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A new study analyzed nearly four decades of deep ocean observations to reveal significant cooling and freshening of deep water in the Subtropical North Atlantic. The results suggest that warmer, saltier deep waters observed across other parts of the Atlantic may reach the region within the next 10 years, potentially influencing large-scale sea level changes and altering the flow of ocean currents in the region.

Methane emissions from a large open-cast coal mine in Australia are three to eight times higher than reported. This has been revealed in a study based on aircraft-based measurements by the University of Bremen and Airborne Research Australia (ARA). It is the first time that precise data has been available.

New research from the University of Western Australia has highlighted the impact of the 2023–24 summer's extreme heat and drought on Perth's ecosystems.

An international team of polar ecologists, geographers, and marine scientists has found that global warming has, over the past 20 years, melted enough glacier ice in Greenland that an additional 1,620 kilometers of that country's coastline is now exposed to the elements.

As flood threats rise, wetlands across South Carolina could play an important role in fending off high water before it soaks homes, businesses, roads and other property that people depend on.

Source: Earth’s Future

Ecosystems in the Southern Ocean, the body of water surrounding Antarctica, are under threat from climate change. The area’s inhabitants, from whales to krill to phytoplankton, face changes such as a loss in sea ice and rising ocean temperatures. If species that are unique to the area, such as the Antarctic toothfish, dwindle in population as a result, this decrease could affect fishery operations and lead to cascading socioeconomic and geopolitical consequences.

Scientists use marine ecosystem models to understand how fragile regions such as the Southern Ocean will respond to changing climate, as well as to develop management and conservation plans. The Fisheries and Marine Ecosystem Model Intercomparison Project (FishMIP) combines results from an ensemble of marine ecosystem models, but it includes relatively few models that focus on the Southern Ocean. Though scientists have made progress in understanding this area’s food webs and biogeochemical processes in the past decade, work remains to be done on assessing how the ecosystem may evolve under different climate change scenarios.

Murphy et al. are developing a new suite of models to complement FishMIP called the Southern Ocean Marine Ecosystem Model Ensemble (SOMEME). By consulting experts in fields such as ocean and biogeochemical modeling, the team determined that the variables used across FishMIP (sea surface temperature, sea ice concentration, and phytoplankton biomass) made it a sufficient framework for their new suite. The SOMEME effort seeks to address some of the gaps in FishMIP by better representing regional elements, including sea ice, species such as Antarctic krill, the historical impacts of whaling, and the connections between fisheries and climate.

These additions will help scientists understand how climate change can affect the region and how those effects can be mitigated, the researchers say. The team expects the model will grow more capable as they incorporate artificial intelligence into the approach and as the project gains more collaborators. (Earth’s Future, https://doi.org/10.1029/2024EF004849, 2025)

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

Citation: Owen, R. (2025), Forecasting the future of Southern Ocean ecosystems, Eos, 106, https://doi.org/10.1029/2025EO250086. Published on 26 March 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.

From alluvial fans to lake beds, Mars has no shortage of surface features that were clearly sculpted by flowing water. But evidence of a planetary-scale body of water on the Red Planet—that is, an ocean—has been comparatively lacking.

Now, researchers have analyzed radar data collected by a Mars rover and found buried sediments arranged much in the same way as terrestrial coastal deposits. The discovery is evidence that an ancient ocean once persisted over much of the Red Planet’s northern hemisphere, according to the team.

“We can generate a profile of the subsurface structure.”

In 2021, China’s Tianwen-1 spacecraft touched down on Mars’s northern hemisphere in the Utopia Planitia region. Its payload, the 250-kilogram Zhurong rover, spent the next 12 months making a 1,921-meter traverse of Mars’s northern lowlands. Some of the data the rover collected included ground-penetrating radar measurements.

Ground-penetrating radar works by directing electromagnetic waves into the ground and measuring at what depths they’re reflected by boundaries between different materials. It’s commonly used by geoscientists on Earth to map buried layers of sediment and is also used by archaeologists to find buried artifacts.

“It allows us to see beneath the Martian surface,” said Hai Liu, a geophysicist at Guangzhou University in China. “We can generate a profile of the subsurface structure.” Liu and his graduate student Jianhui Li, also a geophysicist at Guangzhou University, coled the new research.

A Layer Cake, but Tilted

The team used the method to probe up to tens of meters below the Martian surface. The data revealed layers of sedimentary deposits that were tilted, like a partially collapsed layer cake. The tilt ranged from about 6° to 20°, sloping down to the north. That level of tilting, and its consistent orientation revealed over much of Zhurong’s largely southward traverse, suggests that the region was once home to a coastline, the researchers concluded.

The angle at which sediment builds up on a coast is determined by how far waves and tides travel inland. (Martian tides would have been largely driven by the Sun; its two moons, Phobos and Deimos, are far too small to exert much of a tidal force.)

The slopes of coastal sedimentary deposits on Earth are similar, Li, Liu, and their colleagues showed.

Shorelines Here and There

The idea that Mars once hosted an ocean isn’t new—data from spacecraft orbiting the planet have revealed surface features consistent with shorelines roughly 300 kilometers south of Zhurong’s location. (Some research has called those findings into question, however.) And one way of explaining the so-called Martian dichotomy—the stark difference in elevation, cratering, and crustal thickness between the planet’s northern lowlands and southern highlands—is that much of the northern hemisphere was once under water.

If an ocean did once cover much of Mars’s northern hemisphere, it must have retreated over time given that the Red Planet is a dry and dusty world today. That shrinking ocean would have left imprints of successive generations of coastlines north of its southernmost reach, said Abdallah Zaki, a geomorphologist at the Jackson School of Geosciences at the University of Texas at Austin who was not involved in the research.

Because Zhurong explored an area that might have once been a shoreline, it’s logical for the rover to have spotted coastal deposits, said Zaki, who studies landscapes shaped by water on both Earth and Mars. “It makes sense.”

It’s unlikely that a smaller body of water such as a lake could have produced these deposits, Li, Liu, and their colleagues concluded. Lakes experience only limited tides, and their waves tend to be much smaller than those in oceans. The tilt sediments around lakes therefore tend to be significantly shallower than what the team measured.

These results were published in the Proceedings of the National Academy of Sciences of the United States of America.

Going Underground

If there was once an ocean on Mars, future datasets could answer an important question: Where did all the water go? It’s likely that some evaporated and was lost to space, but some of it could still be lurking under the Martian surface.

“A lot of it could have moved underground,” said Michael Manga, a planetary scientist at the University of California, Berkeley and a member of the research team. Last year, Manga and his colleagues published a study in which they used seismic data from the InSight lander on Mars to constrain the amount of water potentially permeating subsurface rocks. The team concluded that it was a lot, enough to cover the entirety of Mars to a depth of 1–2 kilometers.

“We need to get more subsurface data.”

Continuing to explore what lies beneath Mars’s surface is critical to understanding how the Red Planet was influenced by water, Zaki said. “We need to get more subsurface data.”

Zaki and other researchers are looking forward to the European Space Agency’s upcoming launch of the ExoMars mission, which will include a rover known as Rosalind Franklin. The roughly 300-kilogram rover, named for the scientist who codiscovered DNA’s double-helix structure, will be equipped with ground-penetrating radar and a 2-meter drill.

—Katherine Kornei (@KatherineKornei), Science Writer

Citation: Kornei, K. (2025), Buried sediments point to an ancient ocean on Mars, Eos, 106, https://doi.org/10.1029/2025EO250115. Published on 26 March 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.

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

Approximately 41% of Southeast Asia’s peatland forests were impacted by land-use change, and conversion to tree plantations is one of the most common practices. However, data on the altered greenhouse gas production and emissions in these systems remain extremely limited.

Taillardat et al. [2025] measure the concentration, composition, and age of carbon in water and soil at an industrial, short-rotation Acacia plantation in peatland areas of Sumatra, Indonesia. Exceptionally high levels of dissolved organic carbon, carbon dioxide, and methane were found in porewater and drainage networks, indicating that these plantations are carbon hotspots. This was century-old carbon in the water, highlighting the combination of both high productivity and exposure of old carbon-dense substrates to exposure in a plantation setting.  

Citation: Taillardat, P., Moore, J., Sasmito, S., Evans, C. D., Alfina, T., Lok, S., et al. (2025). Methane and carbon dioxide production and emission pathways in the belowground and draining water bodies of a tropical peatland plantation forest. Geophysical Research Letters, 52, e2024GL112903. https://doi.org/10.1029/2024GL112903

—Valeriy Ivanov, Editor, Geophysical Research Letters

Text © 2024. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

New research into lithium mining in the "Lithium Triangle" of Chile, Argentina and Bolivia—source of more than half of the world's lithium resources—shows that the commonly accepted models used to estimate how much water is available for lithium extraction and what the environmental effects may be are off by more than an order of magnitude.

SummaryLocating the sources of observed disturbances in potential-field data is a challenging problem due to the non-unique nature of the inverse problem. The Euler deconvolution method was created to solve this issue, particularly for idealized sources (such as spheres and planar vertical dykes). Euler deconvolution has become widely used in potential-field methods due, in large part, to its low computational cost and ease of implementation into software. However, it is widely known that Euler deconvolution suffers from some shortcomings: 1) non-uniqueness of the solution with respect to the depth of the source and the structural index (a parameter that represents the idealised shape of the source); 2) sensitivity to short-wavelength noise in the data derivatives which are used as inputs for the method. Here, we present a new method called Euler inversion which is a reformulation of the inverse problem of Euler’s homogeneity equation as an implicit mathematical model rather than a parametric one. Euler inversion is a constrained, non-linear inverse problem capable of estimating both the model parameters (location of the source and constant base level) and the predicted data (potential field and its derivatives). We show that Euler inversion is less sensitive than Euler deconvolution to short-wavelength noise and to the presence of interfering sources in the data window. By also estimating the predicted data, Euler inversion is also able to estimate the best integer structural index to be used for inversion. Our results show that the estimated structural index minimizes the data misfit and coincides with those of the simulated sources. Furthermore, most matrices involved in the method are either sparse or diagonal, making Euler inversion computationally efficient. Tests on synthetic data and a real aeromagnetic dataset from Rio de Janeiro, Brazil, demonstrate the effectiveness of Euler inversion to delineate sources with variable geometries and correctly estimate their depths.

SummarySolving the wave equation is essential to seismic imaging and inversion. The numerical solution of the Helmholtz equation, fundamental to this process, often encounters significant computational and memory challenges. We propose an innovative frequency-domain scattered wavefield modeling method employing neural operators adaptable to diverse seismic velocities. The source location and frequency information are embedded within the input background wavefield, enhancing the neural operator’s ability to process source configurations effectively. In addition, we utilize a single reference frequency strategy, which enables scaling from larger-domain forward modeling to higher-frequency scenarios, thereby improving our method’s accuracy and generalization capabilities for larger-domain applications. Several tests on the OpenFWI datasets and realistic velocity models validate the accuracy and efficacy of our method as a surrogate model, demonstrating its potential to address the computational and memory limitations of numerical methods.

SummaryThe response of well water temperature to earthquakes is crucial for understanding subsurface seismic fluid dynamics. However, recent studies have primarily focused on observations at a single depth and have employed single-aquifer models, which may lead to controversies when explaining fluid flow. In this study, we develop single- and double-aquifer models to estimate well-water temperature variations at different depths in response to changes in pore pressure, permeability, and aquifer recharge temperature. The results indicate that variations in aquifer pore pressure and permeability result in significant differences in vertical flow velocity and temperature changes at various depths. When the borehole bottom is impermeable, for a single aquifer, temperature variation is maximal above the aquifer and variable at the aquifer depth, but nearly zero below the aquifer; for two aquifers, different pore pressure and permeability changes in each aquifer produce distinct temperature variation patterns, with minimal temperature change below the lower aquifer. If the borehole bottom is permeable, temperature variation becomes obvious below the lower aquifer. When cold or hot water from the aquifers flows into the borehole, significant temperature perturbations remain confined within a few metres of the aquifer within one day. Finally, a field case study investigates the co-seismic water temperature responses at three depths in the Chuan No. 03 well, triggered by the 2008 Mw 7.9 Wenchuan earthquake. The double-aquifer model effectively explains the complex co-seismic temperature fluctuations at different depths. Observation at a single depth risk missing crucial information, and multi-depth temperature observation is a promising approach for interpreting and monitoring groundwater responses to earthquakes.

Humans have remodeled the Earth so profoundly that in 2000, atmospheric chemist Paul Crutzen and biologist Eugene Stoermer proposed that the Holocene epoch had ended and the "Anthropocene," or human epoch, had begun.

Wetlands in the Middle Yangtze River Basin (MYRB) are facing significant ecological challenges due to climate change and human activities. A recent study investigated the spatiotemporal changes in wetland ecological quality from 2001 to 2020 and projected future trends under different climate scenarios.

Mesoscale eddies, oceanic gyres about 100 kilometers in diameter, are ubiquitous features of the global ocean and play a vital role in marine ecosystems. Eddies, which form in biologically productive coastal upwelling regions, are important transporters of carbon and nutrients. These eddies trap water masses and migrate into the open ocean, where productivity is comparatively low. As such, they have a significant influence on the nutrient and carbon cycles within the ocean.

Siberia, a province located in Russia, is a significant geographical region playing a crucial role in the world's carbon cycle. With its vast forests, wetlands, and permafrost regions (permanently frozen grounds), Siberia stores a considerable amount of carbon on a global scale. But climate change is rapidly altering Siberia's landscape, shifting its vegetative distribution and accelerating the permafrost thaw.

As climate change continues to accelerate at an alarming pace, innovative and scalable solutions are more critical than ever. This week, the American Society for Microbiology (ASM) and the International Union for Microbiological Societies (IUMS) released "Microbial Solutions for Climate Change," a report developed by their scientific advisory group (SAG) of global experts.

Along with nitrogen and carbon, phosphorus is an essential element for life on Earth. It is a central component of molecules such as DNA and RNA, which serve to transmit and store genetic information, and ATP (adenosine triphosphate), which cells need to produce energy.

The monsoon rains have long remained the lifeblood of India, providing the lion's share of the water used for drinking and irrigation. The yearly arrival of the rains, which quenches the thirst of the harsh summers, is caused by the movement of cloud bands from the equator towards the north.

Author(s): Zhen-Ke Dou, Chong Lv, Yousef I. Salamin, Nan Zhang, Feng Wan, Zhong-Feng Xu, and Jian-Xing Li

Compact spin-polarized positron accelerators play a major role in promoting significant positron application research, which typically require high acceleration gradients and polarization degrees, both of which, however, are still greatly challenging. Here, we put forward a spin-polarized positron a…

[Phys. Rev. E 111, 035209] Published Tue Mar 25, 2025