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Author(s): Adrian Scurtu

A dusty plasma cloud hosting a counter-rotating vortex lobe pair is driven through controlled neutral-gas pressure ramps spanning nearly an order of magnitude in rate. The transient response is characterized by the longitudinal transport exponents αL and αR, extracted from mean-squared displacements…

[Phys. Rev. E 114, 035209] Published Tue Sep 08, 2026

Meltwater rivers flowing from Svalbard glaciers are carrying ancient methane from rocks beneath the ice into the open air, new research published in Nature Communications shows.

SummaryThe essence of earthquake early warning lies in the rapid and reliable prediction of the ground motion field after an earthquake occurs. While current numerical ground motion prediction methods based on data assimilation avoid the challenge of estimating source parameters, their interpolation processes do not adequately consider the source rupture directivity effects—a key physical factor controlling the spatially heterogeneous pattern of ground motions, resulting in limited prediction accuracy. To address this limitation, we break the traditional framework of numerical ground motion prediction methods and propose a novel real-time method that couples the source and ground motion field. This method incorporates a line-source model, dynamically extracts rupture directivity information, and estimates the line-source strike by comparing observed and predicted ground motion fields in real time, thereby continuously refining subsequent ground motion predictions. Tests using the 2016 Kumamoto earthquake (Mw 7.0) as an example demonstrate that the rupture direction inferred by this method within the early post-event period (within 28s) aligns closely with the results from detailed post-event inversion. After correction for the directivity effects, the accuracy of ground motion prediction is superior to that of traditional numerical prediction methods. The MAE of peak intensity predictions is reduced by 16.1%, 5.4%, and 19.6% for predictions of 5s, 10s, and 20s in advance, respectively.

SummaryGravity curvature is defined as the third-order derivatives of the gravitational potential. It has been proposed as a potential observable for future satellite gradiometry due to its enhanced sensitivity to short-wavelength components of Earth’s gravity field. Previous studies reported that gravity curvature exhibits apparently weaker spatial correlation with Moho geometry than gravity and gravity-gradient observations, raising concerns about its applicability for Moho inversion. In this study, we systematically assess the capability of gravity-curvature data for Moho recovery, with particular emphasis on the contrasting behaviors of spatial- and spectral-domain inversion schemes. The nonlinear spatial inversion is implemented using the iterative regularization, whereas the spectral inversion follows a spherical harmonic Parker-Oldenburg formulation. Synthetic and real-data tests reveal a clear methodological dependence. Spectral inversion demonstrates robust and stable performance, as it primarily exploits the inherent spectral content of the gravitational field and is insensitive to altered spatial patterns. In contrast, spatial inversion is strongly influenced by data-model correlation, with performance improving at higher observation altitudes but degrading under near-surface scenario. At satellite altitudes, with the effect of iterative stabilization, the spatial inversion yields roughly consistent performance to the spectral inversion. These findings highlight that the inversion capability of gravity curvature depends critically on the inversion framework. When spatial distribution and spectral content are properly considered, gravity curvature can provide a promising constraint for density interface inversion by enhancing sensitivity to specific spatial scales.

A new study reveals that microbial life deep within Earth has persisted and repeatedly flourished through hundreds of millions of years of mountain-building and erosion. By analyzing minerals, fluids and gases from a 2.3-kilometer-deep (1.4-mile-deep) borehole in central Sweden, researchers have uncovered episodic bursts of methane-producing life linked to major geological events that shaped Scandinavia. The paper is published in the journal Communications Earth & Environment.

Permafrost refers to permanently frozen ground. The rock is held together by ice, much like cement binds concrete. However, when the ice thaws, the ground becomes weak and unstable. During an earthquake, this can trigger a series of natural hazards. An international research team investigated precisely such an event.

The news has been full of headlines about findings from a United Nations report: The world is set to exceed the 1.5°C global warming target set out in the 2015 Paris Agreement. The report has raised concerns and questions about what a 1.5°C increase could mean for our world.

An increase in pollution from wildfires and heat waves risks undermining international efforts to improve air quality and protect human and ecosystem health, according to a new report from the World Meteorological Organization (WMO), which traces the complex interrelationships between air quality and climate.

In a new report, the United Nations Environment Program (UNEP) concludes that global warming is expected to exceed 1.5°C within the next few years. This makes two questions increasingly important: how high will temperatures rise, and how long will the increase last?

A journey back in time to the Late Cretaceous: A swampy rainforest with conifers and tree ferns stretches as far as the eye can see, dinosaurs roam through the misty wetlands, and the climate is mild and warm. The average annual temperature is 12°C (54°F)—around two degrees higher than in present-day Germany. There is plenty of water, too, as dry periods are regularly followed by monsoon-like rainy seasons.

Enough satellite and drone imagery is now available to allow some initial analysis of the landslide that started the 26 August 2026 debris flow in Nepal and Tibet.

Much has been written over the last ten or so days about the tragic debris flow that has caused such high levels of damage and loss of life in Tibet and Nepal. The various narratives have at times been excellent, simply wrong, reflective and/or challenging. Loyal readers will know that I tend not to write about events that are being well-covered by others, so I have resisted writing whilst I have been on leave with my daughter Holly.

But it is interesting to note that little has been written about the landslide that started the terrible cascade of events. It is worth some reflection ahead of a detailed analysis that will come from the group convened by Dan Shugar to interpret the event.

There is an incredibly useful compendium of satellite images on a website compiled by the Hidenori Watanave Laboratory at The University of Tokyo. This includes images from Planet Labs, Vantor and Landsat 9 in a very accessible format. It is worth a look, not least because it has imagery of the site of the landslide both before and after failure. Of course, there is also some drone footage of the aftermath that was posted to LinkedIn by Guoxiong Zheng. This allows us to start to understand the landslide itself, but we are going to need better data to fully understand this event.

The site of the landslide was [28.2921, 85.5271]. The most recent Google Earth imagery of this site is heavily shadowed, but there is a good image from 2017:-

Google Earth image from 2017 showing the site of the 26 August 2026 landslide in Nepal.

The Watanave Lab imagery collection has a Planet Labs image from 25 August 2026 showing the site. This is lower resolution than the Google Earth image:-

Planet Labs image from 25 August 2026 showing the site of the 26 August 2026 landslide in Nepal. Image via Watanave Lab.

Comparing the two sets of images, I don’t see much that would have indicated that a failure was incipient. Indeed, perhaps the lack of obvious change is a surprise.

The Watanave Lab imagery has two post-failure images, of which this one is the more useful:-

Planet Labs image from 28 August 2026 showing the aftermath of the 26 August 2026 landslide in Nepal. Image via Watanave Lab.

Two caveats here – first, the image is draped on a DEM that won’t accurately reflect the post-failure topography (see the drone footage below). And second, there is cloud in the imagery that becomes draped on the topography, which is of course an error.

The site of the landslide had a highly complex morphology, with very steep slopes and perhaps a strongly developed overhang. One might hypothesise that this oversteepened upper slope failed catastrophically, triggering failure on the lower slope. There has been much conjecture that climate change might have played a role, and the increased occurrence of these events in general is very likely to be climate-related, but I am uncertain as to whether this particular event has a climate change signature. It is entirely possible that this was a progressive failure in a slope that was both oversteepened and deteriorating.

It is entirely possible to construct a climate change narrative for this event, but it cannot be assumed.

The landslide itself is very large. The source zone is about 2,000 metres long and the elevations are about 5,140 metres at the crown and 3,990 metres at the toe, so about 1,150 metres. This is a very steep slope.

The landslide generated a seismic signal the equivalent of a M=5.7 earthquake, indicating a volume in the order of 100 million cubic metres.

The imagery clearly shows that the shear surface was in bedrock, not within the ice or at the ice-rock boundary. It is interesting to look at the images collected by drone. This is the upper portion of the landslide scar:-

The upper part of the scar from the 26 August 2026 landslide in Nepal. Image from drone footage posted to LinkedIn by Guoxiong Zheng.

At the crown, the interface between the glacier and the bedrock is clear, confirming that this was primarily a bedrock landslide. The scar has a weak wedge shape in this area (?), probably indicating that the failure exploited existing weaknesses (as you’d expect). Is there a hint that the shear surface is weathered? I suspect so, but it is hard to be certain.

Lower down, the landslide scar is more planar and is covered with debris left behind and that has fallen from the exposed scar:-

The lower part of the scar from the 26 August 2026 landslide in Nepal. Image from drone footage posted to LinkedIn by Guoxiong Zheng.

This has now left a very steep slope, albeit one without overhangs, so the potential for further collapses needs to be considered.

The geomorphology of this area, and the slopes along the channel downstream, are now going to evolve. This could involve further collapses in the coming years.

A much more detailed review of this landslide is needed. It will be all too easy to focus on the debris flow and its terrible impacts – and this is important – but we must not lose sight of the need to understand the initial failure too.

Finally, I have seen quite a lot of commentary that this event was in some way unprecedented in scale. It was not. Three much larger landslides and debris flows are recorded in valley fills in the Pokhara area of Nepal. These events are related to earthquakes that occurred in ∼1100, 1255, and 1344 AD – i.e. in the medieval period. These three events generated about 5 km3 of sediment.

The potential for even larger landslides must be considered when proposals to mitigate these hazards through the construction of even larger dams are made.

Return to The Landslide Blog homepage 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.

Water has always been one of California's most contested resources. For more than a century, battles have raged over how much of the state's water should be diverted to farmland, pumped into cities or used to conserve aquatic ecosystems—and at times, these clashes have even led to violence. The state's water system consists of a dizzying array of reservoirs, rivers, dams and aqueducts, making it challenging even for experts to understand the trade-offs of different management decisions.

The waters of the remote Scottish island of Jura have long been famous for making whiskey. Now, the island's rivers have helped geologists learn more about how rivers erode rocks, providing new evidence that what streams carry plays an important role in how they carve through landscapes.

More than two dozen University of Victoria researchers contributed to "Canada's Changing Climate Report 2026," the country's most comprehensive assessment of how climate change is affecting communities, ecosystems and coastlines across Canada.

С.П. Кулик, С.Н. Молотков

Совместные ограничения квантовой механики и специальной теории относительности открывают новые возможности для квантовых коммуникаций. В данном сообщении обсуждается протокол релятивистского квантового распределения ключей (КРК) через открытое пространство. Протокол не требует однофотонных состояний, достаточно ослабленных когерентных состояний лазерного излучения. При небольшом среднем числе фотонов в когерентных состояниях состояния с разными значениями относительной фазы не могут быть достоверно различимы. Не нужно использовать состояния "ловушки", как в decoy state-методе, которые являются обязательными для нерелятивистских протоколов КРК, что упрощает оптическую часть на приёмной стороне, и обойтись без активных элементов — фазового модулятора. На передающей стороне не требуется модулятор интенсивности, который необходим для реализации decoy state-метода в нерелятивистских системах. Протокол обеспечивает распределение ключей при больших потерях в линии связи ≈ 60 дБ. В протоколе используются только два информационных состояния, поэтому не нужно согласование базисов, все зарегистрированные посылки используются в ключе, что увеличивает скорость распределения ключей. Наиболее подходящим применением релятивистских систем КРК является распределение ключей между стационарными неподвижными объектами, например, станциями сотовой связи или другими объектами, прокладка волоконной линии между которыми является дорогостоящей или практически невозможной. В отличие от анализа криптостойкости нерелятивистских систем КРК, в котором используется довольно изощрённый математический аппарат, анализ стойкости релятивистского КРК проводится на интуитивно понятном для физической аудитории уровне, не требует предварительных специальных знаний и доступен аспирантам и студентам старших курсов университетов, знакомым с основами квантовой оптики, квантовой информатики и квантовой криптографии в объёме стандартных университетских курсов.

SummarySeismic imaging of the Earth’s interior has steadily improved in the past 40 years. Full-waveform inversion (FWI) has been the most recent driver of global and local tomography. Although mineral physics experiments link seismic properties to temperature, pressure and composition of the mantle, direct integration of seismic observations and thermodynamic calculations has not yet been achieved. This work illustrates a framework that integrates FWI techniques with mineral physics to directly invert seismic waveforms for mantle temperature and chemical composition. The forward model is based on interpolation of pre-calculated tables of mantle properties, namely density and P- and S-wave speeds. The inverse problem is formulated as an optimization problem. The gradient of the objective function with respect to temperature and composition is computed using the chain rule which allows us to split it into independent seismic and thermodynamic parts. For the seismic part, the gradient is computed with the adjoint method. For the thermodynamic part, gradients of the pre-calculated tables are obtained by analytically deriving the interpolation function, while accounting for the pressure–density coupling, under the assumption of hydrostatic loading. As a proof of concept, we applied this approach on 2-D synthetic models containing thermal and compositional anomalies where P–SV elastic wave propagation is simulated. The optimization problem is solved using the L-BFGS algorithm. We mitigate the trade-off between the effect of temperature and composition by applying a linear transformation to the model parameters before carrying out the minimization and then transforming back once a solution is found. The proposed framework enables the integration of diverse geophysical datasets as well as the incorporation of additional information on the potential origin of certain mantle anomalies based on petrological constraints, which are crucial to tackle the non-uniqueness of the inverse problem.

SummaryInterfacial slip at fluid–solid boundaries can significantly modify hydraulic transport in tight porous media, yet its implications for representative wave-induced fluid-flow mechanisms have not been systematically investigated. In this study, we develop a physically explicit multiscale poroelastic framework to investigate how pore-scale interfacial slip propagates through representative poroelastic relaxation mechanisms. Starting from oscillatory viscous flow in a cylindrical pore with interfacial slip boundary conditions, we derive a slip-modified pore-scale transport model that provides a physically explicit realization of hydraulic transport under slip conditions. Rather than introducing a new wave-induced attenuation mechanism, the derived transport model is consistently incorporated into the Biot, Biot–squirt, and White–squirt formulations to systematically examine how the same pore-scale transport modification influences viscous flow, squirt-flow relaxation, and mesoscopic pressure diffusion. The results show that interfacial slip systematically reduces viscous resistance, enhances dynamic permeability, and primarily manifests as a shift of the characteristic frequencies governing wave-induced fluid flow. Although the same transport modification is introduced into each model, its macroscopic manifestation depends on the governing relaxation mechanism, leading to distinct responses in the Biot, Biot–squirt, and White–squirt frameworks. Comparisons with laboratory measurements on tight carbonate samples demonstrate that the proposed framework reproduces the principal trends of seismic dispersion and attenuation while maintaining physically reasonable model parameters. These results establish a physically explicit connection between pore-scale interfacial transport and multiscale seismic wave propagation, providing a physically consistent basis for incorporating interfacial effects into poroelastic wave-propagation models and for improving the interpretation of seismic responses in tight porous media.

Since scientists can't drill 2,900 km (1,800 miles) to the boundary between Earth's core and deep mantle, they must use information relayed by seismic waves recorded during earthquakes to study this region. In a new study published in the journal JGR Solid Earth, a group of scientists used deep learning to study a large set of a specific type of seismic wave. The analysis revealed six continuous bands of irregularities at the core-mantle boundary (CMB) that had previously appeared only as sparse patches.

Lakes may look like picturesque stopping points along a river or stream, but they can have a big influence on what happens to carbon as it moves through a landscape. New research suggests that the more lake-rich a network of streams is, the more carbon is released into the atmosphere rather than carried downstream.

Has El Niño reached the West Coast? You might think it has. After all, the ocean off Southern and Central California is unusually warm. But that warmth is from a recent marine heat wave that predates the current El Niño. Much of the Pacific Coast is experiencing relatively normal conditions while still awaiting the impacts of what could be a very strong El Niño.