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Publication date: 1 January 2026

Source: Advances in Space Research, Volume 77, Issue 1

Author(s): Huseyin Er, Aykut Ozdonmez, M. Emir Kenger, B. Batuhan Gürbulak, Ilham Nasiroglu

The Atlantic Meridional Overturning Circulation (AMOC) is the system of currents responsible for shuttling warm water northward and colder, denser water to the south. This "conveyor belt" process helps redistribute heat, nutrients, and carbon around the planet.

The mid-ocean ridge runs through the oceans like a suture. Where Earth's plates move apart, new oceanic crust is continuously formed. This is often accompanied by magmatism and hydrothermal activity. Seawater seeps into the subsurface, is heated to temperatures above 400°C, and rises again to the ocean floor.

The Huíla plateau, bounded by dramatic cliffs and chasms, stands above the arid coastal plains in the country's southwest.

Source: Global Biogeochemical Cycles

The Atlantic Meridional Overturning Circulation (AMOC) is the system of currents responsible for shuttling warm water northward and colder, denser water to the south. This “conveyor belt” process helps redistribute heat, nutrients, and carbon around the planet.

During the last ice age, occurring from about 120,000 to 11,500 years ago, millennial-scale disruptions to AMOC correlated with shifts in temperature, atmospheric carbon dioxide (CO2), and carbon cycling in the ocean—as well as changes in the signatures of carbon isotopes in both the atmosphere and the ocean. At the end of the last ice age, a mass melting of glaciers caused an influx of cold meltwater to flood the northern Atlantic, which may have caused AMOC to weaken or collapse entirely.

Today, as the climate warms, AMOC may be weakening again. However, the links between AMOC, carbon levels, and isotopic variations are still not yet well understood. New modeling efforts in a pair of studies by Schmittner and Schmittner and Boling simulate an AMOC collapse to learn how ocean carbon storage, isotopic signatures, and carbon cycling could change during this process.

Both studies used the Oregon State University version of the University of Victoria climate model (OSU-UVic) to simulate carbon sources and transformations in the ocean and atmosphere under glacial and preindustrial states. Then, the researchers applied a new method to the simulation that breaks down the results more precisely. It separates dissolved inorganic carbon isotopes into preformed versus regenerated components. In addition, it distinguishes isotopic changes that come from physical sources, such as ocean circulation and temperature, from those stemming from biological sources, such as plankton photosynthesis.

Results from both model simulations suggest that an AMOC collapse would redistribute carbon throughout the oceans, as well as in the atmosphere and on land.

In the first study, for the first several hundred years of the model simulation, atmospheric carbon isotopes increased. Around year 500, they dropped sharply, with ocean processes driving the initial rise and land carbon controlling the decline. The decline is especially prominent in the North Atlantic in both glacial and preindustrial scenarios and is driven by remineralized organic matter and preformed carbon isotopes. In the Pacific, Indian, and Southern Oceans, there was a small increase in carbon isotopes.

In the second study, model output showed dissolved inorganic carbon increasing then decreasing, causing the inverse changes in atmospheric CO2. In the first thousand years of the model simulation, this increase in dissolved inorganic carbon can be partially explained by the accumulation of respired carbon in the Atlantic. The subsequent drop until year 4,000 is primarily driven by a decrease in preformed carbon in other ocean basins. (Global Biogeochemical Cycles, https://doi.org/10.1029/2025GB008527 and https://doi.org/10.1029/2025GB008526, 2025).

—Rebecca Owen (@beccapox.bsky.social), Science Writer

Citation: Owen, R. (2026), What could happen to the ocean’s carbon if AMOC collapses, Eos, 107, https://doi.org/10.1029/2026EO260016. Published on 6 January 2026. Text © 2026. 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.

When it rains, it pours. And that's good news for California's water supply.

SummaryThe amplitude of the ${{P}_s}$ phase relative to the direct P wave (i.e., the ${{P}_s}/P$ ratio) provides valuable information about the contrasts across the crust-mantle boundary. Understanding how these amplitudes respond to variations in subsurface parameters improve interpretation of lithospheric structures. We examined the sensitivity of eight key parameters, including compressional and shear wave velocities, lower crustal and upper mantle densities, ray parameter, and Moho depth, to receiver function (RF) amplitudes and ${{P}_s}/P$ ratios. Using the synthetic RF (synRF) code of Ammon et al. (1990), we applied a Monte Carlo approach to generate randomized parameter sets, incorporated random noise, and tested both sharp and gradational Moho structures. The results show that lower crustal shear velocity has the strongest influence on all RF amplitudes and ${{P}_s}/P$ ratios, while lower crustal ${{V}_p}$, density, and upper mantle ${{V}_s}$ have moderate effects, and upper mantel ${{V}_p}$ and density show weaker sensitivity. In both sharp and gradational models, lower crustal and upper mantle shear velocities largely control the ${{P}_s}/P$ ratio. Theoretical ${{P}_s}/P$ ratios exhibit higher correlation with observed RFs than synthetic ones. Compared with the Shen & Ritzwoller (2016) model, our analysis yields ∼10% lower uncertainties in lower crustal ${{V}_s}$ and smaller uncertainties in lower crustal density derived from ${{P}_s}/P$ ratios, with consistent results in complex regions such as the northern Rocky Mountains. This study establishes the first quantitative framework linking ${{P}_s}/P$ ratio variability to lower crustal velocity and density while explicitly quantifying parameter sensitivity and uncertainties, clarifying how Moho sharpness and noise affect amplitude stability.

SummaryMacnae (2025) presented a physical interpretation of the Cole Cole Complex Conductivity model in the case of porous materials with sulphides. According to his paper, the Cole Cole parameters determined from such model can be easily interpreted in terms of underlying physics. His model is partly based on the electrochemical polarization model of Wong (1979) to explain the relationship between the chargeability and the volumetric content of sulfide. None of the statements made by Macnae (2025) are however novel. That said, we agree with Macnae (2025) that the Cole Cole complex resistivity relaxation time is quite useless in deciphering the underlying physics of the induced polarization problem.

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.

Today, top appropriators in the U.S. Senate and House of Representatives released a three-bill appropriations package for fiscal year 2026 (FY26) that largely rejects drastic cuts to federal science budgets that President Trump proposed last year. The “minibus” package, negotiated and agreed upon by both political parties, outlines a budget that preserves most, but not all, funding for key science programs related to space, weather, climate, energy, and the environment across multiple agencies.

“This is a fiscally responsible package that restrains spending while providing essential federal investments that will improve water infrastructure in our country, enhance our nation’s energy and national security, and spur scientific research necessary to maintain U.S. competitiveness,” Susan Collins (R–ME), chair of the Senate Appropriations Committee, said in a statement.

In May 2025, President Trump released a budget request to Congress that proposed slashing billions of dollars in federal science funding. However, during the many rounds of meetings throughout the year, appropriators in both chambers and on both sides of the aisle seemed disinclined to follow the proposed budget, including when it came to funding for climate research, clean energy initiatives, environmental protections, and other topics that run counter to administration priorities.

 
Related

•  Dig into the details: Three Bill Package
•  Statement and Summaries from the Majority (GOP)
• Statement and Summaries from the Minority (Democrats)
•  Review the President’s Budget Request
•  Get Involved: AGU Science Policy Action Center
 

This new three-bill package follows suit in rejecting many of the president’s more drastic cuts to science programs.

“This package rejects President Trump’s push to let our competitors do laps around us by slashing federal funding for scientific research by upwards of 50% and killing thousands of good jobs in the process,” Vice Chair Senator Patty Murray (D–WA) said in a statement. “It protects essential funding for our public lands, rejects steep proposed cuts to public safety grants that keep our communities safe, and boosts funding for key flood mitigation projects.”

Here’s how some Earth and space science agencies fare in this package:

• Department of Energy (DOE) Non-Defense: $16.78 billion, including $8.4 billion for its Office of Science, $3.1 billion for energy efficiency and renewable energy programs, and $190 million for protecting the nation’s energy grids.
• Environmental Protection Agency (EPA): $8.82 billion, preserving funding to state-level programs that protect access to clean water, drinking water, and air. The bill also retains funding for the Energy Star energy efficiency labelling program and increases funding to state and Tribal assistance grant programs.
• NASA: $24.44 billion, including $7.25 for its science mission directorate, which would have seen a 47% decrease under the President’s budget request. The bills maintain funding for 55 missions that would have been cut, as well as for STEM engagement efforts and Earth science research that similarly would’ve been cut. It also increases spending for human exploration.
• National Institute of Standards and Technology (NIST): $1.847 billion, including funds to advance research into carbon dioxide removal.
• National Oceanic and Atmospheric Administration (NOAA): $6.171 billion, including $1.46 billion to the National Weather Service to improve forecasting abilities and boost staffing. The budget also earmarks funds to preserve weather and climate satellites, and maintain climate and coastal research.
• National Park Service (NPS): $3.27 billion, with enough money to sustain FY24 staffing levels at national parks.
• National Science Foundation (NSF): $8.75 billion, including $7.18 billion for research-related activities. That would support nearly 10,000 new awards and more than 250,000 scientists, technicians, teachers, and students.
• U.S. Forest Service (USFS): $6.13 billion, with just under half of that put toward wildfire prevention and management. Funded programs not related to wildfire prevention include forest restoration, forest health management, hazardous fuels reduction, and repurposing unnecessary roads as trails.
• U.S. Geological Survey (USGS): $1.42 billion, including money to maintain active satellites and topographical mapping programs.

This is the latest, but not the last, step in finalizing science funding for FY26. The bills now head out of committee to be voted upon by the full chambers of the Senate and House, reconciled between chambers, and then signed by the president.

—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 © 2026. 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.

When we think of global warming, what first comes to mind is the air: crushing heat waves that are felt rather than seen, except through the haziness of humid air. But when it comes to melting ice sheets, rising ocean temperatures may play more of a role—with the worst effects experienced on the other side of the globe.

The first study from GreenDrill—a project co-led by the University at Buffalo to collect rocks and sediment buried beneath the Greenland Ice Sheet—has found that the Prudhoe Dome ice cap was completely gone approximately 7,000 years ago, much more recently than previously known.

As temperatures rise around the world, city heat becomes increasingly unbearable during the hottest seasons. The urban heat island effect causes cities to become significantly warmer than surrounding rural areas due to human activities and building materials that trap heat.

Single-celled algae in the ocean known as coccolithophores play an important role in the marine carbon cycle when they take up bicarbonate from seawater to build their shells. Coccolithophore numbers have been increasing globally in recent years, meaning their influence is growing, even as scientists still don't fully understand the factors driving their explosive growth. One explanation could be changes to the alkalinity of ocean water, specifically, greater amounts of bicarbonate available for the tiny creatures to use.

A long stretch of humid heat followed by intense thunderstorms is a weather pattern historically seen mostly in and around the tropics. But climate change is making humid heat waves and extreme storms more common in traditionally temperate midlatitude regions such as the midwestern U.S., which has seen episodes of unusually high heat and humidity in recent summers.

Three hundred years ago, the central United States was a land of wetlands—more than 150 million hectares of them. All that water made the region highly attractive to farmers, who, over time, converted most of it into agricultural land.

For the wetlands that remain, protections secured by the Clean Water Act are often the only thing preventing wetland conversion or development, especially when state protections are weak, said Kylie Wadkowski, a landscape ecohydrologist and doctoral candidate at Stanford University. 

With wetlands, “you actually can’t do whatever you want,” said Elliott White Jr., a coastal socioecosystem scientist at Stanford University. “That’s how this Sackett case came about.”

The Supreme Court’s 2023 Sackett v. EPA decision ruled in favor of two landowners backfilling a lot containing wetlands. The decision changed the definition of the term “waters of the United States”—which is used in the Clean Water Act—to exclude wetlands without continuous surface connections to larger, navigable bodies of water. In November 2025, the Trump administration’s EPA proposed to set new rules for water regulations that may be even looser than the updated Sackett definition.

According to research by Wadkowski and White presented on 15 December 2025 at AGU’s Annual Meeting in New Orleans, the changing definition will leave millions of hectares of wetlands unprotected and more vulnerable to development. 

Wadkowski and White are the first to analyze wetland protections in detail on a nationwide scale, said Adam Ward, a hydrologist at Oregon State University who was not involved in the research. “This represents a huge advance in understanding what is being protected and what is losing protections,” he said.

What Will Happen to Wetlands?

Wadkowski and White found that under Sackett, 16.4 million hectares of wetlands, an area about the size of Wisconsin, are either unprotected or have undetermined status. Under the EPA’s newest proposed rule, that number could increase; the proposed rule contains many subjective and ill-defined terms that could be interpreted by regulators to mean even more wetlands lose protections, Ward said.

The approach the researchers took—using the available wetland, stream, and land conversion data with spatial modeling—was “incredibly logical,” Ward said. “They’re using machine learning tools, using the information we have to try and gap-fill and create the most comprehensive analysis that they can, and that’s a huge step in the right direction.”

Rates of vulnerability were not consistent across the United States. A breakdown of protections based on land management categories showed that 43.5% of wetlands on lands managed by tribes was protected under Sackett, compared to the national average of 66%.

Wetlands in the Great Plains states North Dakota, South Dakota, Nebraska, Montana, and Minnesota were the least protected. This area of the country is often called the “prairie pothole” region because many of its wetlands are depressions in the landscape fed by groundwater and disconnected from larger surface water bodies. Under Sackett, these geographically isolated wetlands rely entirely on state-level protections, which are also often weaker in agricultural regions, Wadkowski said.

“The economic pressure and agricultural [conversion] happens a lot more in the Plains states,” she said. “And those are also the states that have less state level protections.”

With a rule that “emphasizes overland [surface] flow and connection to streams and rivers, it shouldn’t surprise us at all that it excludes wetlands that aren’t wet because of overland [surface] flow,” Ward said.

Wadkowski plans to continue to evaluate how various legal frameworks might affect wetland conversion rates in the future by comparing their estimates of protected wetlands under Sackett and the new EPA proposal with past data on wetland conversion rates under previous definitions of “waters of the United States.”

Informing Policy

To best protect wetlands, policymakers should ensure their policies line up with the available science, White said. 

Part of that strategy includes acknowledging that wetlands that are not connected to larger bodies of water year-round via surface water and therefore may not be protected under the Sackett decision may still be connected to broader water systems through groundwater, Wadkowski said. “Think about water bodies as not just on the surface.”

“Policymakers need to more thoughtfully engage with the scientific community for a more clear understanding of what a wetland is and what wetlands actually need.”

The Sackett decision and the new EPA proposal do not reflect the scientific consensus, White said. “Policymakers need to more thoughtfully engage with the scientific community for a more clear understanding of what a wetland is and what wetlands actually need.” Scientists, too, need to better engage with policymakers, he added.

For example, said Ward, part of the reason that wetland rule frameworks are so contentious is that none have yet been informed by enough clear, comprehensive science to make enforcement efficient or practical. “We have heaps of scientific understanding, but the scientific community writ large has not been invited to formally weigh-in on how to design a rule that reflects our understanding,” he wrote in an email.

In a presentation on 15 December at AGU’s Annual Meeting, Ward made the case for a new, large-scale U.S. headwater stream monitoring network, which would help reduce some of the uncertainty inherent in wetland regulations. “If you don’t understand the stream network, you can’t possibly understand the wetland protections,” he said.

Scientific engagement, however, has been made more difficult by the courts, according to Ward: Within the past 5 years, the Supreme Court has begun to invoke the major questions doctrine, which preserves major rulemaking on matters of environmental regulations for Congress, giving agencies like the EPA less incentive to seek input from scientists. 

“In parallel with our advances in understanding [wetland science] is a court system that is essentially cutting scientists out of the loop,” Ward said.

The public comment period for the EPA’s newest proposed rule closes on 5 January.

—Grace van Deelen (@gvd.bsky.social), Staff Writer

Citation: van Deelen, G. (2026), After Sackett, a Wisconsin-sized wetland area is vulnerable, Eos, 107, https://doi.org/10.1029/2026EO260018. Published on 5 January 2026. Text © 2026. 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.

Recurring high-energy flood events are not the exception but the rule in the Ahr Valley in western Germany—and this occurs over periods of centuries to millennia. This is shown in a study recently published in the journal Earth Surface Processes and Landforms and led by Leipzig University. Researchers from the Helmholtz Center for Environmental Research (UFZ) and the Leibniz Institute for the History and Culture of Eastern Europe (GWZO), both in Leipzig, also participated in the study.

A new study reveals that microplastics are impairing the oceans' ability to absorb carbon dioxide, a process scientists find crucial for regulating Earth's temperature.

Source: AGU Advances

Single-celled algae in the ocean known as coccolithophores play an important role in the marine carbon cycle when they take up bicarbonate from seawater to build their shells. Coccolithophore numbers have been increasing globally in recent years, meaning their influence is growing, even as scientists still don’t fully understand the factors driving their explosive growth. One explanation could be changes to the alkalinity of ocean water, specifically, greater amounts of bicarbonate available for the tiny creatures to use.

For more information on how coccolithophores grow and flourish, Zhang et al. looked to the last time the phytoplankton surged in number, between 300,000 and 500,000 years ago. Using fossilized coccolithophore morphology and examining carbon isotope ratios, the authors constructed models that allowed them to pick apart the ingredients for coccolithophore success.

Comparisons of inorganic to organic carbon ratios in the shells, as well as comparisons of photosynthesis and calcification rates revealed by carbon isotope ratios, showed a large increase in calcification linked to greater bicarbonate uptake. Though increasing alkalinity was likely a factor in the coccolithophores’ increased growth, it doesn’t explain all of it, the authors say. Instead, greater nutrient availability allowed coccolithophore populations to swell, both by giving them more food to use and by allowing them to move to shallower depths where there was more sunlight for photosynthesis.

The findings have implications for the present day, as we see marine phytoplankton numbers shifting alongside changes in ocean chemistry. Previous works focused on the change in seawater alkalinity and pH. But more information on how nutrient availability influences coccolithophore growth is needed, the authors conclude, especially in light of proposed geoengineering schemes that could shift the types of nutrients available. (AGU Advances, https://doi.org/10.1029/2024AV001609, 2025)

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2026), How a move to the shallows 300,000 years ago drove a phytoplankton bloom, Eos, 107, https://doi.org/10.1029/2026EO260010. Published on 5 January 2026. Text © 2026. 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.

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

Las olas de calor marinas describen casos de aguas extraordinariamente cálidas que pueden permanecer en la superficie del océano durante meses. Al igual que las olas de calor que experimentamos en tierra, las olas de calor marinas pueden alterar la química ambiental y estancar los procesos biológicos. Mientras que las pérdidas catastróficas de megafauna son indicadores evidentes de un sistema de estrés, los investigadores han comenzado a recopilar datos suficientes para entender cómo los organismos microbianos en la base de las redes tróficas oceánicas están respondiendo a las olas de calor.

Un nuevo estudio publicado en Nature Communications presenta una década de mediciones que documentan dos olas de calor sucesivas en el noreste del Océano Pacífico. El equipo interdisciplinario de autores de este artículo utilizó una combinación de una boya robótica autónoma, un crucero oceanográfico y datos satelitales para entender cómo las comunidades microbianas de la región se reorganizaron en respuesta a estos eventos extremos.

Los investigadores descubrieron que la producción de materia orgánica incrementó en la superficie del océano durante las olas de calor, pero las partículas ricas en carbono no se hundieron, ni flotaron, más bien, se quedaron en su lugar.

La bomba biológica de carbono

Fitoplancton—diminutos microbios fotosintetizadores—activan la bomba biológica de carbono. Al usar la luz solar y el dióxido de carbono (CO2) para crecer, el fitoplancton extrae carbono de la atmósfera y lo incorpora al ciclo del carbono océanico. El zooplancton se alimenta en los extensos campos con estos organismos similares a plantas, transportando carbono a zonas más profundas de la columna de agua en forma de pellets fecales y pedazos de plancton a medio comer. Eventualmente, algunas de estas partículas se sumergen lo suficientemente como para alimentar los ecosistemas de las profundidades oceánicas.

“La capacidad del océano para capturar carbono depende de los microbios en la base de la red trófica.”

Esta bomba de carbono representa un amortiguador globalmente relevante frente a los impactos del cambio climático, ya que el océano absorbe aproximadamente la cuarta parte del CO2 emitido por la actividad humana. Algunas estimaciones sugieren que nuestras concentraciones atmosféricas actuales de CO2, podrían incrementar hasta un 50% si la bomba biológica de carbono dejará de transportar carbono hacia las profundidades del océano.

“La capacidad del océano para capturar carbono depende de los microbios en la base de la red trófica, entonces es muy importante que nosotros comencemos a entender cuáles son los impactos de las olas de calor marinas en las comunidades microbianas”, explicó Mariana Bif, autora principal del nuevo estudio. Bif es profesora asistente en la Universidad de Miami y anteriormente fue investigadora en el Instituto de Investigación del Acuario de la Bahía de Monterey, o MBARI por sus siglas en inglés.

Cuando la red trófica se enreda

En ambas olas de calor marinas rastreadas en el estudio, los investigadores encontraron que la bomba de carbono biológica mostraba señales de sobrecalentamiento. Las partículas ricas en carbono se quedaron estancadas aproximadamente a los 200 metros (660 pies) debajo de la superficie, pero durante las dos olas de calor, distintos mecanismos causaron esta acumulación.

La primera ola de calor incluida en el estudio empezó en el 2013, cuando vientos inusualmente débiles sobre el Pacífico no lograron devolver el aire cálido del verano hacia el territorio continental de los Estados Unidos. La ola de calor, apodada “the Blob” fue noticia cuando las aguas cálidas, estancadas y deficientes en oxígeno provocaron mortandades masivas de fauna en todos los rincones del Pacífico antes de disiparse en 2015.

En 2019, la nubosidad irregular sobre el océano y  prepararon el escenario para que otra ola de calor barriera con el noreste del Pacífico. Esta segunda ola de calor elevó nuevamente las temperaturas y pasó a conocerse como “the Blob 2.0”.

Bif y sus coautores encontraron que durante ambas olas de calor, la comunidad microbiana marina experimentó un cambio en sus “mandos intermedios”.

Dentro de los primeros años del Blob, las condiciones físicas y químicas favorecieron a especies más pequeñas de fitoplancton, lo que a su vez favoreció a un nuevo grupo de alimentadores zooplanctónicos. Esta discreta red trófica, eventualmente creó una capa oceánica llena de partículas orgánicas que eran demasiado ligeras para hundirse en las aguas más densas de las profundidades.

Durante el Blob 2.0, las concentraciones de las partículas de materia orgánica fueron aún más altas, pero el incremento no provino totalmente de la producción primaria. Esta vez las condiciones favorecieron a especies frugales. Los organismos oportunistamente capaces de alimentarse de detritos y de materia orgánica de menor calidad se volvieron más predominantes, mostrando que el sistema estaba ciclando y reciclando carbono para mantenerlo en la parte superior de la columna de agua. Dentro de esta comunidad, los parásitos prosperaron, y organismos (incluido un grupo de radiolarios) que nunca antes se habían observado en el noreste del Pacífico comenzaron a aparecer regularmente.

Midiendo en medio de la nada

La gama de tecnología utilizada en el estudio lo distingue de esfuerzos previos para catalogar los efectos de las olas de calor marinas

“Ahora nosotros estamos entrando en una era de ‘big data’ en la biogeoquímica oceánica, mientras que antes estábamos limitados a lo que podíamos recolectar desde los barcos.”

“Ahora nosotros estamos entrando en una era de ‘big data’ en la biogeoquímica oceánica, mientras que antes estábamos limitados a lo que podíamos recolectar desde los barcos,” dijo Stephanie Henson, científica principal en el Centro Nacional de Oceanografía en Southampton (NOC Southampton, por sus siglas en inglés), Reino Unido. Henson no participó en el estudio.

Henson explicó que las boyas autónomas y otros sistemas de monitoreo avanzado están permitiendo a los investigadores trabajar con un set de datos que se extiende más allá de la duración de un crucero oceanográfico.

“La gente ha estado estudiando las respuestas a las olas de calor marinas en sistemas como los arrecifes de coral, etcétera”, dijo Henson, explicando que los investigadores han observado que no todas las respuestas biológicas son iguales de una ola de calor marina a otra. Sin embargo, señaló que este estudio fue el primero que demuestra que los flujos de carbono en el océano, también presentan respuestas complejas a las olas de calor marinas.

Para revisar los signos vitales del Pacífico antes, durante y después de cada una de las olas de calor, los investigadores recurrieron a la Red Global de Biogeoquímica Oceánica (GO-BGC, por sus siglas en inglés). Los instrumentos GO-BGC son un subconjunto de la red Argo, una red global de miles de boyas robóticas autónomas. Cada boya se desplaza libremente con las corrientes oceánicas, monitoreando el pH, la salinidad, la temperatura y otros parámetros

Mariana Bif se prepara para desplegar una boya GO-BGC en la Bahía de Bengala. La boya derivará libremente en las corrientes oceánicas a aproximadamente 1.000 a 2.000 metros de profundidad, regresando a la superficie cada 10 días para enviar datos sobre la temperatura, salinidad y química oceánica, vía satélite, a los investigadores en tierra. (El océano Índico no fue parte del nuevo estudio, pero Bif utilizó boyas GO-BGC en el Pacífico para realizar la investigación.) Créditos: Sudheesh Keloth, Julio, 2025

A pesar de todo lo que pueden hacer, las boyas no son capaces de recolectar muestras microbianas. Para esto, en lugar de que Bif buscara la data, la data llegó a Bif.

Steven Hallam, microbiólogo de la Universidad de Columbia Británica y coautor en el nuevo estudio, se puso en contacto con Bif después de leer una entrevista con ella sobre su trabajo en olas de calor marinas. Él tenía la corazonada de que las muestras de ADN planctónico almacenadas en el refrigerador de su laboratorio podrían ser de ayuda para la investigación de Bif sobre el ciclo del carbono en el océano. Científicos del grupo de laboratorio de Hallam habían publicado previamente investigaciones sobre comunidades bacterianas en la misma región, usando muestras recolectadas durante los cruceros oceanográficos a lo largo del transecto Line P frente a la costa de Columbia Británica.

Después de un intercambio por correo electrónico, el grupo de laboratorio de Hallam analizó las muestras, expandiendo el análisis de las bacterias a la composición de la comunidad entera, lo que resultó en una contribución significativa al estudio de Bif.

Mientras la historia de cómo el ADN planctónico vino a Bif es un testimonio del poder entre la comunicación y colaboración en la ciencia, Henson notó que los transectos de la Line P, no necesariamente se superponen espacialmente con las regiones de mayor impacto de las olas de calor marinas, y combinar los conjuntos de datos de diferentes escalas (como los datos obtenidos en barcos y los datos de flotadores autónomos) debería hacerse cautelosamente.

Además, Henson añadió, “Es lo mejor que podemos hacer por el momento”

Incertidumbres persistentes

Respecto a las investigaciones futuras, Bif está involucrada en algunos nuevos proyectos explorando regiones marinas desoxigenadas, pero dijo: “Mi enfoque siempre es en los flotadores BGC-Argo”.

Bif indicó que será interesante observar los datos de BGC-Argo desde los flotadores que están en medio de la ola de calor marina afectando actualmente el Pacífico Norte. Esa ola de calor ya está mostrando señales de desaceleración, aunque los científicos dicen que probablemente permanecerá durante el invierno.

“No estoy seguro de si esto va a tener el alcance que tuvieron algunas de las olas de calor marinas anteriores en la región”, dijo Nick Bond, quien no estuvo involucrado en esta investigación pero estudió las olas de calor marinas como parte de su rol anterior como climatólogo del estado de Washington. Ahora él es investigador sénior en la Universidad de Washington.

“Lo que no medimos, no podemos entenderlo. Necesitamos más inversiones para monitorear el océano.”

Bond añadió que mientras haya “evidencia tentativa” de que el calentamiento climático puede estar incrementando la frecuencia de olas de calor marina en el Pacífico, aún hay mucho más por aprender antes de que los científicos puedan pronosticar con precisión cómo se comportarán en el futuro.

Mientras tanto, otra incógnita que se avecina para este campo de investigación se está desarrollando nuevamente en tierra firme.

“Hay un poco de incertidumbre en la comunidad porque al momento, para el programa global Argo, Estados Unidos contribuye aproximadamente con la mitad de los flotadores que se despliegan”, dijo Henson, aludiendo su preocupación a los recortes presupuestarios recientes en Estados Unidos. Sin embargo, ella explicó que otros países están intensificando sus contribuciones para mantener a flote el programa Argo.

“Lo que no medimos no podemos entenderlo. Necesitamos más inversiones para monitorear el océano” dijo Bif.

—Mack Baysinger (@mack-baysinger.bsky.social), Escritor de ciencia

This translation by translator (@Cecilia Ormaza) was made possible by a partnership with Planeteando y GeoLatinas. Esta traducción fue posible gracias a una asociación con Planeteando and GeoLatinas.

Text © 2026. 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.

Yukon Geological Survey

Contributors: Derek Cronmiller, Theron Finley, Panya Lipovsky, Jan Dettmer

A guest post featuring images and a commentary of landslides in Yukon Territory in Canada triggered by the 6 December 2025 M=7.0 Hubbard Glacier Earthquake.

The 6 December 2025 Mw=7.0 Hubbard Glacier Earthquake in the St. Elias Mountains of Yukon caused widespread mass wasting activity in an area near Mt. Logan, Canada. On 12 December 2025, the Yukon Geological Survey completed an overview flight of the area to collect photographs and document seismically induced activity in the region. Based on the preliminary USGS finite fault model, the earthquake rupture appears to have been shallow, with approximately 2 m of slip occurring at ~6 km depth but no evidence of earthquake surface rupture was identified. However, we documented extensive surface effects including more than 200 landslides, many snow and ice avalanches, and widespread damage to glaciers throughout the area.

View southwest towards Mt King George. Snow avalanche and serac collapse scars are visible on the ridge in the foreground, large rock avalanche scars on the NE face of Mt. King George are visible in the background, triggered by the Landslides from the 6 Dec 2025 Hubbard Glacier Earthquake.

Landslide activity was concentrated on the Mt King George massif, where rock–ice avalanches and rockfall were the most common failure types. Based on preliminary earthquake relocations, the King George massif directly overlies a portion of the fault rupture and rises to a height of 3,741 m, approximately 1,900 m above the surrounding Hubbard Glacier.

Landslide scars and debris on the NW end of the King George massif, looking toward Mt Logan (5,959 m). Note the lack of snow cover here due to concentrated avalanche and landslide activity, as compared to distant peaks.

Landslide activity continued for several days after the main earthquake, likely due to a combination of aftershocks and progressive failure of slopes that were damaged by the earthquake or destabilized by earlier landsliding. At least one rock avalanche occurred between 11 and 12 December as constrained by Landsat imagery.  At the time of the overview flight, slide scars on the east and northeast sides of Mt King George remained active, with ongoing rockslides and rockfall producing large dust clouds. The large slide scar on the east face of Mt King George appeared to have liquid water flowing down its centre, suggesting either discontinuous permafrost within the massif or significant heating associated with slope failure.

A large landslide scar on the east face of Mt King George appeared to have liquid water running out from approximately halfway down the scar (arrow). This scar was producing active rockfall at the time of the overview flight and filling adjacent valleys with dust.

The largest observed landslide was a rock and ice avalanche produced by a partial collapse of the southwest ridge of Mt King George. The basal failure surface occurred along a southwest-dipping planar discontinuity oriented subparallel with the pre-existing slope of the south flank of the ridge . The crown of the slide originated at approximately 3,000 m above sea level and descended roughly 1,300 m along a tributary glacier before coming to rest on the Hubbard Glacier, approximately 7.4 km from the source area. This corresponds to an overall travel angle of approximately 10 degrees. Such high mobility is typical of rock avalanches on glaciers (c.f.  Evans and Clague 1988), where movement is enhanced by the low-friction surface of the glacier, entrainment of snow and ice, and by water inputs generated through frictional melting (Sosio et al., 2012).

Source area and runout of the largest (9 square km) landslide triggered by the Mw=7.0 6 December 2025 Hubbard Glacier Earthquakeearthquake on the southwest ridge of Mt King George. The planar surface of failure for the largest rock and ice avalanche on the southern flank of the SW ridge of Mt King George.

Snow avalanches were common on all aspects and were triggered in a more extensive region than landslides. Some of the largest snow avalanches occurred on the north and east aspects of Mt King George and McArthur Peak (a sub-peak of Mt Logan) and produced plumes that in some cases extended 2-3 km across the glacier at the base of the slopes where they initiated. Damage to glaciers was also extensive; the collapse of snow bridges and seracs on icefalls was widespread on the Hubbard Glacier and adjacent tributaries. A partial collapse of a glacier occurred between Mt King George and Mt Queen Mary, an area immediately above many of the most intense aftershocks. This portion of glacier is covered by debris from a rock avalanche off the NE face on Mt King George which may have contributed to its failure. The most intensely affected area is in a popular recreation zone of Kluane National Park and may have significant impact on the objective hazards skiers and mountaineers face in the region over the coming years.

Partial collapse of a glacier between Mt King George and Mt Queen Mary. The length of the failure is approximately 2.4 km. Widespread collapse of seracs and snow bridges on the south side of Mt Queen Mary. The field of view mid-photo is approximately 5 km across. Widespread collapse of seracs and snow bridges on the south side of Mt Queen Mary. The field of view mid-photo is approximately 5 km across. Rock avalanche below Mt King George triggered by the 6 December 2025 Hubbard Glacier Earthquake. The runout distance is 1.4 km.

All photos provided courtesy of the Government of Yukon.

References:

Evans, S. G., & Clague, J. J. 1988. Catastrophic rock avalanches in glacial environments. In Proceedings of the Fifth International Symposium on Landslides, 2, pp. 1153–1158. Lausanne, Switzerland.

Sosio R., Crosta, G.B., Chen, J.H. and Hungr, O. 2012. Modelling rock avalanche propagation onto glaciers. Quaternary Science Reviews 47, 23–40

Return to The Landslide Blog homepage Text © 2026. 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.