Feed aggregator

Every year during December and January, in the Indian Himalayan state of Uttarakhand, rural communities carry out traditional burning on steep hill slopes to regenerate grass. These carefully timed burns, which take place when fuel stocks are low, are needed to support livestock and, indirectly, agriculture in the region.

Glaciers are melting worldwide. In some regions, they could even disappear completely. Looking at the number of glaciers disappearing, the Alps could reach their peak loss rate as early as 2033 to 2041. Depending on how sharply the planet warms, this period may mark a time when more glaciers vanish than ever before. Worldwide, the peak glacier loss rate will occur about ten years later and could rise from 2,000 to 4,000 glaciers lost each year.

Located in the western portion of the Brazilian Amazon, Terra Indígena do Vale do Javari (Valea do Javari Indigenous Land) is one of the world’s largest continuous patches of pristine tropical rainforest and harbors the world’s highest concentration of noncontacted Indigenous peoples.

The region gained global attention in 2022 with the assassinations of Brazilian anthropologist Bruno Pereira and British journalist Dom Phillips. The murders revealed the increasing pressure locals face in preserving the environmental and cultural integrity of their way of life and staving off the organized crime that often accompanies illegal logging and poaching in the region.

Wildfires are contributing to this pressure, and researchers are using innovative mapping techniques to try to understand their dynamics within the territory and its surroundings. A team of biodiversity and remote sensing experts based in Brazil and the United States will present some of their findings on 16 December at AGU’s Annual Meeting 2025.

Mapping wildfires around the still-pristine region may help identify priority areas for conservation and inform policy planning in forest protection, said coauthor Gabriel de Oliveira, a remote sensing and vegetation dynamics researcher with the University of South Alabama.

“Our goal was to understand whether the forest’s natural resistance to fire has held firm over 4 decades and how pressures in the surrounding landscape might be changing that,” said de Oliveira.

“Vale do Javari is certainly a highly threatened region because it is far from everything and very much at the mercy of organized crime.”

The team used MapBiomas Fire Collection data, which record the annual and monthly mapping of burned areas in Brazil from 1985 to 2024. They supplemented these data with additional satellite-derived thermal information to map where fires have occurred since 1985 inside Vale do Javari and surrounding buffer zones extending 50, 100, and 200 kilometers outward.

Researchers who study fire in the Amazon see this ongoing study as a valuable brick in the growing wall of knowledge about fire in protected lands. “They’re using MapBiomas data to see what has burned and how often it burned,” said Ane Alencar, science director at the Amazon Environmental Research Institute (IPAM Amazônia).

“Vale do Javari is certainly a highly threatened region because it is far from everything and very much at the mercy of organized crime. Any tool or study that reveals the threats facing that Indigenous land is very valuable, so it looks quite interesting,” she added.

Ultimately, de Oliveira hopes the new research will help inform conservation strategies in the area. “If we could detect where fire is already recurring or creeping closer, we could begin to identify zones that deserve urgent attention from policymakers,” he said.

Finding Patterns

Fires have become a growing concern in isolated Indigenous lands across the Amazon.

According to a recent analysis by the Observatory of Isolated Indigenous Groups, the past 25 years of satellite data show that in 2024, more than 10,000 hot spots (burn scars) were detected in Brazil alone. The analysis was conducted between January and September across 67 Indigenous territories and protected areas with isolated groups and represents both a 221% increase above the long-term average and a roughly 50% increase from its previous peak in 2010.

The landscapes of Indigenous and protected areas are typically less disturbed compared with the rest of the Amazon, so an abrupt spike in hot spot activity signals processes that researchers say deserve close attention.

A similar pattern emerges when considering not just the number of hot spots but their scope, the total area burned within Indigenous lands across Brazil. For most of the past decade, that figure remained around 1.5 million hectares per year. But in 2024, during one of the most severe droughts on record, total burned area inside Indigenous territories jumped to about 3 million hectares, an increase of 81%, according to IPAM Amazônia. Nearly a quarter of all area burned in the Amazon in 2024 occurred within Indigenous territories.

For researchers who study territories such as Vale do Javari, these trends are troubling not only because they indicate rising fire pressure but because Indigenous lands play critical roles in ecology and public health. A 2023 study showed that Indigenous territories act as major buffers against wildfire smoke, for instance, preventing large amounts of particulate pollution from reaching more densely populated areas nearby. A 2025 analysis identified Vale do Javari as one of Brazil’s most significant hot spots for future species discovery, meaning that habitat loss there could extinguish biodiversity that scientists have not even documented yet.

Those broader patterns align with what de Oliveira and his collaborators are observing on the ground and in satellite records. Their analysis showed that the forest interior of Vale do Javari remains relatively resistant to burning, but the surrounding landscape has changed markedly. In the 200-kilometer buffer zone, annual burned area has risen sharply in recent decades, with some of the highest values on record appearing in the past 2 years. “The signals are strongest at the edges,” de Oliveira said. “You see repeated fire in certain locations, and those are the places where degradation begins.”

To detect degradation that might not yet appear in traditional deforestation maps, the team also examined thermal anomalies from Landsat and Sentinel data. Deviations in surface temperature, de Oliveira said, can indicate canopy opening or drying under the trees. “A healthy, closed canopy regulates energy very efficiently,” he explained. “But when the canopy thins or fire has passed through multiple times, the ground heats up more. That thermal signature tells us something is happening below the leaves, even before clear-cutting takes place.”

The group validated some of these signals with fieldwork in regions just outside the Indigenous territory. They have not yet worked inside Vale do Javari itself.

The researchers found that small paths, recurring burn scars, and subtle canopy disruptions appear to align with known routes used for illegal logging, poaching, and other forms of encroachment. “It’s not the classic pattern of a large clear-cut,” said de Oliveira. “It’s a much slower, quieter process—fire escaping from pasture or burning the same patch of forest two or three times until it loses its resilience.”

Research as a Conservation Tool

“Repeated fire—especially combined with extreme drought—moves the system toward collapse.”

The gradual erosion of forest health is one of the team’s main concerns. “If a forest burns once, it can recover,” de Oliveira said. “But repeated fire—especially combined with extreme drought—moves the system toward collapse. You may not see deforestation immediately, but the structure and function of the forest are already changing.”

De Oliveira and his fellow researchers hope their maps will serve as a tool for early intervention, particularly in the buffer zones with the highest fire risk. The next step, de Oliveira said, is to work with local and federal agencies to establish targeted conservation strategies that extend beyond Indigenous land boundaries.

“Protection cannot stop at the line on a map,” he added. “We need buffer zone policies and monitoring systems that recognize how these landscapes are connected. Vale do Javari is still a stronghold, but the data show that what happens around it will determine its future.”

—Meghie Rodrigues (@meghier.bsky.social), Science Writer

Citation: Rodrigues, M. (2025), Fire encroaches on one of the Amazon’s most pristine Indigenous lands, Eos, 106, https://doi.org/10.1029/2025EO250467. Published on 15 December 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.

As Earth’s population continues to grow and strain environmental resources, researchers are increasingly examining how humans might one day build settlements beyond Earth. Not many construction materials can withstand extreme temperatures and low-pressure environments like those that exist on Mars, however. New research explores an unconventional candidate: ice.

“This study…is expanding and questioning, How do we support life on other worlds?” said Rafid Quayum, a postbaccalaureate student at Harvard University and a researcher on the project. “Can we come up with a solution that’s environmentally friendly and also inspired by Earth’s systems?”

Ice, Quayum’s team says, offers a rare combination of benefits that can mitigate many of the environmental challenges astronauts would face: It absorbs radiation, transmits visible light, and can create a passive greenhouse effect inside enclosed habitats. That assumes, of course, that astronauts can harvest it.

Icy Habitats

Humans have been building temporary and permanent structures out of ice and snow for centuries. From the igloos and quinzhee of some Inuit peoples in Greenland and the Canadian Arctic to Kamakura in Japan, people have long recognized that ice can retain heat, keep out the elements, and be sourced in many cold environments.

But while ice retains its insulating qualities in environments beyond Earth, it may not be readily available, explained Armin Kleinboehl, a planetary scientist at the Jet Propulsion Laboratory in Pasadena, Calif., who was not involved in the study. Sourcing ice locally, especially on Mars, would be challenging. While Mars’s poles contain abundant ice, their harsh seasonal cycles make them unsuitable for long-term habitats, he said.

Unlike shelters built from regolith, ice domes would allow natural light to filter in, an advantage for both plant growth and human psychological well-being.

“If you were to build a build a habitat in those regions, you would want people to get out before the polar winter sets in,” Kleinboehl said. Instead, mission planners often target the northern midlatitudes, where shallow subsurface ice may be easier to access, he added.

Still, ice has certain advantages as a building material. Unlike shelters built from regolith, the fine layer of planetary topsoil made of dust, soil, and broken rock, ice domes would allow natural light to filter in, an advantage for both plant growth and human psychological well-being, Quayum said.

What’s more, even if surface ice isn’t easily accessible in the regions on Mars where humans might want to build, the resources are abundant on icy worlds like Ceres and Callisto, the researchers noted. Sourcing the ice from other planetary bodies could reduce the energy and cost of transporting materials from Earth.

Keeping Warm in Cold Environments

Quayum’s team modeled hypothetical ice domes that could be built on Mars’s surface, explored techniques to create them, and simulated what the conditions would be like inside. They placed their simulated domes at the midlatitudes of Mars, where ice is less accessible than at the poles but sunlight is more abundant. In these regions, daily temperatures swing from −56°C to −37°C, which is not enough to melt the ice, according to the model.

Removing dust and regolith allows the resulting ice shell to transmit sunlight while acting as radiation shielding.

In addition to temperature, Mars’s atmospheric pressure, which is less than 1% of Earth’s, also presented a challenge. Because liquid water cannot exist stably at such low pressures—it boils and freezes almost simultaneously—the team proposed using vacuum distillation to purify locally sourced ice. With this technique, heated ice vaporizes rather than melts. The vapor can then be captured, condensed into a liquid under high pressure, purified, and refrozen into clear, contaminant-free ice. Removing dust and regolith during this process allows the resulting ice shell to transmit sunlight while acting as radiation shielding, Quayum explained.

In the modeled ice domes, hydrophobic seals reinforced the dome by preventing any interior melted water from seeping into the shell, where it could weaken the ice. An aerogel insulating layer further slowed heat transfer to keep the outer layer below its melting point. Inside the habitat, sunlight warmed the air.

“There will be convection, like on Earth, to mix heat around, which should result in a fairly uniform temperature throughout [the dome],” said Robin Wordsworth, a planetary scientist at Harvard University and a researcher on the project.

The heat from that air then moved outward through the ice by conduction, a process that prevented the shell from losing strength. Temperature models and 3D structural simulations suggest the dome could remain stable at average Martian temperatures of roughly −58°C.

The team will present these results on 16 December at AGU’s Annual Meeting 2025 in New Orleans.

Testing Beyond Theory

The team said that a lot of research is still needed to determine whether ice domes could be a viable habitat for future Martian astronauts. Like Earth, Mars has seasonal variations that could affect the long-term durability of the domes, an effect they hope to investigate further.

To try to move Mars ice habitats beyond theory, the researchers aim to conduct field tests in extreme environments on Earth that mimic Martian conditions, such as the subzero temperatures of Antarctica and low-pressure environments like the Himalayas. If those are successful, structural habitability could eventually be tested on Mars itself.

“It would be something really exciting for scientists to be able to travel to other planetary environments, conduct field work, and be able to stay in habitats…using ice,” said Quayum.

—Olivia Maule (@ocmaule), Science Writer

Citation: Maule, O. (2025), Could future Mars habitats be made of ice?, Eos, 106, https://doi.org/10.1029/2025EO250456. Published on 15 December 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.

Taking the train or subway can be a time and cost-efficient way for city dwellers to commute. But during the summer months, some metro riders risk exposure to extreme heat, the deadliest weather-related hazard in the United States, while walking to and from stations.

A team of researchers at George Mason University in Fairfax, Va., analyzed the surface temperatures of walkways within a 10-minute walk of the three U.S. metro systems with the largest ridership. Then, they considered how socioeconomic factors, such as age and race, and development patterns, such as parking lots and indoor walkways, were related to differing levels of heat exposure.

The project began out of curiosity, said Luis Ortiz, an urban climate scientist at George Mason University. “It combines two of my big passions,” he said. As a longtime urban heat researcher and avid public transit user, Ortiz sought to answer a question from his day-to-day life: “If you’re a pedestrian using public transportation, what does your heat exposure look like?”

Black, Asian, and Hispanic commuters experience higher exposure to extreme heat.

The scientists combined station ridership data and Landsat 8 estimates of surface temperature to map where pedestrian public transit users were most exposed to heat on the New York City Subway, the Washington Metro, and the Chicago “L.” Ortiz will present the results on 16 December at AGU’s Annual Meeting 2025 in New Orleans.

The researchers found that the correlation between socioeconomic and demographic variables and surface temperatures were highest for the Chicago L and lowest for the Washington Metro. One pattern the researchers observed across all three cities is that commuters with minoritized identities, including Black, Asian, and Hispanic commuters, experience higher exposure to extreme heat, said coauthor Alireza Ermagun, a transportation scientist. So, too, do elderly populations and metro users between age 25 and 44.

Researchers analyzed the surface temperatures within a 10-minute walk of a metro station in three U.S. cities. Credit: Luis Ortiz, George Mason University

One result from the Washington Metro system seemed to contradict these correlations: Some of the hottest stations are in relatively wealthy areas of northern Virginia. Researchers attribute the unexpected finding to people driving to metro stations and parking a car. “They have massive parking lots there that get very hot in the afternoon,” Ortiz said.

A Green Solution

Urban planners should use research like this to strategize where to put shade and green space, said Nadav Sprague, an environmental epidemiologist at Harvard University who was not involved in the study. “Having access to shade is very important,” he said.

Many of the walking routes with high heat exposure have very few trees, Ortiz said. He said that trees “solve several of the issues” that cause heat stress by providing shade, reducing heat radiation into the body, and cooling the air.

“The best shade shelters are the trees.”

Transit users agree. “The best shade shelters are the trees,” said Jasper Elysian, a student at the University of Illinois Chicago who takes public transit to school, work, and almost everywhere. When it’s available, Elysian uses shade to combat the heat but said they would like to see more trees near transit stops.

Quantifying heat exposure to understand who is exposed and how is important, Sprague said, because it’s a hyperlocal problem requiring localized solutions. This research “gets at the point that each…place [faces] different implications of climate change.”

To better understand each city’s specific challenges, Ortiz and Ermagun said they want to collect more data on how often people in these cities in different socioeconomic situations use public transit and whether this usage is affected by the heat exposure they endure.

Recognizing that cities and counties have limited budgets, Ermagun hopes the team’s analysis will help decisionmakers identify where funds can be most useful in mitigating climate vulnerability. The ideal audience for this work, he said, is transportation designers.

—Pepper St. Clair (@pepperstclair.bsky.social), Science Writer

Citation: St. Clair, P. (2025), City dwellers face unequal heat exposure en route to the metro, Eos, 106, https://doi.org/10.1029/2025EO250461. Published on 15 December 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.

Between 128,000 and 186,000 years ago, when ice covered the Sierra Nevada, a lake 100 miles long and 600 feet deep sat in eastern California in what is now the Mojave Desert.

A swarm of at least six earthquakes reaching up to magnitude 2.9 rattled San Ramon near San Francisco, the U.S. Geological Survey reports.

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

In the last few days on November 2025, Cyclone Senyar brought torrential rainfall to parts of Indonesia, and in particular to Sumatra. At the time or writing, at least 1,022 people are known to have been killed and 206 more are missing.

One area that has been particularly badly impacted is Malalak, which is located in Agam Regency in West Sumatra – at [-0.39384, 100.27425]. This is a Google Earth image of the town, collected in February 2025:-

Google Earth image of Malalak in Indonesia, collected in February 2025.

Note the presence of the volcanoes close to the town, and the deeply incised river channels. This is a location at risk from channelised debris flows.

Unfortunately, this is a cloudy place, so obtaining good imagery is hard. But on 1 December 2025, Planet Labs captured an image using their PlanetScope sensors that give a sense of what has happened. This is the image:-

Satellite image of Malalak in Indonesia, in the aftermath of the catastrophic debris flows. Image copyright Planet Labs, used with permission, collected on 1 December 2025.

The sources of the landslides in the images remain hidden. However, it is evident is five substantial channelised debris flows that have affected the area, many of which have multiple upstream sources. There are some smaller events too. There is a high level of destruction as many of these landslides have flowed through the urban areas.

Reuters has a gallery of images of the aftermath of the landslides at Malalak, and there is some footage of the aftermath of the events too:-

Hopefully, imagery will become available that gives a sense of the source of these failures. In my mind, to be in a town with multiple channelised debris flows from different directions is hellish. This scenario appears to have occurred in several locations in Indonesia at the end of November.

Acknowledgement

Thanks as always to Planet Labs (2025) for their amazing imagery.

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.

A team of researchers led by the Nanjing Institute of Geology and Paleontology of the Chinese Academy of Sciences (NIGPAS), in collaboration with colleagues from Shanghai Jiao Tong University, the University of Bristol, and Nanjing University, has identified the primary non-environmental factors controlling lithium-to-magnesium ratio (Li/Mg) fractionation. Their findings were recently published in Earth and Planetary Science Letters.

Tropical storms such as typhoons, hurricanes, and cyclones are Earth's most powerful weather systems. Born over warm oceans, they travel thousands of kilometers to land, traversing waters now polluted with plastics, from coastal runoff to the vast oceanic garbage patches.

Glacial earthquakes are a special type of earthquake generated in cold, icy regions. First discovered in the Northern Hemisphere more than 20 years ago, these quakes occur when huge chunks of ice fall from glaciers into the sea.

Publication date: Available online 8 December 2025

Source: Advances in Space Research

Author(s): Xia Wu, Weirong Gao, Siliang Yang, Caisheng Wei, Chuan Ma

Publication date: Available online 8 December 2025

Source: Advances in Space Research

Author(s): Alberto Regadío, Juan José Blanco, J. Ignacio García Tejedor, Carlo Luis Guerrero, Du Toit Strauss

Publication date: Available online 8 December 2025

Source: Advances in Space Research

Author(s): Bhanu Kumar, Anjali Rawat, Aaron J. Rosengren, Shane D. Ross

Publication date: Available online 6 December 2025

Source: Advances in Space Research

Author(s): Jiahao Qin, Hongxia Wang, Xudong Gao, Qian Wang, Xi Chen

SummaryThis study introduces a novel inversion approach to resolve the layered anisotropic structure of the Earth’s crust and upper mantle using harmonic patterns observed in Ps receiver functions (RFs). Designed for dense seismic networks, our method effectively captures the complexity and deformation of subsurface structures by leveraging the decomposition of RF patterns into five harmonic functions representing distinct terms in a harmonic regression model. Our approach combines residual weighting at individual and coherency weighting between stations to reduce noise and enhance structural signal, followed by a direct inversion of harmonic patterns alongside a multi-phase stack. This process is optimized using a Markov chain Monte Carlo framework to iteratively explore model space and define posterior distributions, which yields robust model parameter estimates with quantified uncertainties. We validated our approach with both synthetic models and real data from the dense SEISConn seismic transect in Northern Connecticut. The synthetic test highlighted the reliability of coherency weighting in reducing noise. Real data analysis revealed anisotropic and structural features consistent with geological expectations and previous studies, including shallow anisotropy in western Connecticut, a shallowing Moho towards the Hartford basin, and indications for a west-dipping layer beneath the Moho in the lithospheric mantle. Our approach offers a promising tool for revealing the details of anisotropic features beneath dense seismic profiles, facilitating insights into tectonic history and lithospheric deformation.

SummaryLarge-scale geodetic monitoring of volcanic earthquakes is essential for understanding the physical mechanisms governing volcanic activity and magma migration. Recently, a significant earthquake swarm occurred around the Scotia plate. Geodetic data of 14 permanent GNSS stations on the Antarctic Peninsula, King George Island, the South Sandwich Islands, and South America were collected and analyzed, to monitor the crustal deformation of King George Island, the expansion of Bransfield Strait, the drift of Scotia plate, and sea level anomalies. Tidal data from four permanent tide stations were analyzed to monitor sea level anomalies. Results showed that after earthquakes the King George Island’s movement speed increased tenfold and its direction altered by 90 degrees. Land surface fluctuations in southeast King George Island were observed a year before the earthquakes, followed by continuous uplift. A combinatorial model including a point pressure source and expanding dike fit well with new geodetic monitoring data, revealing the impact of volcanic activity on this region. Geodetic monitoring and modeling quantitatively depicted the pre-seismic, co-seismic, and post-seismic phases of geological changes, providing new evidence and insights into the complex geological structures.

SummaryA 220 km long active seismic profile crossing the Saronic and Corinth Gulfs was performed using 35 4C Ocean Bottom Seismographs (OBS) and 4 3C stand-alone land stations. We recorded shots fired along line at every 120 m from a 48-l airgun array of 51 bar-m power. The velocity model was developed by first break tomographic inversion, followed by kinematic and dynamic ray tracing. The final velocity model was used to prestack depth migrate the Common Receiver Gathers. Moho depth below the central Corinth Basin is located at 32 km, thinning to 22 km below the Lechaio Gulf, at the transition to the Saronic Basin. In the Saronic domain Moho is found at 19 to 21 km depth, whereas below we identified a low velocity upper mantle of Vp 7.5 to 7.6 km/s, extending to 34 km depth. This is a low velocity asthenosphere wedge that intruded from the Cyclades region below the Saronic Gulf, driving the volcanic activity. It does not extend in the Corinth Rift domain to the west, where Pn is 8.0 km/s. Two major extensional detachments were mapped along the profile: one to the NW in the central Corinth Gulf, east of Galaxidi, corresponding to the onshore Itea-Amfissa Detachment, having a throw of more than 2000 m; the other to the SE, west of Agios Georgios Island, separates the Cycladic Metamorphic Core Complex from the non-metamorphic internal nappes of the Hellenides. Thrusting to the NW observed in the SE Saronic Basin has doubled the thickness of the high velocity limestones. At 20 km SE of Agios Georgios Island a major dextral strike slip fault was mapped. Normal faults with more than 1 km throw are observed around the Isthmus of Corinth trending E-W and WNW-ESE. Maximum thickness of 2000 m of Middle Miocene-Quaternary sediments (Vp 2.1–2.8 km/s and 3.4 km/s) is observed in the Corinth Gulf and minimum of 200 m of Quaternary sediments above the western Cyclades. Beneath the volcanoes of Aegina, Methana, Paphsanias, and Sousaki the crust has a lateral Vp velocity increase of nearly 3 per cent, whereas depth migrated data show high reflectivity, indicating magma intrusions through the crust. Mesozoic limestones with Vp 5.2 to 5.8 km/s and 1800 to 2000 m thickness occur along the profile, corresponding probably to the Tripolis external carbonate platform, whereas limestones and flysch with Vp 4.3 to 5.5 km/s are overlying, probably corresponding to pelagic sequences like the Pindos nappe. The Saronic domain is characterized by arc-parallel NW-SE structures, hosting the volcanic arc, and is tectonically controlled by magma uplift and thermally triggered deformation. The Corinth domain is affected by E-W transverse-oblique structures of a rapidly developing continental rift, and deformation driven by fracturing of a brittle crust of the Central Hellenic Shear Zone.

Much of the heavy rains that hit the Philippines during the Amihan northeast monsoon season between November and March are triggered by "shear lines": kilometers-long bands of converging warm and cold air that are constantly shifting and difficult to spot even via satellite.

The climate is changing and nowhere is it changing faster than at Earth's poles. Researchers at Penn State have painted a comprehensive picture of the chemical processes taking place in the Arctic and found that there are multiple, separate interactions impacting the atmosphere.