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Publication date: Available online 17 November 2025

Source: Advances in Space Research

Author(s): Yu Chen, Guangxing Wang, Massimo Menenti

Publication date: Available online 17 November 2025

Source: Advances in Space Research

Author(s): Bushra Ansari, Sanat K. Biswas

Publication date: Available online 17 November 2025

Source: Advances in Space Research

Author(s): Ayşe Yadikar Habalı, Volkan Bakış

Who owns the rainforest—and who has the right to use it—might seem like a simple question.

Why do some earthquakes release more energy than others? A research team led by Prof. Dr. Armin Dielforder from the University of Greifswald has managed to demonstrate a clear physical connection between the energy released during earthquakes and the strength of rocks deep in the Earth's crust.

As a result of climate change, rising sea levels are threatening low-lying coastal areas around the world, such as the Wadden Sea in the North Sea. Tidal basins form a natural protective barrier there. They connect the mainland with the offshore islands. They fill with seawater during high tide and empty again during low tide. Sediments are deposited in the process, causing the seabed to rise steadily.

Shackleford Banks is an 8-mile-long barrier island off the coast of North Carolina made up of sandy beaches, marshes, and maritime forests. There are no vacation rentals, boardwalks, or seafood restaurants serving the residents of Shackleford Banks. That’s because the residents are more than 100 wild horses that call the sandy dunes of this island home.

The delicate ecosystem of Shackleford Banks is facing the effects of a changing climate, such as increasingly volatile storms and flooding, drought, erosion, and saltwater intrusion. The island’s low elevation means its freshwater sources can be infiltrated with salt water during king tide events and storm surges. During stretches of drought, freshwater sources for the island’s equine residents can run dry, leaving the horses to compete for these vital resources.

“These horses have been out here long enough to adapt and survive, but freshwater availability is a critical resource,” said Matthew Sirianni, a geoscientist at East Carolina University who will present his research on 16 December at AGU’s Annual Meeting. Sirianni and colleagues monitored freshwater sources on Shackleford Banks, finding that horse behavior changed when freshwater sources were scarce. As saltwater intrusion and coastal hazards increase along the islands off the coast of North Carolina known as the Outer Banks, these findings can improve understanding of how to manage wildlife during a changing climate.

Foraging for Fresh Water

Wild horses have lived on Shackleford Banks for centuries. One theory suggests they arrived in the 1500s, swimming to shore after Spanish explorers were shipwrecked along the East Coast. Genetic testing suggests today’s Shackleford Banks horses are related to Spanish horse breeds, but early English settlers also brought horses with them that may also have escaped or been abandoned along the Outer Banks.

A horse digs in a pool of surface water at a groundwater seep during low tide on Shackleford Banks. These temporary pools will be flooded by the next high tide. Credit: Matthew Sirianni

Today, Shackleford Banks’s wild horse population must be kept to a manageable number so that the island and its resources aren’t overwhelmed. National Park Service workers dart the mares with hormonal birth control each year to keep herd size low. The small, hardy equines have adapted to a life of eating marsh grass, sea oats, and wax myrtle. They drink from ponds and freshwater seeps, and they also dig holes in the sand to reach the freshwater belowground when other sources have dried up.

In the new study, researchers monitored surface and groundwater levels and conductivity—a proxy measurement for salinity because higher conductivity values mean saltier water—in six water sources (two ponds, one groundwater seep, and three dig sites) located across the island.

“Barrier islands often develop a freshwater lens in the subsurface that floats on top of the denser, saltier water,” Sirianni said. “By monitoring water level and water conductivity, we can, over time, see whether the freshwater lens is shrinking, growing, or getting saltier, which tells us how the island’s water resources are responding to things like tides, storms, or droughts.”

Researchers installed motion-activated trail cameras near the water sources to capture still shots of animals drinking. They then grouped time-stamped photos to connect the horses’ drinking activities with water level and conductivity data. From there, they searched for water usage patterns, as well as for information about how long horse-dug holes (some as deep as 3 feet) stayed full of fresh water.

“Preliminary results from July 2024 to April 2025 indicate that horses spend more time drinking at dig sites, where conductivity is lower and more stable, compared to ponds and the groundwater seep, where conductivity is higher and more variable. However, when rainfall is low, dig sites often run dry, leading horses to drink from these higher-conductivity sources,” Sirianni said.

A Saltier Future?

“In the past, we’ve said that horses wouldn’t drink brackish water, but we were wrong. They do drink brackish water when that’s the only thing available to them.”

“With the research that [Sirianni] is doing, we have learned that these ponds can be really brackish,” said Linda Kuhn, a volunteer veterinarian with the National Park Service who was not involved with the research. “In the past, we’ve said that horses wouldn’t drink brackish water, but we were wrong. They do drink brackish water when that’s the only thing available to them.”

If the freshwater sources become saltier, history has already shown how the wild horses could be in trouble. On the island of Chincoteague, Virginia, equine deaths and illness were linked to a toxic increase in salinity in freshwater supplies, possibly wrought by the storm surge from Hurricane Erin.

It took 2 weeks for volunteers and observers to figure out what was wrong at Chincoteague. “Here we have [Sirianni] giving us data in real time. He also has cameras out there so he can see who’s drinking.” In light of what happened to the Chincoteague ponies after Hurricane Erin, “it’s just such an important study at this time,” Kuhn said.

“These horses have been here for many years and weathered many storms, so…they are a symbol of wildness and freedom even in the face of adversity.”

And with the potential for stronger, damaging storms in the future, the wild horses in this precarious island habitat may face more water and food shortages—along with danger from the land itself. Previous modeling studies suggest sea level rise will cause the already shallow groundwater table to reach the surface, as well as cause the shoreline to retreat as land subsidence and erosion worsen.

Sirianni plans to continue monitoring Shackleford Banks’s wild horses and water sources through at least July 2026 while he works on a final study manuscript about his findings. But he hopes to fund this research into the future. “These horses have been here for many years and weathered many storms, so I like that they are a symbol of wildness and freedom even in the face of adversity,” he said.

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

Citation: Owen, R. (2025), What salty water means for wild horses, Eos, 105, https://doi.org/10.1029/2025EO250433. Published on 21 November 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Geophysical Research Letters

Ancient Mars boasted abundant water, but the cold and dry conditions of today make liquid water on the Red Planet seem far less probable. However, the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) detected strong radar reflections from a 20-kilometer-wide area over the base of Mars’s southern polar ice cap, hinting at the possibility of liquid water below the icy surface. Such a finding would have major implications for the planet’s possible habitability.

But sustaining liquid water underneath the ice might not be feasible without very salty brines or localized volcanic heat. Scientists have deliberated about other possible “dry” explanations for the bright reflections detected by MARSIS, such as layers of carbon dioxide and water ices or salty ice and clay causing elevated radar reflectivity.

Aboard the Mars Reconnaissance Orbiter, the Shallow Radar (SHARAD) uses higher frequencies than MARSIS. Until recently, though, SHARAD’s signals couldn’t reach deep enough into Mars to bounce off the base layer of the ice where the potential water lies—meaning its results couldn’t be compared with those from MARSIS.

However, the Mars Reconnaissance Orbiter team recently tested a new maneuver that rolls the spacecraft on its flight axis by 120°—whereas it previously could roll only up to 28°. The new maneuver, termed a “very large roll,” or VLR, can increase SHARAD’s signal strength and penetration depth, allowing researchers to examine the base of the ice in the enigmatic high-reflectivity zone.

Morgan et al. examined 91 SHARAD observations that crossed the high-reflectivity zone. Only when using the VLR maneuver was a SHARAD basal echo detected at the site. In contrast to the MARSIS detection, the SHARAD detection was very weak, meaning it is unlikely that liquid water is present in the high-reflectivity zone. The researchers suggest that the faint detection returned by SHARAD under this portion of the ice cap is likely due to a localized region of smooth ground beneath the ice. They add that further research is needed to reconcile the differences between the MARSIS and SHARAD findings. (Geophysical Research Letters, https://doi.org/10.1029/2025GL118537, 2025)

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

Citation: Owen, R. (2025), Maybe that’s not liquid water on Mars after all, Eos, 106, https://doi.org/10.1029/2025EO250437. Published on 21 November 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

Continental extension often unfolds in multiple deformation phases, where earlier faults steer the geometry and behavior of later ones. In a new study, Liu et al. [2025] explore the complexity of fault interaction by analogue modeling. 

The models reveal how shifts in stress—from biaxial to triaxial and back—govern the evolution of the fault network. In the triaxial phase, faults from the earlier biaxial phase are reactivated and new conjugate faults appear. When stress shifts back to biaxial, older faults may become inactive or partly reactivated. Stress conditions determine whether old faults block or guide the growth of new ones. Their modeling results are applied to explain the patterns of abandoned, reactivated and newly developed faults seen in the Aegean and Barents Seas. In general, their findings help to shed light on both the tectonic history of their study areas and the distribution of earthquakes.

Citaiton: Liu, J., Rosenau, M., Kosari, E., Brune, S., Zwaan, F., & Oncken, O. (2025). The evolution of fault networks during multiphase triaxial and biaxial strain: An analogue modeling approach. Journal of Geophysical Research: Solid Earth, 130, e2025JB031180. https://doi.org/10.1029/2025JB031180

—Birgit Müller, Associate Editor, JGR: Solid Earth

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

The explosiveness of a volcanic eruption depends on how many gas bubbles form in the magma—and when. Until now, it was thought that gas bubbles were formed primarily when the ambient pressure dropped while the magma was rising.

Across Europe, scientists and citizens are uncovering a hidden legacy of contamination beneath their feet. From Denmark's first PFAS crisis to a new generation of soil-mapping initiatives, a continent is learning to see—and stop—the pollution it once ignored

Imagine trying to predict wind patterns as air flows across a landscape. It's a straightforward task over a flat plain—but becomes more complex when the terrain shifts to jagged mountain ranges. Here, wind does not simply sweep over peaks; it is deflected, slowed, and forced into gravity waves.

A recent study led by scientists at NASA's Jet Propulsion Laboratory in Southern California and the nonprofit Aerospace Corporation shows how high-resolution maps of ground-level ammonia plumes can be generated with airborne sensors, highlighting a way to better track the gas.

A mysterious swarm of earthquakes that occurred near the Greek island of Santorini in early 2025 was caused by rebounding sheets of magma slicing through Earth's crust, according to a new study by an international team involving a UCL (University College London) researcher.

While it is well known that climate change is heating the world's oceans, it was thought that the deep sea was safe from its effects—until now. Researchers have discovered that a rapidly warming part of the Atlantic is leading to the heating up of Arctic Ocean depths.

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

Rising sea levels have put thousands of facilities containing hazardous materials at risk of flooding this century, according to a new study published in Nature Communications. 

Global sea level rise is accelerating, leading to an increase in coastal flooding that scientists expect to worsen. As seas rise, floodwater reaches infrastructure that was not built to withstand it.

“Flooding from sea level rise is dangerous on its own—but when facilities with hazardous materials are in the path of those floodwaters, the danger multiplies.”

These extreme events can release toxins into the environment. For example, an estimated 10 million pounds of pollutants from refineries, petrochemical facilities, and manufacturing sites spilled into the environment following flooding from Hurricane Harvey in 2017.

The new study reports that 5,500 facilities containing hazardous substances are at risk of a similar event, threatening the health of nearby communities. 

“Flooding from sea level rise is dangerous on its own—but when facilities with hazardous materials are in the path of those floodwaters, the danger multiplies,” Lara Cushing, an environmental researcher at the University of California, Los Angeles and lead author of the new study, told The Guardian. 

In the study, scientists analyzed the location of 47,646 coastal power plants, sewage treatment facilities, fossil fuel infrastructure sites, industrial facilities, and former defense sites. Then, they used sea level rise projections under various climate scenarios to determine whether those sites were at risk from a 1-in-100-year flood event by 2100. 

They found that 11% of the sites analyzed were at risk of such a flood by 2100 in a high-emissions, business-as-usual scenario (RCP 8.5). Eighty percent of the at-risk sites were in just seven states: Louisiana, Florida, New Jersey, Texas, California, New York, and Massachusetts. Oil and gas wells made up a large proportion of sites considered to be at risk. 

These maps and graphs show the number and types of coastal facilities at risk of flooding due to sea level rise by 2050 and 2100 under a high-emissions, business-as-usual scenario. Credit: Cushing et al. 2025, doi:10.1038/s41467-025-65168-2, CC BY 4.0

In total, 22% of coastal sewage treatments facilities, 24% of coastal refineries, 44% of coastal fossil fuel ports and terminals, 12% of coastal industrial facilities, 21% of former coastal defense sites, and 21% of coastal fossil fuel and nuclear power plants are at risk of flooding by 2100. 

Disproportionate Effects

Marginalized groups are more likely to live near hazardous waste sites and industrial facilities, making these groups more vulnerable when such facilities flood. 

In the study, researchers analyzed the location of at-risk sites compared to community demographics. They found that households in Hispanic neighborhoods, households with incomes below twice the federal poverty line, and households that rented rather than owned their homes were especially likely to be located within one kilometer (0.62 miles) from a facility at risk of flooding.

 
Related

•  Read the study: “Sea level rise and flooding of hazardous sites in marginalized communities across the United States.”
•  Climate Central Report: Toxic Tides
•  Thousands of Toxic Sites Across U.S. Face Risk of Coastal Flooding
•  Sea Level Rise Threatens Hundreds of Wastewater Treatment Plants
• Sea Level Rise May Swamp Many Coastal U.S. Sewage Plants
 

“These projected dangers are falling disproportionately on poorer communities and communities that have faced discrimination and therefore often lack the resources to prepare for, retreat, or recover from exposure to toxic floodwaters,” Cushing said.

Reducing greenhouse gas emissions is key to slowing sea level rise and reducing flooding. The study’s projections showed that restricting greenhouse gas emissions to a low-emissions scenario (RCP 4.5) would reduce the number of at-risk sites from 5,500 to 5,138. 

In addition, the authors write that keeping communities safe from future hazardous floodwaters will require federal and state governments to “provide publicly available, accessible, and continually updated data on projections of [sea level rise]-related flooding threats.”

—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 science or scientists? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Climate change will make monsoon storms in South Asia wetter and weaker, with more storms pushing further inland across India.

As global efforts intensify around restoring coastal wetlands to curb climate change, a new JCU-led study published in Reviews of Geophysics is the first to link wetland restoration and carbon cycling with groundwater dynamics, showing that subsurface flows can tip the balance from storing carbon to emitting it.

After a long and deadlocked bidding process for Australia and Pacific Island nations to co-host the UN climate summit (COP31), the event will now be hosted by Turkey. Australia's Climate Minister, Chris Bowen, will reportedly take a key role as "COP President for negotiations". More details are yet to emerge.

In recent years, more and more lobbyists from the oil, gas and coal industries have taken part in international climate negotiations. Estimates of lobbyist numbers have risen sharply, from 503 at the 2021 Glasgow talks to 1,773 at last year's talks in Azerbaijan's capital Baku.