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This is an authorized translation of an Eos article. Esta es una traducción al español autorizada de un artículo de Eos.

Una estalagmita en una cueva de Yucatán ha proporcionado una nueva percepción del rol que la sequía puede haber jugado en los cambios sociopolíticos Mayas hace más de 1,000 años. Un análisis reciente de un proxy de precipitación en las tierras bajas Mayas reveló que varios episodios de sequía severa y prolongada durante el Período Clásico Terminal Maya (aproximadamente 800-1000 CE), un período en el que los grandes centros urbanos experimentaron cambios sociopolíticos importantes.

Los investigadores sugieren que, así como el cambio climático actúa como un multiplicador de amenazas hoy en día, la sequía puede haber amplificado los problemas existentes en los centros políticos Mayas como Chichén Itzá y Uxmal, añadiendo estrés climático a las sociedades que ya estaban bajo presión.

“Estos eventos climáticos habrían afectado a cada sitio individual de una manera muy específica dependiendo de la resiliencia de ese sitio en ese momento”, afirmó el investigador principal Daniel James, quien estudia la reconstrucción paleoambiental en la Universidad London College. “Esperamos que la precisión de este registro permita que [el análisis] se realice en sitios individuales … entonces podremos realmente comenzar a construir una imagen de lo que estoy seguro será una amplia variedad de respuestas sociales al cambio climático a lo largo del tiempo y a lo largo de la región”.

Sequías Extendidas Durante las Temporadas Húmedas

Durante el Período Clásico Terminal Maya, varias ciudades-estado Mayas en las tierras bajas del sur (en la actual México, Belice y Guatemala) experimentaron agitación sociopolítica, abandono de sitios y despoblación. Los centros políticos y culturales cambiaron hacia el norte. Aunque los cambios sociales están claros en el registro arqueológico, aún existe un debate generalizado sobre los posibles impulsores de estos cambios, así como por qué algunas ciudades-estado sobrevivieron, mientras otras no.

Este mapa de las tierras bajas Mayas en Yucatán marca sitios de estudios paleoclimáticos previos con cuadrados blancos, con el sitio de este estudio, Grutas Tzabnah, marcado con una X. Mientras que los círculos blancos denotan sitios de las Tierras Bajas del Norte Maya, y las estrellas denotan sitios de interés para este estudio. La tierra está sombreada con base en su elevación en metros sobre el nivel del mar (msnm). Los contornos azules delinean las precipitaciones totales anuales medias modeladas de 1979 a 2022, en milímetros por año. Crédito: James et al., 2025, https://doi.org/10.1126/sciadv.adw7661, CC BY 4.0

La sequía surge a menudo en estos debates como un potencial desestabilizador: las lluvias insuficientes o impredecibles pueden dar lugar a inestabilidades alimentarias, interrupciones comerciales, enfermedades e incluso conflictos militares. Sin embargo, estudios paleoclimáticos previos fallaron en precisar los momentos y la duración de las sequías en las tierras bajas Mayas durante el Período Clásico Terminal, dijo James.

James y sus colegas caminaron a una cueva llamada Grutas Tzabnah, en el estado de Yucatán, México, ubicada cerca de varios grandes sitios Mayas Clásicos, incluidos Chichén Itzá y Uxmal. Esta cueva ha sido buscada previamente para estudios de paleoclima de la región debido a su accesibilidad y las formaciones de cuevas bien conservadas. Además, Grutas Tzabnah es también una cueva relativamente poco profunda, lo que significa que el agua no tarda mucho en gotear en la cueva desde el nivel del suelo.

Los investigadores eligieron una estalagmita que ha estado creciendo por miles de años y muestra distintas capas de crecimiento anual. Esta estalagmita en particular creció rápido en las capas que datan del Período Clásico Terminal Maya, dijo James, entonces el equipo fue capaz de colectar 10-20 puntos de datos dentro de cada capa anual para determinar la precipitación subanual y estacional.

Los investigadores Daniel James (izquierda), Ola Kwiecien (centro) y David Hodell (derecha) instalan un automuestreador de agua por goteo en las Grutas Tzabnah para analizar los cambios estacionales en la química del goteo. Crédito: Sebastian Breitenbach, 2022

“Tú puedes ver temporadas húmedas y temporadas secas en nuestro registro, mientras que los registros previos de la misma cueva están viendo la precipitación media anual”, dijo James. “La precipitación de la temporada húmeda es la que determina el éxito o el fracaso de la agricultura, a diferencia del promedio anual”.

Ellos midieron la edad de las capas empleando datación radiométrica de uranio-torio y la cantidad de precipitación usando una relación isotópica estable de oxígeno, O dentro de la calcita. Las muestras de estalagmita que registraron un bajo O indican más precipitación, mientras que las O más altas indican menos precipitaciones. El equipo calibró sus cálculos paleoclimáticos con mediciones modernas de agua de lluvia y goteo de cuevas en unos pocos años para asegurarse de que podían convertir las mediciones de O de la estalagmita a precipitaciones.

De 871 a 1021, la estalagmita registró ocho sequías extremas durante las temporadas húmedas, cada una con una duración de al menos 3 años. Una sequía de 4 años que inició en 894 fue interrumpida por un solo año húmedo y fue seguida por otros 5 años de sequía de temporada húmeda. Unas décadas más tarde, la región había experimentado 13 años consecutivos de sequía en la temporada húmeda (929–942), más larga que cualquier sequía multianual de los registros históricos locales. Esta investigación fue publicada en Science Advances en agosto.

“La cronología hace de este uno de los registros de paleoclima más detallados disponibles para comprender las interacciones entre humanos-clima durante el período de colapso Maya.”

“Este nuevo estudio representa un avance significativo en nuestra comprensión de los patrones de sequía del Clásico Terminal, principalmente debido a su excepcional resolución temporal y robusto control de la edad con incertidumbres de solo unos pocos años”, dijo Sophie Warken, quien estudia los espeleotemas y variabilidad climática en la Universidad Heidelberg en Alemania y no participó en esta investigación.

“Este enfoque de alta resolución permite a los autores examinar el momento y la duración de los episodios de sequía individuales con mucha precisión, los cuales estudios previos solo pudieron identificar como amplios períodos de desecación”, agregó Warken. “La cronología hace de este uno de los registros paleoclimáticos más detallados disponibles para comprender las interacciones entre humanos-clima durante el período del colapso Maya.”

Una pieza del Rompecabezas

Mientras que este registro de precipitaciones es un gran avance, Warken dijo que le gustaría verlo verificado usando proxies adicionales como elementos traza, así como un período de calibración moderno más largo. También, a ella le gustaría ver este registro extendido antes y después del Período Clásico Terminal para evaluar si esas sequías fueron realmente excepcionales para la región.

“Estas redes paleoclimáticas ampliadas también podrían proporcionar importantes líneas de base para evaluar los cambios climáticos recientes y futuros en esta región vulnerable”, agregó ella.

A pesar de que las sequías prolongadas coinciden con los principales cambios sociales, James advirtió que esto no significa que la sequía causara estos cambios o que fuera incluso el factor más importante.

“Otras dificultades como la hambruna, la enfermedad y la violencia interna podrían haber sido causadas por la sequía o, de hecho, podrían haber existido previamente y haber hecho que la sociedad fuera más susceptible y menos preparada para las dificultades climáticas”, dijo James.

“Me encantaría que estos datos se utilicen para separar historias individuales de sitios individuales de resiliencia y supervivencia, así como también las historias de desintegración de sistemas y abandono y pérdida de población.”

Es importante destacar que la evidencia arqueológica sugiere que dos ciudades Mayas cercanas a esta cueva, Chichén Itzá y la capital regional de Uxmal, no declinaron al mismo ritmo (Uxmal declinó mucho más rápido). Comprender las presiones que experimentaron las dos ciudades, incluida la sequía, será clave para crear una imagen holística de cómo funcionaron las ciudades durante el Período Clásico Terminal.

“Mientras que el estrés climático probablemente jugó un papel importante en las transformaciones del Clásico Terminal”, dijo Warken, “la respuesta de los Mayas a la sequía fue probablemente mediada por las vulnerabilidades sociales, políticas y económicas existentes que variaron entre diferentes centros y regiones”.

“Esto podría deberse a lo bien gobernados que estuvieron, cuán rígido o flexible era su sistema político o qué tan buena era su gestión del agua en ese momento”, dijo James.

“Me encantaría que estos datos se utilicen para separar historias individuales de sitios individuales de resiliencia y supervivencia, así como también las historias de desintegración de sistemas y abandono y pérdida de población”, añadió.

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Escritora Asociada

This translation by Solange Fiallos Ayala (@sol_fiallos_ec) was made possible by a partnership with Planeteando. Esta traducción fue posible gracias a una asociación con Planeteando.

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 oceans have to play a role in helping humanity remove carbon dioxide from the atmosphere to curb dangerous climate warming. But are we ready to scale up the technologies that will do the job?

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

Satellite company Blacksky has released a high resolution satellite image, captured on 12 November 2025, showing the aftermath of the 11 November 2025 landslide at Hongqi Bridge in China. The image was captured by their Gen-3 instrument, and distributed via Twitter:-

The aftermath of the 11 November 2025 landslide at Hongqi Bridge in Sichuan Province, China. Image captured by Blacksky and released via Twitter.

On Reddit, there is a good short video of the site too, which includes this still:-

The aftermath of the 11 November 2025 landslide at Hongqi Bridge in Sichuan Province, China. Still from a video posted to Reddit.

This is a rock slope landslide with several metres of movement on the back scarp. Essentially the rock spur has failed. On one side (the left on the photograph above) the slope has collapsed down to the level of the lake (and probably below), whilst the main mass has a lower level of displacement (although I suspect that the failure is still through the mass to below the lake). It appears that the tunnels remain largely intact. The main part of the cantilever bridge has performed well, with the largest piers and their bridge decks remaining intact. However, the missing section is going to be very challenging to replace.

It appears that filling of the lake might have been suspended (satellite imagery shows no change in the level since the landslide occurred). One hopes that this is to allow a reappraisal of the stability of the slopes along the reservoir banks. I would be particularly concerned about those slopes that have had excavations close to the current level of the lake. There will also be some concern about the stability of this landslide. Is it possible that further filling of the lake could induce a further collapse, endangering the main bridge pillars?

Acknowledgement

Many thanks to loyal reader Alasdair for finding the image and the video.

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.

SummaryEvaluating sedimentary texture is crucial for managing of aquifers and assessing groundwater quality. Direct methods of aquifer characterization (like pumping tests) are of limited value because of their invasive character and connection to boreholes, which results in scarce data networks. Non-invasive geophysical methods complement the invasive methods. Among geophysical methods, the spectral induced polarization (SIP) method, which allows measuring frequency dependent complex electrical impedance, is especially promising in this context, because it offers insights into the specific surface area (which is the proxy of the clay content), as well as into textural features of porous media (like pore-size or grain-size distributions).However, SIP data concerning sand-clay mixtures remain scarce. This lack of experimental data, in turn, hinders further development of the IP theory of clayey media. To fill this gap, we carried out a set of experiments to study SIP signatures of artificial sand-clay mixtures with varying clay content, clay types, and pore water salinity. The dataset includes nine mixtures with kaolinite or bentonite in various contents. We equilibrated each mixture with six NaCl solutions ranging in salinity from 0.1 to 30 g l−1. Based on these measurements, we first obtained the formation factor and the surface conductivity values of the samples. Then, we interpreted this dataset in terms of the real and imaginary conductivity, the formation factor, the in-phase surface conductivity, and the normalized total chargeability. Finally, based on the Debye decomposition approach, we converted the IP spectra into relaxation time distributions (RTDs) to analyse dominant relaxation times in comparison with micro-computed tomography (μCT) images.We show that the in-phase conductivity of the sand-bentonite mixtures strongly exceeds that of the sand-kaolinite mixtures with the same clay content. We attributed this difference to the higher surface conductivity of the bentonite clays. The quadrature conductivity exhibits a clear dependence on the clay type, its content, and the conductivity of the pore water. Our observations reveal that both quadrature conductivity and normalized chargeability increase with kaolinite content. However, for the bentonite samples, these parameters show maxima rather than a gradual trend. We explained this behaviour when comparing RTDs with μCT images. This comparison allowed us to identify elements of texture (sand grains coated with a thin film made of clay, clay aggregates of different sizes, clay “bridges” connecting two grains or multiple grains, etc.), which are responsible for IP of various intensities and different time constants. The size and morphology of these elements depend on the clay content, mineralogy, the clay phase topology, and pore water salinity.Ultimately, the combined application of the SIP and μCT methods to a variety of sand-clay mixtures enabled us to differentiate the samples with different clay types, contents, and water salinities. We believe that these petrophysical results can serve as the basis for SIP application to detect remotely different clay types and content, and to monitor the water salinity in clayey rocks, soils, and sediments.

SummaryDirect Current Electrical Resistivity Tomography (ERT) is a widely used geophysical method for near-surface investigations, offering high-resolution imaging for geological, engineering, and environmental applications. While traditional ERT surveys typically target depths of 0–200 m, technological advancements have enabled deeper investigations, commonly referred to as Deep ERT. In this study, we explore the practical challenges and methodological improvements associated with Deep ERT, particularly when combined with Induced Polarization (IP) measurements. Rather than other electromagnetic methods, ERT offers a more straightforward framework for analyzing IP effects, which can potentially correlate with the volume fraction of ore minerals. Nevertheless, deep IP investigations are often challenged by weak signal strength and various sources of electromagnetic interference. To address these challenges, we evaluated key strategies including survey planning, high-power current injection, unconventional electrode configurations, and advanced signal processing techniques. The adoption of nodal geophysical recording systems eliminates the logistical constraints of cabled multi-electrode setups, improving flexibility and data acquisition efficiency. Additionally, continuous full time-series recording allows for enhanced noise filtering and signal stacking, ultimately increasing the signal-to-noise ratio and extending the effective exploration depth. We demonstrate this methodology through a comprehensive case study conducted at the Koillismaa Linear Intrusion Complex in Finland, where a 3D Deep ERT-IP survey successfully delineated conductive and chargeable anomalies at depths exceeding 1.5 km. These anomalies closely align with independent gravity and borehole logging data, consistent with the mafic-ultramafic intrusion structures. Our results emphasize the importance of balancing data quality, survey efficiency, and spatial resolution in survey design. This work not only provides a robust workflow for the implementation of Deep ERT-IP surveys but also represents the first documented successful acquisition of high-quality IP data at these substantial depths, significantly advancing the state of deep geoelectrical exploration.

SummaryDistributed Acoustic Sensing (DAS) technology has gained widespread attention in seismic exploration due to its high spatial resolution and low deployment cost. However, the presence of coupling noise in DAS data significantly affects the accurate extraction and interpretation of seismic signals. Coupling noise typically appears as narrowband stripe-like or zigzag-like interference and shares similar characteristics with seismic signals in the time-space (T-S) domain, making it challenging for traditional denoising methods to achieve effective signal-noise separation without residual noise or signal leakage. To address these challenges, this paper proposes a deep learning-based dual-domain fusion approach that integrates both T-S and frequency-wavenumber (F-K) domain information to enhance the accuracy of coupling noise separation. The method leverages the narrowband characteristics of coupling noise in the F-K domain while incorporating spatiotemporal information from the T-S domain to achieve cross-domain feature fusion, thereby improving the separability between signals and coupling noise. Experimental results demonstrate that the proposed method significantly improves coupling noise suppression performance on both synthetic and field DAS vertical seismic profile (VSP) data while minimizing signal leakage. Furthermore, in corridor stacking experiments, the method effectively reduces the impact of coupling noise on seismic interpretation, improving the reliability of subsurface formation analysis. Compared to conventional F-K filtering, single-domain network and denoising diffusion model, the proposed approach achieves superior performance in terms of coupling noise suppression and signal amplitude preservation.

SummaryElectrical properties of porous media consisting of solid and fluid phases have been continuously investigated in the study of geomaterials given their strong link to pore space characteristics (e.g. pore size and connectivity). Over the past decades, numerous theoretical models have been developed to determine the electrical conductivity of the porous media as a function of conductivities of their constituents and their relative proportions. In this paper, we present a new theoretical model to calculate the electrical conductivity of a weakly transversely isotropic (TI) porous medium with two conducting phases. We first use the well-established series and parallel electrical connections, together with a newly introduced coefficient g, to construct a conductive cell that represents the porous medium’s microscopic structure. We then obtain the macroscopic weakly TI conductivity stacking these cells in one dimension. We innovatively introduce a normal probability distribution to simulate the distribution of porosities across cells. Good agreement between our theoretical predictions and literature data validates the model for weakly TI porous media. We also show that series and parallel connections of the solid and liquid phases provide reliable building blocks for more advanced models, and that using a normal distribution to simulate electrical anisotropy in quasi-isotropic or weakly TI porous media is viable. Finally, we use the model to study the effects of key variables on weakly TI conductivity. We find that increasing the coefficient g reduces electrical conductivity and that the Electrical Anisotropy Coefficient (EAC) attains its maximum at 50 per cent porosity in weakly TI porous media with two conducting phases.

Publication date: Available online 9 November 2025

Source: Advances in Space Research

Author(s): Mahdi Momeni, Yenca Migoya-Orué

Publication date: Available online 7 November 2025

Source: Advances in Space Research

Author(s): Junyu Chen, Baolin Wu, Zhaobo Sun

Publication date: Available online 7 November 2025

Source: Advances in Space Research

Author(s): Ali Haji Elyasi, Mohsen Nasseri, Peyman Badiei

Publication date: Available online 7 November 2025

Source: Advances in Space Research

Author(s): K. Kanishkar, J. Rufina Sherin, L. Gowri

Publication date: Available online 7 November 2025

Source: Advances in Space Research

Author(s): Jinwen Zeng, Xiufeng He, Wei Zhan, Haijun Yuan, Jinsheng Tu

Publication date: Available online 7 November 2025

Source: Advances in Space Research

Author(s): Siva Sai Kumar Rajana, Sambit Prasanajit Naik, Sampad Kumar Panda, Chiranjeevi G Vivek, Sridevi Jade

Satellite-based Earth observation provides a unique and powerful tool in tracking climate adaptation, an international study involving University of Galway researchers has shown.

Mangrove ecosystems rank among the most efficient "blue carbon" systems on Earth, capable of absorbing and storing vast quantities of atmospheric carbon dioxide (CO2). However, mangroves also release methane (CH4), a potent greenhouse gas, potentially offsetting a portion of their climate mitigation benefits.

Source: Journal of Geophysical Research: Earth Surface

Arctic coastlines are falling into the sea. Wave action, rising sea levels, and thawing permafrost are all contributing to the massive erosion that has forced whole towns to move farther from the water’s edge.

To understand how these forces combine to bring down cliffs, Omonigbehin et al. created a microcosm of an Arctic coastline in a lab. First, the researchers mimicked soil containing permafrost by mixing water and sand in ratios designed to maximize the density of the sand, then compacting the mixture with a hydraulic press and freezing it. The researchers pummeled these blocks of faux permafrost with water in a cooled wave flume, a long and narrow tank in which waves are generated so researchers can observe their effects. In this study, the scientists varied the wave height and frequency to see how the permafrost would respond.

The method reproduced observed patterns of erosion that hollow out the bases of coastal bluffs. Wave height had the strongest influence on the rate of erosion, with the highest-wave conditions causing twice as much erosion as low-wave conditions. Wave frequency, on the other hand, strongly influenced the height of the notch carved out by the waves.

When the researchers increased the ice content in the soil by adding more water prior to freezing, they found that the higher ice content decreased the initial erosion rate (because the ice took longer to thaw). This finding suggests that coastlines with higher ice content that currently appear stable may not see high erosion rates in the immediate term but could erode abruptly if the current global warming rate is sustained—a finding that’s consistent with the theory that climate change will trigger tipping points. However, the researchers caution that more research is needed to confirm this finding. (Journal of Geophysical Research: Earth Surface, https://doi.org/10.1029/2025JF008528, 2025)

—Saima May Sidik (@saimamay.bsky.social), Science Writer

Citation: Sidik, S. M. (2025), Lab setup mimics Arctic erosion, Eos, 106, https://doi.org/10.1029/2025EO250422. Published on 14 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.

More than 75 million people work in the garment industry, many of them in the world’s hottest countries. As climate change warms the air and oceans, so too does it seep into the stuffy chambers of garment factories, where conditions are highly uncomfortable if not downright unsafe.

In research recently published in The Lancet, scientists tested different interventions for protecting workers from rising temperatures in Bangladesh, a nation where 80% of its export revenue comes from the garment industry. The 4 million Bangladeshi people, mostly women, who sew ready-made garments often work 12-hour shifts 6 days a week in humid and poorly ventilated buildings. Prolonged heat stress can put strain on their cardiovascular systems and increase their risk of heat stroke, especially because many workers have existing kidney and cardiovascular issues.

“I think it’s really important that we get ahead of the curve and start identifying solutions…that are both effective in today’s climate, but also future-proof.”

“Bangladesh has already been identified as one of the most climate-change-vulnerable countries in the world,” said lead author James Smallcombe, a thermal physiologist at the University of Sydney. “I think it’s really important that we get ahead of the curve and start identifying solutions…that are both effective in today’s climate, but also future-proof.”

His team began by outfitting a factory in Bangladesh with temperature and humidity sensors to determine hot spots that might respond to building-level changes. They then re-created the factory conditions inside a climate-controlled chamber, where volunteer participants conducted factory work while having their physical health and productivity assessed.

Here are the most promising solutions from the study.

1. Green and White Roofs

Most factory roofs in Bangladesh are made of hard concrete or sheet metal, both of which trap heat.

Friendlier “green” roofs require planting a layer of vegetation on top, and “white” roofs involve applying a layer of reflective white paint. While white roofs are cheap to retrofit, green roofs require more installation and maintenance costs—resources that, in turn, contribute to enhancing biodiversity and storing carbon.

Factory owners are often reluctant to make such capital investments, especially in an era of tariffs and economic uncertainty. If they do, however, such building-level changes can lower indoor heat by a dramatic 2°C–3°C (3.6°F–5.4°F) and reduce individuals’ core temperature, heart rate, and level of dehydration.

2. Electric Fans

While air conditioners (ACs) are nearly ubiquitous in the United States, they are hardly a global panacea due to their high costs and energy demands. Electric fans may solve both of ACs’ ills, but they improved only physical comfort in the study, not physiological strain.

Using fans as cooling devices can be deceptively tricky, explained environmental physiologist George Havenith of Loughborough University, United Kingdom: At temperatures above 43°C (109°F), fans push heat onto the skin more than they help evaporate sweat.

Havenith, who was not a part of the new study, noted that fans with a water spray function can also cool the body, as can combining normal fans with wet clothing—known as the “wet T-shirt method” of alleviating heat stress. A major benefit of fans is that they can direct airflow to particularly vulnerable areas of a factory, such as stations where ironing and steaming create extra heat.

3. Water Breaks

One of the best ways to cool the body is from the inside out. Researchers found that taking a water break once or twice an hour lowered participants’ core temperatures, heart rate, level of dehydration, and discomfort when paired with an electric fan.

However, noted Vidhya Venugopal, an occupational and environmental health researcher at the Sri Ramachandra Institute of Higher Education and Research in Chennai, India, garment workers are typically paid at a per-piece rate, making them reluctant to take breaks and receive less income. Even if employers distributed water to each station, she said, many factories lack bathroom facilities, meaning workers would have nowhere to relieve themselves. Venugopal was not involved in the new research.

“We have the scientific evidence to prove that these things can work. The main challenge is, How do we get them into a policy framework?”

Notably, the break helps more if it’s in a cooler location, said Dung Phung, a public health scientist at the University of Queensland who was not involved in the study. His own research in Thailand showed that lumber workers’ health improved after taking breaks under trees or in a cool house.

Ultimately, said study coauthor Fahim Tonmoy, a climate change adaptation researcher at Griffith University in Australia, “we have the scientific evidence to prove that these things can work. The main challenge is, How do we get them into a policy framework?”

The team hopes their findings on productivity may move the needle; unmediated heat stress lowered workers’ efficiency so much that even taking breaks improved their output. Tonmoy also said clothing companies can create incentives by buying only from factories that implement such solutions.

As temperatures in Southeast Asia “get hotter by the day,” said Venugopal, making changes will only become more vital. “We are not talking about a few people,” she said. “We are talking about millions and millions.”

—Hannah Richter (@hannah-richter.bsky.social), Science Writer

Citation: Richter, H. (2025), Garment factories are heating up. Here’s how workers can stay cool, Eos, 106, https://doi.org/10.1029/2025EO250425. Published on 14 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.

As tectonic stress is released during an earthquake, rock slips, and Earth’s crust is damaged, like a wound to the skin. And like skin, the scar-like wounds left after an earthquake can heal, and the impacted area can recover its strength over time. A study published in Science indicates that such recovery may be limited to only the upper crustal layers. The deep crust takes much longer to recover—or possibly doesn’t recover at all.

Lasting Change to the Deeper Crust

The findings stemmed from what was meant to be only a test of a new technique.

Jared Bryan, a geophysicist at the Massachusetts Institute of Technology (MIT) and first author of the new study, was refining a method to investigate localized damage to Earth’s crust by measuring the speed at which seismic waves generated by distant earthquakes pass through it.

Bryan wanted to use the technique to study volcanoes, but as a test, he turned to California’s 2019 Ridgecrest earthquake sequence—a magnitude 6.4 foreshock followed by a magnitude 7.1 main shock. “What brought me originally to working on the Ridgecrest fault zone was just that I wanted an obvious signal that I could use to calibrate my technique,” Bryan said. Conveniently, the region had readily available seismic wave data from 34 permanent seismic stations within 74 miles (120 kilometers) of the fault zone.

Between 2015 and 2023, 5,500 earthquakes generated seismic signals that traveled through Earth’s crust and arrived vertically at the seismic stations, allowing the team to track the seismic wave velocities before and after the Ridgecrest earthquake. Earthquake damage creates fractures in the rock, measurably slowing seismic waves passing through it. After the test, Bryan planned to use the technique to study volcanoes. But the results were too intriguing to abandon.

Previous studies of earthquake damage were limited to the shallow crust, typically less than 6 miles (10 kilometers) down, or averaged the results across all depths.

“You could never tell where those changes really were a function of depth, and that’s crucial,” said geophysicist Roland Bürgmann from the University of California, Berkeley, who wasn’t involved in the study.

The technique researchers used in the new study, however, detects changes equally well throughout the entire crustal column, from the surface down to 15 miles (25 kilometers). “What we were most excited about was using this method that allows us to image how things change in the Earth beyond the depth that we typically think about doing that sort of work,” said William Frank, a geophysicist at MIT and coauthor of the study.

Tracking the seismic waves passing through the crust around the Ridgecrest earthquake, the researchers saw that in the upper crust, waves slowed, then returned to normal within months, indicating the crust had, indeed, been damaged but had recovered.

The finding that the lower crust experiences slow, evolving, and enduring damage is “completely new and novel.”

However, seismic waveform data from deeper down, between 6 and 9 miles (10 and 15 kilometers), indicated that the damage accumulated more slowly and did not heal over the 3-year-plus time span analyzed after the quake. Bryan said that data showing changes to waveforms are usually subtle, requiring careful quantification, but that was not the case with data from the deeper crust. “I could see, visually, this permanent change at the time of the earthquake,” he said.

Bürgmann said that the finding that the lower crust experiences slow, evolving, and enduring damage is “completely new and novel.”

Looking Beyond Ridgecrest

The scientists suggest two possible outcomes for damage to the deep crust. Either the damaged area will recover, albeit over decades or centuries rather than months, or the changes will be permanent, and the fault zone’s structure will progressively shift with each earthquake.

Since the Ridgecrest region has not experienced as many earthquakes as more mature fault zones, it’s possible “we’re watching these fault zones mature in real time,” Bryan said.

The team wants to apply the same method to more mature faults like the well-studied San Andreas zone to the west. If data indicate the deeper crust of a mature fault zone heals after an earthquake, the lasting damage at Ridgecrest could be a characteristic of fault evolution.

Research on recovery in the deep crust is “going to place important constraints on how we model that evolution and how that then impacts our future forecasts of where and how earthquakes might happen,” Frank said.

—Andrew Chapman (@andrewchapman.bsky.social), Science Writer

Citation: Chapman, A. (2025), The Ridgecrest earthquake left enduring damage in Earth’s deep crust, Eos, 106, https://doi.org/10.1029/2025EO250421. Published on 14 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.

A large landslide has destroyed a 662 m long highway viaduct in China.

Over the last two days there has been considerable media coverage of a large, highly destructive rockslide that occurred at Hongqi Bridge in Sichuan Province, China. There is a very interesting set of images of the bridge during construction on the Highest Bridges site – the bridge was 662 metres long with pillars 172 m high, constructed to divert the G317 road as a result of the construction of the 312 m high Shuangjiangkou Dam.

The location of Hongqi Bridge is [31.82084, 101.90537]. The road exits a tunnel on a steep slope on the east side of the river, crossing via the bridge, and then enters another tunnel on the west side.

This is a video of the landslide:-

This is clearly a rockslide that has destroyed the pillars on the west side of the channel. It is interesting to see the amount of dust being generated. Note that there is a lot of false information circulating about this collapse, including AI generated videos and footage from other sites.

Reports suggest that cracks were noted in the slope and in the structures on 9 November 2025, with the road being closed the following day. The rockslide occurred on 11 November 2025.

This Google Earth image shows the site before construction of the bridge started:-

Google Earth image from 2010 of the site of Hongqi Bridge in Sichuan Province, China.

First inspection of that site suggests that it is immensely challenging from an engineering geomorphological perspective. There are hints of palaeo-landslides, fractured rock masses and loose deposits in a very steep, active topography.

Impoundment of water started on 1 May 2025, and satellite images suggest that the water level has been rising rapidly. Landslides during first impoundment are common – Three Gorges for example suffered many examples. The video suggests that the initial large scale failure might have occurred just above the road level, where the slopes have been excavated to create the road platform. This then propagated both downslope and upslope.

At this stage, the failure might be attributed to some combination of increased groundwater levels and poor engineering design / construction, especially with respect to the cut slopes.

The engineers now face two problems. First, reinstating this key road is going to be extremely challenging and time consuming. The highway has to cross this gorge, which of course will have been flooded. This will be a long and very expensive operation.

Second, as impounding continues, are there other potentially unstable slopes? An abundance of caution is needed given the height of the dam.

Return to The Landslide Blog homepage Text © 2023. The authors. CC BY-NC-ND 3.0
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AbstractSeismic observations reveal significant anisotropy in the D″ region, providing direct constraints on mantle flow and deformation. However, the global anisotropy pattern and its relationship with subduction history, mineral deformation, and rheology in the lower mantle remain unclear. We analyze published regional shear-wave splitting and null measurements, along with waveform inversions, which reveal rapid lateral variations in anisotropy near the edges of large low shear velocity provinces (LLSVPs). We combine mineral physics results of temperature- and pressure-dependent elastic tensors, slip systems, and phase transition mechanisms to explore potential deformation scenarios. We set up models that begin with dynamic thermochemical convection, tracking the deformation history driven by the subduction, evolving crystal fabrics, and cumulative seismic anisotropy. Models show that post-perovskite (pPv) with a (001)-dominant slip system, combined with viscosity changes and texture inheritance during the bridgmanite-post-perovskite (Br-pPv) phase transition and the reverse transition, best reproduces the distinct anisotropy patterns observed in upwelling regions such as plume roots and LLSVP edges. The nominal model is time-dependent, showing strong seismic anisotropy when slabs impinge on the CMB that diminishes toward the LLSVP, followed by plume development at the LLSVP edge with significant anisotropy. Within LLSVPs, internal convective upwellings and downwellings can explain the intermittent, spatially clustered anisotropy. We further demonstrate the potential for constraining LLSVP composition through the observed weaker anisotropy within these structures compared to the surrounding mantle, with our results favoring a Br-rich composition. Computations indicate that the bulk of the lower mantle remains nearly isotropic despite significant texture accumulation through dislocation glide, and that seismic anisotropy can extend several hundred kilometers above the core–mantle boundary.