EOS

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: AGU Advances

Coastal landscapes evolve under the combined influence of wave action, climatic variations, sea‑level change, and tectonic processes. Shoreline evolution is especially important along rocky coasts such as those of the western United States, where it shapes hazards to people and infrastructure and affects exposure to events like tsunamis. In this context, tectonically driven uplift plays a key role over both individual earthquake cycles and longer timescales associated with fault-system and topographic development.

Using a compilation of coastal change metrics and statistical analyses, Lopez and Masteller [2026] identify a tentative link between tectonics and shoreline change. On decadal timescales, uplift can slow coastline retreat, as might be expected. Over many earthquake cycles, however, higher long-term uplift associated with cumulative subduction-zone deformation appears to enhance shoreline retreat. These findings highlight some of the interactions between coastal and solid earth hazards. They also point toward future models that integrate similar constraints to improve our understanding of how earthquakes build topography and how sea level, coastal processes, and tectonics together modulate short‑ and long‑term coastal risk.

Citation: Lopez, C. G., & Masteller, C. C. (2026). Tectonics as a regulator of shoreline retreat and rocky coast evolution across timescales. AGU Advances, 7, e2025AV002065. https://doi.org/10.1029/2025AV002065

—Thorsten Becker, Editor, AGU Advances

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.

Six people were killed when intense rainfall triggered over 6,500 landslides

On 16 June 2024, an extreme rainfall event triggered a dense cluster of landslides and channelised debris flows in Wuping County, Fujian Province, China. This is one of many such events in recent years – anecdotally at least, these events are becoming more common and more severe.

Thus, I very much welcome a paper in the journal Landslides (Liao et al. 2026) that describes this event. The paper is not open access, but this link should allow you to read the full manuscript. The authors highlight the impact of the event – six people were killed (two of whom were never recovered) and hundreds of houses were damaged.

The cluster of landslides centres on the area around [24.94745, 116.29172]. This Planet Labs image, captured on 27 November 2024 after the event, shows some of the landslides triggered:-

Landslides triggered by the 16 June 2024 rainfall event in Wuping County, Fujian Province. Image copyright Planet Labs, used with permission, collected on 27 November 2024.

Note the presence of multiple shallow landslides that have combined to form channelised debris flows. In the centre of the image, by the marker, there is a small reservoir that has been almost entirely infilled by debris from the landslides.

In total, Liao et al. (2026) have mapped 6,526 landslide triggered by the rainfall event. The main initiating rainfall appears to have been a period between 14:00 and 18:00 on 16 June 2024, during which 161 mm was recorded, with a peak intensity of 55 mm per hour. Interestingly, though, the landslide density correlates with rainfall total prior to the main initiating event, rather than to the total rainfall. I wonder whether this indicates that the key parameter (the distribution of peak rainfall intensity, for example) is not being captured in the data?

Very helpfully, Liao et al. (2026) have investigated the mechanism of the landslides in some detail. They find that behaviour differed according to the bedrock lithology. In areas underlain by granite, failure occurred on the interface between the weathered and the unweathered materials, a common situation. In most cases, granitic landslides did not generate channelised debris flows.

On the other hand, in areas underlain by greywacke, failures also occurred in these interface areas, but channelised debris flows were more common. This may be related to the steeper local topography in the greywacke areas.

The paper by Liao et al. (2026) further helps us to understand these clusters of landslides and channelised debris flows, which are proving to be so very destructive. Expect more of these events in the coming months and beyond.

Reference and acknowledgement

Liao, Z., Wu, J., Ma, J. et al. 2026. Characteristics and initiation mechanism of clustered landslides triggered by an extreme rainfall in Wuping County, Fujian Province, China. Landslides. https://doi.org/10.1007/s10346-026-02712-1.

Many thanks to the wonderful people at Planet Labs for providing access to the satellite imagery.

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Scientists who work across disciplines often dread the question, “What is your field of expertise?” A geographer working in an environmental science department or a social scientist working in an ecology department might find it difficult to articulate how their research, knowledge, and professional networks fit within established fields to colleagues long accustomed to their institutions’ disciplinary expectations and norms.

Most academic structures are still largely organized around relatively narrow disciplinary perspectives, even as the world’s biggest challenges require interdisciplinary solutions.

These moments of discomfort may seem trivial, but they signal a systemic barrier for many scientists and for scientific innovation and problem-solving: Most academic structures are still largely organized around relatively narrow disciplinary perspectives, even as the world’s biggest challenges require interdisciplinary solutions. Addressing natural hazards, biodiversity loss, poverty, and food insecurity simultaneously, for example, depends on scientists collaborating across fields and engaging with partners in other sectors of society.

This issue is not just one of semantics, especially for younger scientists and others who regularly experience its effects. Departments incentivized to select against interdisciplinary science and the absence of clear institutional “homes” for interdisciplinary scientists can create challenges for hiring, evaluation, and promotion. It can also reduce researchers’ sense of professional belonging and increase their feelings of being an imposter, which can affect their ability to contribute and even lead to the loss of scientific talent to other career paths.

Experiences in the field of land system science reflect broader tensions with interdisciplinarity across academic science. Researchers studying land system science, as we do, often find that their work resists neat disciplinary labels. Because this field encompasses the many ways that people and nature interact across Earth’s land surface and how these interactions shape global challenges like biodiversity loss, it can be difficult to describe the field in terms of preexisting academic departments and to identify appropriate funding sources and publication venues.

Here we share experiences navigating tensions that have come with pursuing interdisciplinary science, and we describe how one global interdisciplinary science community, the Global Land Programme (GLP), became a home for our work. Communities such as the GLP not only bring people together but also help create new pathways for turning research into solutions.

Our experiences also suggest practical lessons and actionable steps—especially for early-career scholars—for finding or building supportive communities that span fields and sectors, foster belonging, spark scientific innovation, and connect science to society.

Perceived Deficiencies Versus Demonstrated Proficiencies

As interdisciplinary scientists working across institutions around the world, we’ve seen firsthand the tribulations of bridging silos. Colleagues have often questioned our scientific skills and seen us as outsiders. Some have asked whether our interdisciplinary doctoral degrees “count” as legitimate academic credentials or told us that our research “isn’t science.” Even after establishing our careers, we’ve heard comments such as “Your research doesn’t fit into this science foundation’s remit.”

These critiques can be especially harsh for researchers who already encounter structural barriers within scientific institutions [Liu et al., 2023; Bentley and Garrett, 2023; Woolston, 2021; Carrigan and Wylie, 2023]. Having other people—particularly colleagues around whom you work—define you by perceived deficiencies rather than demonstrated proficiencies is hardly constructive for advancing research into complex challenges.

The scientific literature reveals a disconnect between policy-level acceptance of interdisciplinarity and its practical adoption within academic and research institutions.

National- and international-level policies are increasingly encouraging interdisciplinary research. The European Union, for example, is adopting integrated One Health policy approaches that recognize the interconnections of human, animal, plant, and environmental health and require collaboration across previously distinct disciplines and sectors.

Yet the scientific literature reveals a disconnect between policy-level acceptance of interdisciplinarity and its practical adoption within academic and research institutions, showing that the barriers we’ve faced are widely shared [Andrews et al., 2020; Berkes et al., 2024]. Such obstacles include skepticism from peers, disciplinary prejudice, and funding and department structures that privilege individual, siloed fields. We often must frame research proposals as either social science or natural science, for example, because work that straddles or combines both rarely gets funded.

Unsupportive responses from funding agencies, departments, and colleagues can be demoralizing when added to the background stresses of academia. On the other hand, opportunities to commiserate and trade tips with others can be lifelines. Building communities of interdisciplinary scientists is thus essential, especially for younger scholars who often face the steepest barriers with disciplinary divides [Haider et al., 2018].

Discovering a Global Community

To thrive as an interdisciplinary scientist, one might need to “feel comfortable being uncomfortable” [Marx, 2022]. Achieving such confidence requires mentorship and peer relationships in community. In each of our cases, the GLP provided the professional and emotional support that we greatly needed to feel fulfilled in our careers.

As current or former members of the GLP’s Scientific Steering Committee, we are admittedly biased toward the program’s merits. Nonetheless, having come from different scientific backgrounds, career stages, and geographies, we believe that our collective experiences illustrate how global cross-disciplinary communities can cultivate a supportive culture and amplify the reach and impact of community members’ science.

The GLP emerged in the mid-2000s as a successor to earlier global change research projects focused on land use and land cover, with the goal of bringing together natural and social scientists to study land systems as coupled human-environment systems [de Bremond et al., 2019]. Since then, it has become the reference community for land system science, as well as a home for scientists whose work was falling through disciplinary cracks.

Speakers discuss the GLP’s Science Plan during the 5th Open Science Meeting in 2024. Credit: Ximena Fargas

The organization has been guided by a unifying programmatic framework—articulated in its Science Plan—that incorporates knowledge across disciplines to address pressing global challenges (e.g., biodiversity loss, food insecurity, and poverty). The Science Plan, reevaluated and updated every 5 years, offers a living, collaborative road map of interdisciplinary research priorities—a rarity in academia, where competition for resources and rewards often leaves scientists reluctant to share ideas.

This road map enables researchers to orient their work toward impactful cross-disciplinary research themes and projects. It also outlines the GLP’s core priorities and analytical perspectives, drawing on a range of viewpoints and knowledge, which can guide us to develop shared ideas of what is possible.

The Global Land Programme’s activities have built a culture of mutual respect that values ecological and cultural context and encourages engagement with a broad range of perspectives.

Over time, the collaborative spirit of the GLP’s members has resulted in a rich interdisciplinary community of land system scientists that provides a space for them to reflect on dimensions of academic life other than research (as exemplified, e.g., by this article). Besides offering a supportive professional environment, apart from the skepticism we often encounter in more discipline-specific settings, the GLP’s activities have built a culture of mutual respect that values ecological and cultural context and encourages engagement with a broad range of perspectives.

The GLP has also delivered tangible results for science and society. GLP scientists have advanced modeling of land use going back millennia, contributed to global biodiversity assessments (e.g., in support of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services), codeveloped new visions for land systems, and made datasets that help track land use changes, such as deforestation, publicly available. The GLP also works to translate land system science into forms relevant for policy and practice. For example, GLP scientists authored “Ten Facts About Land Systems for Sustainability,” a framework intended to inform both research and policy understandings of sustainable land governance.

What began as a space for researchers from across disciplines to connect around land system challenges has become an engine for both scientific innovation and societal relevance. This success adds to our trust in the GLP’s approach to supporting researchers in the often-challenging space of interdisciplinary science.

If You Don’t Have a Community, Make One

For interdisciplinary scientists lacking a home, one path forward is to build a new community of researchers with shared interests.

We were fortunate to find the GLP early in our careers, as not all scientists have access to such communities. But the comfort and confidence that come with belonging should not—and need not—depend on luck. For interdisciplinary scientists lacking a home, one path forward is to build a new community of researchers with shared interests.

Establishing a community of practice within a broader existing organization or research community or even creating a new forum for social networking can provide a space that empowers scientists, including early-career researchers, to navigate interdisciplinary work by connecting with peers who share related interests and challenges.

Experiences from existing communities of practice suggest that these spaces tend to work best when they grow organically [Watkins et al., 2018]. Making it easy for people to join, observe, and participate at their own pace helps create welcoming entry points and encourages such growth. Allowing people to gradually step in, share perspectives, and assume roles and responsibilities strengthens the common dynamic that often develops in these communities, in which a core of more active members is surrounded by a larger group of less active, though still involved, members.

In practice, many scientific communities thrive by communicating through simple and familiar platforms, such as mailing lists, online forums and channels, and recurring online meetups, which lower barriers to participation across institutions and regions. Reaching out to existing societies or research networks—AGU or FLARE (Forests & Livelihoods: Assessment, Research, and Engagement), for example—for guidance on coordination or to help gain visibility or seed funding can also help burgeoning communities avoid reinventing the wheel.

Furthermore, mentorship from people who have built research communities from the ground up in adjacent fields can be valuable for advising groups on how to grow and address challenges. Knowledgeable mentors can also help groups understand how to sustain a community, an aspect that is often critical to long-term viability.

The GLP was initiated as researchers working on different issues related to land began to connect, forging collaborations that eventually grew into a global network, which itself now comprises a variety of smaller networks, including working groups and regional (nodal) offices. The recently created Early Career Network, launched through webinars and other online communications, is providing a space where young scholars are encouraged to create their own governance structures and articulate what they need in terms of capacity building from the larger community.

Members of the GLP’s Scientific Steering Committee visit an agave farm in Oaxaca in 2024. Credit: Rieley Auger

Growing the GLP has not always been an easy process, however. Sustaining the community has required continually maintaining support and funding from multiple institutions. To date, much of the growth has relied on volunteer work, with members of the GLP’s Scientific Steering Committee, working groups, and nodal offices providing unpaid service above and beyond their existing professional responsibilities. This arrangement of distributed labor underscores the importance of effective coordination for maintaining connections and momentum across the network.

The experiences of the GLP and other groups show that new interdisciplinary communities can start small and run largely on volunteer energy, which we recognize is not something all researchers—especially those early in their career—have to spare. If the communities can then reach a critical mass of participants, they may be able to secure institutional support and professional coordination to help them thrive over the long term.

Harnessing Interdisciplinarity

We came to realize that with our expertise, we can generate innovative ideas that advance science at the intersections between disciplines.

Earlier in our careers, we used to internalize criticisms about not belonging or excelling in any one discipline. Then we came to realize that with our expertise, we can generate innovative ideas that advance science at the intersections between disciplines. Indeed, people with interdisciplinary profiles can fill critical research gaps—and should be seen as assets, not liabilities. Many universities and funders understand this truth at the leadership level, but challenges remain in how interdisciplinarity is evaluated within departments and by hiring, promotion, and grant review panels.

To help move the needle, we actively characterize ourselves as interdisciplinary land system scientists in our tenure and promotion documents, preferring to own the position and emphasize its strengths, rather than to shy away from it. Individuals acting on their own, however, may have only limited influence. That is why building and sustaining communities is so important: They create the collective weight needed to demonstrate value, shift norms, and motivate institutional change.

Within community-building efforts, it is key to create space for participation from researchers with varied backgrounds and experiences. The GLP supports this approach through its distributed subnetworks, including working groups and regional nodes, and by convening international Open Science Meetings on different continents that bring together hundreds of scientists every few years. GLP members frequently present on the program’s work as well as strategies and approaches at other conferences, helping spread the word about the value of growing interdisciplinary communities.

As more researchers connect across disciplinary and geographic boundaries, the scientific enterprise will be better positioned to pursue sustainable solutions that address complex, urgent problems to secure livelihoods and food security for the global population and to safeguard our planet’s biodiversity and environmental health.

References

Andrews, E. J., et al. (2020), Supporting early career researchers: Insights from interdisciplinary marine scientists, ICES J. Mar. Sci., 77(2), 476–485, https://doi.org/10.1093/icesjms/fsz247.

Bentley, A., and R. Garrett (2023), Don’t get mad, get equal: Putting an end to misogyny in science, Nature, 619, 209–211, https://doi.org/10.1038/d41586-023-02101-x.

Berkes, E., et al. (2024), Slow convergence: Career impediments to interdisciplinary biomedical research, Proc. Natl. Acad. Sci. U. S. A., 121(32), e2402646121, https://doi.org/10.1073/pnas.2402646121.

Carrigan, C., and C. D. Wylie (2023), Introduction: Caring for equitable relations in interdisciplinary collaborations, Catalyst Feminism Theory Technosci., 9(2), 1–16, https://doi.org/10.28968/cftt.v9i2.41070.

de Bremond, A., et al. (2019), What role for global change research networks in enabling transformative science for global sustainability? A Global Land Programme perspective, Curr. Opinion Environ. Sustainability, 38, 95–102, https://doi.org/10.1016/j.cosust.2019.05.006.

Haider, L. J., et al. (2018), The undisciplinary journey: Early-career perspectives in sustainability science, Sustainability Sci., 13, 191–204, https://doi.org/10.1007/s11625-017-0445-1.

Liu, M., et al. (2023), Female early-career scientists have conducted less interdisciplinary research in the past six decades: Evidence from doctoral theses, Humanit. Soc. Sci. Commun., 10(1), 918, https://doi.org/10.1057/s41599-023-02392-5.

Marx, V. (2022), Cross-disciplinary ways to connect and blend, Nat. Methods, 19(10), 1149, https://doi.org/10.1038/s41592-022-01622-z.

Watkins, C., et al. (2018), Developing an interdisciplinary and cross‐sectoral community of practice in the domain of forests and livelihoods, Conserv. Biol., 32(1), 60–71, https://doi.org/10.1111/cobi.12982.

Woolston, C. (2021), Discrimination still plagues science, Nature, 600(7887), 177–179, https://doi.org/10.1038/d41586-021-03043-y.

Author Information

Laura Vang Rasmussen (lr@ign.ku.dk), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark; Rachael Garrett, Department of Geography and Conservation Research Institute, University of Cambridge, Cambridge, U.K.; A. Sofia Nanni, Instituto de Ecología Regional, Horco Molle, Yerba Buena, Argentina; also at Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, San Miguel de Tucumán, Argentina; Navin Ramankutty, School of Public Policy and Global Affairs and Institute for Resources, Environment and Sustainability, University of British Columbia, Vancouver, Canada; and Ariane de Bremond, Global Land Programme, Department of Geographical Sciences, University of Maryland, College Park

Citation: Rasmussen, L. V., R. Garrett, A. S. Nanni, N. Ramankutty, and A. de Bremond (2026), Creating communities to help interdisciplinary scientists thrive, Eos, 107, https://doi.org/10.1029/2026EO260058. Published on 13 February 2026. 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 © 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.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Journal of Geophysical Research: Solid Earth

Quartz is widely thought to control the mechanical strength of Earth’s continental crust, but measuring its strength at high pressure and temperature has long been challenging.

Medina et al. [2026] deform polycrystalline α-quartz at crustal pressure and temperature conditions while directly monitoring stress inside the sample using in situ synchrotron X-ray diffraction. Unlike traditional experiments that rely on external load measurements, this approach derives stress from lattice strain within the quartz itself, avoiding long-standing uncertainties related to friction corrections. The results show that quartz strength varies systematically with temperature, transitioning from lattice-resistance–controlled plasticity below 800 °C to dislocation creep at higher temperatures.

Remarkably, the new measurements are broadly consistent with classic deformation experiments despite the very different experimental techniques. The data also show little pressure dependence over the tested conditions, suggesting that temperature plays the dominant role in controlling quartz strength in much of the crust. These findings provide a more reliable experimental foundation for flow laws used to model crustal deformation, earthquakes, and mountain-building processes.

Citation: Medina, D. A. J., Kaboli, S., Patterson, B. M., & Burnley, P. C. (2026). Strength α-quartz: New results from high pressure in situ X-ray diffraction experiments. Journal of Geophysical Research: Solid Earth, 131, e2025JB032753. https://doi.org/10.1029/2025JB032753

—Jun Tsuchiya, Editor, JGR: Solid Earth

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.

In NW India, rainfall in the 2025 monsoon was 27% above the long term average. Over 2,500 people were killed in India and Pakistan by landslides and floods as a result.

In India and Pakistan, the 2025 summer monsoon generated unusual amount of landslide activity. I described some of these events along the way, most notably in India. In Pakistan, it is much harder to get a good picture of the events that occur in the higher mountain areas.

A new open access paper (Sana et al. 2026) in the journal Landslides provides an initial commentary on these events. By their calculation, 1,528 people were killed in floods and landslides in India and 1,006 were killed in Pakistan.

The paper provides a description of some of the more serious events, which is in itself very helpful, but the most interesting aspect is the consideration of the underlying causes. Across all of India, the total monsoon rainfall was 10% above the long term average, but in Northwest India, which was most seriously impacted area, rainfall was 27% above the long term average. In addition, there was an unusually large number of shorter duration extreme rainfall events, which were primarily responsible for the landslides and floods. This graph, from Sana et al. (2026), provides the 2026 monsoon rainfall record for Mandi district in Himachal Pradesh, for example:-

Rainfall data for the monsoon months of June to August 2025 for Mandi district highlighting cloudburst events. Graph from Sana et al. (2026).

An example of these shorter rainfall events occurred in Khyber Pakhtunkhwa (KP) province between 14 and 25 August 2025, when a succession of cloudbursts triggered landslides and floods in Buner, Swat, Shangla, Mansehra and Dir districts, killing 504 people and leaving thousands more homeless.

But Sana et al. (2026) also remind us that rainfall alone is not the cause of these landslides and floods. Vulnerability has also increased dramatically – for example, there has been a sharp decline in forest cover across much of the area. There has also been growth in urban areas, often with poor planning control, meaning that much of the population is occupying more hazardous locations. And, as I have noted before, poor quality infrastructure development (especially road building) is driving instability across large swathes of hillslopes, rendering them vulnerable to the changed rainfall patterns.

I write on the morning after the decision by the frankly nonsensical decision by the Trump government to reverse the 2009 endangerment finding regarding greenhouse gases, an event that will be judged harshly by future generations. However, in the medium term, this will further exacerbate the issues of increasing rainfall intensities, which drive these horrific events.

It is really helpful that Sana et al. (2026) have provided this intial commentary and analysis of the 2025 monsoon landslides and floods. I will look forward to seeing more detailed analyses in due course.

Reference

Sana, E., Kritika & Kumar, A. 2026. Preliminary investigation of rainfall-induced landslides and related damages by the 2025 extreme monsoon in the Northwestern Himalayan region. Landslides. https://doi.org/10.1007/s10346-026-02703-2

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Bright streaks of material trickle down the slopes of many of Mercury’s craters, but scientists have struggled to understand how these geologically young features, called slope lineae, appeared on a seemingly dead world. Now, researchers have used machine learning to analyze more than 400 slope lineae in the hope of understanding the streaks’ origin.

The analysis of images from NASA’s decade-gone MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) mission showed that lineae seem to stream from bright hollows on the sunward side of crater slopes and mainly appear on craters that punched through a thin volcanic crust to a volatile-rich layer beneath. The lineae, the team theorized, could have formed when that exposed layer heated up and released volatiles like sulfur to drip downslope.

“We have these modern data science approaches now—machine learning, deep learning—that help us look into all those old data sets and find completely new science discoveries in them,” said Valentin Bickel, a planetary geomorphologist at Universität Bern in Switzerland and lead researcher on the study.

Streaks and Stripes

MESSENGER orbited Mercury from 2011 to 2015, and observations from those 4 years remain some of the best data we have on our solar system’s smallest planet.

The images revealed that although there is not a lot of geologic activity happening today, the planet remains chock-full of oddities.

One of those strange phenomena is the existence of slope lineae streaking down from the rims of many of Mercury’s craters. The higher-resolution MESSENGER images show that Mercury’s lineae are made of bright material and are geologically young, with crisply defined edges and no small craters superimposed on top. But planetary scientists had not conducted any systematic analysis of lineae before now, focusing instead on understanding the planet’s similarly bright, but more numerous, hollows.

“The first things we as geologists like to do is put things on a map.”

Bickel and his team sought to fill that knowledge gap. Their machine learning tool looked at more than 112,000 MESSENGER images with spatial resolutions finer than 150 meters (492 feet), identified 402 individual lineae, and cataloged their properties in a uniform way.

“The first things we as geologists like to do is put things on a map,” Bickel said.

Most of MESSENGER’s high-resolution images cover the northern hemisphere, Bickel explained, so most (93%) of the lineae the team cataloged were in the north. Ninety percent of lineae are located within craters. They are hundreds or thousands of meters long, are less than 20 meters (65 feet) tall, and are located on steeper-than-average crater slopes. Most lineae extend from young, bright hollows or hollow-like features.

But the most telling commonality among lineae is that they prefer the side of craters facing the equator, which is the side that receives the most sunlight.

The MESSENGER mission imaged slope lineae in Mercury’s craters on 1 August 2012 (left) and 19 October 2013 (right). Credit: NASA/JHUAPL/Carnegie Institution of Washington

That trend led the researchers to their theory of how lineae form. An impact exposes Mercury’s shallow but volatile-rich bedrock layer. Insolation, or heat from the Sun, draws out volatile gases in those rocks, and those volatiles then slowly drip down the crater wall, leaving bright deposits behind.

“The fact that lineae are on slopes that are facing the Sun implies that insolation might play a role in activating the process,” Bickel said. “And whenever insolation is so prominent, that implies that volatile material is involved. And in Mercury’s case has to come from the subsurface.”

The team published these results in Communications Earth and Environment.

Making a More Complete Map

Susan Conway, a planetary geomorphologist at the French National Centre for Scientific Research (CNRS) in Nantes, France, said planetary scientists have long accepted that Mercury’s hollows are produced by the loss of subsurface volatiles.

“Given that the slope lineae often originate at what appear to be hollows on the crater wall and have the same colour as them, the inference that slope lineae are also linked to volatile loss makes sense,” Conway wrote in an email.

Across the solar system, “slope lineae are pretty common,” added Conway, who was not involved with this research. “Several different kinds have been documented on Mars—slope streaks believed to be dust avalanches, recurring slope lineae whose formation is still debated and could be related to volatiles.” Granular flows on the Moon as well as lineae on Ceres and some icy moons in the outer solar system also resemble those on Mercury.

But a good 10% of Mercury’s known lineae don’t appear within craters, and conversely, there are plenty of craters with hollows that don’t have lineae. Other mechanisms are likely at work there, Bickel said.

“BepiColombo will image the whole surface at a resolution that would enable us to see most slope lineae.”

Thankfully, planetary scientists won’t have to wait long to test this theory. The BepiColombo spacecraft will arrive at Mercury in November and will begin science operations in early 2027. The joint mission from the European Space Agency and the Japan Aerospace Exploration Agency will image more of the planet’s surface than MESSENGER did and at a consistently higher spatial resolution.

Bickel and other Mercury scientists expect that BepiColombo will image more slope lineae across the planet, including smaller lineae, dimmer lineae, and lineae at southern latitudes. It will likely reimage some lineae-dense locations and reveal whether the streaks have changed in the 16 years since MESSENGER’s last images. And it may even capture repeat snapshots of a few locations, allowing scientists to see whether lineae change on short timescales.

“BepiColombo will image the whole surface at a resolution that would enable us to see most slope lineae,” Conway said. “We’ll get a complete picture of their spatial distribution, which will enable us to better test the volatile-driven hypothesis.”

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

Citation: Cartier, K. M. S. (2026), Oozing gas could be making stripes in Mercury’s craters, Eos, 107, https://doi.org/10.1029/2026EO260052. Published on 12 February 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.

Fast ice, also called landfast sea ice, is a relatively short-lived ice that forms from frozen seawater and attaches like a “seatbelt” to larger ice sheets. It can create 50- to 200-kilometer-wide bands that last anywhere from a few weeks to a few decades and act as a site for valuable geochemical processes, breeding grounds for emperor penguins, and a protective buffer between caustic Antarctic winds and waters and inland bodies of ice.

In new research published in Nature Communications, scientists found that buried sediments can track the long-term growth of Antarctic fast ice—and that the ice’s freezing and thawing may be linked to cycles of solar activity. Given that this ice plays a significant role in protecting Antarctica’s larger ice sheets, the research could have major implications for understanding the ongoing impacts of climate change in Antarctica.

“Fast ice, especially in the summertime, is suffering the same fate as overall pack ice,” said Alex Fraser, a glaciologist at the University of Tasmania, who was not involved in the study. We’ve seen a “dramatic decrease” over the past decade, he said. “We’re down to around half of the ‘normal’ [amount].”

“To understand how humans are changing the planet, we first need to know how the planet changes on its own.”

Over the past several decades, the only way for scientists to track fast ice has been through satellite data, which can reveal the ice’s history over only the past 40 or so years. This narrow range has prohibited researchers from understanding the ice’s behavior prior to human-induced climate change.

“To understand how humans are changing the planet, we first need to know how the planet changes on its own,” said Mike Weber, a geoscientist at Universität Bonn in Germany and a coauthor of the study. The new work aimed to establish a “blueprint” for how fast ice behaves in the long term, allowing researchers to better understand how the ice contracts or expands when exposed to greenhouse gas emissions.

Sediment Secrets

To better understand fast ice history, the team turned to sediment cores from Victoria Land in eastern Antarctica. By scrutinizing laminated layers within the cores, the researchers were able to pinpoint key markers that correspond to ebbs and flows in fast ice going back 3,700 years.

The team found that lighter sediment layers formed during summer months marked by prolonged ice loss, whereas darker layers formed during regular seasonal thawing. They also found evidence that different species of small organisms called diatoms grew during summer months versus thawing periods, further enabling the science team to distinguish the cycles. By combining these and other data unearthed from the sediments, the researchers identified recurring periods of open-water and low-ice conditions pinned to solar cycles—called the Gleissberg and Suess-de Vries solar cycles—that occur approximately every 90 and 240 years, respectively.

The link to solar cycling was surprising at first, but the researchers suggested the explanation is straightforward: Solar activity can influence winds over the Southern Ocean, transporting warm air over the Victoria Land coast and leading to ice melt.

“Laminated sediments are always intriguing because you know they’re hiding a message.”

“Laminated sediments are always intriguing because you know they’re hiding a message,” said Tesi Tommaso, a biogeochemist at the National Research Council of Italy’s Institute of Polar Sciences and lead author of the study. “When we realized that over long timescales, this laminated pattern was linked to solar activity, it actually made perfect sense—it was super exciting.”

In future work, the team plans to dig up deeper sediment cores to push fast ice records back even further. The data would be “incredibly informative,” said Tommaso.

“We have finally developed a high-resolution ‘time machine’ for a critical but poorly understood part of Antarctica,” Weber said. “It’s a testament to how interconnected our atmosphere, ocean, and ice really are.”

—Taylor Mitchell Brown (@tmitchellbrown.bsky.social), Science Writer

Citation: Brown, T. M. (2026), Sediments offer an extended history of fast ice, Eos, 107, https://doi.org/10.1029/2026EO260054. Published on 12 February 2026. 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.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Earth and Space Science

Atmospheric conditions over Antarctica affect global climate cycles, and are thus critical for climate assessment. However, studying atmospheric changes in Antarctica is quite challenging as they are driven by a variety of processes at local scale not easily captured by global models. Monitoring seasonal atmospheric pressure changes is one way to keep track of the evolving Antarctic atmosphere.

Because changes in stratospheric conditions influence the flux of cosmic rays reaching Earth’s surface, Santos et al. [2025] use measurements from a water-Cherenkov cosmic-ray detector, to monitor variations in the 100-hPa geopotential height (about 15 kilometers) over the Antarctic Peninsula. After conducting a thorough statistical analysis of the data, the authors develop a simple model linking surface pressure and cosmic ray count data, validating it against observed ERA5 100-hPa geopotential height reanalysis data. The model is especially accurate in (southern hemisphere) spring, but it performs well also at other times of the year.

With their model, the authors demonstrate that water-Cherenkov cosmic-ray detectors can be reliably used as proxies for atmospheric pressure changes, thus adding a new, simple, and effective tool to monitor and study lower stratospheric dynamics over Antarctica.

Citation: Santos, N. A., Gómez, N., Dasso, S., Gulisano, A. M., Rubinstein, L., Pereira, M., et al. (2025). Cosmic ray counting variability from water-Cherenkov detectors as a proxy of stratospheric conditions in Antarctica. Earth and Space Science, 12, e2025EA004298. https://doi.org/10.1029/2025EA004298

  —Graziella Caprarelli, Editor-in-Chief, Earth and Space Science

Text © 2026. The authors. CC BY-NC-ND 3.0
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Earth systems may be on the brink of long-term, irreversible destabilization, sending our planet on a “hothouse Earth” trajectory, a scenario in which long-term temperatures remain about 5°C (9°F) higher than preindustrial temperatures, according to a new paper.

In the paper, published in One Earth, scientists argue that uncertainties in climate projections mean Earth system components could be at a higher risk than we think of reaching crucial tipping points such as the melting of the Greenland Ice Sheet and the thawing of the world’s permafrost—points of destabilization that, once breached, are irreversible.

“As we move to higher temperatures, we go into higher risk zones,” said Nico Wunderling, a coauthor of the new paper and a climate scientist at the Potsdam Institute for Climate Impact Research and Goethe University Frankfurt, both in Germany. Scientists know higher temperatures will activate interactions between tipping elements, he said.

The new paper “strongly builds” on a 2018 perspective paper linking the possibility of hothouse Earth to tipping points, said Swinda Falkena, a climate scientist at Utrecht University in the Netherlands who was not involved in either publication.

Uncertain Earth Systems

Scientists use climate models—simulations of Earth systems—to project how rising emissions may impact global temperatures, weather patterns, ice sheets, ocean circulation, and more.

But those models are never perfect representations of our planet. Climate models contain uncertainties regarding the sensitivity of Earth systems to increased levels of carbon dioxide and the role of climate feedbacks, including land and ocean carbon sinks. Simulations have particular trouble modeling potential tipping points, such as weakening ocean circulation and the dieback of the Amazon rainforest, and the interactions between them, Wunderling said.

These uncertainties mean it’s virtually impossible to reliably estimate the timing of some tipping points and that some Earth system components could be closer to tipping points than scientists thought.

In recent years, scientists have noticed that the rate of climate change has outpaced some projections. In 2024, for instance, global temperatures briefly reached 1.5°C (2.7°F) above preindustrial levels, surpassing the Paris Agreement target and indicating that Earth is virtually certain to consistently break this limit in the long term. In another example of real climate change outpacing models, exceptionally high temperatures in 2023, 2024, and 2025 led experts at Berkeley Earth, a nonprofit climate research organization, to suggest scientists may need to rethink their analyses of Earth’s warming rate.

“Warming now seems to have accelerated, which is not something we expected,” Falkena said. “That gets us to think, ‘Okay, is there something we’re missing?’”

The paper identifies 16 Earth system components (such as ice sheets, permafrost, and rainforests) that could reach tipping points, 10 of which could accelerate global heating if triggered. These 10 tipping points include the collapse of major ice sheets, the collapse of Arctic sea ice, the loss of mountain glaciers, the abrupt thaw of boreal permafrost, and the dieback of the Amazon rainforest.

The authors point out that these tipping elements are linked and even interact with each other to create feedback loops. For example, melting ice sheets would reduce Earth’s ability to reflect sunlight, amplifying warming. Melting ice sheets could also weaken the Atlantic Meridional Overturning Circulation, or AMOC (an ocean current key to regulating Earth’s temperature), which could cause the conversion of Amazon rainforest (a critical carbon sink) into dry savanna.

A Hothouse Trajectory

The higher Earth’s temperature rises, “the more likely it is to trigger self-amplifying feedbacks.”

If enough of these tipping points are reached, Earth’s climate could be steered toward a hothouse Earth scenario, the authors write. And although there is “no precise answer” to the question of whether humanity is at risk of triggering hothouse Earth, Wunderling said the 1.5°C (2.7°F) limit set by the Paris Agreement was made with tipping point thresholds in mind.

If Earth’s temperature exceeds preindustrial levels by 2°C (3.6°F), then “we certainly run into a high-risk zone for tipping elements,” Wunderling said. The higher Earth’s temperature rises, “the more likely it is to trigger self-amplifying feedbacks.”

One 2024 modeling study showed that Earth had a high risk of breaching at least one of four climate tipping elements—the Greenland Ice Sheet collapse, the West Antarctic Ice Sheet collapse, the AMOC collapse, and a dieback of the Amazon rainforest—if temperatures do not return to below the 1.5°C (2.7°F) mark. (Scientists say the prospect of lowering Earth’s temperatures with new policies or technology after exceeding this mark is slim.)

Falkena said the likelihood of a hothouse Earth trajectory is low, but the fact that such a severe scenario is plausible at all means it’s something worth the world’s concern. As models improve, scientists will be able to better quantify the risk of a hothouse Earth trajectory.

“While averting the hothouse trajectory won’t be easy, it’s much more achievable than trying to backtrack once we’re on it.”

“While averting the hothouse trajectory won’t be easy, it’s much more achievable than trying to backtrack once we’re on it,” said Christopher Wolf, a research scientist at Terrestrial Ecosystems Research Associates, a former postdoctoral scholar at Oregon State University, and a coauthor of the new study, in a press release.

The world hasn’t sufficiently cut down on emissions, though: Earth is on track to warm by about 2.8°C (5.04°F) by 2100. In 2025, global carbon emissions rose by 1.1% compared to 2024 levels, and in the United States, total emissions rose by 2.4%. The level of carbon dioxide in the atmosphere is likely higher than it has been in at least 2 million years, and average global temperatures are likely warmer than at any point in the past 125,000 years, according to the authors.

The uncertainty about when tipping points may be breached, combined with ever-higher global temperatures, should be taken as a reason for urgent action to combat or mitigate climate change, the authors write.

“In order to avoid high-end climate risks, it is necessary to go down to net zero, to mitigate as quickly as we can,” Wunderling said.

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

Citation: van Deelen, G. (2026), Earth’s climate may go from greenhouse to hothouse, Eos, 107, https://doi.org/10.1029/2026EO260057. Published on 11 February 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
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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.

Update, 12 February: At a press conference today, President Donald Trump announced that the EPA has revoked the 2009 Endangerment Finding.

Trump said regulations related to the finding were “crippling,” and designed to “facilitate the green new Scam.”

“Effective immediately, we are repealing the ridiculous Endangerment Finding,” he said.

AGU immediately denounced the repeal.

Revoking the finding repeals the EPA’s authority to regulate greenhouse gas emissions and removes all greenhouse gas emissions regulations for vehicles, according to the EPA.

11 February: The Endangerment Finding is a scientific determination made by the EPA that greenhouse gases threaten public health. It is the legal underpinning for major U.S. climate rules under the Clean Air Act. Revoking the finding repeals the EPA’s authority to regulate greenhouse gas emissions and removes all greenhouse gas emissions regulations for vehicles, according to the EPA. 

“I think it’s a historic low, frankly, for EPA to be taking this stance now,” Benjamin DeAngelo, a former EPA official involved in writing the 2009 finding, told POLITICO. 

Leavitt called the planned finalization the “largest deregulatory action in American history.” She said the repeal of the finding would increase energy affordability and, especially, lower vehicle costs, allegedly saving Americans “$1.3 trillion in crushing regulations.” Businesses and groups prioritizing free markets support the administration’s claim, with the editorial board of the Washington Post writing that rescinding the Endangerment Finding will “end the federal government’s power over cars.”

President Donald Trump and EPA Administrator Lee Zeldin will make the announcement to finalize the repeal on 12 February.

The EPA based its July proposal to revoke the finding on an Energy Department report written by five climate contrarians that downplayed accepted climate science. The National Academies of Sciences, Engineering and Medicine, an independent organization meant to advise the federal government on scientific matters, conducted their own review of the report and found that the 2009 Endangerment Finding was “beyond scientific dispute.”

The science supporting the Endangerment Finding “has only gotten stronger” since 2009, DeAngelo told POLITICO. 

 
Related

•  Trump EPA to Take Its Biggest Swing Yet Against Climate Change Rules
•  EPA ‘Endangerment Finding’ Explained: 5 Facts About the Science and Health Risks
•  Public Speaks Out Against EPA Plan to Rescind Endangerment Finding
•  The EPA is Barreling Toward a Supreme Court Climate Showdown
•  AGU Denounces Trump Administration’s Repeal of the EPA Endangerment Finding
•  Get Involved: AGU Science Policy Action Center
 

In public hearings in August, hundreds of people, including children, scientists, doctors, parents, advocates, and members of Congress, spoke out against the proposal to revoke the Endangerment Finding. Many cited immediate health concerns, worry about the health and safety of future generations, and a fear that the proposal would accelerate environmental degradation.

The move by the EPA will likely be challenged in the courts—which may be one reason the Trump administration has pushed its finalization through so rapidly, according to The New York Times. Legal scholars say the current, conservative-majority Supreme Court is more likely to uphold decisions supporting deregulation while Trump is still in office. 

The administration wants “to not just do what other Republican administrations have done, which is weaken regulations. They want to take the federal government out of the business of regulation, period,” Jody Freedman, director of Harvard Law School’s Environmental and Energy Law Program, told The New York Times.

—Grace van Deelen (@gvd.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
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Source: Community Science

Geographic information system (GIS) maps help researchers, policymakers, and community members see how environmental risks are spread throughout a given region. These types of interactive, layered maps can be used for storytelling, education, and environmental activism. When community members are involved in their use and creation, GIS maps can also be a tool for equity.

Lively et al. outlined a project focusing on mapping the features and flooding risks at and around the Tar Creek Superfund site in Ottawa County, Okla. Ottawa County is home to 10 federally recognized Tribal Nations. Residents have experienced decades of health and environmental harm from the region’s legacy of zinc and lead mining, most of which occurred within the Quapaw Reservation. Although mining ceased in 1970, giant piles of mining waste, mine water discharges, and unstable ground have poisoned residents and made entire towns unlivable. For almost a century, floods have spread these contaminants across downstream communities.

Technical experts and community members with local knowledge worked together to build a GIS map that can be used by community members and leaders. It depicts how floodwaters run through former mining sites, which then ferry toxic waste throughout the region’s creeks and soils.

The map is viewable in various layers that show the locations of different kinds of mining waste, tribal land boundaries, and flood zones designated by the Federal Emergency Management Agency (FEMA). Users can also view layers showing soil types and the locations of aquifers, fault lines, and wells.

Between 2021 and 2023, members of the Local Environmental Action Demanded Agency (LEAD), a community-led organization, connected with GIS professionals through AGU’s Thriving Earth Exchange. This program partners local organizations with volunteer scientists and experts to address environmental or geoscience-related issues in their communities. Many members of the project team contributing to the Tar Creek project were local to the Miami, Okla., region.

Though much of the actual map building was completed by the GIS expert team member, decisions on what to include in each layer of the map were made by LEAD representatives and nonscientist community members. This coproduction defined equity not only by who built or contributed to the map but also by how it is used by the community as a key storytelling tool—helping to educate officials and residents about the ongoing environmental and health risks when flooding occurs in the region. For the team, it was important not to just make the map but also to use it: Production without activism, the researchers said, would make for an unfinished project. (Community Science, https://doi.org/10.1029/2024CSJ000077, 2026)

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

Citation: Owen, R. (2026), Making a map to make a difference, Eos, 107, https://doi.org/10.1029/2026EO260035. Published on 11 February 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.

Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Earth and Space Science

The color of the oceans is an important diagnostic parameter as it reflects the health of oceans, monitors CO2 variability, and tracks ecosystem changes due to environmental stressors. Remote observations of the ocean color (OC) are routinely performed, but rapid changes in this parameter are difficult to capture. Geostationary platforms are uniquely suited for this purpose, because they monitor the same area and can therefore detect changes in real time. However, measurements of OC from geostationary satellites are not routinely performed.

The Tropospheric Emissions: Monitoring of Pollution (TEMPO) geostationary instrument monitors air quality and pollution over North America. Using a new approach, Fasnacht et al. [2025] apply a combination of statistical and machine learning techniques to TEMPO hyperspectral hourly measurements, and obtain OC values across the USA coastal regions and the Great Lakes.

Thus, the authors demonstrate the feasibility of capturing hourly variability of environmental parameters from deep space. This reinforces the scientific value of future dedicated geostationary ocean color missions, such as the Geosynchronous Littoral Imaging and Monitoring Radiometer (GLIMR), and the Geostationary Extended Observations (GeoXO) Ocean Color Instrument (OCX).  

Citation: Fasnacht, Z., Joiner, J., Bandel, M., Ibrahim, A., Heidinger, A., Himes, M. D., et al. (2025). Exploiting machine learning to develop ocean color retrievals from the tropospheric emissions: Monitoring of pollution instrument. Earth and Space Science, 12, e2025EA004341. https://doi.org/10.1029/2025EA004341

—Graziella Caprarelli, Editor-in-Chief, Earth and Space Science

Text © 2026. The authors. CC BY-NC-ND 3.0
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Editors’ Vox is a blog from AGU’s Publications Department.

The surface of Mars represents the comprehensive geochemical inventory of the interactions between the lithosphere, atmosphere, and/or hydrosphere over a period of more than four billion years. By investigating the chemical composition and variability of surface materials, we can reconstruct the planet’s evolutionary history and investigate how different geological processes shaped the surface environment of Mars over geologic time. Due to their unique properties and global distribution, reactive salts of chlorine, called oxychlorine species, constitute an important component of the Martian surface.

A new article in Reviews of Geophysics investigates the state of the knowledge and discusses potential areas of future exploration for oxychlorine species on Mars. Here, we asked the author to give an overview of oxychlorine species on Mars, how scientists study them, and what questions remain.

Why is it important to understand the composition of the surface environment of Mars?

Certain surface materials can serve as diagnostic indicators of early and contemporary aqueous activity on the Martian surface.

Certain surface materials—such as salts and hydrated minerals—can serve as diagnostic indicators of early and contemporary aqueous activity on the Martian surface. Accurately understanding the formation, evolution, and preservation of these minerals that formed in aqueous systems can provide crucial constraints on the chemistry and availability of water that are needed to evaluate habitability conditions on Mars. Furthermore, characterizing the modern surface composition is the essential first step in deconvoluting geochemical cycles as well as assessing regolith toxicity, important for future robotic, sample return, and human missions to Mars.

In simple terms, what are oxychlorine species and where have they been found on Mars?

Oxychlorine species are chemical compounds composed of chlorine and oxygen, ranging from stable salts like perchlorate and chlorate to reactive gases and transient intermediates. This diversity arises from the multiple oxidation states of chlorine, which vary from -1 in chloride (Cl-) to +7 in perchlorate (ClO4-). While perchlorate and chlorate (ClO3-) have been identified on Mars, highly reactive intermediates are also likely to exist, at least transiently, during oxychlorine formation and destruction processes.

These compounds are widely distributed across the Martian surface. The Phoenix lander first detected them in the northern plains, while the Curiosity and Perseverance rovers have confirmed their presence in soil, sediment, and rock samples within the Gale and Jezero craters, respectively. Furthermore, oxychlorine salts have been identified as inclusions within pristine Martian meteorites. These widespread detections suggest that oxychlorines are a global component of the Martian regolith, influencing the planet’s geochemical and environmental evolution.

The locations of oxychlorine detections on the surface of Mars. Credit: Mitra [2025], Figure 2

How do scientists detect and sample oxychlorine species?

Scientists have successfully employed various analytical techniques to identify oxychlorine species on the surface of Mars. The Phoenix lander used ion selective electrodes in the Wet Chemistry Laboratory (WCL) to detect perchlorate anions in the Martian regolith. Additional measurements from the Thermal and Evolved Gas Analyzer (TEGA) and the Surface Stereo Imager (SSI) also confirmed the presence of perchlorate anions. At Gale Crater, the Curiosity rover’s Sample Analysis at Mars (SAM) instrument identified these species by heating samples and measuring the evolution of oxygen and chlorine-bearing gases, such as HCl.

More recently, the Perseverance rover used its Raman and X-ray fluorescence spectroscopy instruments—SHERLOC, SuperCam, and PIXL— to detect oxychlorine species within altered rock assemblages at Jezero Crater. Beyond in situ analysis, orbital instruments like CRISM can be used to detect hydrated oxychlorine salts using visible and near-infrared spectroscopy. Finally, multiple analytical methods in terrestrial laboratories can detect oxychlorine species using spectroscopy, chromatography, and diffraction techniques.

What are recent advances in our understanding of oxychlorine formation and destruction on Mars?

Early research focused on atmospheric production, but the low abundance of oxygen-bearing gases in the Martian atmosphere failed to explain the high concentrations of perchlorate on Mars. Recent studies have identified three additional formation mechanisms: plasma redox chemistry during electrostatic discharges, heterogeneous reactions between chlorine-bearing salts and energetic radiation, and aqueous processes. Among these, the irradiation of chloride minerals and ices by ultraviolet light or galactic cosmic rays is particularly effective on contemporary Mars because the thin atmosphere allows radiation to interact directly with the surface.

Regarding destruction, perchlorate salts can degrade into chlorate when exposed to galactic cosmic radiation. Furthermore, chlorate can be effectively consumed by dissolved ferrous iron or ferrous minerals at temperatures as low as 273 K. While perchlorate remains kinetically stable in the presence of most redox-sensitive materials, reactive intermediates like hypochlorite (ClO–) and ClO2 gas readily react with organic compounds, leading to their mutual destruction.

Oxychlorine cycle on Mars. Credit: Mitra [2025], Figure 5

What does the presence of oxychlorine tell us about Mars’ history?

Oxychlorine species record the unique environmental history of Mars. Chlorine isotope data and detections in meteorites, such as Tissint and EETA79001, suggest an active oxychlorine cycle spanning 4 billion years, indicating that oxidizing fluids have been widespread throughout Martian history. Unlike Earth, where the nitrate-to-perchlorate ratio is high (~104), the ratio on Mars is less than one, except for inclusion in EETA79001. This discrepancy highlights fundamentally different geochemical fixation processes and nitrogen-chlorine cycles between the two planets.

Furthermore, chlorates are effective iron oxidants under Mars-relevant conditions and likely contribute to the formation of the planet’s ubiquitous ferric minerals. Additionally, as potent freezing point depressants, these salts may stabilize transient liquid brines even in modern equatorial regions. As a halogen-rich planet, Mars hosts a reactive surface chemistry where oxychlorine species play a substantially more dominant role than they do on Earth.

Is the presence of oxychlorine species helpful or harmful to human exploration and possible use of Mars?

Oxychlorine species can act as a potential hazard as well as a critical in situ resource for future human exploration.

Oxychlorine species can act as a potential hazard as well as a critical in situ resource for future human exploration. Perchlorate and chlorate salts can thermally decompose to release molecular oxygen (O2) and can thus potentially be used for human consumption. Approximately 60 kg of the Martian regolith, containing ~0.5 to 1 wt.% oxychlorine salt, could theoretically provide a single person’s daily oxygen supply. On the other hand, perchlorate is a well-known contaminant in drinking water since it interferes with thyroid functioning and can cause a goiter. Therefore, perchlorate in the Martian regolith could be a possible source of contamination for drinking water or agricultural systems. Owing to high chemical reactivity and oxidation potential, oxychlorine salts present in the Martian regolith are likely to pose persistent cleaning challenges for habitats, suits, and equipment during extra vehicular activity (EVA) on Mars. Additionally, agriculture in the oxychlorine-laden regolith might lead to contamination of plants and vegetables and could eventually lead to biomagnification in humans.

What are some of the remaining questions where additional research is needed?

While oxychlorine research has flourished over the last two decades, critical gaps remain regarding the spatial distribution and formation rates of distinct species. Recent detections of atmospheric HCl and electrostatic discharges necessitate a rigorous re-evaluation of Martian atmospheric chemistry. By leveraging emerging terrestrial models of chlorate formation, new pathways for Martian oxychlorine production can be proposed. Determining the relative contributions of atmospheric, plasma redox, and heterogeneous pathways is vital to understanding the evolution of the chlorine cycle and estimating equilibrium concentrations and residence times.

Furthermore, the chemical reactivity of transient intermediates, specifically ClO2 gas and chlorite, remains poorly understood regarding organic preservation at low temperatures. We also require precise thermodynamic data on complex salt mixtures to accurately predict brine stability. Ultimately, experimental validation of these salts as a viable in situ resource for oxygen and fuel is imperative for future human exploration and the interpretation of returned Martian samples.

—Kaushik Mitra (kaushik.mitra@utsa.edu; 0000-0001-9673-1032), The University of Texas at San Antonio, United States

Citation: Mitra, K. (2026), A double-edged sword: the global oxychlorine cycle on Mars, Eos, 107, https://doi.org/10.1029/2026EO265004. Published on 10 February 2026. 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 © 2026. The authors. CC BY-NC-ND 3.0
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A major part of the Atlantic Meridional Overturning Circulation (AMOC), a large-scale ocean circulation pattern, was warmer during the peak of Earth’s last ice age than previously thought, according to a new study published in Nature. 

The study’s results contrast with those from previous studies hinting that the North Atlantic was relatively cold and that AMOC was weaker when faced with major climate stress during the Last Glacial Maximum (LGM), about 19,000–23,000 years ago. 

The findings add confidence to models that scientists use to project how AMOC may change in the future as the climate warms, said Jack Wharton, a paleoceanographer at University College London and lead author of the new study.

Deepwater Data

The circulation of AMOC, now and in Earth’s past, requires the formation of dense, salty North Atlantic Deep Water (NADW), which brings oxygen to the deep ocean as it sinks and helps to regulate Earth’s climate. Scientists frequently use the climatic conditions of AMOC during the LGM as a test to determine how well climate models—like those used in major global climate assessments—simulate Earth systems. 

However, prior to the new study, few data points existed to validate scientists’ models showing the state of NADW during the LGM. Scientists in 2002 analyzed fluid in ocean bottom sediment cores from four sites in the North Atlantic, South Pacific, and Southern Oceans, with results suggesting that deep waters in all three were homogeneously cold.

Researchers sampled 16 sediment cores from across the North Atlantic to deduce how waters may have circulated during the peak of the last ice age. Credit: Jack Wharton, UCL

“The deep-ocean temperature constraints during the [Last Glacial Maximum] were pretty few and far between,” Wharton said. And to him, the 2002 results were counterintuitive. It seemed more likely, he said, that the North Atlantic during the peak of the last ice age would have remained mobile and that winds and cold air would have cooled and evaporated surface waters, making them saltier, denser, and more prone to create NADW and spur circulation.

“This is quite new,” he remembered thinking. “What kind of good science could help show that this is believable?”

Wharton and his colleagues evaluated 16 sediment cores collected across the North Atlantic. First, they measured the ratio of trace magnesium and calcium in microscopic shells of microorganisms called benthic foraminifera. This ratio relates to the temperature at which the microorganisms lived. The results showed much warmer North Atlantic Deep Water than the 2002 study indicated. 

Wharton felt cautious, especially because magnesium to calcium ratios are sometimes affected by ocean chemistry as well as by temperature: “This is quite new,” he remembered thinking. “What kind of good science could help show that this is believable?”

The team, this time led by Emilia Kozikowska, a doctoral candidate at University College London, verified the initial results using a method called clumped isotope analysis, which measures how carbon isotopes in the cores are bonded together, a proxy for temperature. The team basically “did the whole study again, but using a different method,” Wharton said. The results aligned. 

Ratios of magnesium to calcium contained in benthic foraminifera, tiny microbes living in marine sediment, offer insights into the temperature of North Atlantic waters thousands of years ago. Credit: Jack Wharton and Mark Stanley

Analyzing multiple temperature proxies in multiple cores from a broad array of locations made the research “a really thorough and well-done study,” said Jean Lynch-Stieglitz, a paleoceanographer at the Georgia Institute of Technology who was not part of the research team but has worked closely with one of its authors. 

The results, in conjunction with previous salinity data from the same cores, allowed the team to deduce how the North Atlantic likely moved during the LGM. “We were able to infer that the circulation was still active,” Wharton said. 

Modeling AMOC

The findings give scientists an additional benchmark with which to test the accuracy of climate models, Lynch-Stieglitz said. “LGM circulation is a good target, and the more that we can refine the benchmarks…that’s a really good thing,” she said. “This is another really nice dataset that can be used to better assess what the Last Glacial Maximum circulation was really doing.”

“Our data [are] helping show that maybe AMOC was sustained.”

In many widely used climate models, North Atlantic circulation during the LGM looks consistent with the view provided by Wharton’s team’s results, indicating that NADW was forming somehow during the LGM, Lynch-Stieglitz said. However, no model can completely explain all of the proxy data related to the LGM’s climatic conditions.

“Our data [are] helping show that maybe AMOC was sustained,” which helps reconcile climate models with proxy data, Wharton said. Lynch-Stieglitz added that a perhaps equally important contribution of the new study is that it removes the sometimes difficult-to-simulate benchmark of very cold NADW during the LGM that was suggested in research in the early 2000s. “We don’t have to make the whole ocean super cold [in models],” she said.

Some climate models suggest that modern-day climate change may slow AMOC, which could trigger a severe cooling of Europe, change global precipitation patterns, and lead to additional Earth system chaos. However, ocean circulation is highly complex, and models differ in their ability to project future changes. Still, “if they could do a great job with LGM AMOC, then we would have a lot more confidence in their ability to project a future AMOC,” Lynch-Stieglitz said.

Wharton said the results also suggest that another question scientists have been investigating about the last ice age—how and why it ended—may be worth revisiting. Many hypotheses rely on North Atlantic waters being very close to freezing during the LGM, he said. “By us suggesting that maybe they weren’t so close to freezing…that sort of necessitates that people might need to rethink the hypotheses.”

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

Citation: van Deelen, G. (2026), The AMOC of the ice age was warmer than once thought, Eos, 107, https://doi.org/10.1029/2026EO260053. Published on 10 February 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
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Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Geophysical Research Letters  

Thunderstorms, produced when air rises through the depth of the troposphere, are notoriously difficult to represent in global climate models. Whether air parcels have the energy to rise or not does not depend solely on their characteristics, notably their “Convective Available Potential Energy” (CAPE). It is relative to the state of the environment around them. Specifically, the intensity that they reach, which translates into the potential to produce hail, lightning or damaging winds, depends on how much surrounding air is “entrained” from the sides as the air rises.

Peters et al. [2026] propose a new formulation for CAPE, that they call ECAPE for Entraining CAPE, which incorporates the effect of entrainment from first principles. To verify their theory, they first show that it predicts the geographical distribution of thunderstorms hotspots, such as the U.S. Great Plains, the Pampas of South America, and the African Sahel. They then use it to explain why thunderstorms are more intense over land than over oceans: because of a higher lifting condensation level (LCL) over land, that is, a higher bar that rising air has to reach before it can rise all the way to the top. In addition to solving this longstanding issue, the very fine resolution of the analysis (100m, 1hr) provides an invaluable benchmark for the current generation of kilometer-scale global models being developed.

Citation: Peters, J. M., Chavas, D. R., Su, C.-Y., Murillo, E. M., & Mullendore, G. L. (2026). A unified theory for the global thunderstorm distribution and land–sea contrast. Geophysical Research Letters, 53, e2025GL120252. https://doi.org/10.1029/2025GL120252   

—Alessandra Giannini, Editor, Geophysical Research Letters

Text © 2026. The authors. CC BY-NC-ND 3.0
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Editors’ Vox is a blog from AGU’s Publications Department.

Coastal (tidal) wetlands are low-lying ecosystems found where land meets the sea, including mangroves, saltmarshes, and seagrass meadows. They are shaped by tides and support a mix of marine and terrestrial processes. However, agricultural and urban development over the past century have drained, modified, or degraded many of these coastal wetland ecosystems and now require restoration efforts.

A new article in Reviews of Geophysics explores how subsurface hydrology and biogeochemical processes influence carbon dynamics in coastal wetlands, with a particular focus on restoration. Here, we asked the lead author to give an overview of why coastal wetlands matter, how restoration techniques are being implemented, and where key opportunities lie for future research.

Why are coastal wetlands important?

Coastal wetlands provide many benefits to both nature and people. They protect shorelines from storms and erosion, support fisheries and biodiversity, improve water quality by filtering nutrients and pollutants, and store large amounts of carbon in their soils. Despite covering a relatively small area globally, they punch well above their weight in terms of ecosystem services, making them critical environments for climate regulation, coastal protection, and food security.

What role do coastal wetlands play in the global carbon cycle?

Coastal wetlands are among the most effective natural systems for capturing and storing carbon.

Coastal wetlands are among the most effective natural systems for capturing and storing carbon. This stored carbon is often referred to as “blue carbon”. Vegetation in these ecosystems, such as mangroves, saltmarsh, and seagrass, take up carbon dioxide from the atmosphere through photosynthesis and transfer it to sediments through roots. These plants can store carbon 40 times faster than terrestrial forests. Because coastal wetland sediments are often waterlogged and low in oxygen, this carbon can be stored for centuries to millennia. In addition to surface processes, groundwater plays an important but less visible role by transporting dissolved carbon into and out of wetlands. Understanding these hidden subsurface pathways is essential for accurately estimating how much carbon wetlands store and how they respond to environmental change.

How has land use impacted coastal wetlands over the past century?

Over the past century, coastal wetlands have been extensively altered or lost due to human activities. Large areas have been drained, filled, or isolated from tides to support agriculture, urban development, ports, and flood protection infrastructure. These changes disrupt natural water flow, reduce plant productivity, and expose carbon-rich soils to oxygen, which can release stored carbon back into the atmosphere as greenhouse gases. In many regions, groundwater flow paths have also been modified by drainage systems and groundwater extraction, further altering wetland function. As a result, many coastal wetlands have shifted from long-term carbon sinks to sources of emissions.

How could restoring wetlands help to combat climate change?

Restoring coastal wetlands can help combat climate change by re-establishing natural processes that promote long-term carbon storage.

Restoring coastal wetlands can help combat climate change by re-establishing natural processes that promote long-term carbon storage. When tidal flow and natural hydrology are restored, wetland plants can recover, sediment accumulation increases, and carbon burial resumes. Importantly, restoration can also reconnect groundwater and surface water systems, helping stabilize (redox) conditions that favor carbon preservation in sediments. While wetlands alone cannot solve climate change, they offer a powerful nature-based solution that delivers climate mitigation alongside co-benefits such as coastal protection, biodiversity recovery, and improved water quality. Getting restoration right is key to ensuring these systems act as carbon sinks rather than sources.

What are the main strategies being deployed to restore coastal wetlands?

Common restoration strategies include removing or modifying levees and tidal barriers, reconnecting wetlands to natural tidal regimes, re-establishing natural vegetation through improving the hydrology of the site, and managing sediment supply. Increasingly, restoration projects are recognizing the importance of subsurface processes, such as groundwater flow and salinity dynamics, which strongly influence vegetation health and carbon cycling. Successful restoration requires site-specific designs that consider hydrology, geomorphology, and long-term sea-level rise.

What are some remaining questions where additional research efforts are needed?

Despite growing interest in wetland restoration, major knowledge gaps remain. One key challenge is quantifying how groundwater processes influence carbon storage and greenhouse gas emissions across different wetland types and climates. We also need better long-term measurements to assess whether restored wetlands truly deliver sustained carbon benefits under rising sea levels and increasing climate variability. Finally, integrating hydrology, biogeochemistry, and ecology into predictive models remains difficult but essential. Addressing these gaps will improve carbon accounting, guide smarter restoration investments, and strengthen the role of coastal wetlands in climate mitigation strategies.

—Mahmood Sadat-Noori (mahmood.sadatnoori@jcu.edu.au; 0000-0002-6253-5874), James Cook University: Townsville, Australia

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: Sadat-Noori, M. (2026), Coastal wetlands restoration, carbon, and the hidden role of groundwater, Eos, 107, https://doi.org/10.1029/2026EO265003. Published on 9 February 2026. 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 © 2026. The authors. CC BY-NC-ND 3.0
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Source: Water Resources Research

If humans want to live in space, whether on spacecraft or the surface of Mars, one of the first problems to solve is that of water for drinking, hygiene, and life-sustaining plants. Even bringing water to the International Space Station (ISS) in low Earth orbit costs on the order of tens of thousands of dollars. Thus, finding efficient, durable, and trustworthy ways to source and reuse water in space is a clear necessity for long-term habitation there.

Current systems, like the Environmental Control and Life Support System (ECLSS) on the ISS, offer a blueprint for closed-loop water reclamation, but they need improvements for future applications. Meanwhile, recent technological and scientific advances are pointing to new ways of finding, purifying, and managing water resources in demanding environments. In a new review, Olawade et al. provide an overview of the current state of extraterrestrial water management, as well as of the field’s prospects and challenges.

Water systems in space need to be closed loop, highly efficient, and durable, all while having low energy requirements, the authors say. Currently, the ECLSS is prohibitively energy intensive, and may not be efficient enough, for use on longer missions. Future suggested approaches for filtration and recycling include photocatalysis to purify water via light, bioreactors to filter urine and wastewater, ion-exchange systems to remove dissolved salts and heavy metals from extracted water, and ultraviolet or ozone disinfection to kill pathogens. Each comes with its own pros and cons: Microbial fuel cells in bioreactors could produce electricity, for example, but photocatalytic purification has low energy demands.

Sourcing water on places like the Moon or Mars would require either extracting water bound up in regolith or drilling into ice bodies. Sufficiently powering water reclamation systems is another concern, making energy-efficient systems a priority. Water system durability is also important, both to protect inhabitants and to reduce the need for onerous maintenance work.

Emerging technologies could meet many of these challenges. The authors point to advances in nanotechnology, which could be used to create highly tailored membranes for filtration that are more effective and resistant to fouling, and to the use of artificial intelligence (AI) to autonomously manage water systems, as two areas of promise. (Water Resources Research, https://doi.org/10.1029/2025WR041273, 2026)

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2026), A road map to truly sustainable water systems in space, Eos, 107, https://doi.org/10.1029/2026EO260023. Published on 9 February 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.

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.

Students who have applied for the Graduate Research Fellowship Program (GRFP) from the National Science Foundation (NSF) have had their applications returned without review—even though their proposed research appears to fall squarely within the fields of study outlined in the program solicitation.

In response, a group of scientists created a template letter for students to share concerns with their representatives.

GRFP provides 3 years of financial support over a 5-year fellowship program for outstanding graduate students pursuing full-time degrees in science, technology, engineering, or math (STEM), including STEM education. The program solicitation, posted in September 2025, lists the following fields as eligible.

1. Chemistry
2. Computer and Information Sciences and Engineering
3. Engineering
4. Geosciences
5. Life Sciences
6. Materials Research
7. Mathematical Sciences
8. Physics & Astronomy
9. Psychology
10. Social, Behavioral, and Economic Sciences
11. STEM Education and Learning Research

However, at least dozens of applicants in those fields have received emails, obtained by Eos, that stated that their proposals were ineligible.

 Related

•  Thread in the GRFP subreddit
•  Grant Witness Template for Letter to Representatives
•  Get Involved: AGU Science Policy Action Center

 

“The proposed research does not meet NSF GRFP eligibility requirements. Applicants must select research in eligible STEM or STEM education fields,” the email read.

Neuroscience, physiology, ecology/biogeochemistry, and chemistry of life sciences are among the proposal research topics that have been returned without review (RWR), according to posts on Reddit and Bluesky.

One Redditor described the RWR as “soul-crushing.” “The dropdown menu part is what gets me,” they wrote, referring to how they selected a category from a list within the application. “What do you mean I am ineligible in a category that YOU provided?!”

Karolina Heyduk, an ecologist and evolutionary biologist at the University of Connecticut, shared on Bluesky that one of her student’s applications was rejected. Heyduk told Eos over email that she has no idea why, as the research—on photosynthesis in bromeliads—was “clearly within stated fields that are eligible, and had no agriculture, health, or policy angles.”

“The GRFP is an opportunity for new scientists to propose their best ideas and get their first shot at external funding. While not everyone will be funded, there is some expectation of a fair and transparent review process, and that doesn’t seem to be happening this year. For new grad students, or those applying this year, the outright rejection without a clear reason is incredibly discouraging,” she told Eos.

Rejected Appeals

Some applicants have appealed the decision, after having advisers look over their applications, and have received responses, also obtained by Eos, affirming that the decision is final.

“As your application was thoroughly screened based on these eligibility criteria, the RWR determination will stand and there will be no further consideration of your application,” the email text read.

Last March, the New York Times compiled, via government memos, agency guidance, and other documents, a list of words that the Trump administration indicated should be avoided or limited. The list included “climate science,” “diversity,” “political,” and “women.”

On Reddit threads, applicants who received RWR are speculating over whether their applications may have been automatically rejected for the use of so-called banned words. One student used the word “underrepresented” in a personal statement, to reference a program to which they had previously been accepted. Others, applying for neuroscience fellowships that involved studies with rats, wondered whether the word “ethanol” had been flagged. Another said they had tried to avoid using banned words, but that it was “unavoidable.”

“My project is about bears and ‘black’ is a trigger word,” they wrote. “Insane.”

Reaching out to Representatives

The group behind the template letter for students includes Noam Ross, who is among the creators of Grant Witness, a project to track the termination of scientific grants under the Trump administration. The letter notes that, after NSF awarded significantly fewer GRFP awards than usual in the spring, it released its guidance for this year’s application more than a month later than usual—leaving students with much less time than usual to complete their applications, and leaving others ineligible to apply.

“I request that you contact the NSF administrator to ask why eligible GRFP applications are being rejected without review and to ask them to remedy the situation quickly, as review panels are convening imminently,” the letter reads. “We cannot allow the continued degradation of our scientific workforce, and [the cutting] off the opportunities for so many future scientists.”

—Emily Gardner (@emfurd.bsky.social), Associate Editor

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
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Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Space Weather 

The solar wind is a continuous stream of charged particles released from the Sun into the solar system. It plays a major role in space weather, which can impact satellites, astronauts, and power systems on Earth. Forecasting the solar wind often depends on detailed maps of the Sun’s magnetic field and complex models of the solar corona, which introduce uncertainty and are not always available.

Owens et al. [2026] present a new approach that uses solar wind measurements near Earth to reconstruct solar wind conditions closer to the Sun. By tracing the solar wind back towards its source, the method provides realistic starting conditions for solar wind models without relying on magnetic maps. The authors show that this approach can produce realistic solar wind conditions while reducing assumptions and sources of error. This simpler set-up allows the method to be applied consistently across different modelling frameworks.

This work represents an important step towards more robust and accessible solar wind modeling. In the long term, it can help improve space weather forecasts and our ability to protect technology and infrastructure in space and on Earth.

Citation: Owens, M. J., Barnard, L. A., Turner, H., Gyeltshen, D., Edward-Inatimi, N., O’Donoghue, J., et al. (2026). Driving dynamical inner-heliosphere models with in situ solar wind observations. Space Weather, 24, e2025SW004675. https://doi.org/10.1029/2025SW004675

—Tanja Amerstorfer, Associate Editor, Space Weather

Text © 2026. The authors. CC BY-NC-ND 3.0
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Source: Journal of Geophysical Research: Biogeosciences

From 1948 to 1953, a gold mine called Giant Mine released about 5 tons of arsenic trioxide per day into the environment around Yellowknife, Northwest Territories, Canada. Emissions declined from the 1950s until the mine closed in 2004, but the surrounding landscape remains highly contaminated with arsenic.

Little et al. recently studied how the spring thaw influences arsenic levels in four Yellowknife area lakes and how phytoplankton populations alter arsenic biogeochemistry during this transition period. The researchers sampled each lake twice per year in 2022 and 2023: once in late April, before the beginning of the spring thaw period, and once 7–10 days later, when the thaw had begun but the ice was still thick enough to safely walk on, making sample collection feasible.

Sammy’s, Handle, Frame, and Jackfish lakes spanned a gradient of arsenic contamination levels when measured before the thaw in 2022—from 5.5 micrograms per liter in Sammy’s Lake to 350 micrograms per liter in Frame Lake. In Handle, Frame, and Jackfish lakes, arsenic levels went down as the spring thaw began, but Sammy’s Lake followed the opposite trend. The difference likely lies in how much arsenic the lakes contained to begin with. With Sammy’s Lake starting at such a low level, arsenic from meltwater exacerbated the contamination. In the other three lakes, the concentration of arsenic in meltwater was lower than or similar to the starting concentration in the lake, so meltwater diluted the contamination.

Arsenic exists mostly in two oxidation states: arsenite and the less toxic, less mobile arsenate. Because arsenate is more stable under oxic conditions, the influx of highly oxygenated snow and ice meltwater during the spring thaw period was accompanied by a predictable shift in the predominant form of arsenic in the lakes.

The winter of 2022 was significantly colder than 2023, with the difference reflected in the thickness of the ice: 76–130 centimeters in 2022 compared with 65–72 centimeters in 2023. The warm winter did not alter the final arsenic concentration or speciation in the water at the end of the thaw. However, an increase was observed in plankton communities in more mature life stages and in taxa that are more competitive in warmer conditions. This result is important, the authors say, because late winter and spring thaw plankton community dynamics set the stage for the following open-water season. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG009231, 2026)

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

Citation: Sidik, S. M. (2026), How the spring thaw influences arsenic levels in lakes, Eos, 107, https://doi.org/10.1029/2026EO260051. Published on 6 February 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.