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DASPack: Controlled Data Compression for Distributed Acoustic Sensing

Geophysical Journal International - Sat, 10/11/2025 - 00:00
SummaryWe present DASPack, a high-performance, open-source compression tool specifically designed for distributed acoustic sensing (DAS) data. As DAS becomes a key technology for real-time, high-density, and long-range monitoring in fields such as geophysics, infrastructure surveillance, and environmental sensing, the volume of collected data is rapidly increasing. Large-scale DAS deployments already generate hundreds of terabytes and are expected to increase in the coming years, making long-term storage a major challenge. Despite this urgent need, few compression methods have proven to be both practical and scalable in real-world scenarios. DASPack is a fully operational solution that consistently outperforms existing techniques for DAS data. It enables both controlled lossy and lossless compression by allowing users to choose the maximum absolute difference per datum between the original and compressed data. The compression pipeline combines wavelet transforms, linear predictive coding, and entropy coding to optimise efficiency. Our method achieves up to 3 × file size reductions for strain and strain rate data in lossless mode across diverse datasets. In lossy mode, compression improves to 6 × with near-perfect signal fidelity, and up to 10 × is reached with acceptable signal degradation. It delivers fast throughput (100–200 MB s−1 using a single-thread and up to 750 MB s−1 using 8-threads), enabling real-time deployment even under high data rates. We validated its performance on 15 datasets from a variety of acquisition environments, demonstrating its speed, robustness, and broad applicability. DASPack provides a practical foundation for long-term, sustainable DAS data management in large-scale monitoring networks.

To prevent rapid sea-level rise, study urges reducing emissions now

Phys.org: Earth science - Fri, 10/10/2025 - 17:33
The timing of emissions reductions, even more so than the rate of reduction, will be key to avoiding catastrophic thresholds for ice-melt and sea-level rise, according to a new Cornell University study.

Destined to melt: Study warns glaciers' ability to cool surrounding air faces imminent decline

Phys.org: Earth science - Fri, 10/10/2025 - 16:57
Glaciers are fighting back against climate change by cooling the air that touches their surfaces. But for how long? The Pellicciotti group at the Institute of Science and Technology Austria (ISTA) has compiled and re-analyzed an unprecedented dataset of on-glacier observations worldwide. Their findings, published today in Nature Climate Change, demonstrate that glaciers will likely reach the peak of their self-cooling power by the next decade before their near-surface temperatures spike up and melting accelerates.

Autonomous robot glider to circle the globe in historic ocean mission

Phys.org: Earth science - Fri, 10/10/2025 - 14:19
Guided by the rhythms of the sea and the promise of discovery, Teledyne Marine and Rutgers University will set Redwing, an autonomous underwater vehicle, on its journey on Friday, Oct. 10, leading to its launch into the Atlantic Ocean off the coast of Martha's Vineyard in Massachusetts.

Pacific circulation key to lower CO₂ during ice ages, simulations show

Phys.org: Earth science - Fri, 10/10/2025 - 13:26
New research from the University of St Andrews has shed light on a crucial mechanism of lowering atmospheric CO2 during Earth's past ice ages.

Zircon Crystals Could Reveal Earth’s Path Among the Stars

EOS - Fri, 10/10/2025 - 12:53

Tiny crystals in Earth’s crust may have recorded meteorite and comet impacts as our planet traveled through the spiral arms of the Milky Way over more than 4 billion years, according to new research.

The study is one of the first to suggest that galactic-scale processes can affect Earth’s geology, and researchers think similar evidence might be found on other bodies in the solar system, including the Moon and Mars.

“This is something that could connect the Earth, the Moon, and Mars into the wider galactic surroundings.”

“This is so interesting and exciting—we are potentially seeing something that is not just unique to Earth,” explained geologist Chris Kirkland of Australia’s Curtin University, the first author of the new study published in Physical Review Research. “This is something that could connect the Earth, the Moon, and Mars into the wider galactic surroundings.”

Kirkland and his coauthor, University of Lincoln astrophysicist Phil Sutton, studied changes in oxygen isotopes in a database of tens of thousands of dated crystals of zircon—a silicate mineral with the chemical formula ZrSiO4 that is common in Earth’s crust. They compared their findings to maps of the Milky Way galaxy that show its neutral hydrogen, or H1.

H1, with one proton and one electron, is the most abundant element in the universe, and its density is particularly high in the arms of the Milky Way galaxy.

Because they are almost exactly the same size, uranium atoms sometimes replace the zirconium atoms in zircon. Uranium radioactively decays into lead over time, so geologists can study the levels of uranium and lead isotopes in zircon crystals to determine when the crystals formed, sometimes in the first phases of the evolution of Earth’s crust about 4.4 billion years ago.

“Zircon crystals are a geologist’s best friend…we can get a lot of information from a single zircon grain.”

“Zircon crystals are a geologist’s best friend,” Kirkland said. “They have an inbuilt clock, and they carry a chemical signature that tells us how they formed—so we can get a lot of information from a single zircon grain.”

Queen’s University geochemist Christopher Spencer, who was not involved in the study, said that the work was fascinating and provocative. “I think the study is a reminder that Earth does not evolve in isolation and that interdisciplinary thinking, however speculative at first, can open up new ways of framing questions about our planet’s history.”

Oxygen Isotope Ratios

The key to the latest research was in the ratios of isotopes—forms of the same chemical element that have different numbers of neutrons—in the oxygen atoms of zircon’s silicate group.

The relative levels of oxygen isotopes in samples of zircon crystals can tell geologists whether the crystals formed high in the crust, perhaps while interacting with water and sediments, or deeper within Earth’s mantle.

Kirkland said the latest study examined the distribution of the ratios of oxygen isotopes found in a dataset of zircon crystals sampled from around the world. The scientists evaluated the data’s “kurtosis,” or the measure of how flat or peaked a distribution is. A dataset with high kurtosis has a narrow distribution, with most values occurring in the middle and causing a sharp peak in the distribution curve. In contrast, a dataset with low kurtosis has a wide distribution with more high and low values, causing a wider distribution curve with a less pronounced peak.

The researchers determined that periods of high oxygen isotope kurtosis corresponded to times when our solar system was crossing the dense spiral arms of the Milky Way galaxy. Such crossings occurred roughly every 187 million years on average during our solar system’s 748-million-year orbit around the galactic center at a speed of about 240 kilometers per second.

In addition to H1, the spiral arms are filled with many more stars than the interstellar space between them. The gravity of those stars seems to have disturbed the Oort Cloud—the haze of billions of icy rock fragments that surrounds our solar system. That, in turn, caused more meteors and comets to strike Earth as it passed through the galactic arms, leading to the subsequent melting of the crust in many places, Kirkland said. “By looking at the variability of the [zircon] signal over time, we were able to get an indication of how different the magma production on the planet was at that time.”

Professor Chris Kirkland uses an ion microprobe to date zircon mineral grains. Credit: C. L. Kirkland

He warned that correlation does not mean causation but said that in this case there seemed to be no other plausible cause for the periodic kurtosis of the oxygen isotope ratios in zircons. “It is very important that we are able to see the frequency of [meteor and comet] impacts” on Earth, Kirkland said. “Rather than an internal process, we seem to be looking at an external process.”

Some other experts suggest the new study is notable for outlining the concept that galactic processes could have left geological traces, but it is not yet conclusive proof.

Earth scientist Craig Storey of the University of Portsmouth in the United Kingdom, who was not involved in the new study, said crustal melting did not necessarily prove an increase in meteorite or comet impacts. Instead, natural processes here on Earth, such as volcanic or tectonic movements, could have caused melting of the crust at several stages of our planet’s geological history.

He is also concerned that some of the proposed correlations in the study may not be correct. “It is an interesting idea, and there are potentially ways to test it, but I don’t think this is the way to test it,” Storey said.

—Tom Metcalfe (@HHAspasia) Science Writer

Citation: Metcalfe, T. (2025), Zircon crystals could reveal Earth’s path among the stars, Eos, 106, https://doi.org/10.1029/2025EO250379. Published on 10 October 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.

New 3D Model Reveals Geophysical Structures Beneath Britain

EOS - Fri, 10/10/2025 - 12:53
Source: Journal of Geophysical Research: Solid Earth

Magnetotelluric (MT) data, which contain measurements of electric and magnetic field variations at Earth’s surface, provide insights into the electrical resistivity of Earth’s crust and upper mantle. Changes in resistivity, or the ability to conduct an electrical current, can indicate the presence of geologic features such as igneous intrusions or sedimentary basins, meaning MT surveys can complement other kinds of geophysical surveys to help reveal Earth’s subsurface. In addition, such surveys can play an important role in improving understanding of the risks space weather poses to human infrastructure.

Montiel-Álvarez et al. present the first 3D electrical resistivity model of Britain, based on long-period MT data (using measurements gathered every second for 4–6 weeks at a time) from across the island. Their model, called BERM-2024, points to previously recognized as well as likely new tectonic and geological structures. The authors also model the effects of a recent solar storm on Earth’s geoelectric field, validating the usefulness of MT-based approaches for space weather impact forecasting.

The BERM-2024 electrical resistivity model is based on MT data from 69 sites in Britain, including both new and legacy datasets. Creating the final model involved processing the raw time series data and accounting for the “coastal effect” caused by the conductivity of ocean water when inverting the data—or calculating causes based on observations.

Sensitivity tests of the new model indicate it resolves features to depths of 200 kilometers (125 miles), including many known from other geophysical surveys and geological observations. It also reveals new anomalies, including highly conductive areas under Scotland’s Southern Uplands Terrane and a resistive anomaly under the island of Anglesey. More intriguing, a large, previously unknown conductive anomaly appears in their model between 85 and 140 kilometers (52–87 miles) beneath the West Midlands region.

The authors tested the utility of their resistivity model for estimating the electric field at Earth’s surface, which is key in forecasting the effects of geomagnetically induced currents caused by space weather. To do so, they obtained a time series of the horizontal electric field across Britain during a solar storm that occurred on 10–11 October 2024, which led to bright displays of aurora borealis across the Northern Hemisphere. They found good agreement between their modeled time series and those measured at observatories, indicating that electrical resistivity models are a tool that can provide accurate information for space weather impact planning. (Journal of Geophysical Research: Solid Earth, https://doi.org/10.1029/2025JB031813, 2025)

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2025), New 3D model reveals geophysical structures beneath Britain, Eos, 106, https://doi.org/10.1029/2025EO250381. Published on 10 October 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.

Modelling the seismic reflection characteristics in stressed layered media using reflectivity method

Geophysical Journal International - Fri, 10/10/2025 - 00:00
SummaryInitial stress exerts a crucial impact on the elastic properties and thus the wave reflection in the layered media. However, the stress effect on wave reflection characteristics in such media remain insufficiently understood. To address this issue, we develop a composite matrix reflectivity method incorporating initial overburden stress (CMRMS) by means of acoustoelasticity theory, enabling accurate modeling of seismic wave propagation in stressed layered media. The proposed method can better simulate multiple reflections, converted waves and transmission loss of seismic waves in layered media, compared to the classic stress-dependent reflection coefficient equation for a single interface. Moreover, our method can degenerate into the existing methods in the cases of no initial stress and single interface, which verifies its correctness. We further extended the CMRMS to elastic and viscoelastic non-welded interfaces using the linear-slip theory and standard linear solid model, respectively. The extended method is used to investigate the impacts of non-welded interface compliance, overburden stress, fluid viscosity and frequency on seismic reflection characteristics within layered model. It is shown that the stress effect magnitude on interface reflection significantly depends on the interface depth, due to cumulative transmission losses from overlying layers. Moreover, increasing either the compliance or the number of overlying non-welded interface significantly reduces the reflection amplitude at deeper interface. Our results show the potential of the proposed composite matrix reflectivity method to consider the joint effects of initial stress, multiple waves and transmission loss in both forward modelling and inverse applications.

Parched soils can spark hot drought a nation away

Phys.org: Earth science - Thu, 10/09/2025 - 20:20
Dry soils in northern Mexico may trigger episodes of simultaneous drought and heat wave hundreds of miles away in the southwestern United States, such as Arizona, New Mexico, and Texas, according to a new study. These "hot droughts" in the region increasingly persist through consecutive days and nights rather than easing up after sundown, the research also found, leaving no window for afflicted areas to recover.

Hydropower dams face uncertain future as climate change drives sedimentation and glacier disappearance

Phys.org: Earth science - Thu, 10/09/2025 - 18:40
An EPFL engineer has illustrated some of the complex ways in which climate change will affect hydropower facilities, taking the Gries dam in Valais Canton as a case study.

Storms are changing. Should hurricane scale change too?

Phys.org: Earth science - Thu, 10/09/2025 - 17:20
As climate change continues to reshape the intensity and behavior of hurricanes, meteorologists and researchers are examining whether the Saffir-Simpson Hurricane Wind Scale, a decades-old classification system, still adequately communicates the full scope of hurricane hazards. While the scale remains a widely recognized tool, experts like Zachary Handlos, director of Atmospheric and Oceanic Sciences at Georgia Tech, suggest that a complementary system could enhance public understanding of the broader risks hurricanes pose.

Absorptive roots drive forest soil carbon accumulation through iterative effects, study finds

Phys.org: Earth science - Thu, 10/09/2025 - 17:00
Since the 1980s, scientists have known fine roots (< 2 mm) are critical to ecosystem carbon cycling, with research long suggesting their contribution to soil carbon accrual may exceed that of aboveground plant parts like leaves. Yet more than 40 years later, a key knowledge gap remains: the role of multi-decadal root iterative dynamics (growth, turnover, decomposition) in soil carbon accumulation—especially for "absorptive roots," the finest, most metabolically active roots (typically the distal 2–3 root orders or < 0.5 mm in diameter).

A step toward AI modeling of the whole Earth system

Phys.org: Earth science - Thu, 10/09/2025 - 16:56
Modelers have demonstrated that artificial intelligence (AI) models can produce climate simulations with more efficiency than physics-based models. However, many AI models are trained on past climate data, making it difficult for them to predict how climate might respond to future changes, such as further increases in the concentration of greenhouse gases.

Interpretable deep learning network significantly improves tropical cyclone intensity forecast accuracy

Phys.org: Earth science - Thu, 10/09/2025 - 15:06
Predicting tropical cyclones (TCs) accurately is crucial for disaster mitigation and public safety. Although the forecasting accuracy of TC tracks has improved substantially in recent decades, progress in the forecasting of TC intensity remains limited. In recent years, deep learning methods have shown great potential in TC intensity prediction; however, they still face challenges, including limited interpretability, cumbersome feature engineering, and unreliable real-time operational forecasts.

Pinpointing Sewage Seeps in Hawaii

EOS - Thu, 10/09/2025 - 13:09

In Hawaii, most of the population relies on private septic tanks or cesspools to dispose of sewage and other wastewater. There are more than 88,000 cesspools in the state, with about 55,000 on the Big Island alone. These systems, as opposed to more strictly regulated municipal wastewater treatment units, have a higher risk of sewage leaking into the porous substrate.

A recent study published in Frontiers in Marine Science identifies sewage-contaminated submarine groundwater discharge (SGD) sites, pinpointing specific locations that stakeholders may want to prioritize for mitigation efforts.

Modeling and Mapping

Previous studies estimated that groundwater flows deliver 3 to 4 times more discharge to oceans than rivers do, making them significant pathways for transporting pollutants.

In response to pollution concerns from the local community, a team from Arizona State University, with the support of the Hawaiʻi Marine Education and Research Center, used airborne mapping to identify locations where SGD reached the ocean along the western coastline of the Big Island.

Sewage-contaminated water (colored blue in this photograph) enters the ocean from submarine groundwater discharge sites on the Kona coast of the Big Island. Credit: ASU Global Airborne Observatory

To precisely identify these freshwater-seawater interfaces, researchers built on previous studies that used thermal sensors to capture the temperature difference between the two bodies of water. Figuring out which of these discrete interface points were problematic “was very challenging,” said Kelly Hondula, a researcher at the Center for Global Discovery and Conservation Science and first author of the study.

The team identified more than 1,000 discharge points and collected samples from 47 locations. “We chose points where we could localize freshwater emerging from the land or points of high community interest,” explained Hondula.

In addition to aerial surveys, researchers analyzed the discharge points by monitoring their salinity gradients and measuring levels of Enterococcus, a group of bacteria that frequently serve as key fecal indicators in public health testing. They integrated these data into a statistical model that used upstream land cover and known sewage sites to predict the likelihood of sewage and bacterial contamination for each SGD site along the western Hawaiʻi coastline.

The techniques allowed scientists to identify regions of the built environment that are associated with contamination. Besides areas with septic systems and cesspools, they found a high correlation between sewage discharge and development within the first 500 meters of the coast.

“Sewage going into the ground comes out in the ocean, with often a worrying level of waste contamination.”

The geology of a discharge point also contributes to its risk of contamination. Discharge points around the island’s South Kona region, for instance, feature “some of the youngest and most porous volcanic substrate in the archipelago, with little soil development and a high degree of hydrologic connectivity between point sources of pollution and coastal waters,” the authors wrote. Although South Kona has relatively sparse development, increased land use will likely have a disproportionate effect on groundwater quality, they concluded.

“We were surprised to find such clear results: Sewage going into the ground comes out in the ocean, with often a worrying level of waste contamination,” said Hondula.

Mapping Mitigation

As communities continue to invest in coastal development, understanding the effect of sewage discharge and how to avoid it is becoming an increasingly pressing concern worldwide.

As such, the new study “contributes to the growing body of evidence correlating sewage-tainted groundwater discharge with coastal water quality, showing a strong linkage between wastewater and development in the nearshore area. That’s something that land managers and conservation scientists should really take into account,” said Henrietta Dulai, a geochemist at the University of Hawaiʻi at Mānoa who was not involved in the study.

The state of Hawaii has recognized the particular risk posed by largely unregulated cesspools leaking sewage-contaminated groundwater to the ocean. In fact, there is a state mandate to eliminate cesspools by 2050, but the associated cost is slowing the process.

Many scientists say the costs of phasing out cesspools is far outweighed by the health benefits. “We need to consider the financial sides of replacing cesspools versus the benefit of preserving the water quality for the environment and the people,” said Tristan McKenzie, a researcher at the University of Gothenburg, Sweden, who was not involved in the study. “Studies like this highlight why we need to act now.”

—Anna Napolitano (@anna83nap; @anna83nap.bsky.social), Science Writer

Citation: Napolitano, A. (2025), Pinpointing sewage seeps in Hawaii, Eos, 106, https://doi.org/10.1029/2025EO250376. Published on 9 October 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 Step Toward AI Modeling of the Whole Earth System

EOS - Thu, 10/09/2025 - 13:08
Source: Journal of Geophysical Research: Machine Learning and Computation

Modelers have demonstrated that artificial intelligence (AI) models can produce climate simulations with more efficiency than physics-based models. However, many AI models are trained on past climate data, making it difficult for them to predict how climate might respond to future changes, such as further increases in the concentration of greenhouse gases.

Clark et al. have taken another step toward using AI to model complex Earth systems by coupling an AI model of the atmosphere (called the Ai2 Climate Emulator, or ACE) with a physical model of the ocean (called a slab ocean model, or SOM) to produce a model they call ACE2-SOM. They trained ACE2-SOM on output of a 100-kilometer-resolution physics-based model from a range of climates.

In response to increased atmospheric carbon dioxide, consistent with its target model, ACE2-SOM predicted well-known responses, such as surface temperature increasing more strongly over land than over ocean, and wet areas becoming wetter and dry areas becoming drier. When the researchers compared their results with those of a 400-kilometer-resolution version of the physics-based model they were emulating, they found that ACE2-SOM produced more accurate and cost-effective predictions: ACE2-SOM used 25 times less power while providing a resolution that was 4 times finer.

But ACE2-SOM struggled when the researchers asked it to predict what would happen if atmospheric carbon dioxide levels rose rapidly (suddenly quadrupling, e.g.). While the ocean surface temperature took the appropriate time to adjust, the atmosphere almost immediately shifted to the equilibrium climate under the new carbon dioxide concentration, even though physical laws would dictate a slower response.

To become fully competitive with physics-based models, AI climate models will need to become better able to model unusual situations, the authors write. The slab ocean model used in this study is also highly simplified. So to maintain their efficiency advantage while improving realism, AI models will also need to incorporate additional parts of the Earth system, such as ocean circulation and sea ice coverage, the researchers add. (Journal of Geophysical Research: Machine Learning and Computation, https://doi.org/10.1029/2024JH000575, 2025)

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

Citation: Sidik, S. M. (2025), A step toward AI modeling of the whole Earth system, Eos, 106, https://doi.org/10.1029/2025EO250362. Published on 9 October 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.

La salinidad del Océano Austral podría estar desencadenando la pérdida de hielo marino

EOS - Thu, 10/09/2025 - 13:08

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

El Océano Austral existe en un estado de equilibrio precario. El mar está estratificado, con agua fría en la superficie y agua relativamente cálida debajo. Es una situación inherentemente inestable — en igualdad de condiciones, el agua cálida debería subir a la superficie. Pero es más salada y, por lo tanto, más densa, por lo que permanece en el fondo. La capa superior fría, en cambio, se mantiene más dulce con las nevadas y el hielo marino, que se forma cerca de la costa y luego se desplaza hacia el norte entrando al océano abierto antes de derretirse.

Durante los últimos diez años, la capa de hielo marino ha ido disminuyendo a medida que las temperaturas oceánicas se han calentado. El rápido deshielo ha aportado aún más agua dulce a la superficie, lo que debería reforzar la capacidad aislante de la capa de agua fría y permitir que el hielo marino vuelva a expandirse.

Sin embargo, ese ciclo de retroalimentación parece haberse interrumpido. Nuevos datos satelitales han revelado que el océano alrededor de la Antártida, contra todo pronóstico, se está volviendo más salado.

El estudio fue publicado en Proceedings of the National Academy of Sciences of the United States of America (PNAS).

Medir donde es difícil medir

El hielo marino, los mares agitados y la oscuridad permanente hacen que resulte prácticamente imposible monitorear la salinidad del Océano Austral desde un barco durante el invierno. Solo en años recientes ha sido posible medir la salinidad del océano Austral desde el espacio. Los satélites pueden observar la temperatura de brillo de la superficie oceánica, una medida de la radiación emitida en la superficie del océano. Cuanto más dulce es el agua, mayor es la temperatura de brillo.

La técnica funciona bien en aguas más cálidas, pero en aguas frías la temperatura de brillo no varía tanto como cambia la salinidad. Dado que estos cambios ya son, en general, bastante sutiles, los satélites no habían podido detectarlos con precisión en las regiones polares. En estas zonas, el hielo marino también tiende a nublar la señal.

Los avances recientes en tecnología satelital, sin embargo, han mejorado notablemente la sensibilidad de las lecturas de brillo, y los nuevos algoritmos permiten a los investigadores eliminar el ruido generado por el hielo marino.

El oceanógrafo Alessandro Silvano, de la Universidad de Southampton, y sus colegas analizaron los últimos 12 años de registros de salinidad del satélite de la Agencia Espacial Europea para la medición de la humedad del suelo y la salinidad oceánica (SMOS, por sus siglas en inglés). Para Alex Haumann, científico climático de la Universidad Ludwig-Maximilians de Múnich, Alemania, e integrante del equipo, contar con estos datos de amplio alcance — que cubren todo el Océano Austral con una resolución de 25 kilómetros cuadrados — representa un cambio revolucionario. “Debido a la gran cobertura y la serie temporal que puedes obtener, es super valioso. Es realmente una nueva herramienta para monitorear este sistema”, afirmó.

Con el calentamiento, esperamos que fluya más agua dulce hacia el océano. Por lo tanto, es bastante impactante que aparezca esta agua más salada en la superficie”

Sin embargo, cuando el equipo observó que la salinidad había aumentado durante ese periodo, no pudieron evitar cuestionar la tecnología. Para verificar lo que estaban observando, recurrieron a las boyas Argo, boyas automatizadas que toman muestras de agua a una profundidad de hasta 2000 metros. Una red de boyas flota en los mares del mundo, incluido el océano Austral.

Para sorpresa y consternación de Silvano, las boyas corroboraron los datos satelitales. “Muestran la misma señal”, dijo. “Pensamos, de acuerdo, esto es real. No es un error.”

Al comparar los datos sobre la salinidad con las tendencias del hielo marino, el equipo observó un patrón inquietante. “Existe una correlación muy alta entre la salinidad superficial y la capa de hielo marino”, explicó Haumann. “Cuando la salinidad es alta, el hielo marino es escaso. Cuando la salinidad es baja, hay más hielo marino.”

“Con el calentamiento, esperamos que fluya más agua dulce hacia el océano. Por lo tanto, es bastante sorprendente que aparezca esta agua más salada en la superficie”, afirmó Inga Smith, física especializada en hielo marino de la Universidad de Otago en Nueva Zelanda, que no participó en la investigación.

Un régimen cambiante

La explicación más plausible para el aumento de la salinidad, según Silvano, es que las delicadas capas de agua antártica se han alterado y el agua más cálida y salada que se encuentra debajo está ahora saliendo a la superficie, lo que hace que esta sea demasiado cálida para que se forme hielo marino.

Aunque subrayó que es demasiado pronto para determinar la causa de la surgencia, Silvano planteó que podría estar provocado por el fortalecimiento de los vientos del oeste alrededor de la Antártida, como consecuencia del cambio climático. Afirmó que teme que el mecanismo natural de control de daños de la Antártida, en el que el deshielo libera agua dulce, que a su vez atrapa el agua cálida de las profundidades y finalmente permite que se forme más hielo marino, se haya roto de forma irreversible.

El debilitamiento de la estratificación oceánica amenaza, en cambio, con crear una nueva y peligrosa retroalimentación en la que las potentes corrientes de convección traen aún más agua cálida y salada de las profundidades, lo que conduce a una pérdida descontrolada de hielo.

“Creemos que esto podría ser un cambio de régimen, un cambio en el sistema oceánico y glacial, en el que hay menos hielo de forma permanente”, señaló Silvano.

“Tenemos que encontrar formas de monitorear el sistema, porque está cambiando muy rápidamente”

Wolfgang Rack, glaciólogo de la Universidad de Canterbury en Nueva Zelanda, quien no participó en la investigación, dijo que el registro satelital aún no es lo suficientemente largo como para demostrar si el aumento en la salinidad es una anomalía o un nuevo estado normal, no obstante, añadió: “Es bastante improbable que se trate de una simple anomalía, porque la señal es muy significativa.”

Zhaomin Wang, oceanógrafo de la Universidad de Hohai en Nankín, China, que no participó en la investigación, afirmó que el estudio era un “resultado muy sólido,” pero advirtió que aún es demasiado pronto para atribuir de forma concluyente el retroceso del hielo marino a la surgencia. “Es bastante difícil desentrañar la causa y el efecto entre el cambio del hielo marino antártico y el cambio de la salinidad de la superficie”, dijo, “porque es un sistema acoplado, lo que dificulta determinar qué proceso inicia los cambios”.

Para Haumann, los hallazgos muestran lo crucial que es la nueva tecnología para rastrear los cambios en el océano Austral. “Tenemos que encontrar formas de monitorear el sistema, porque está cambiando muy rápidamente”, dijo. “Esta es una de las regiones más distantes de la Tierra, pero una de las más críticas para la sociedad. La mayor parte del exceso de calor que tenemos en el sistema climático va a parar a esta región, y esto nos ha ayudado a mantener el planeta a una tasa de calentamiento relativamente moderada”.

“Ahora no sabemos realmente qué va a pasar con eso», dijo.”

Bill Morris, Escritor científico

This translation by Saúl A. Villafañe-Barajas (@villafanne) was made possible by a partnership with Planeteando and Geolatinas. Esta traducción fue posible gracias a una asociación con Planeteando y Geolatinas.

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.

Nature inspires researchers to help recover trillions of dollars in critical resources

Phys.org: Earth science - Thu, 10/09/2025 - 12:45
An advanced filtration system inspired by nature that can recover untapped critical resources such as copper and lithium from mining waste is being developed by scientists from The Australian National University (ANU) in collaboration with Rio Tinto.

Formation of multiscale structures in a self-gravitating dusty plasma with matter current

Physical Review E (Plasma physics) - Thu, 10/09/2025 - 10:00

Author(s): Chinmoy Bhattacharjee

I investigate the formation of multiscale magnetic-field structures in a rotating, self-gravitating dusty plasma comprising electrons, ions, and charged dust grains. By incorporating the gravitomagnetic field, arising from mass currents in rotating astrophysical objects, into a three-component fluid…


[Phys. Rev. E 112, 045206] Published Thu Oct 09, 2025

Particle-in-cell simulations of burning inertial confinement fusion capsule implosions

Physical Review E (Plasma physics) - Thu, 10/09/2025 - 10:00

Author(s): Johannes J. van de Wetering, Justin R. Angus, W. Farmer, V. Geyko, D. Ghosh, D. Grote, C. Weber, and G. Zimmerman

Anomalies observed in the neutron spectral shift of high-yield shots at the National Ignition Facility (NIF) suggest the presence of suprathermal ions [E. P. Hartouni et al., Nat. Phys. 19, 72 (2023)], implying that kinetic effects play a significant role in burning inertial confinement fusion (ICF…


[Phys. Rev. E 112, 045207] Published Thu Oct 09, 2025

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