them to their position on Earth’s surface when the eruptions occurred.

The results, published in 2006, revealed that most of the eruptions occurred at the edges of one of the BLOBs. These findings supported the idea that large mantle plumes at BLOB edges hurl heat energy toward the surface and create LIPs. Activity at LIPs can trigger supervolcanoes, rip supercontinents apart, and release vast amounts of greenhouse gases. LIPs have even been implicated in some of Earth’s major mass extinctions.

The neat fit between eruptions and the position of the BLOBs, researchers claimed, showed that the BLOBs were immobile; tectonic plates moved relative to them, but the BLOBS themselves stayed where they were.

Not So Fast…

Nicolas Flament, a geophysicist and geodynamicist with the University of Wollongong (UOW) in Australia, said the idea of fixed BLOBs was initially attractive to researchers because it promised to fill a knowledge gap in the paleomagnetic history of Earth.

Geologists trace the movement of tectonic plates using paleomagnetic evidence, written by Earth’s magnetic field on volcanic rocks as they cool and solidify. These data can reveal the latitudinal position of an eruption on Earth’s surface, but they cannot reveal anything about longitude.

“Everything moves.”

If BLOBs are fixed in one spot, Flament said, ancient eruptions could be linked to the edges of the BLOBs, providing a much-needed reference for paleolongitude.

As a geodynamicist, however, Flament inhabits a world where, he said, “everything moves.” The concept of fixed BLOBs didn’t sit well with him. In 2022, he and some colleagues ran models that rewound Earth’s clock back a billion years. These models showed that the position of volcanic materials at the surface could be explained just as well if the BLOBs moved.

Flament and his team contend that subducting slabs disrupt the BLOBs, and they regularly break apart and remeld just like continents do at the surface. But by Flament’s own admission, there is a weakness in these findings. Like the Torsvik-led research, it “assumed that there was a link between the BLOBs and the eruptions…We didn’t actually check” to confirm that the link was there.

Bridging the Gap

Now a team led by UOW Ph.D. student Annalise Cucchiaro that includes Flament has shown through statistical modeling that large volcanic eruptions are, indeed, connected to the BLOBs. The team mapped volcanic deposits against billion-year reconstructions of mantle movement. The research was published in Communications Earth and Environment.

The scientists found a significant link between volcanic deposits and the mantle plumes that models predicted, “essentially filling that gap,” Flament said.

The researchers found no significant relationship between mantle paths and the BLOB edges, however—mantle plumes could originate from anywhere on the BLOB, not just the edge. As plumes rise through Earth’s interior, they encounter “mantle wind”—lateral movement of semisolid rock that may cause the plumes to tilt by as much as 5° from vertical. This tilting, the research showed, could account for many of the volcanic eruptions that were not directly over a BLOB.

The research also suggested that the BLOBs are slightly denser and less viscous than the surrounding mantle. Rather than being completely static, the BLOBs likely move around at a rate of about 1 centimeter per year.

Qian Yuan, a geophysicist with Texas A&M University who was not involved in the study, called the findings “very reasonable.” Yuan was the author of the asteroid origin theory of BLOB formation.

“The subducting slab is the strongest driving force of the manual convection,” he said, “so in all our models, we show the BLOBs will move around.”

Big Bottoms

Fred Richards, a geodynamicist at Imperial College London who was not involved in the study, has researched BLOBs extensively, looking for a model that accommodates everything known about them from seismological and geophysical data.

The UOW research, he said, adds to a growing body of evidence that the lower parts of the BLOBs are dense, but not too dense to prevent them from moving around. Linking a dense, viscous base to the eruption record, he said, is “something that hasn’t been clearly shown before.”

—Bill Morris, Science Writer

Citation: Morris, B. (2025), Blame it on the BLOBs, Eos, 106, https://doi.org/10.1029/2025EO250302. Published on 15 August 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: Geophysical Research Letters

Off the southern coast of Chile, three tectonic plates meet at a point known as the Chile Triple Junction. Two are oceanic plates, the Nazca and the Antarctic, which are separating in an active spreading center, creating a mid-ocean ridge between them. At the same time, both plates—spreading ridge included—are sliding into the mantle beneath a third plate, the South American. The Chile Triple Junction is the only place on Earth where an active spreading center is subducting under a continental plate.

Just to the east of the triple junction, beneath South America’s Patagonia region, a gap known as a slab window exists between the subducting oceanic plates. Caused by the subduction of the spreading center, the window exposes the overriding South American plate to hot mantle material from below.

Knowing the size and geometry of this opening is key for parsing out the area’s complex geology. However, limited offshore observations have left researchers unsure of where the slab window begins.

Recently, a new array of seismic stations deployed on the ocean floor off of Chile’s coast has boosted opportunities for observation. According to Azúa et al., the new seismic data help to pinpoint the beginning of the Patagonian slab window to just south of the Chile Triple Junction.

The seismic data captured shallow tectonic tremors, a type of “slow earthquake” that releases energy more gradually than conventional quakes—often over the course of several days. Slow earthquakes are increasingly being studied to enhance understanding of plate boundaries.

Using nearly 2 years’ worth of the new ocean bottom seismic data, the research team detected about 500 shallow tremors near the Chile Triple Junction. When they compared the locations of these tremors with the locations of previously detected conventional earthquakes, they noticed a distinct gap between where the two types of events occur.

The researchers interpret the gap in seismic activity as evidence of the youngest part of the Patagonian slab window, formed within the past 300,000 years.

Although further research will be needed to confirm and build on these findings, this work represents the first direct evidence of the offshore edge of this hole between the two subducting plates. (Geophysical Research Letters, https://doi.org/10.1029/2025GL115019, 2025)

—Sarah Stanley, Science Writer

Citation: Stanley, S. (2025), Finding the gap: Seismology offers slab window insights, Eos, 106, https://doi.org/10.1029/2025EO250299. Published on [DAY MONTH] 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.

In the face of growing global pressures, a new report from Securing Antarctica's Environmental Future (SAEF), including University of Adelaide researchers, highlights the opportunity to strengthen and future-proof Antarctic governance by responding to emerging conservation threats with coordinated, proactive measures.

SummaryCrashing ocean waves, or surf, have previously been identified as persistent generators of coherent infrasound signals from 0.5 to 20 Hz. Here, we demonstrate that infrasonic and seismic (seismo-acoustic) signals from surf are composed of repetitive transient events which can be detected and characterized using template matching. Using data collected from a series of field experiments designed to study seismo-acoustic surf signals in Santa Barbara, California, we show that source regions of these events can be constrained primarily to just offshore of a local coastal headland using a reverse-time-migration implementation on a small spatial scale (<5 km2). Our data include one continuously running infrasound sensor (September 2022–July 2023) to examine temporal signal evolution, complemented by several short-duration campaigns involving various infrasound arrays, co-located seismometers, and video recordings. Throughout varied oceanographic and atmospheric conditions, we detect up to tens of thousands of independent surf repeaters per day over the course of a year. The amplitudes of detected infrasound signals are correlated with offshore significant wave height and local wind speed. We identify coincident arrivals of seismic and infrasound signals with similar spectral characteristics, suggesting a linked source mechanism locally producing both the seismic and acoustic transient signals. Source regions estimated from array- and network-based methods correspond to the surf zone as seen in video footage, and the directions of selected transient signals align with the location of a rocky reef shelf nearshore. This work showcases the ability to extract near-real-time information about the coastal sea state from seismic and acoustic signal features.

SummaryCurrent geodetic velocities show that over half (up to 10 mm/yr) of Arabia-Eurasia shortening in the west is accommodated within a relatively narrow zone across the Kura basin of Azerbaijan, in which the most prominent active structure is the Kura fold-and-thrust belt, bordering the southern margin of the Greater Caucasus. The GNSS velocities furthermore suggest equivalent amounts of north-south right-lateral shear across the eastern Kura basin along the West Caspian fault zone that is accommodating relative motion between the Kura basin and the South Caspian basin. Although destructive historical earthquakes are known to have occurred, their spread is restricted geographically and their moment release accounts for only half of the accumulated deformation. These observations can be explained by incompleteness of the historical record, that the faults fail in rare larger earthquakes, or that they slip aseismically. To distinguish between these hypotheses we produce an InSAR velocity field using Sentinel-1 SAR data to image active tectonic deformation within the Kura basin of Azerbaijan. Tectonic signals are superimposed on those relating to non-tectonic processes, including widespread mud volcano inflation that highlights the important role of fluid flow within the basin sediments. We show aseismic creep occurs on two parallel faults of the West Caspian fault zone, and infer this also on the Kura Fold and Thrust Belt from sharp gradients in velocity indicating active fold growth. Recent paleoseismic studies of the faults imaged here indicate discrete slip events, and we speculate that the creep may be episodic, perhaps triggered by deeper earthquake events or by periods of enhanced fluid mobilisation. Together, the right-lateral and left-lateral faults appear to accommodate a large-scale expulsion of the Absheron region towards the South Caspian basin, perhaps driven by gravitational potential energy contrasts.

SummaryWhile global sea level rise is a major concern for ocean-connected coastal regions, inland seas such as the Black Sea exhibit water level changes primarily governed by regional hydrological and climatic factors. Understanding the drivers of water level variability in the Black Sea is essential due to its sensitivity to river inflow, evaporation, and limited connection to the global ocean. This study, for the first time, integrates satellite altimetry and satellite gravity data from 2003 to 2023 to analyze the long-term and seasonal variations in the Black Sea water levels, as well as local sea level variability and its driving factors. The results indicate that the sea level in the Black Sea experiences a positive trend of 1.04 ± 0.39 mm/yr. This comes, however, with a negative trend on a seasonal scale during autumn (–1.14 ± 0.27 mm/yr), which contrasts with the rising trends observed in other seasons. We found that the loading deformation induced by global mass redistribution contributes to 39 per cent of the Black Sea level trend, leading to an overestimation of actual climate-induced sea level change by 0.41 mm/yr. We further found that the reduction of precipitation and river inflow from surrounding basins leads to an increase in the salinity of the Black Sea, driving the decline in steric sea level. On the other hand, it has also increased the water mass of the Black Sea, compensating for the steric sea level drop.

Roughly two-thirds of all emissions of atmospheric methane—a highly potent greenhouse gas that is warming planet Earth—come from microbes that live in oxygen-free environments like wetlands, rice fields, landfills and the guts of cows.