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A new paper published in Biological Reviews has revealed the potential of desert ecosystems in the global fight against climate change. The review, led by Prof. Zeng Fanjiang from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences, synthesizes evidence showing that deserts can function as vital carbon sinks through innovative management and technology.

The Atlantic Meridional Overturning Circulation (AMOC), an ocean current system that transports heat from the tropics to the North Atlantic, plays a vital role in regulating the global climate. Most climate models project a decline in AMOC strength under anthropogenic greenhouse gas warming. However, it remains unclear whether the AMOC has slowed over the past century, and if so, when this slowdown began.

They power green energy, enhance defense systems, and drive the future of microelectronics. Known as critical minerals, elements like lithium, cobalt, and nickel are vital to national security and innovation. Yet the U.S. faces a growing challenge: securing stable, domestic supplies for critical minerals. Today, the nation remains heavily reliant on imports, often from geopolitically unstable or adversarial regions.

Berry Glacier, a tributary of the Getz Ice Shelf in West Antarctica, has deteriorated dramatically in the past three decades, according to researchers in the Department of Earth System Science at the University of California, Irvine.

Climate change is accelerating continental rifting, the geological process where landmasses slowly pull apart. According to a new study published in the journal Scientific Reports, the East African Rift System (EARS) became more tectonically active after its major lakes shrank due to a drier climate 4,000 to 6,000 years ago. This could have caused more frequent earthquakes and volcanic eruptions.

Dr. Peter Shi from Macquarie Business School explains how low-carbon supply chain finance helps businesses reduce emissions, unlock green funding and build resilient, profitable networks amid global climate challenges.

Earth scientists have discovered how continents are slowly peeled from beneath, fueling volcanic activity in an unexpected place: the oceans.

In August 2025, I recorded 104 fatal landslides leading to 2,365 fatalities, a record total number of landslides for August.

Loyal readers will know that each year, August is one of the two peak months for fatal landslides. In 2025, I recorded 104 fatal landslides leading to 2,365 fatalities (but please see below as I have severe doubts about the latter number).

This is an unusually high level of loss both in terms of the number of fatalities and the number of events.

This is the monthly total number of landslides for 2025 to the end of August:-

The number of fatal landslides to the end of August 2025 by month.

Loyal readers will also be aware that I like to use pentads (five day blocks) for inter-annual comparisons. This is the 2025 plot to pentad 49 (2 September 2025):-

The number of fatal landslides to 2 September 2025, displayed in pentads. For comparison, the long term mean (2004 to 2016) from Froude and Petley (2018) and the exceptional year of 2024 are also shown.

The graph demonstrates that to the end of August, 2025 was running a very long way above the long term mean number of landslides, and indeed was close to the absolutely exceptional number recorded in 2024.

The number of fatal landslides in August 2025 was dominated by events in South Asia, and in particular in India. That will need further analysis in due course. In terms of fatalities, the total was driven by the 31 August 2025 landslide at Tarasin in Sudan, which is reported to have killed 1,573 people. However, as I noted in a blog post, I have severe doubts about this total. At this stage, I do not have a reliable alternative total, so I have included the number as reported locally.

In terms of the number of fatal landslides, 2025 had the highest August total in my dataset. The previous highest total was 78 in 2018.

August 2025 was the third warmest August globally in the instrumental record, but it was cooler than both 2023 and 2024. In this case, it appears that the rainfall pattern from the summer monsoon in South Asia has had a major impact.

Reference

Froude M.J. and Petley D.N. 2018. Global fatal landslide occurrence from 2004 to 2016. Natural Hazards and Earth System Science 18, 2161-2181.  https://doi.org/10.5194/nhess-18-2161-2018

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.

The way clusters of differently sized water droplet populations are distributed within clouds affects larger-scale cloud properties, such as how light is scattered and how quickly precipitation forms. Studying and simulating cloud droplet microphysical structure is difficult. But recent field observations have provided crucial, centimeter-scale data on cloud droplet size distributions in stratocumulus clouds, giving researchers an opportunity to better match their models to reality.

SummarySeismic reflection and transmission provide essential insights into the composition of reservoir solids and fluids. Reservoir media often consist of layered structures that contain solids, fluids, pores, and cracks. In such complex layered media, the stable and accurate modeling of seismic wave propagation is crucial for effective reservoir evaluation using seismic waves. By solving the cracked porous medium wave equation for layered structures using the propagator matrix method, we calculate the frequency-dependent oblique incident P-SV and SH wave reflection and transmission for the layered poroelastic media containing cracks. This approach accounts for the combined effects of impedance contrast and crack squirt flow on wave reflection and transmission. The newly developed model includes interlayer fluid flow, crack squirt flow, and global fluid flow. Among these mechanisms, interlayer fluid flow and crack squirt flow can both be prominent in the seismic frequency band. Then, the model was applied to simulate seismic reflection and transmission in cracked interlayer and interface geological structures. The results show that the pore-crack squirt flow mechanism plays a significant role in determining seismic reflection and transmission. Increased crack density and gas saturation significantly enhance P-wave reflection and generate seismic reflection bright spots, while for the S-wave reflection, the effect is largely controlled by crack density, and, when crack density is high, is moderately affected by fluid saturation. This fluid sensitivity results from the crack squirt flow mechanism, which is absent from the classical Biot-Gassmann theory. In all known limiting cases, the model predictions agree with those from the Biot-Gassmann theory.

SummaryIntermontane basins in active orogenic regions face significant seismic hazard due to their proximity to sustained tectonic activity. While the sediments deposited in these basins create a relatively flat topography suitable for urban and infrastructure developments, their unconsolidated sedimentary fill locally amplifies earthquake-induced ground motions, thereby increasing the seismic hazard and risk. Documented observations suggest that ground motion estimates in these basins are often poorly constrained due to oversight of surrounding surface topography and insufficient sub-surface information about deeper basin layering, leading to inaccurate hazard assessments. In this study, we systematically evaluate the implications of these two factors on ground motion characteristics up to 4.4 Hz, which is crucial for earthquake engineering practices. We conducted 3D simulations around the Kathmandu catchment area (Nepal) using hypothetical thrust-faulting moment tensor sources at various depths and locations. The results show a significant reduction, by an order of magnitude, in the peak ground velocities (PGV) at the catchment area due to surface topography. However, this effect is prominent only for very shallow earthquakes producing predominant surface waves; for deeper sources, the de-amplification may be negligible or even result in amplification due to scattered body waves converted into surface waves. To incorporate basin-specific material properties, we performed the analysis in a computationally-feasible 2D domain, which shows that the existence of topography can reduce the energy entering the basin, hence resulting in a reduced basin amplification. The deeper layers of the Kathmandu basin play a critical role in controlling the spatial variability of the observed amplification, with significant differences within the basin compared to scenarios that exclude these deeper layers. We conclude that neglecting topography in ground motion predictions may lead to an overestimation of ground motion amplification in the basin. Pronounced topographic features in the surrounding of intermontane basins can result in further scattering of the received energy content from earthquakes occurring outside of the basin, especially for the high-frequency motions. In addition, in order to provide site-specific measures of ground motion in intermontane basins, high spatial resolution of the underlying geological structure is deemed imperative.

SummaryInterpreting geophysical inversion results across diverse applications presents significant challenges, particularly when the resulting images lack distinct, sharp interfaces. Incorporating prior information to constrain the inversion process introduces additional complexity, especially when this prior information itself contains uncertainties. This work explores methods for improving the geometric representation of geologic structures using integrated geophysical and geologic models. While many existing approaches are either data-driven or model-driven techniques, they often fail to fully integrate available data into a dynamic, unified geomodel. We present an approach that integrates geologic models and geophysical data through structure-based inversion. Our approach preserves geological realism through an implicit model while imaging sharp contrasts within the geophysical inversion models. To address the ambiguities of solving for both the geometry and physical parameters, we adopt a sequential inversion process, first resolving shifts of geologic interfaces, then inverting for geophysical parameters using the updated geometry as a structural constraint. The method’s efficacy is demonstrated through cross-hole travel-time tomography using two synthetic and one field data set from the Mont Terri Rock Laboratory (MTRL). The field data results validate the capability of our approach to recover subsurface interface geometries from geophysical data that are comparable to the interpolated interfaces from borehole data. While we demonstrate the method for seismic travel time data in cross-hole geometry, the flexible open-source implementation allows application to 3D scenarios and other geophysical methods.

Mining is a controversial topic: On one hand, we need raw materials such as copper for the transition to climate-friendly technologies, but on the other hand, exploration and raw material extraction are primarily associated with environmental pollution and exploitation.

Climate change is leading to stronger flood disasters. TU Wien and Joanneum Research have developed a new model that shows how private and public protection measures interact.

No one knows when the next major earthquake will strike. In the meantime, researchers are working to understand how these events could disrupt access to health care in densely populated regions—and how best to prepare for them.

A weak spot in Earth’s protective magnetic field is growing larger and exposing orbiting satellites and astronauts to more solar radiation, according to more than a decade of measurements by three orbiting observatories.

“The region of weak magnetic field in the South Atlantic has continued to increase in size over the past 11 years.”

The observations by the European Space Agency’s Swarm trio of satellites found that Earth’s already weak magnetic field over the South Atlantic Ocean—a region known as the South Atlantic Anomaly (SAA)—is getting worse and that it has grown by an area half the size of continental Europe since 2014. At the same time, a region over Canada where the field is particularly strong has shrunk, while another strong field region in Siberia has grown, the measurements show.

“The region of weak magnetic field in the South Atlantic has continued to increase in size over the past 11 years since the launch of the Swarm satellite constellation,” explained Chris Finlay, a geomagnetism researcher at the Danmarks Tekniske Universitet. “Although its growth was expected based on early observations, it is important to confirm this change in Earth’s magnetic field is continuing.” Finlay is the lead author of a new study published in the journal Physics of the Earth and Planetary Interiors that analyzes data from the Swarm satellites.

Geomagnetic Field

The three satellites were launched in 2014 to precisely monitor magnetic signals from Earth’s core and mantle, as well as from the ionosphere and magnetosphere. Earth’s magnetic field (technically, the “geomagnetic field”) is thought to be generated by a rotating core of molten iron, roughly 2,900 kilometers, or 1,800 miles, beneath our feet. But the strength of the field changes continuously, and scientists are still learning about its exact mechanisms.

“Satellites experience higher rates of charged particles when they pass through the weak field region…astronauts will also experience these charged particles.”

The geomagnetic field protects life on Earth’s surface from harmful charged particles in solar radiation. We can see the effects of charged particles from the Sun interacting with the geomagnetic field in the upper atmosphere during aurorae such as the northern lights.

And because it extends into space, the geomagnetic field also protects orbiting spacecraft, including most satellites and the International Space Station (ISS). However, the study authors warn that spacecraft—and spacefarers—that enter the South Atlantic weak spot during their orbits of our planet could now be exposed to more radiation.

For spacecraft hardware, this radiation could cause more malfunctions, damage, or even blackouts. “The main consequence is for our low-Earth-orbit satellite infrastructure,” Finlay said. “These satellites experience higher rates of charged particles when they pass through the weak field region, which can cause problems for the electronics.”

Danger to Astronauts

People in orbit will also face higher risks from radiation, including a greater chance of DNA damage and of suffering cancer during their lifetimes. “Astronauts will also experience these charged particles, but their times in orbit are shorter than the lifetime of most low-Earth-orbit satellites,” Finlay said. (On average, astronauts on the ISS spend about 6 months in low Earth orbit, but satellites typically spend more than 5 years there—about 10 times as long.)

The geomagnetic field is relatively weak compared with more familiar forms of magnetism: Its intensity ranges from about 22,000 to 67,000 nanoteslas. In comparison, a typical refrigerator magnet has an intensity of about 10 million nanoteslas.

In the SAA, the geomagnetic field’s intensity is lower than 26,000 nanoteslas. According to the study, the region’s area has grown by almost 1% of the area of Earth’s surface since 2014. The weakest point in the SAA now measures 22,094 nanoteslas—a decrease of 336 nanoteslas since 2014.

In the region of strong geomagnetic field over northern Canada, the intensity is greater than 57,000 nanoteslas. The study found that the area has shrunk by 0.65% of the area of Earth’s surface, while its strongest spot has fallen to 58,031 nanoteslas, a drop of 801 nanoteslas since 2014. In contrast, a strong field region in Siberia has grown in size, increasing in area by 0.42% of Earth’s surface area, with the maximum field intensity increasing by 260 nanoteslas since 2014 to 61,619 nanoteslas today.

Scientists have discovered that the weak region in Earth’s magnetic field over the South Atlantic—known as the South Atlantic Anomaly—has expanded by an area nearly half the size of continental Europe since 2014. Credit: ESA (Data source: Finlay, C.C. et al., 2025)

These changes in the Northern Hemisphere were unexpected, Finlay said. “It is related to the circulation patterns of the liquid metal in the core, but we are not certain of the exact cause,” he said.

The study did not, however, find any sign of an impending magnetic field reversal. Earth’s magnetic field has already reversed hundreds of times, but “we know from paleomagnetic records that Earth’s magnetic field has weakened many times in the past, displaying weak field regions like the South Atlantic Anomaly, without reversing,” Finlay said. “We are more likely seeing a decade to century timescale fluctuation in the field.”

“Hardened” Spacecraft

The heightened danger from solar radiation to satellites and astronauts passing over the SAA could be mitigated by ensuring that spacecraft are “hardened” to withstand it, Finlay said: “Since the weakness is growing, the satellites will experience such effects over a larger area, [so] this should be taken into account when designing future missions.”

Geophysicist Hagay Amit of Nantes Université in France, who wasn’t involved in the latest study but who has studied the SAA, noted that several scientists have proposed possible reasons for the observed changes in the geomagnetic field, but the actual mechanisms remain unknown. “Overall, [the authors] convincingly demonstrated that continuous high-quality geomagnetic measurements are crucial for providing vital insights into the dynamics in the deep Earth,” he told Eos in an email.

—Tom Metcalfe (@HHAspasia), Science Writer

Citation: Metcalfe, T. (2025), A weak spot in Earth’s magnetic field is going from bad to worse, Eos, 106, https://doi.org/10.1029/2025EO250417. Published on 10 November 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

The way clusters of differently sized water droplet populations are distributed within clouds affects larger-scale cloud properties, such as how light is scattered and how quickly precipitation forms. Studying and simulating cloud droplet microphysical structure is difficult. But recent field observations have provided crucial, centimeter-scale data on cloud droplet size distributions in stratocumulus clouds, giving researchers an opportunity to better match their models to reality.

The simulations of characteristic droplet size distributions that those models are providing are likely too uniform, say Allwayin et al. This muddled microphysical structure could be leading cloud simulations, and the climate models that use them, astray.

The authors compare the new observed data on cloud microphysical structure with results from large-eddy simulations (LES) of stratocumulus clouds. At convective scales, the model showed intriguing correlations between droplet cluster characteristics and overall cloud physics. For example, regions of the clouds dominated by drizzle tended to have larger drops but not necessarily more total water content, and the updraft regions of clouds tended to have smaller drops and a narrower distribution of droplet size.

However, across larger spatial scales, the characteristic droplet size distributions in the model looked very similar across different parts of a cloud. This diverges sharply from the observations, which show that the size distributions vary across large-eddy scales within the cloud.

One explanation could be that the process of entrainment—in which drier air is introduced into a cloud and causes evaporation—is not well resolved in these models, the authors say, noting a relationship between observations of characteristic droplet size distributions and local entrainment rates. In addition, models often assume that boundary layer properties such as surface fluxes and aerosol types are uniform across clouds.

The authors argue that a better understanding of cloud microphysics and its link to entrainment and boundary fluxes is needed to advance atmospheric modeling. The LES runs in this study are idealized cases, the researchers add, which should be kept in mind when interpreting their results. Future work should focus on understanding the role of horizontal gradients in aerosol concentrations, as well as on improving model entrainment layers, the authors suggest. Lagrangian schemes in LES models could hold more promise for this work. (Geophysical Research Letters, https://doi.org/10.1029/2025GL116021, 2025)

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2025), Understanding cloud droplets could improve climate modeling, Eos, 106, https://doi.org/10.1029/2025EO250420. Published on 10 November 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.

Lake Turkana in northern Kenya is often called the cradle of humankind. Home to some of the earliest hominids, its fossil-rich basin has helped scientists piece together the story of human evolution. Now, researchers from Syracuse University and the University of Auckland are revealing that the lake's geologic history may be just as significant as its anthropological one.

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

According to Wikipedia, Pikillaqta is a large archaeological site located 20 km to the east of Cusco in Peru. Inhabited by the Wari people, it was abandoned at about 900 AD for reasons that have not been clear. At the point of abandonment, the site was incomplete, with several key buildings still being under construction. Thus, there has been considerable speculation as to why the site was left by the Wari people.

This area of Peru has a high level of seismic hazard. In the historical record, major earthquakes occurred in 1650, 1950 and 1986 in the immediate area. In a paper just published in the journal Geoarchaeology, Garcia et al. (2025), explore the hypothesis that the abandonment of Pikillaqta might be associated with earthquakes and a landslide at the site. Note that, although the paper is behind a paywall, the link should provide access for all.

The image below shows the site in 2017 – note the scarp to the northeast of the site:-

Google Earth image from 2017 showing Pikillaqta (note the different spelling on Google Earth), and the projected source of the debris flow.

A large part of Garcia et al. (2025) focuses on documenting so-called Earthquake Archaeological Effects at Pikillaqta – these are pieces of evidence in the archaeological record of past earthquake events. They have found 149 pieces of evidence, such as collapsed walls, and they infer from the orientations of these that they record the impacts of two large earthquakes (one between 856 and 988 CalAD and one between 770 and 900 CalAD) that have been identified from palaeoseismological studies of local faults.

But interestingly, Garcia et al. (2025) have also investigated a geological deposit, up to 3 m deep, in and around some of the buildings. This has the sedimentological characteristics of a debris flow, and it contains a fragment of an animal bone that has been dated to 766–898 cal AD. They have then used a high resolution digital elevation model to map the debris flow deposit. They have concluded that it initiated from the scarp to the northeast (see the label on the the Google Earth image) and then flowed through parts of Pikillaqta.

Radiocarbon dating is not precise, so this debris flow could have been triggered by an earthquake, or it could have been associated with exceptional rainfall (or a combination of the two, of course). But there is little doubt that the earthquakes and the landslide caused substantial damage to the site at about the time of abandonment, even when construction was ongoing.

The authors recognise that this is an unproven hypothesis, and encourage further research. But it is deeply fascinating to see how earthquakes and landslides may have shaped the events at this key archaeological site.

Reference

García, B., C. Benavente, M. Á. Rodriguez-Pascua, et al. 2025. Prehistoric Evidence of Crustal Earthquakes and Debris Flow in Archaeological Site of Pikillaqta in Cusco: Archaeological Implications. Geoarchaeology  40: 1-14. https://doi.org/10.1002/gea.70033.

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

New Zealand—particularly the South Island/Te Waipounamu—is one of the most seismically active regions in the world. For this reason, the country has acknowledged the importance of building awareness and preparedness.