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Antarctica is Earth’s most remote continent, barely touched by human activities.

It is, however, not immune to the kind of environmental damage that plagues more populated parts of the world. In a new study, researchers found chemicals originating from everyday personal care products (PCPs), such as cosmetics, detergents, pharmaceuticals, and deodorants, in Antarctic snow.

Contaminants in PCPs—loosely defined as semivolatile organic compounds that are industrially produced at a global scale, used in large volumes, and relatively persistent in the environment—are increasingly being recognized as pollutants. Both the Arctic Monitoring and Assessment Programme and the Scientific Committee on Antarctic Research have encouraged further research on PCP ingredients and the creation of monitoring plans for tracking their presence at the poles.

Looking for these pollutants, researchers collected 23 surface snow samples from 18 sites along the Ross Sea coast during the Antarctic summer of 2021–2022. Though some sampling locations were near areas with human activity, including Italy’s seasonally occupied Mario Zucchelli research station, the majority were situated hundreds of kilometers from human settlements.

The scientists reached these remote locations by piggybacking on helicopter rides transporting other teams maintaining weather stations or deploying scientific instruments. “This way we halved the impact of our sampling, because they needed to go there in any case,” said Marco Vecchiato, an analytical chemist at Ca’ Foscari University in Venice, Italy, who led the study.

Back in Italy, Vecchiato and his colleagues analyzed the snow samples under clean-room conditions to prevent contamination.

“This very different behavior during the season means that [PCPs] are very sensitive to the environmental conditions.”

They found PCP chemicals in every sample, with varying chemical concentrations suggesting different capacities for atmospheric transport. Of the 21 chemicals analyzed, three compound families were particularly notable. Salicylates, commonly used as preservatives in cosmetics (including lotions, shampoos, and conditioners) and pharmaceutical products, were the most prevalent, followed by UV filters associated with sunscreens. Fragrances such as musks were also detected.

Most of these substances were dissolved in the snow. The UV filter octocrylene, however, which has been associated with coral reef damage and banned in places like the U.S. Virgin Islands and Palau, was found bound to solid particles within the snow.

The researchers observed an unexpected seasonal variation in the amount of PCPs within the samples: Samples collected later in the summer had about 10 times higher PCP levels than those collected earlier in the season, though the relative proportions of each pollutant within a sample remained consistent.

Seasonal fluctuation suggests that Antarctic summer air circulation plays a role in transporting pollutants from distant sources to the continent’s interior. During summer, oceanic winds blowing inland dominate over winds originating from the polar plateau, which are stronger during the rest of the year. That shift may push pollutants far inland.

“This very different behavior during the season means that [PCPs] are very sensitive to the environmental conditions,” Vecchiato said.

One of the researchers presented the team’s preliminary findings at the European Geosciences Union General Assembly in May, and the scientists have a more comprehensive analysis currently underway, according to Vecchiato.

A Local or Distant Source

Finding organic pollutants in seemingly pristine polar environments isn’t surprising. In the 1960s, scientists found large concentrations of persistent organic pollutants (POPs), including the widely used pesticide DDT (dichlorodiphenyltrichloroethane), in Antarctica. POPs don’t degrade naturally and travel thousands of kilometers through the atmosphere, with some eventually getting trapped in snow and ice. Permanently frozen places such as glaciers and polar regions become natural traps. Starting in the early 2000s, the United Nations’ Stockholm Convention on Persistent Organic Pollutants established international cooperative efforts to eliminate or restrict the production and use of POPs.

Though they might travel by a mechanism similar to that used by persistent organic pollutants, unlike POPs, PCPs “do break down in the environment,” said Alan Kolok, a professor of ecotoxicology at the University of Idaho. However, “if those fragrances are not coming from the [research] stations themselves,” he asked, “where are they coming from?”

“Thousands of people are currently accessing the Antarctic continent, and my conclusion is that wherever we humans go, we bring contaminants.”

To rule out a local origin for the PCP pollutants, researchers analyzed sewage from the Mario Zucchelli research station. The outpost did contribute some pollution, but the relative abundance of each compound in the sewage differed from that found in the snow, suggesting that the PCPs detected in the broader Antarctic environment likely originated from more distant sources.

“My suspicion is that for these types of compounds—personal care products, pharmaceutical products—there must be a local source,” said Ricardo Barra Ríos, an environmental scientist at the Universidad de Concepción in Chile who has analyzed PCP pollution in Antarctic coastal waters related to research stations. “Thousands of people are currently accessing the Antarctic continent, and my conclusion is that wherever we humans go, we bring contaminants.”

Vecchiato disagreed. In a separate study published earlier this year, he and other colleagues found PCPs, including fragrances and UV filters, in the snows of the Svalbard archipelago in the Arctic. In that study, the researchers linked the presence of these compounds to atmospheric patterns that carried pollution from northern Europe and the northwestern coast of Russia.

“Most of these contaminants should have a limited mobility, but actually, we found them in remote regions,” Vecchiato said. “Does that mean that the models are wrong or that our analysis is wrong?” he asked. “No, probably we are missing a piece [of the puzzle], or maybe the use of these contaminants is so huge that we still have a relevant concentration in remote areas, even if they should not be prone to this kind of transport.”

—Javier Barbuzano (@javibar.bsky.social), Science Writer

Citation: Barbuzano, J. (2025), Is your shampoo washing up in Antarctica?, Eos, 106, https://doi.org/10.1029/2025EO250209. Published on 3 June 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.

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

En 2017, Paulo Tarso Oliveira, profesor de hidrología en la Universidad de São Paulo, se encontró con una noticia sobre una pequeña aldea a orillas del río São Francisco, uno de los principales ríos del noreste de Brasil. El artículo informaba que los habitantes estaban presentando tasas inusualmente altas de hipertensión arterial, y relacionaba esta anomalía con el clima seco de la región y el bajo caudal del río. A medida que el nivel freático descendía, el agua oceánica comenzaba a infiltrarse hacia el agua subterránea de la región, elevando los niveles de sal en el suministro y provocando problemas de salud entre la población.

“Muchas veces, la gente no se da cuenta, pero las aguas superficiales y subterráneas están conectadas y deben considerarse como un todo”.

Intrigado, Oliveira investigó más a fondo. Más adelante descubrió que el flujo del río estaba disminuyendo porque los pozos estaban extrayendo agua del acuífero subyacente. “Muchas veces, la gente no se da cuenta, pero las aguas superficiales y subterráneas están conectadas y deben considerarse como un todo”, señaló Oliveira.

En lugares donde el nivel freático se encuentra bajo el lecho de un río, el río puede filtrar agua hacia el acuífero subyacente. Este proceso, conocido como filtración del caudal fluvial, ocurre de forma natural dependiendo de las formaciones geológicas subyacentes y los niveles de agua subterránea. Sin embargo, la construcción de pozos que extraen agua en exceso de los acuíferos puede intensificar este fenómeno.

Oliveira y sus colegas descubrieron que la situación en la cuenca del São Francisco no es un caso aislado. Al evaluar pozos en todo Brasil, los investigadores encontraron que en más de la mitad de ellos el nivel del agua estaba por debajo del nivel de los arroyos cercanos.

Mapeo de pozos

En 2023, Oliveira y el estudiante de maestría José Gescilam Uchôa comenzaron a mapear los ríos de Brasil para identificar zonas en riesgo de pérdida de agua. Se basaron en datos públicos sobre niveles de ríos y ubicación de pozos, proporcionados por el Servicio Geológico de Brasil. Sin embargo, la mayoría de los pozos registrados carecían de información suficiente. Como resultado, se enfocaron en 18,000 pozos con datos completos, distribuidos a lo largo de miles de ríos en el país.

Los investigadores compararon el nivel del agua en cada pozo con la elevación del arroyo más cercano. En el 55 % de los casos, el nivel del agua en los pozos era inferior a la elevación de los arroyos vecinos.

José Uchôa realiza mediciones en un río de São Paulo. Crédito: Laboratorio de Hidráulica Computacional, Universidad de São Paulo

“Nuestros datos sugieren que el uso de aguas subterráneas está afectando significativamente el caudal de los ríos”, señaló Uchôa. “Este es, y seguirá siendo, un motivo de creciente preocupación para la gestión del agua en el país”.

El estudio, publicado en Nature Communications, también identificó regiones críticas, incluida la cuenca del São Francisco, donde más del 60 % de los ríos podrían estar perdiendo agua debido a la intensa extracción subterránea. Esta extracción se asocia principalmente con actividades de irrigación.

En la cuenca del Verde Grande, en el este de Brasil, donde la irrigación representa el 90 % del consumo de agua, el 74 % de los ríos podrían estar perdiendo agua hacia los acuíferos.

Oliveira considera que los resultados son conservadores y que la situación podría ser aún peor, ya que los investigadores no tomaron en cuenta los pozos ilegales. Un estudio realizado en 2021 por el geólogo Ricardo Hirata, de la Universidad de São Paulo, estimó que alrededor del 88 % de los 2.5 millones de pozos en Brasil son ilegales, al carecer de licencia o registro para operar.

Hirata, quien no participó en la nueva investigación, advirtió que el estudio se basó únicamente en el 5 % de los pozos existentes, ubicados principalmente en regiones donde la explotación de aguas subterráneas es más intensa.

“Quizá esto también esté ocurriendo en otras regiones del país con alta demanda de irrigación, y simplemente no lo sabemos por falta de datos”.

Hirata también subrayó que, aunque los investigadores identificaron ríos que potencialmente están perdiendo agua hacia los acuíferos, esos datos por sí solos no son suficientes para determinar si los ríos realmente se están secando. Para evaluar eso, se deben considerar otros factores, como la cantidad de agua extraída del acuífero en comparación con el caudal del río, el grado de conexión entre el acuífero y el río, y cuánta agua se extrae del acuífero en relación con las variaciones estacionales del caudal.

“El hecho de que el nivel de agua de un pozo esté por debajo del de un río cercano no necesariamente afecta al río o al acuífero”, explicó Hirata.

Las áreas identificadas como críticas por el estudio se ubican principalmente en regiones áridas, donde ya se esperaba que ocurriera filtración del caudal de manera natural, señaló André F. Rodrigues, hidrólogo de la Universidad Federal de Minas Gerais, quien no participó en la investigación.

El estudio es relevante porque resalta un problema creciente, dijo Rodrigues, pero se necesitan análisis más locales para obtener una imagen más detallada del problema y considerar, por ejemplo, los efectos del clima y los cambios estacionales. “Quizá esto también esté ocurriendo en otras regiones del país con alta demanda de irrigación, y simplemente no lo sabemos por falta de datos”, comentó.

Un problema en crecimiento

La expansión descontrolada de pozos y la extracción excesiva de agua subterránea no solo afectan la salud de las personas, el abastecimiento de agua y la agricultura, sino que también pueden desestabilizar el suelo, provocando hundimientos (subsistencia). Fenómenos similares se han observado en regiones de China, Estados Unidos e Irán.

El panorama no es nada alentador para Brasil. Es probable que la cantidad de pozos se multiplique, ya que se espera que las áreas de riego se incrementen en más del 50 % en los próximos 20 años, según la agencia nacional del agua de Brasil.

“Probablemente veremos un círculo vicioso de degradación, en el que la disminución en la cantidad y calidad del agua superficial, combinada con el aumento de los períodos de sequía, obligará a los agricultores a perforar más pozos para mantener la producción de alimentos, intensificando aún más la extracción de aguas subterráneas y agravando el problema”, advirtió Oliveira.

La sobreexplotación de aguas subterráneas es una preocupación a nivel mundial. La mayoría de los acuíferos han mostrado un descenso en lo que va del siglo XXI, y los estudios por modelado sugieren que la filtración de caudales será más común en las próximas décadas. Aun así, este problema ha sido en gran medida ignorado en regiones tropicales como Brasil, que alberga el 12 % de los recursos de agua dulce renovables del planeta.

Esta falta de atención se debe en parte al escaso financiamiento y vigilancia, y en parte a una creencia persistente de que en los países tropicales y húmedos los ríos suelen ganar agua de los acuíferos y no perderla, mencionó Oliveira. “Debemos actuar ahora si queremos evitar que regiones enteras queden devastadas en el futuro”.

Los investigadores hacen un llamado a realizar más estudios y establecer un monitoreo sistemático de los pozos para identificar las zonas más secas y evaluar el impacto de nuevos pozos sobre los ríos. Actualmente, Brasil solo cuenta con 500 pozos de observación monitoreados constantemente por el gobierno, en comparación con los 18,000 que existen en Estados Unidos, a pesar de que ambos países tienen extensiones territoriales similares. “La vigilancia es extremadamente importante y está tremendamente subestimada”, enfatizó Uchôa.

—Sofia Moutinho (@sofiamoutinho.bsky.social), Escritora de ciencia

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.

Editors’ Vox is a blog from AGU’s Publications Department.

Rock glaciers are debris landforms found in many mountain ranges on Earth. They represent the movement of permanently frozen ground over long periods of time and can be used to understand how climate change is affecting permafrost.  

A new article in Reviews of Geophysics explores the use of “Rock Glacier Velocity” to measure how fast these landforms move each year, and its relationship with climatic factors. Here, we asked the authors to give an overview of Rock Glacier Velocity, how scientists measure it, and what questions remain.

What makes rock glaciers unique landforms? 

Rock glaciers primarily form where the ground temperature ranges from approximately -3 to 0°C. Generated by gravity-driven deformation of permafrost, rock glaciers exhibit distinct morphologies indicative of a cohesive flow. The motion mechanism, known as rock glacier creep, involves shearing in one or more layers (i.e., shear horizons) at depth within the permafrost and deformation of the frozen materials above. Changes in rock glacier creep rates depend primarily on changes in ground temperature. Rock glaciers provide a unique opportunity to indirectly document the evolution of permafrost temperatures in mountainous regions.

Remote sensing and field photos of rock glaciers. Credit: Hu et al. [2025], Figure 1

What is “Rock Glacier Velocity” and why is it important to measure? 

“Rock Glacier Velocity (RGV)” refers to the time series of annualized surface velocity reflecting the movement related to rock glacier creep. Since 2022, RGV has been accepted by the Global Climate Observing System (GCOS) as an Essential Climate Variable (ECV) Permafrost Quantity. An ECV is defined as “a physical, chemical, or biological variable (or group of linked variables) that is critical for characterizing the Earth’s climate.” An ECV Quantity is a measurable parameter necessary for characterizing an ECV. Rock Glacier Velocity is instrumental in assessing the state of permafrost under climate change, especially in places where direct monitoring is scarce. From a climate-oriented perspective, relative changes in Rock Glacier Velocity are significant.

What are the main factors that control Rock Glacier Velocity? 

Rock Glacier Velocity is collectively controlled by the geomorphologic features such as slope and landform geometry, as well as the thermo-mechanical properties of the frozen ground, such as ice content, subsurface structure, temperature, and the presence of unfrozen water under permafrost conditions. On a given rock glacier, relative changes in surface velocity over time usually reflect the climatic impacts, with temperature forcing being the dominant factor, especially when temperatures approach 0°C.

How do scientists observe and monitor Rock Glacier Velocity at different spatial scales? 

An illustration showing different survey methods for quantifying Rock Glacier Velocity. Credit: Hu et al. [2025], Figure 5a

Rock Glacier Velocity can be observed and monitored using in-situ and remote sensing methods. Global Navigation Satellite System (GNSS), theodolite, and total station surveys, provide point-based in-situ measurements. Regional-scale surveys typically employ remote sensing techniques, such as laser scanning, photogrammetry, radar interferometry, and radar offset tracking. In-situ RGV time series’ are rare and have mostly been provided from the European Alps, but they can be more than 20 years long. The goal is to leverage the experience gained from the systematic compilation of those in-situ time series to expand the RGV collection to regional-scale surveys using remote sensing techniques.

What kinds of patterns have been observed in Rock Glacier Velocity? 

According to the Rock Glacier Velocity data from across the European Alps, rock glaciers have generally accelerated alongside increasing air temperatures over the past three decades. At the interannual scale, RGV exhibits a regionally synchronous pattern with distinct acceleration phases (i.e., 2000–2004, 2008–2015, and 2018–2020) which are interrupted by deceleration or a steady kinematic state. However, systematic monitoring and documentation of Rock Glacier Velocity is currently lacking in many parts of the world.

How is climate change expected to influence Rock Glacier Velocity? 

Among the climatic factors, multi-annual air temperature changes primarily influence Rock Glacier Velocity by altering the ground thermal state of rock glaciers. Snow cover acts as an insulating layer whose development varies from year to year, causing the ground temperature to deviate from the air temperature on an interannual scale.

In general, warmer ground temperatures favor rock glacier movement. This pattern is expected to occur in many rock glaciers in the future as the climate continues to warm.  When the ground temperature reaches 0°C, some rock glaciers experience drastic acceleration. However, consequent thawing at the tipping point of 0°C causes the rock glacier creep to decline.

What are some of the remaining questions where additional modeling, data, or research efforts are needed? 

First, a standardized strategy for monitoring Rock Glacier Velocity using different methods is under development. We call for more systematic and consistent velocity measurements that can be used to generate Rock Glacier Velocity data products.

Second, the mechanisms linking climatic factors to Rock Glacier Velocity still need to be explored further, such as whether water infiltrates the partially frozen body of a rock glacier and how cold temperatures influence winter deceleration.

Additionally, an in-depth understanding of the relationship between Rock Glacier Velocity, environmental factors, and permafrost conditions requires observations combined with laboratory work and numerical modeling. This is necessary in order to incorporate rock glacier processes into land surface models and predict future changes in a warming climate.

—Yan Hu (huyan@link.cuhk.edu.hk, 0000-0001-8380-276X), University of Fribourg, Switzerland; and Reynald Delaloye (0000-0002-2037-2018), University of Fribourg, Switzerland

Editor’s Note: It is the policy of AGU Publications to invite the authors of articles published in Reviews of Geophysics to write a summary for Eos Editors’ Vox.

Citation: Hu, Y., and R. Delaloye (2025), Rock Glacier Velocity: monitoring permafrost amid climate change, Eos, 106, https://doi.org/10.1029/2025EO255017. Published on 3 June 2025. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

The clean-up and site restoration of a New Zealand research station in Antarctica has provided valuable lessons on the challenges of contaminated sites, according to a study in the journal Polar Record.

Author(s): Shu-Chao Duan, Shao-Tong Zhou, Gang-Hua Wang, Ming-Xian Kan, Qiang Xu, Bo Xiao, Hai-Bin Ou, Long Xie, and Qiang Wang

Inertial confinement of fusion plasmas can be realized using the dynamic Z pinch, an electromagnetically driven cylindrical implosion system that is also used to generate intense x rays. However, the Z pinch is subject to magnetic Rayleigh-Taylor (MRT) instability, which must be suppressed for pract…

[Phys. Rev. E 111, 065203] Published Tue Jun 03, 2025

In September 2023, a bizarre global seismic signal was observed which appeared every 90 seconds over nine days—and was then repeated a month later. Almost a year later, two scientific studies proposed that the cause of these seismic anomalies were two mega tsunamis which were triggered in a remote East Greenland fjord by two major landslides which occurred due to warming of an unnamed glacier.

In the United States, earthen levees are an integral part of flood control systems, protecting around 23 million Americans and crucial infrastructure. Recently, the American Society of Civil Engineers' 2025 Report Card for America's Infrastructure rated the nation's levees a D+, with an estimated $70 billion needed for maintenance to bring them into a state of good repair.

Nine people have been killed in a series of landslides, triggered by heavy rainfall, that have struck an army camp.

At about 7 pm local time on 1st June 2025, a series of landslides struck an army camp at Chaten in the Lachen District of Sikkim in India. It is believed that nine people have been killed, although at the time of writing six of these people were still missing, including an army officer, his wife and daughter.

Chaten is located at [27.7188, 85.5581]. This is a Google Earth image of the site, collected in March 2022:-

Google Earth image of the site of the 1 June 2025 landslide at Chaten in Sikkim, India.

The best imagery of the landslides that I have found is on a Youtube video posted by Excelsior News:-

This still captures the site well:-

The 1 June 2025 landslides at Chaten in Sikkim, India. Still from a video posted to Youtube by Excelsior News.

The image shows two main landslide complexes (plus one in the background). Each consists of a series of shallow slips on steep terrain – the one on the left has at least three initial failures, on the right there are also at least three). These have combined to create open hillslope landslides that have stripped the vegetation and surficial materials. Note the very steep lower slopes to the river.

These shallow landslide complexes are characteristic of extremely intense rainfall events, which saturate the soil and regolith from the boundary with the underlying bedrock. This causes a rapid loss of suction forces and a reduction in effective stress, triggering failure. The high water content of the soil then promotes mobility.

It is interesting to note that the natural vegetation has been removed from these slopes. It would be premature to assert that this was an underlying cause of the landslides, but it may have been a factor.

It appears that there has also been erosion of the riverside cliffs, which has left other parts of the camp in severe danger.

Sadly, given the terrain and the availability of people to participate in a rescue (which is one advantage of an event in an army camp), the prospects for those who are missing are not postive.

Return to The Landslide Blog homepage Text © 2023. The authors. CC BY-NC-ND 3.0
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SummaryInfrasonic signals of interest can occur during periods with persistent, coherent, background noise, which may be natural or anthropogenic. For high signal-to-noise (SNR) ratio transient signals, an “overprinting” of the coherent background may occur, and the signal may still be detected. However, this approach fails for low SNR signals of interest, which may be obscured by coherent noise. An infrasound beamforming method based on generalized least squares (GLS) is investigated for detecting transient signals of interest in the presence of coherent and incoherent background noise. This approach relies on an estimate of the noise covariance, captured in a covariance matrix, to effectively null contributions to the array response from noisy directions of arrival. Synthetic array data is used to investigate the performance of the GLS beamformer compared to the Bartlett beamformer when coherent and incoherent backgrounds are present. Additionally, the effects of array element number and relative strength of the interfering signal on the GLS estimates is investigated. GLS empirical area under the curve estimates suggest that the beamformer can recover coherent power for a signal of interest lower in amplitude than the coherent background, but this effectiveness degrades more quickly with SNR for a four element array compared to a six or eight element infrasound array. Finally, infrasound from the Forensic Surface Experiment, a bolide signal observed at IMS array I37NO, and a volcanic signal recorded at the Alaska Volcano Observatory array ADKI are used to evaluate GLS performance on recorded data. A ten minute window was used to capture the background noise, and the coherent background signal was nulled in all three examples.

In the southern flanks of the Indian Ocean and the central and eastern Pacific, just north of the Antarctic Circumpolar Current, lie the Subantarctic Mode Waters. As part of the global ocean conveyor belt, these large masses of seawater transfer substantial amounts of heat and carbon northward into the interiors of the Indian and Pacific oceans. These waters hold about 20% of all anthropogenic carbon found in the ocean, and their warming accounted for about 36% of all ocean warming over the past two decades—making them critical players in Earth's climate system.

Along with nutrients like nitrogen and phosphorus, iron is essential for the growth of microscopic phytoplankton in the ocean. However, a new study led by oceanographers at the University of Hawaii'i (UH) at Mānoa revealed that iron released from industrial processes, such as coal combustion and steel making, is altering the ecosystem in the North Pacific Transition Zone, a region just north of Hawai'i that is important for fisheries in the Pacific.

When it comes to carbon emissions, there's no bigger foe than the building and construction sectors, which contribute at least a third of global greenhouse gases.

A small international team of volcanologists has built a more detailed picture of the Campi Flegrei caldera's internal structure using high-resolution seismic imaging and results from rock physics experiments conducted on core samples collected from deep wells.

A newly published study finds that California's Salton Sea emits hydrogen sulfide, a toxic and foul-smelling gas, at rates that regularly exceed the state's air quality standards. The presence of these emissions in communities surrounding the Salton Sea is "vastly underestimated" by government air-quality monitoring systems, the researchers found.

A study co-led by Irina Gorodetskaya, a researcher at the Interdisciplinary Center of Marine and Environmental Research (CIIMAR), brings together all up-to-date data on the phenomenon of atmospheric rivers in Antarctica and reveals the uncertainties arising from the effects of climate change.

New research led by the University of Sydney adds to our understanding of how rapidly rising sea levels due to climate change foreshadow the end of the Great Barrier Reef as we know it.

body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news regarding law and policy changes that impact science and scientists today.

In a move that worried politicians and space scientists alike, President Trump announced on 31 May that he will withdraw his nomination of Jared Isaacman for the position of NASA administrator, according to Semafor. Isaacman’s nomination received bipartisan support and he was expected to easily pass a Senate confirmation vote in a few days.

 
Related

•  White House to pull NASA nominee Isaacman
•  Trump withdraws Jared Isaacman’s nomination as NASA administrator
• The Planetary Society reissues urgent call to reject disastrous budget proposal for NASA
• Get Involved: AGU Science Policy Action Center

This is seismic.Isaacman had clearly articulated a strong support for science, and the withdrawal of his nomination yet further imperils NASA's Science Mission Directorate.www.semafor.com/article/05/3…

— Paul Byrne (@theplanetaryguy.bsky.social) 2025-05-31T20:49:52.860Z

Trump cited a “thorough review of prior associations” as the reason for withdrawing the nomination. It was not immediately clear whether he was referring to Isaacman’s past donations to Democrats or his ongoing associations with former DOGE head and SpaceX CEO Elon Musk, who spent the weekend distancing himself from the president. Both of these associations were public at the time of Isaacman’s nomination.

Isaacman, a billionaire, private astronaut, and CEO of credit processing company Shift4 Payments, was questioned by the Senate Committee on Commerce, Science, and Transportation in a nomination hearing in April. Despite a few contentious moments regarding Isaacman’s association with Musk and some waffling over NASA’s Moon-to-Mars plan, the committee ultimately approved Isaacman’s nomination with strong bipartisan support.

When Trump announced Isaacman’s nomination in December 2024, very early for a NASA administrator, space scientists greeted the news with cautious optimism. Isaacman had vocally expressed support for the imperiled Chandra X-ray Observatory, and is a known space enthusiast.

Now, with the withdrawal of his nomination just days after a president’s budget request that would devastate Earth and space science, scientists fear for the future of NASA.

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
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North America's deepest gorge, Hells Canyon, which slithers along the border of Idaho and Oregon, is a surprisingly new addition to the Earth's ancient landscape. A recent study suggests that a monumental shift in Snake river drainage around 2.1 million years ago reshaped the topography, carving out Hells Canyon, which plunges an astonishing 2,400 m, significantly deeper than the Grand Canyon.

Source: AGU Advances

In the southern flanks of the Indian Ocean and the central and eastern Pacific, just north of the Antarctic Circumpolar Current, lie the Subantarctic Mode Waters. As part of the global ocean conveyor belt, these large masses of seawater transfer substantial amounts of heat and carbon northward into the interiors of the Indian and Pacific Oceans. These waters hold about 20% of all anthropogenic carbon found in the ocean, and their warming accounted for about 36% of all ocean warming over the past 2 decades—making them critical players in Earth’s climate system.

Prior research has suggested Subantarctic Mode Waters form when seawater flowing from warm, shallow subtropical regions mixes with water flowing from cold, deep Antarctic regions. But the relative contributions of each source have long been debated.

Fernández Castro et al. used the Biogeochemical Southern Ocean State Estimate model to investigate how these water masses form. The model incorporates real-world physical and biogeochemical observations—including data from free-roaming floats—to simulate the flow and properties of seawater. The researchers used it to virtually track 100,000 simulated particles of water backward in time over multiple decades to determine where they came from before winding up in Subantarctic Mode Waters.

The particle-tracking experiment confirmed that subtropical and Antarctic waters indeed meet and mix in all areas where Subantarctic Mode Waters form but offered more insight into the journeys and roles of the two water sources.

In the Indian Ocean, the simulations suggest, Subantarctic Mode Waters come mainly from warm, shallow, subtropical waters to the north. In contrast, in the Pacific Ocean, Subantarctic Mode Waters originate primarily from a water mass to the south known as Circumpolar Deep Water.

Along their southward flow to the subantarctic, subtropical waters release heat into the atmosphere and become denser, while ocean mixing reduces their salinity. Meanwhile, the cooler Circumpolar Deep Water absorbs heat and becomes fresher and lighter as it upwells and flows northward from the Antarctic region to the subantarctic.

These findings suggest that Subantarctic Mode Waters affect Earth’s climate differently depending on whether they form in the Indian or Pacific Ocean—with potential implications for northward transport of carbon and nutrients. Further observations could help confirm and deepen understanding of these intricacies. (AGU Advances, https://doi.org/10.1029/2024AV001449, 2025)

—Sarah Stanley, Science Writer

Citation: Stanley, S. (2025), On the origins of Subantarctic Mode Waters, Eos, 106, https://doi.org/10.1029/2025EO250207. Published on 2 June 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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Author(s): Ajaz Mir, Pintu Bandyopadhyay, Madhurima Choudhury, Krishan Kumar, and Abhijit Sen

We compare model solutions of a forced Kadomtsev-Petviashvili (fKP) equation with experimental observations of dust acoustic precursor solitons excited by a supersonically moving charged cylindrical object in a dusty plasma medium. The fKP equation is derived from a three-fluid-Poisson model of the …

[Phys. Rev. E 111, 065201] Published Mon Jun 02, 2025