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An international study by marine scientists based in Singapore has revealed that sea-level rise in the Indian Ocean began accelerating far earlier than previously thought, with corals providing an unbroken natural record of ocean change stretching back to the early 20th century.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: AGU Advances

Climate models predict that rising greenhouse gas levels cool the stratosphere, while the healing of the Antarctic ozone hole—driven by the reduction of ozone-depleting substances under the Montreal Protocol since the beginning of the 21st century—should warm the Antarctic lower stratosphere. However, observations for the period from 2002 to 2022 reveal unexpected changes: warming in the Southern Hemisphere (SH) subtropical lower stratosphere and cooling over Antarctica.

Sweeney et al. [2025] identify the cause as a slowdown in stratospheric circulation that moves stratospheric air and chemicals from low to high latitudes. These circulation changes, which are most pronounced from October to December, lead to warming in the subtropical lower stratosphere of the Southern Hemisphere and cooling in the Antarctic lower stratosphere. They also mask the anticipated ozone recovery over Antarctica during this period. Accounting for these circulation changes removes the anomalous warming of the SH subtropical lower stratosphere and reveals an obvious Antarctic lower stratospheric warming and enhanced ozone recovery. These findings highlight the crucial role of the stratospheric circulation in shaping temperature and ozone changes.

Citation: Sweeney, A., Fu, Q., Solomon, S., Po-Chedley, S., Randel, W. J., Steiner, A., et al. (2025). Recent warming of the southern Hemisphere subtropical lower stratosphere and Antarctic ozone healing. AGU Advances, 6, e2025AV001737. https://doi.org/10.1029/2025AV001737

—Donald Wuebbles, Editor, AGU Advances

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.

The most severe rainfall event ever recorded in Nepal impacted about 2.6 million people, causing losses of US$370 million and about 270 lives.

Between 26 and 28 September 2024, a devastating late monsoon rainfall event in Nepal triggered hundreds of landslides. In landslide terms, this was the most serious event recorded in Nepal outside of a major earthquake – economic losses are estimated to have been 1% of the country’s GDP and about 270 people were killed or left missing.

An initial analysis (Lamichhane et al. 2025 – the paper is behind a paywall, but the link should allow you to access it) has just been published in the journal Landslides – a very welcome paper. The authors, the majority of whom are Nepali, deserve praise for the speed at which this has been compiled, its comprehensive analysis and the diligence with which they have provided location information for the major events they describe. This is a model that others should seek to follow.

A substantial part of the paper examines the rainfall event itself. In central Nepal, 25 weather stations recorded their highest ever 24 hour rainfall. One station, at Godavari in Lalitpur District, recorded 311.6 mm. Peak hourly intensities were also high by Nepal standards – Godavari recorded 26.8 mm between 7 and 8 pm on 28 September 2024 – again, an unusually high figure for Nepal. Over the three day period, Godavari recorded 366.0 mm of rainfall.

Lamichhane et al. (2025) rightly highlight that the disaster was probably the consequence of a rainfall event that occurring in the late monsoon period, when the ground is already saturated, and that then involved high rainfall intensities, a high 24 hour rainfall total and a high 72 hour rainfall total. This is a toxic combination.

Lamichhane et al. (2025) then describe some of the more serious landslide events. The greatest losses occurred were caused by the Jhyaple Khola landslide, situated on the Tribhuvan Rajpath highway. The location is [27.71146, 85.20236] – the site is shown in the Google Earth image below, with the marker showing the point at which the landslide struck the road:-

Google Earth image of the site of the Jhyaple Khola landslide in Nepal, collected on 12 December 2023.

This is a Google Earth image of the site after the landslide:-

Google Earth image of the aftermath of the Jhyaple Khola landslide in Nepal, collected on 7 June 2025.

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

This landslide occurred at about 4 am on 28 September 2024. Unfortunately, two buses were at the site, trapped behind an earlier landslide.

Both buses were struck, killing 35 people. Lamichhane et al. (2025) describe the landslide as a 3 m deep debris flow that was rich with large pieces of woody debris. They rightly point out that the failure originated about 80 m above the road, but I would also highlight that the source appears to be another section of road. It is unclear to me as to whether the failure was on the cut slope above the road or a fill slope below it. That road appears on images from 2004, so it is not new.

Lamichhane et al. (2025) detail many other examples of landslides across Central Nepal, and even these are just a fraction of the total. Whilst the rainfall was unprecedented, they rightly highlight the anthropogenic issues that were the root of the disaster:-

“Major landslides and debris flow sites were linked to intense rainfall, unregulated sand mining, poorly managed rivers, haphazard road construction, and highly weathered slopes.”

In addition, they note that the following about the aftermath of the incident:-

“Despite involvement from various agencies, the disaster response fell short, underscoring the need for a more proactive approach to mitigation and management. Public response to rainfall warnings from agencies like Nepal’s Department of Hydrology and Meteorology (DHM) was also insufficient, contributing to tragic fatalities.“

Nepal will face many more events like this in the coming years, and indeed an even larger rainfall event is probably just around the corner. Lamichhane et al. (2025) demonstrates that immediate action is needed. Sadly, I have low confidence that this occur. It feels inevitable that I will describe another event of this type on this blog in the coming years.

Reference

Lamichhane, K., Biswakarma, K., Acharya, B. et al. 2025 Preliminary assessment of September 2024 extreme rainfall–induced landslides in Central Nepal. Landslides. https://doi.org/10.1007/s10346-025-02577-w

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 murky world at the bottom of the oceans is now a little clearer, thanks to a new study that tracks the evolution of marine sediment layers across hundreds of millions of years.

A recent study is shedding light on the factors that contributed to the significant wildfires in Manitoba in May 2025. The research explores how unusual weather patterns and stressed vegetation combined to create an ideal environment for disaster.

From lifelong farmers to backyard gardeners, most plant-lovers know that adding organic matter to a field, vegetable plot or flowerpot increases the soil's moisture. Now, for the first time, Northwestern University scientists have uncovered the molecular mechanisms that enable organic matter to boost soil's ability to retain water—even in desert-like conditions. The study is published in the journal PNAS Nexus.

Anomalies in temperature and salinity that originate in the midlatitude North Atlantic can affect the Atlantic Meridional Overturning Circulation (AMOC) in the Nordic Seas up to a decade later. A new study published in Communications Earth & Environment shows that the anomalies that travel northward with the Atlantic Water are an important part of the system, and actively modulate both the inflow of warm water into the Nordic Seas and the overflow of dense water back into the deep Atlantic.

Lakes have long been viewed as sources of carbon dioxide emissions, but new research suggests they may actually act as carbon sinks. A study led by Uppsala University reveals that lake shorelines store more carbon than previously believed, highlighting the need to include these littoral zones in calculations of the continental carbon balance.

Rare earth elements thread invisibly through daily life, quietly powering everything from laptops to smartphones to cars. "They're essential ingredients for our modern lives," said Virginia Tech mining expert Aaron Noble.

Imagine running a business for over a century without knowing what's in your warehouse. That's essentially what many African countries are doing with their mineral wealth. Governments across the continent still have very little knowledge of what lies beneath their soil.

Source: Journal of Geophysical Research: Planets

Despite being thinner and drier than Earth’s atmosphere, Mars’s atmosphere contains clouds composed of tiny water ice crystals. And just as on Earth, these clouds influence the planet’s climate. However, most of what we know about clouds on Mars comes from data collected during the Martian afternoon, so there is still much to learn about how clouds tend to form and dissipate over a full day.

Using data from the Emirates Mars Mission Hope probe, which has orbited Mars since 2021, Atwood et al. have captured the first comprehensive view of nighttime clouds on Mars.

Hope’s high-altitude, low-inclination elliptical orbit was specifically designed to enable observation across all times of day and night and at almost all latitudes and longitudes. The researchers analyzed data collected over nearly two Martian years by the Emirates Mars Infrared Spectrometer, an instrument mounted on Hope that can detect the presence and thickness of clouds, according to how they absorb and scatter infrared light.

The analysis revealed that for much of the Martian year, nighttime clouds are, on average, thicker than daytime clouds. Peaks in cloudiness typically occurred in the early morning and the evening, separated by a midday minimum.

During the cold season on Mars, thick clouds tended to form in a band near the equator, becoming thickest just after sunrise. Also during the cold season, late-evening clouds typically formed in a broader distribution across low latitudes, while early-morning clouds mostly concentrated over a vast volcanic region known as Tharsis, which covers the equator and low latitudes.

These findings shed new light on Martian atmospheric dynamics and could help scientists validate computational models of Mars’s atmosphere, the researchers say. (Journal of Geophysical Research: Planets, https://doi.org/10.1029/2025JE008961, 2025)

—Sarah Stanley, Science Writer

Citation: Stanley, S. (2025), First complete picture of nighttime clouds on Mars, Eos, 106, https://doi.org/10.1029/2025EO250279. Published on 11 August 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.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Water Resources Research

Coal seam gas (CSG) is extracted by pumping out groundwater, which lowers underground pressure, can lead to shrinking of geological layers and make the ground above sink over time.

Cui et al. [2025] present a new way to understand and predict land subsidence caused by CSG extraction. The study introduces a model that links groundwater flow with how the ground moves, including both general sediment compression and the shrinkage of coal as gas is removed. It uses real-world data, such as groundwater levels, gas production, and satellite measurements, to improve the model’s accuracy. By testing this model in the Surat Basin (Queensland, Australia), the authors find that subsidence can reach up to 235 millimeters near some wells and follows a three-stage pattern: growth, stabilization, and partial recovery.

The model helps separate reversible and permanent parts of the subsidence, which is important for long-term planning. This work is especially useful for land managers and farmers concerned about how CSG production may affect agriculture and drainage. More broadly, it provides a practical tool for evaluating the environmental impacts of energy extraction.

Citation: Cui, T., Schoning, G., Gallagher, M., Aghighi, M. A., & Pandey, S. (2025). A coupled hydro-mechanical modeling framework to concurrently simulate coal seam gas induced subsidence and groundwater impacts. Water Resources Research, 61, e2024WR039280.  https://doi.org/10.1029/2024WR039280  

—Gabriel Rau, Associate Editor, Water Resources Research

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.

The picturesque tufa towers on the shores of Mono Lake, formed over centuries by underwater springs and left high and dry as Los Angeles diverted water from nearby creeks, have long been a symbol of the saline lake. Visitors who stroll beside the lapping water take photos of the craggy calcium carbonate formations as flocks of migratory birds soar overhead.

Seismic data and eye-witness reports of a displacement wave point to a large landslide at 5:30 am.

On 10 August 2025, at 5:30 am local time, the Alaska Earthquake Center detected a seismic signal that was almost certainly generated by a landslide. They have posted the record of the seismic signal to Twitter. Their posting included a record of the seismic signal, which looks fairly typical for a landslide:-

The seismic signal from Tracy Arm in Alaska, which was probably generated by a large landslide. Data released by the Alaska Earthquake Center.

There are eye witness reports of the resultant localised displacement wave. BNO News quotes a kayaker who was camping in the affected area.

“Kayaker Sasha Calvey said she and two others were camping on Harbour Island in Tracy Arm Inlet, a fjord about 45 miles south of Juneau, when a landslide or iceberg caused a tidal surge that swept away half of their gear, including one boat, personal items, and cooking equipment.

“Calvey said their gear had been stored about 25 feet above the high tide line, but the water reached it and came within an inch of sweeping away their tent. She added that they placed a radio distress call that was picked up by a boat, which transported them to Juneau.”

The mouth of Tracy Arm is at [57.7778, -133.6167]. This is the latest Planet Labs image of at least a part of the area, captured on 7 August 2025 (last Thursday):-

Satellite image of Tracy Arm inlet. Image copyright Planet Labs, used with permission. Image dated 7 August 2025.

This is steep and rugged terrain, but the image provides no obvious hint of the location of the landslide that occurred three days later, as far as I can see. Hopefully, someone will capture a satellite image in the next few days that will shed light on the location, but that will depend upon the weather. Alternatively, the location might be identified from a boat or from an aerial survey.

I will undoubtedly return to this theme in the coming days.

Reference

Planet Team 2024. 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 dynamic Stern layer (DSL) petrophysical model can be used to interpret field induced polarization data and can be applied to both magmatic (volcanic and igneous) rocks and sediments. Thanks to it, field-scale tomograms of conductivity and normalized chargeability can be transformed into tomograms of porosity, Cation Exchange Capacity (CEC), and temperature. Furthermore, kilometer-scale galvanometric induced-polarization surveys are nowadays doable thanks to the recent development of independent stations measuring the primary and secondary electrical fields. This approach reduces capacitive and inductive coupling effects inherent to systems based on long cables and allow for deeper investigations. We apply here this combined methodology (novel equipment and revised petrophysical model) to a geothermal prospect located at Mashyuza, Republic of Rwanda, in Eastern Africa. At this site, the rifting activity led to the occurrence of an extensional regime favoring the occurrence of a rising thermal plume at the intersection between two faults. The existence of this plume is expressed at the ground surface by the presence of a hot spring at a temperature of ∼52°C (a well nearby provides a temperature of ∼65°C). A time-domain large scale induced polarization survey is performed. The current source signal is produced by a VIP-5000 squared signal injector and injection current values range from 1 A to 4 A, with stacking of 1s on-off signals ranging from 100 to 300 stacks to improve the signal-to-noise ratio. The size of the 3D array is ∼1.5 km and allows a tomography down to a depth of ∼300 meters. The data are inverted with the deterministic least-square technique, penalizing the roughness of the resulting tomograms. The conductivity and normalized chargeability tomograms are combined to get the temperature, porosity, and CEC distributions. The temperature distribution is consistent with the temperature of the hot spring and well. The results are interpreted in terms of ground water flow pattern and dilution of the mineralized thermal water with the fresher surface meteoric water. The survey images a rising plume of warm water from a depth of at least 300 m along intersecting fracture systems.

SummaryTianshan Mountains in Central Asia are one of the largest and most active orogenic belts in the world, characterized by complex structures and strong seismic activity. In this paper, we use recently updated GNSS data to self-consistently estimate the slip rates of major faults in Tianshan region via the elastic block model. Our results indicate that crustal deformation in Tianshan region is predominantly manifested as crustal shortening, regulated by foreland thrust belts and intermontane basin boundary faults. The shortening rate decreases from 14.2 ± 3.4 mm/yr in the west to approximately 3 mm/yr in the east. By estimating the seismic moment accumulation rates of the major seismic belts and comparing them with the historical earthquake catalog, we identify six seismic belts with significant seismic moment deficits. This indicates a potential risk for earthquakes exceeding magnitude 7, including the Kash fault, Keping fault, the Maidan fault zone, and the North Tianshan seismic belt. The Nalati seismic belt exhibits a relatively small seismic moment deficit, indicating the potential of earthquakes in the magnitude range of 6 to 7. In contrast, Qiulitage fault, the West Tianshan seismic belt and the Manas fold-and-thrust belt show a moment surplus, suggesting a low likelihood of strong earthquakes occurring in the near future. This study provides critical data and theoretical support for the prediction and risk assessment of seismic activity in Tianshan region.

An iconic Argentinian glacier, long thought one of the few on Earth to be relatively stable, is now undergoing its "most substantial retreat in the past century," according to new research.

Our ability to predict extreme weather from thunderstorms, like the recent catastrophic flash floods in Texas, is unsettlingly poor, even in the hours leading up to the event. Improvements in understanding, detecting and predicting extreme thunderstorms—and increasing community resilience to them—are badly needed.

In the wake of a wildfire, there's often an assumption that burned landscapes will be more susceptible to landslides. But new research from the University of Oregon suggests it's not always that simple.

Tropical cyclones, commonly known as typhoons or hurricanes, can form in clusters and impact coastal regions back-to-back. For example, Hurricanes Harvey, Irma and Maria hit the U.S. sequentially within one month in 2017. The Federal Emergency Management Agency failed to provide adequate support to hurricane victims in Puerto Rico when Maria struck because most rescue resources and specialized disaster staffers were deployed for the responses to Hurricanes Harvey and Irma.