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SummaryAtmospheric models are based on various types of geophysical data, including lidar and radar. Infrasounds, acoustic waves that can propagate over large distances, have not yet been used in atmospheric models, although they provide valuable information. Besides their sensitivity to atmospheric phenomena such as gravity waves, infrasound also presents the advantage of being omnipresent. Previous studies explored the use of infrasound packet arrival properties for model estimation. However, properties such as arrival times present less information than full waveforms. We aim here to investigate, for the first time, the sensitivity of a full infrasound waveform to model parameters and to use these sensitivities in an inverse problem to recover atmospheric structure. For this purpose, infrasound propagation is modeled by Euler equations (i.e. Navier-Stokes equations in the absence of attenuation effects), and discretization is carried out here using the finite-differences method. Waveform sensitivity to atmospheric parameters is computed through the adjoint method via a novel and optimized double checkpointing-based procedure and validated by comparison with a small perturbation method. As an illustration, these sensitivity kernels are computed for the idealized case of an explosion in Finland, recorded by a CTBT station. These first results demonstrate the high sensitivity of infrasound waveforms to the atmospheric perturbations generated by gravity waves. Moreover, the sensitivity kernels of infrasound waveforms allow us to recover the variations of model parameters by solving an inverse problem. To demonstrate this capability, full waveform non-linear inversions are performed using the Limited Broyden-Fletcher-Goldfarb-Shanno method (L-BFGS): wind and sound speed profiles are inverted for a test case with idealized conditions and a synthetic dataset. These estimates of infrasound sensitivity kernels are closing a knowledge gap that allows the use of infrasound full waveforms to constrain atmospheric models.

SummaryPortland cement remains the most widely used construction material globally, valued for its well-documented properties and performance. However, its production generates substantial CO₂ emissions, mainly due to the decomposition of limestone (CaCO₃) into calcium oxide during clinker formation. In response to these environmental concerns, researchers have been actively exploring ways to lower cement’s carbon footprint and improve its sustainability. One effective strategy involves reducing the clinker content by incorporating supplementary cementitious materials (SCMs). To ensure SCMs enhance performance without compromising safety, it is essential to investigate the properties of blended cements. Natural zeolites have emerged as promising SCMs. Although they do not possess inherent cementitious properties, finely ground zeolites can react with calcium hydroxide in the presence of water, contributing to strength development. This study examines the potential of natural zeolites as SCMs and utilizes the spectral induced polarization (SIP) method to monitor cement hydration and reaction mechanisms. Portland cement mortars containing 25% zeolite were prepared and compared against two reference mixes. Zeolites were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD), while SIP monitoring was conducted continuously over 28 days. Our results reveal that SIP responses are influenced by the specific chemical composition of the mortar. The incorporation of SCMs alters cement chemistry, significantly influencing SIP signals. Over time, we observed an increase in the imaginary conductivity component and a decrease in the real conductivity component. SEM analysis showed the formation of new fibrous mineral habits in zeolite-blended samples, alongside a reduction in pore fluid content. These observations suggest a strong connection between SIP signals and mineralization processes, likely associated with the formation of secondary gels and calcium monosulfoaluminate. The interaction of zeolites with calcium hydroxide promotes the development of calcium aluminate hydrates, which then react with ettringite to form calcium monosulfoaluminate. These results emphasize the importance of studying SIP behavior in cement systems containing SCMs, as assumptions based on ordinary Portland cement may lead to misinterpretations. Our research underscores the potential of SIP as a valuable tool for monitoring cement hydration while offering new insights into the chemical transformations in zeolite-containing mortars. Ultimately, this work contributes to the advancement of more sustainable cement formulations, supporting environmentally responsible construction practices.

Many ecosystems on Earth are affected by pulses of activity: temperature swings between seasons, incoming and outgoing tides, the yearly advent of rainy periods. These variations can play an important role in providing nutrients and other important inputs, but climate change often makes the amplitude of these pulses more extreme, with sometimes catastrophic results.

Florida State University oceanographers have discovered a significant connection between small-scale microbial processes and ecosystem-wide dynamics, offering new insights into the mechanisms driving marine carbon storage.

Climate change is accelerating the reorganization of river-lake systems on the Qinghai-Tibet Plateau, reshaping hydrological and ecological processes in the "Asian Water Tower."

Sixty-million-year-old rock samples from deep under the ocean have revealed how huge amounts of carbon dioxide are stored for millennia in piles of lava rubble that accumulate on the seafloor.

Tropical cyclones can unleash extensive devastation, as recent storms that swept over Jamaica and the Philippines made unmistakably clear. Accurate weather forecasts that buy more time to prepare are crucial for saving lives and are rooted in a deeper understanding of climate systems.

A University of Houston scientist has teamed with international partners to examine how Antarctica's massive glaciers are shifting and how that could predict sea level changes. Their latest collaboration offers the most precise mapping to date in Antarctica of grounding lines, the points where glaciers lift from bedrock and begin to float on the ocean.

Despite continuous efforts to evaluate and predict changes in Earth's climate, most models still struggle to accurately simulate extreme precipitation events. Models like the Coupled Model Intercomparison Project Phases 5 and 6 (CMIP5 and CMIP6) use fairly coarse resolution due to computing constraints, making it a little easier, faster and less expensive to run simulations, while still providing some degree of accuracy.

New study reveals burning of fossil fuels is accelerating winter rainfall changes in the UK and Europe, almost 25 years sooner than expected.

An international team of scientists and students, led by the Arctic University of Norway, and including chemists and engineers from Woods Hole Oceanographic Institution, has announced a remarkable discovery of a venting system on the seafloor of the Arctic. This significant finding was made during the ongoing EXTREME25 expedition aboard the research vessel Kronprins Haakon.

Research led by polar scientists from Northumbria University has revealed new hope in natural environmental systems found in East Antarctica which could help mitigate the overall rise of carbon dioxide in the atmosphere over long timescales.

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

Frontline communities are commonly described as groups most affected by environmental and social challenges. Marston et al. [2025] offer a broader definition based on the experiences of community-based organizations that directly serve these communities.

Drawing on surveys, interviews, and text analysis, the authors show that “frontline” refers not only to vulnerability but also to active leadership, resistance, and cultural strength. The study finds that community-based organizations want support that respects their self-determination and avoids imposing outside definitions of success. They also emphasize the need for respectful, two-way partnerships rather than top-down guidance. These insights matter because misalignment between funders and communities can weaken well-intended projects. The study provides a rare look at what frontline organizations say they truly need. Overall, it offers practical guidance for building ethical, reciprocal, and community-centered partnerships.

Citation: Marston, R., Lutz, N., Mangabat, D., Sánchez Ainsa, G., Stober, J., Brown, M., & Turner, K. M. (2025). A mixed-methods needs assessment of frontline communities: Insights for engagement and partnerships between communities and intermediary organizations. Community Science, 4, e2025CSJ000133. https://doi.org/10.1029/2025CSJ000133  

—Claire Beveridge, Editor, Community Science

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.

Imagining Earth millions of years ago—its landscapes, atmosphere, temperature—is challenging.

In Antarctica, however, rare formations known as blue ice areas may offer a distinct look into that deep past. These areas, which make up barely 1% of the continent, form where strong winds strip away surface snow. Not all blue ice areas contain very old ice, but sometimes the slow movement of the ice sheet preserves ancient layers.

The Allan Hills region, situated on the edge of the East Antarctic Ice Sheet, is one such blue ice area. Here researchers have discovered ice up to 6 million years old—the oldest yet found.

Their study of the ice, published in Proceedings of the National Academy of Sciences of the United States of America, revealed that parts of it formed during periods far warmer than today—times when sea levels were higher and open forests and grasslands covered much of the planet.

The Allan Hills ice cores are not continuous. The oldest continuous ice core, also extracted from Antarctica, may reach back about 1.2 million years. Scientists compare continuous cores to a video: an uninterrupted, sequential history. Blue ice samples like the ones taken from Allan Hills, on the other hand, function as scattered fragments or disassembled snapshots that capture events beyond the video’s timeline.

“The advantage of Allan Hills is how far back these snapshots extend,” said Sarah Shackleton of the Woods Hole Oceanographic Institution and lead author of the study. “Modeling suggests the oldest possible continuous ice core in Antarctica might not go beyond 1.5 million years. To study earlier times, we need alternative samples.”

The Allan Hills project is part of the Center for Oldest Ice Exploration (COLDEX), which seeks to uncover the oldest possible ice records to better understand Earth’s climate history.

A Frozen Archive of Deep Time

The team, led by Shackleton and John Higgins of Princeton University, drilled 200 meters to uncover these ice fragments that trap “ancient precipitation—and, more importantly, ancient air,” Higgins explained. The researchers measured isotopes of gases (such as argon-40) to estimate the ice’s age and isotopes of water (such as oxygen-18 and deuterium) to reconstruct past climates.

According to the study, the Antarctic region cooled by about 12°C over the past 6 million years, documenting the long-term transition from a relatively mild Miocene to the relatively icy world we know today.

This record is critical because while the planet has sustained much hotter temperatures, many of its human inhabitants have not: Although the last interglacial period was warmer, we have rarely experienced the planet as warm as it is today. The past is a valuable source for identifying potential warming scenarios.

“These are pieces of a larger puzzle,” said Lidia Ferri, a glaciologist with the PARANTAR project, a research project carried out at the Universidad de Oviedo in Spain to study Antarctica’s South Shetland Islands. “We can establish cycles and identify inflection points. If the ice disappears, other factors are triggered, like changes in atmospheric dynamics and ocean currents. It’s a deeply interconnected system.”

Toward Future Climate Projections

“We use the planet’s past climate as a way to ground-truth the models we’re developing to predict what’s ahead.”

A main question posed by the new research is why past climates were so warm: Was it because concentrations of atmospheric greenhouse gases were higher, or were other factors at play? By studying the atmospheric remnants trapped in blue ice, the researchers hope to refine the models used to project Earth’s future.

“We use the planet’s past climate as a way to ground-truth the models we’re developing to predict what’s ahead,” Shackleton explained.

Ferri concurred, noting the value of gathering data from different time periods. “Today’s models are becoming more precise because the data is more varied,” she said. “The temperature increase predicted for the next 50 years isn’t the same as one 10,000 years ago, and this ancient data helps enrich those models.”

Despite spartan accommodations and extreme weather, researchers plan to return to Antarctica to collect more data from the PARANTAR project. Credit: Jordi Rovira

The team plans to return to Allan Hills, though Antarctic fieldwork is notoriously challenging. “We’re in a remote field camp with no permanent structures,” Higgins said. “It’s incredibly windy and completely isolated.”

—Mariana Mastache-Maldonado (@deerenoir.bsky.social), Science Writer

Citation: Mastache-Maldonado, M. (2025), New lessons from old ice: How we understand past (and future) heating, Eos, 106, https://doi.org/10.1029/2025EO250441. Published on 24 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: Journal of Geophysical Research: Biogeosciences

Many ecosystems on Earth are affected by pulses of activity: temperature swings between seasons, incoming and outgoing tides, the yearly advent of rainy periods. These variations can play an important role in providing nutrients and other important inputs, but climate change often makes the amplitude of these pulses more extreme, with sometimes catastrophic results.

We need better data on the effects of changes to these pulses of activity, argues Lee. The author describes ongoing efforts to gather such data using the eddy covariance method, which measures exchanges between ecosystems and the atmosphere. The work focuses on fluxes in drylands and coastal blue carbon ecosystems—two ends of the dryness spectrum that are home to high levels of biodiversity and carbon storage and that are under increasing threats from climate change.

Scientists are gathering data from networks of flux towers, with plans to expand their data collection methods, for example, pairing mobile measuring devices with existing towers and synergizing flux data with other measurements. These strategies are increasingly important, the author notes, for assessing unconventional water inputs such as tides and condensation during dry conditions, as well as considering how disturbances like wildfire smoke and dust storms affect ecosystem function. The author argues that understanding how ecosystems are adapting to recent changes to these and other factors is crucial for refining Earth system models and constructing more accurate predictions of how ecosystems will adapt—or fail to adapt—in the future.

The author and his colleagues are also exploring the use of machine learning for Earth science endeavors and are pursuing hybrid approaches that combine process-based models with machine learning techniques. A key advantage of hybrid models is their usefulness in solving parameterization problems and the option to incorporate additional data sources, he notes. These advances could help unlock the potential of flux data to reveal crucial insights about our changing world. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG009249, 2025)

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2025), Understanding flux, from the wettest ecosystems to the driest, Eos, 106, https://doi.org/10.1029/2025EO250438. Published on 24 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.

The Atlantic Meridional Overturning Circulation (AMOC), a system of Atlantic Ocean currents that redistributes heat and nutrients between the tropics and the North Atlantic, is one of the planet's tipping points. That means there is a critical threshold that, once crossed, could trigger abrupt, irreversible climate shifts.

Over the weekend, Planet captured near-perfect images of the Mae Moh Mine landslide in Thailand.

Last week, I posted a set of Planet satellite images that captured most of the 4 November 2025 landslide at Mae Moh Mine in Thailand. However, there was considerable cloud in the imagery, which prevented a full understanding of the landslide. Over the last few days, near perfect conditions have allowed a full, cloud-free image to be captured by Planet:-

The aftermath of the 4 November 2025 landslide at Mae Moh Mine in Thailand. Image copyright Planet, captured on 22 and 23 November 2025, used with permission.

This image is a composite of two sets captured on 22 and 23 November 2025. The crown of the landslider is on the west side, with the failure moving towards the east.

I think there are twof interesting aspects to this landslide. The first is the light coloured material in the upper part of the landslide – this is the mine waste that was being deposited shortly before the failure. It is the dumping of this mine waste that is my primary hypothesis for the cause of this landslide.

The second is the configuration towards the toe of the landslide (on the east side of the image). This is the area in question:-

The lower part of the 4 November 2025 landslide at Mae Moh Mine in Thailand. Image copyright Planet, captured on 22 and 23 November 2025, used with permission.

I have placed a marker at a key point on the image. The main part of the landslide terminates in the area of the marker, but a smaller flow type failure has then developed from this point. This appears to have been quite mobile – note how a lobe has moved to the north. The main portion has moved generally eastward, with one lobe reaching the pond, and another moving towards the southwest. There are indications that this SW tending portion might have been the final movement. The distance from marker to toe is over 1,400 metres – this was a major event in its own right. I’m quite intrigued by this lower failure – was this saturated mine waste that failed through undrained loading, for example?

It is worth reiterating that the 4th November 2025 event is not the first major failure of waste at Mae Moh Mine – a 70 million cubic metre failure occurred on 18 March 2018. In fact, I wrote about that landslide too, back at the time of the failure. I included this quote, originally from The Nation:-

Maliwan Nakwirot, a resident living near the mine in Lampang, yesterday said a landslide in the area on Sunday was the result of misconduct by the mine operator, which had been piling excavated soil into unstable piles instead to storing it in abandoned mine pits.  It is not the first time that there have been landslides at Mae Moh mine. There have already been three major landslides at the mine since last year, as these mountains of soil are not stable and are ready to slide anytime,” Maliwan said.

Interesting! Finally, a brief note as to the scale of this landslide. It covers an area of about 5.7 km2 – this is extremely large. The 2018 failure covered an area of 1.56 km2 and had a volume of 70 million m3. The surface area of this failure is about 3.65 times as large. The volume is unlikely to scale in a linear manner, but might seem to indicate that the volume may exceed 100 million m3? To put that in context, the infamous 2013 Bingham Canyon landslide was “only” 55 million m3.

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.

SummaryElastic rock physics models are widely used to estimate the saturation of hydrate in isotropic sediments. However, for isotropic media, the influence of heterogeneously distributed hydrate on the P- and S-wave velocities remains unclear, leading to uncertainties in hydrate saturation estimates. To address this issue, in this work we proposed a double-solid-matrix model for predicting the velocities of sediments hosting heterogeneously distributed hydrates. A comparison of simulated velocities of our model and two rock physics schemes designed for homogeneous distributed hydrate (i.e. matrix-supporting and pore-floating models) show that, our model predicts higher S-wave velocity than matrix-supporting and pore-floating models, but yields similar P-wave velocity estimates as matrix-supporting model. We apply our model to two marine hydrate sites in the Cascadia margin: Site 1245 from Ocean Drilling Program Leg 204 and Site U1328 from International Ocean Drilling Program Expedition 311. Two locations yield similar results: velocity estimates from our model are much closer to downhole measurements than matrix-supporting and pore-floating models. Moreover, we estimate in situ hydrate saturation and clay concentration using our model, matrix-supporting model, and pore-floating model independently, and find that (i) hydrate saturations predicted by our model conform better with the saturations from chloride concentration and (ii) clay contents calculated by our model fit the best with results from smear slide analysis. This study demonstrates that our double-solid-matrix model can be an effective tool to understand the effect of heterogeneously distributed hydrates on velocities, as well as obtain accurate hydrate content in marine isotropic sediments.

SummaryThe Hainan volcanic field (HNVF) is one of China’s most active Holocene volcanic areas. Due to a lack of comprehensive geophysical research, questions persist regarding the deep magma system of the HNVF. For example, it is unclear whether the intense seismic activity in its eastern part may be a precursor to renewed volcanic activity. We present new three-dimensional electrical conductivity images, derived from magnetotelluric data, that provide a new understanding of the deep magma system in the HNVF. Our results reveal the presence of multiple sets of low-resistivity structures in both shallow and deep regions. Although once associated with past volcanic activity, a widespread shallow low-resistivity layer on the northwest side of the HNVF is not currently indicative of shallow magma chambers. Instead, a deeper large-volume low-resistivity structure in the western part of the HNVF may represent the current crustal magmatic plumbing system. Our analysis suggests that the intense seismic activity in the east of HNVF lacks corresponding low-resistivity structures, which indicates that there is no direct correlation between seismicity and movement of magma. Recent volcanic eruptions are primarily concentrated near the Changliu-Xiangou fault, which may indicate that the migration of magma has utilized crustal weak zones.

Publication date: Available online 18 November 2025

Source: Advances in Space Research

Author(s): Jie Wu, Yuyang Huang, Shunzu Gao, Qian Pan, Yuhao Zheng, Qihui Jiang, Chao Xiong