EOS

It’s not easy to determine how much water there is across a landscape. A measly 1% of Earth’s freshwater is on the surface, where it can be seen and measured with relative ease. But beneath that, measurements vary massively depending on water table depth and ground porosity we can’t directly see.

“We’re operating in a situation where we don’t know how much is going into the savings account every month, and we don’t know how much is in our savings account.”

Reed Maxwell, a hydrologist at Princeton University, likes to think of rainfall, snow, and surface water as a checking account used for short-term water management needs and groundwater as a savings account, where a larger sum should, ideally, be building up over time.

“We’re operating in a situation where we don’t know how much is going into the savings account every month, and we don’t know how much is in our savings account,” he said.

But a new groundwater map by Maxwell and colleagues offers the highest-resolution estimate so far of the amount of groundwater in the contiguous United States: about 306,500 cubic kilometers. That’s 13 times the volume of all the Great Lakes combined, almost 7 times the amount of water discharged by all rivers on Earth in a year. This estimate, made at 30-meter resolution, includes all groundwater to a depth of 392 meters, the deepest for which reliable porosity data exist. Previous estimates using similar constraints have ranged from 159,000 to 570,000 cubic kilometers.

“It’s definitely a move forward from some of the previous [mapping] efforts,” said Grant Ferguson, a hydrogeologist at the University of Saskatchewan who was not involved in the research. “They’re looking at much better resolution than we have in the past and using some interesting techniques.”

Well, Well, Well

Past estimations of groundwater quantity have been based largely on well observations.

“That’s the really crazy thing about groundwater in general,” said Laura Condon, a hydrologist at the University of Arizona and a coauthor of the paper. “We have these pinpricks into the subsurface where there’s a well, they take a measurement of how deep down the water table depth is, and that’s what we have to work with.”

But not all wells are measured regularly. For obvious reasons, there tend to be more wells in places where more groundwater is present, making data on areas with less groundwater scarcer. And a well represents just one point, whereas water table depth can vary greatly over short distances.

Researchers have used these data points, as well as knowledge of the physics of how water flows underground, to model water table depth at a resolution of about 1 kilometer. They’ve also used satellite data to capture large-scale trends in water movement. But those data are of lower resolution: Data from NASA’s GRACE (Gravity Recovery and Climate Experiment) Tellus mission, for instance, have a resolution of about 300 kilometers, about 10,000 times coarser than the new map.

To demonstrate the value of high-resolution data, the team showed what happened when they decreased the resolution of their entire map from 30 meters to 100 kilometers—the spatial resolution of many global hydrologic models. The resulting more pixelated map estimated just above 252,000 cubic kilometers of water, an underestimation of 18% compared to the new map.

In addition to identifying groundwater quantities at high resolution, the new map reveals more nuanced information about known groundwater sources.

For instance, it shows that about 40% of the land in the contiguous United States has a water table depth shallower than 10 meters. “That 10-meter range is that range where you can have groundwater–plant–land surface interactions,” Condon said. “And so that’s just really pointing to how connected those systems are.”

Bias for Good

The new work used direct well measurements as well as satellite data—about a million measurements, made between 1895 and 2023—along with maps of precipitation, temperature, hydraulic conductivity, soil texture, elevation, and distance of streams. Then, the scientists used the data to train a machine learning model.

In addition to its being able to quickly sort through so many data points, Maxwell noted another benefit of the machine learning approach that might sound unexpected: its bias. Early groundwater estimates were relatively simplistic, not accounting for either hydrogeology or the fact that humans themselves pump water out of the ground. The team’s machine learning approach was able to incorporate that information because evidence of groundwater pumping was present in the data used to train it.

“When you hear about bias in machine learning all the time, it’s usually in a negative connotation, right?” Maxwell said. “As it turns out, when you can’t disentangle the signal of groundwater pumping and groundwater depletion from the almost 1 million observations that we used to train this machine learning approach, it implicitly learned that bias.… It’s learned the pumping signals, it’s learned the human depletion signal.”

“Wherever you’re standing, dig down, and there’s water down there somewhere.”

Maxwell and the other researchers hope the map can be a resource for regional water management decisionmakers, as well as for farmers making decisions about irrigation. Condon added that she hopes it raises awareness of groundwater in general.

“Groundwater is literally everywhere all the time,” she said. The map is “filled in everywhere, wherever you are. Some places it’s 300 meters deep, some places it’s 1 meter deep. But wherever you’re standing, dig down, and there’s water down there somewhere.”

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

Citation: Gardner, E. (2026), Report: 13 Great Lakes’ worth of water underlies the contiguous United States, Eos, 107, https://doi.org/10.1029/2026EO260036. Published on 26 January 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

A crucial source of freshwater, groundwater is vulnerable to contamination and overuse. Knowing how long groundwater has been under ground is critical for sustainable management of this resource. The Carbon-14 (14C) and Argon-39 (39Ar) isotopes are environmental tracers especially suited for dating groundwater aged between 50 and 30,000 years. However, ages obtained from previous analyses of these two tracers disagreed with each other.

Musy et al. [2025] use a quantitative framework to understand the effect of groundwater flow within the Earth’s subsurface on the age calculated from 14C and 39Ar measured in aquifers in Denmark. Reactions that affect 14C, the production of 39Ar in the subsurface, and the existence of slow and fast paths for groundwater flow, such as in fractured aquifers, explain the differences observed between age estimates. Accounting for these processes leads to more accurate estimate of groundwater residence times and supports better water resource management.

Citation: Musy, S. L., Hinsby, K., Wachs, D., Sültenfuss, J., Troldborg, L., Aeschbach, W., et al. (2025). Bridging the 39Ar–14C groundwater dating gap: A dual-permeability transport perspective based on numerical modeling and field data. Water Resources Research, 61, e2025WR040370. https://doi.org/10.1029/2025WR040370

—Sergi Molins, Associate Editor, Water Resources Research

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

Understanding how deep continental rocks can be subducted into the Earth’s mantle is essential to understand lithospheric recycling, reconstructing deep subduction and exhumation processes. Minerals formed at great depths often preserve microscopic “exsolution” features, where one mineral separates out from another during cooling or decompression, but their interpretation has remained debated.

Li et al. [2025] performed the first systematic laboratory experiments on kyanite exsolution from aluminiferous stishovite, a high-pressure polymorph of SiO2 (silicon dioxide) stable at depths exceeding 300 kilometers. The experiments show that aluminum almost completely separates from stishovite to form kyanite during decompression, producing distinctive microscopic textures. These findings address a long-standing debate about whether a specific crystallographic relationship between exsolved phases and their host mineral is required to identify exsolution microstructures.

Importantly, the study demonstrates that a strict crystallographic alignment between the host mineral and exsolved phases is helpful but not always required to identify true exsolution. These results provide a robust experimental framework for interpreting similar microstructures observed in natural rocks. Overall, the findings offer compelling new evidence that continental rocks can undergo ultra-deep subduction into the mantle depths of at least about 300 kilometers and later be exhumed back to the Earth’s surface.

Citation: Li, X., Wang, C., Liu, L., Kang, L., Xu, H. J., Zhang, J., et al. (2025). Kyanite exsolution from aluminiferous stishovite in laboratory experiments: New insights into continental ultra-deep subduction. Journal of Geophysical Research: Solid Earth, 130, e2025JB031612. https://doi.org/10.1029/2025JB031612

—Jun Tsuchiya, Editor; and Sujoy Ghosh, Associate Editor, JGR: Solid Earth

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In August 2023, 18 scientists and engineers spent 15 days in barren regions of Iceland to test how well instruments on the VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) spacecraft will perform when investigating the surface of Venus from orbit. This testing was a critical step in developing procedures to enhance the science output of the mission, which will provide the first new data about the planet’s surface in more than 3 decades.

Iceland might not seem an obvious choice as an analogue for Venus.

Among other tasks, the team—including us—traversed rugged Icelandic terrain to sample lava flows for analysis on-site and, later, in the lab. We also used on-the-ground observations of the flows to calibrate and verify corresponding airborne-detected radar signatures, information that will be used to help interpret the radar data they collect on the Venus mission.

At first glance, Iceland might not seem an obvious choice as an analogue for Venus. After all, Iceland is cool, wet, and near the Arctic Circle. Venus is famous for its extremely hot and dry surface, where average temperatures are roughly 870°F (465°C). Yet the two share key commonalities as well.

Iceland is covered in basalt, the same rock that’s thought to make up the low-lying plains on Venus. Also, Iceland is underlain by an active mantle plume that feeds its volcanic vents, and Venus too shows evidence of having mantle plumes below its surface. With these similarities, scientists can make direct comparisons between the diverse morphologies, compositions, and signatures of Icelandic lava flows and those of flows on Venus. Such comparisons are needed to ensure that we can accurately interpret the data VERITAS sends back to answer long-standing questions about our most Earth-like neighbor.

Reading the Radar Signals

Magellan, the last mission to observe Venus’s surface, ended more than 31 years ago after spending 4 years in orbit. Data from Magellan offered unprecedented glimpses of the planet and opened new lines of inquiry for scientists. However, these data are relatively low resolution by today’s standards, complicating efforts to resolve surface features and understand how they relate to Venus’s geologic past.

In June 2021, NASA selected the Discovery-class VERITAS mission as a long-awaited follow-up to Magellan because its suite of instruments have the potential to reveal the processes that caused the evolution of Venus and Earth to diverge. While Venus likely once had surface water and a planetary dynamo, these essential elements of habitability are long gone. However, tectonism and volcanism, driven by robust internal heat production with associated outgassing, probably persist today, as suggested by evidence in a recent study. If Venus has active volcanism and tectonism, then VERITAS should be able to confirm that identification and to detect surface activity that has occurred since Magellan’s visit, such as new volcanic flows and fault scarps.

The VERITAS payload includes a synthetic aperture radar (SAR) platform to view the planet’s surface and to make topographic measurements using a technique called single-pass radar interferometry. Venus’s thick atmosphere precludes the use of visible light imaging for these purposes, leaving SAR as the only current way to observe its surface over wide areas at high resolution.

Like other radar systems, space-based SAR works by transmitting radio waves to a planet and then detecting signals reflected back to a receiver, which gives information about the surface. Radar data are fundamentally different from visible imagery, as the brightness of radar returns depends not only on surface material properties such as albedo and color, but also on surface roughness and electrical permittivity, and on other effects such as the polarization of radar signals and their penetration into a planet’s surface.

Topography is a key metric for unlocking the geologic processes that have shaped the evolutionary history of a planet.

This complexity makes it difficult to determine the geological properties of structures on Venus’s surface directly from their radar signatures. It is impossible to tell from orbital data alone whether any particular radar signature is caused by a rock’s roughness or its composition, because we do not have samples of Venus to test.

Topography is a key metric for unlocking the geologic processes that have shaped the evolutionary history of a planet. Existing topographic data from Venus were obtained by radar altimetry during Magellan at a spatial resolution of 15–20 kilometers and a vertical accuracy of 80–100 meters, each over an order of magnitude coarser than what’s available for other terrestrial bodies.

VERITAS will measure topography using single-pass radar interferometry with a spatial resolution of 240 meters and a vertical accuracy of 5 meters, which is in line with data from the Moon, Mars, and Mercury. This sharper view will dramatically improve scientists’ ability to compare Venus with these bodies and help decipher why it evolved so differently from Earth.

In addition to its radar capabilities, VERITAS’s Venus Emissivity Mapper (VEM) spectrometer will provide the first global-scale view of surface rock types, allowing discrimination of felsic from mafic rocks based on their iron content. These data will help scientists answer key questions about Venus’s history of volcanism and how it shaped the planet’s young surface, as well as about whether large plateaus called tesserae have a similar composition and origin as Earth’s continents (and whether they formed in the presence of water).

What Are Venus’s Rocks Made Of?

Geologic maps of Earth represent the composition and age of rocks in defining geologic units. On Venus, geologic units have been defined based on radar imagery alone, so scientists have had to make assumptions about the composition and formation of features by comparing their morphologies to those of well-known terrestrial features. However, without accurate knowledge of what the Venus rocks are made of, it is difficult to confirm hypotheses of the planet’s geologic history.

• The VERITAS field campaign explored remote regions of Iceland and encountered rugged conditions. Specialized off-road vehicles were required to access the field areas studied. Credit: Gaetano Di Achille
• Team members sometimes had to drive through running streams, as seen here on the drive from Mývatn to Askja. Credit: Debra Buczkowski
• The field team cooked, ate, slept, socialized, and analyzed data at campsites comprising two large tents surrounded by smaller personal tents for sleeping. Credit: Debra Buczkowski
• Terrain in several areas, including here at Askja, was extremely rough, which made for difficult hiking. Credit: Debra Buczkowski

Unlike with Mars or the Moon, ground truth of Venus orbital data is severely limited. The thick atmosphere obstructs remote sensing of rock composition from orbit. And past landers have not survived long enough on the surface to perform extensive testing, primarily because of the extremely hostile temperatures and atmospheric pressure (90 times that of Earth’s) at the surface. The VERITAS field campaign was therefore intended as a reality check, to test our geologic interpretations of radar observations.

Iceland’s extensive lava fields host a variety of volcanic and tectonic features similar to those observed on Venus.

The first goal of the campaign was to improve our ability to process, analyze, and interpret VERITAS-like data for the purpose of understanding Venus’s geology. The expedition in Iceland was an opportunity to create a library of radar signatures associated with specific surface features in volcanic landscapes, with direct measurements of both roughness and composition. The second goal was to test the methodologies and the approach that VERITAS will use to detect surface changes when it arrives at Venus.

Iceland’s extensive lava fields host a variety of volcanic and tectonic features similar to those observed on Venus, making them excellent choices as Venus analogues. The comparative lack of both vegetation and erosion at these sites makes them more comparable to those on Venus than basaltic lava fields elsewhere on Earth. In addition, the relative ages of different Icelandic lava flows are known and well documented, which allows us to determine whether radar data can be reliably used to tease out the ages of flows on Venus.

Three Sites, Three Environments

We focused the field campaign on three main basaltic lava flow fields: Askja, Holuhraun, and Fagradalsfjall. The diversity of geologic landforms within these sites enabled study of a range of features analogous to those that VERITAS will target on Venus. These features include plains volcanism, lobate flows, lava morphologies such as pāhoehoe and a’a, compositions ranging from basaltic to rhyolitic, pyroclastic airfall and wind-driven sedimentary deposits covering volcanic bedrock, tectonic rifts, and small-scale graben. The study areas also allowed us to investigate landforms created by interactions between sediment, tectonic structures, and lava flows and how these features appear in SAR data collected from orbit at different signal frequencies and incidence angles.

• The lava fields studied during the field campaign included Askja and Holuhraun, in Iceland’s central highlands, and Fagradalsfjall, on the Reykjanes Peninsula in the country’s southwest (top left). White lines within the red boxes represent the flight lines flown by the German Aerospace Center (DLR) to collect synthetic aperture radar (SAR) data. Credit: Dan Nunes (map imagery and data: Google, IBCAO, Landsat, Copernicus, SIO, NOAA, U.S. Navy, NGA, GEBCO)
• A tripod-mounted lidar instrument was used to take topographic measurements at all field sites, including here at Holuhraun. Credit: Sue Smrekar
• Researchers collect lidar measurements at the Fagradalsfjall field site. Credit: Dan Nunes
• Field campaign team members work with lidar instrumentation at the Askja site. Orange flags served as tie points for georeferencing the lidar images to airborne radar data. Credit: Debra Buczkowski

The Askja lava field, located in Iceland’s central highlands, is sourced from a central volcano and includes multiple areas with differing textures due to variations in the extent of sedimentation and erosion. Some Askja flows are covered with rhyolitic tephra and basaltic sand, offering additional textural and compositional diversity for study. Volcanism has occurred in the area for thousands of years, with the youngest flow (Vikrahraun) erupting in 1961.

Although geographically close to Askja, the Holuhraun lava field is sourced from a different magmatic reservoir and erupted from fissures. Sand sheets interact with the edges of the Holuhraun flows, especially along their northern boundary. The field also includes an extremely rough flow that was emplaced only about 10 years ago (2014–2015).

Located in southwestern Iceland on the Reykjanes Peninsula, the flows at Fagradalsfjall are even more recent, erupting from fissures starting in 2021 and continuing through 2025. (In fact, Fagradalsfjall was actively erupting at the beginning of the field campaign.) These recent flows, including pāhoehoe flows, are significantly smoother than those at Holuhraun and, because of their young age, have relatively little sediment coverage. Lava ponds and channels are also common here.

Air and Ground Campaigns The F-SAR sensor was installed on DLR’s Dornier 228 aircraft and flown out of Keflavik International Airport (left). The radar antenna mount is on the side of the fuselage just aft of the rear wheels. One of three trihedral radar reflectors deployed for use as reference targets during the campaign is seen at right. Credit: Marc Jaeger

The field campaign comprised both airborne and ground components. The German Aerospace Center (DLR), one of several agencies partnering with NASA on VERITAS, ran the airborne component, flying their F-SAR sensor aboard a twin-propeller plane to collect SAR data at three wavelengths (X-, S-, and L-band) at the same time the ground campaign team members visited each site.

The extensive multifrequency SAR dataset that DLR acquired covers the diverse geological features of the three lava fields and includes imagery that represents the differing spatial and vertical resolution capabilities of the Magellan and VERITAS missions, as well as those of the upcoming European Space Agency EnVision mission to Venus. Figure 1 shows an example of derived F-SAR topographic data for a lava flow at Holuhraun at simulated Magellan and VERITAS resolutions. Whereas the Magellan-like data only allow determination of the general slope of the landscape over a spatial scale of tens of kilometers, the VERITAS-like data enable spatial and vertical discrimination of distinct geologic units.

Fig. 1. A radar backscatter image above the Askja and Holuhraun lava fields (left) is seen here beside digital elevation models (DEM) produced with SAR topographic data at resolutions simulating those of Magellan radar altimeter data (center) and VERITAS radar altimeter data (right). White arrows point to the Holuhraun flow boundaries in all three images. Whereas at Magellan resolution, only a general regional slope can be discerned, at VERITAS resolution, it’s possible to pick out individual lava flows as well as Vaðalda Mountain. Credit: Scott Hensley

F-SAR operations also included deploying radar reflectors that were used as reference targets and regularly imaged to monitor sensor calibration and instrument stability throughout the campaign. In addition, a subset of the raw SAR data acquired was processed on-site within hours of each flight, providing imagery to inform the field teams’ site selection and prioritization within each lava field.

Team members braved river crossings and trekked across often-jagged rocks to take samples and collect information on the surface roughness and composition of the rocks being scanned from the air.

Concurrent with the radar data collection, VERITAS team members braved river crossings and trekked across often-jagged rocks to take samples and collect information on the surface roughness and composition of the rocks being scanned from the air. We simultaneously used lidar scanners to take topographic measurements at all field sites to compare with radar detections and a probe to determine electrical permittivity in sedimented areas. These measurements allowed us to determine how much of the radar backscatter signature at each site was due to the permittivity, rather than to roughness.

In addition, we used a field prototype of VERITAS’s VEM instrument, called the Vemulator, on-site to identify different rock types and compositions. Rock and sediment samples from all field sites were later tested in the lab to confirm field measurements of composition and permittivity, including those from the Vemulator.

Details Come into Focus

Following the field campaign, team members produced maps of the lava flows at all three sites based solely on the radar data, exactly as Venus researchers have made geologic maps of Venus using Magellan data. The new maps were made at three different resolutions: the resolution of the old Magellan data, the resolution of the VERITAS SAR, and the highest resolution available with the data collected during the campaign.

The improvement in SAR resolution from Magellan to VERITAS will permit observations of previously unidentified features on Venus (Figures 2 and 3). Views of the Holuhraun flow at Magellan resolution, for example, are too coarse to discern distinct lava flow units, or facies, whereas at the VERITAS resolution, separate facies, a small vent, and several lava ponds can be distinguished. Being able to identify similar features on Venus will allow us to detect changes on the surface since Magellan’s visit that would indicate recent volcanism, helping to better understand the planet’s volcanic history.

Fig. 2. SAR imagery of the Holuhraun flow is seen here at Magellan’s lower resolution and VERITAS’s higher resolution. In the latter case, lava ponds and a volcanic vent are observed (white arrows). Black boxes indicate the southwestern part of the flow that’s magnified in Figure 3. Credit: Debra Buczkowski Fig. 3. Even when magnified, no features within the Holuhraun flow can be discerned at Magellan resolution, whereas at VERITAS resolution, the volcanic vent (white arrow) and distinct flows coming from it are visible, as are other flow facies. Credit: Debra Buczkowski

Comparing our new aerial-radar-derived maps of the Iceland field sites with published maps based on ground observations enabled us to assess how well our flow boundaries matched what’s seen from the ground. In addition, we were able to determine how similar the observed radar properties were to actual flow composition and roughness. Once the flow boundaries were defined in the SAR datasets, we could also determine how overlying sediment influenced the radar appearances of different lava flows. This information could provide insight into how ashfalls or pyroclastic materials on Venus might obscure or alter the radar signature of underlying rocks.

When it arrives at its destination, VERITAS will create foundational datasets of high-resolution imaging, topography, and spectroscopy of Venus.

When it arrives at its destination, VERITAS will create foundational datasets of high-resolution imaging, topography, and spectroscopy of Venus. These datasets will be on par with those that have revolutionized our understanding of Mercury, Mars, and the Moon.

The 2023 field campaign served as both a test of the VERITAS instruments and a demonstration of what their improved capabilities will offer at Venus. Indeed, the campaign’s success demonstrated how VERITAS will make new discoveries and improve our knowledge of the planet’s past and present, and that it could lay the groundwork to optimize the science return of future Venus missions.

Author Information

Debra L. Buczkowski (debra.buczkowski@jhuapl.edu), Johns Hopkins Applied Physics Laboratory, Laurel, Md.; Jennifer L. Whitten, National Air and Space Museum, Smithsonian Institution, Washington, D.C.; Scott Hensley and Daniel C. Nunes, Jet Propulsion Laboratory, California Institute of Technology, Pasadena; and Marc Jaeger, Microwaves and Radar Institute, German Aerospace Center, Oberpfaffenhofen, Germany

Citation: Buczkowski, D. L., J. L. Whitten, S. Hensley, D. C. Nunes, and M. Jaeger (2026), Discovering Venus on Iceland, Eos, 107, https://doi.org/10.1029/2026EO260032. Published on 23 January 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.

A new satellite image confirms that over 15 houses were buried in a landslide that took the lives of almost 30 people.

Back on 15 January, I wrote about the 3 January 2026 landslide at Burutsi village, in the Democratic Republic of Congo. This landslide killed 28 people and injured 20 more.

This is a remote area, so getting detailed information about the location is very challenging. It is also very cloudy, limiting satellite imagery. However, on 21 January 2028, Planet Labs captured an image of the area using one of their Super Dove instruments. This is the image, draped onto the Google Earth DEM:-

Planet Labs image of the 14 January 2026 landslide at Burutsi in the DRC. Image copyright Planet Labs, captured on 21 January 2026, used with permission.

This is a Google Earth image from 2024 of the same area:-

Google Earth image of the site of the 14 January 2026 landslide at Burutsi in the DRC. Image captured on 8 January 2024.

And here is a slider to compare the two:-

This is a Google Earth image of the affected are in more detail:-

Google Earth image of the site of the 14 January 2026 landslide at Burutsi in the DRC. Image captured on 8 January 2024.

There is nothing obvious in the imagery to suggest that this slope was dangerous, noting of course the masking effect of the dense forest. As reported in the media, the landslide buried about 17 houses and closed the road.

The imagery clarifies the location of the landslide – it’s at [-1.30050, 28.66080].

Acknowledgement

Thanks as ever to the kind people at Planet Labs for providing access to their amazing imagery.

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

Ocean acidification is known to have major impacts on marine habitats under projected climate change. How vulnerable marine organisms in these habitats are to acidification largely depends on the variability of environmental conditions, such as pH, they experience naturally.

Burdett et al. [2025] provide precious time-series evidence that, unlike the open ocean, coastal ecosystems experience high natural environmental variability. For about two thirds of the year, the monitored coastal coralline algae reef was exposed to pH levels as low as those expected for the year 2100 under IPCC projections. The pH levels varied considerably throughout the day and between seasons, associated with biological activity, tidal cycling, and water temperature. Long‐term exposure to such low pH conditions and high variability may help coralline algal communities to adapt to future acidification, providing a level of optimism for the survival of this globally distributed biodiverse habitat.

Citation: Burdett, H. L., Mao, J., Foster, G. L., & Kamenos, N. A. (2025). Persistence of extreme low pH in a coralline algae habitat. Journal of Geophysical Research: Biogeosciences, 130, e2025JG009062. https://doi.org/10.1029/2025JG009062

—Xiaojuan Feng, Associate Editor, JGR: Biogeosciences

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Eight people have been killed or are missing in two landslides triggered by heavy rainfall in New Zealand

Substantial parts of New Zeealand have been suffering extreme rainfall – yet again – causing floods and landslides. The most serious event to date occurred at a camp site at Mount Maunganui on the Bay of Plenty in the North Island. Here, a landslide devastated a campsite close to the coast. Unfortunately, January is the main summer holiday period in New Zealand.

Stuff has a video of the landslide as it occurred. Meanwhile, The Guardian has a Youtube video with imagery of the aftermath:-

This still shows the basic components of the failure:-

The aftermath of the 22 January 2026 landslide at Mount Maunganui. Still from a video posted to Youtube.

The location is reported to be the Mount Maunganui Beachside Holiday Park. This makes the location [-37.63234, 176.17507]. This is Google Earth image of the site:-

Google Earth image of the site of the 22 January 2026 landslide at Mount Maunganui.

The image suggests a complex geology, with maybe a hint of previous landslides (this is very speculative). The geology of this area is primarily volcanic rocks, which may indicate a high landslide susceptibility. The images of the aftermath appear to suggest deeply weathered soils, and note the amount of water flowing through the debris.

News reports indicate that at least six people are missing, some of whom are children., The authorities are continuing to describe the operation at the site as a rescue.

Meanwhile, two other people were killed by an early morning landslide at Welcome Bay Road in Papamoa, also on the Bay of Plenty. This appears to have occurred at about [-37.7231, 176.20896]. One News has an image of the aftermath of the event that appears to show multiple shallow landslides on the same hillside.

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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.

NOAA has finalized a rule that will expedite the permit and license application process for deep seabed mining and allow companies to mine beyond U.S. jurisdictional boundaries.

The changes were published in a 113-page regulation on 21 January.

The changes revise the Deep Seabed Hard Mineral Resources Act (DSHMRA) of 1980, which required individuals or corporations who wanted to explore and mine mineral-rich nodules in the deep sea to apply for an exploration license and a commercial recovery (large-scale extraction) permit separately. Now, applicants may apply for both the exploration license and commercial recovery permit at the same time. 

“By issuing the permit simultaneously, they’re committing to exploitation without the information that you would need to evaluate its impacts.”

“Deep seabed mining is key to unlocking a domestic source of critical minerals for the United States,” Neil Jacobs, NOAA administrator, said in a statement. “This consolidation modernizes the law and supports the America First agenda by enabling U.S. companies to access these resources more quickly, strengthening our nation’s economic resilience and advancing the discovery and use of critical seafloor minerals.” 

Critics are concerned that the move will loosen environmental oversight. “By issuing the permit simultaneously, they’re committing to exploitation without the information that you would need to evaluate its impacts,” Emily Jeffers, senior attorney at the Center for Biological Diversity, told Agence France-Presse.

Beyond U.S. Boundaries

The updated rule also states that DSHMRA gives NOAA the ability to issue exploration licenses and permits for the seabed beyond national jurisdiction. The International Seabed Authority (ISA), an autonomous international governing body, regulates deep sea mining in international waters for countries that are part of the 1982 Law of the Sea Convention. The United States has never been a party to that treaty but has mostly followed its guidelines.

Now, NOAA’s insistence that the United States can regulate U.S. companies’ deep sea mining beyond U.S. waters is expected to cause controversy among members of the ISA, which has for years been negotiating rules to govern mining in international waters. In December, the Trump administration announced it had received an application for mining exploration in international waters from the Metals Company.

The final rule follows an executive order issued last year calling for the rapid development of deep sea mining capabilities both domestically and beyond U.S. jurisdictional boundaries.

 
Related

•  NOAA Accelerates Permitting Timeline for Deep Seabed Mining Applications
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In a response to that order, the ISA called it “surprising because for over 30 years the US has been a reliable observer and significant contributor to the negotiations of the International Seabed Authority.” In the statement, the ISA also said any unilateral action to mine the deep sea “sets a dangerous precedent that could destabilize the entire system of global ocean governance.”

The deep sea has never been commercially mined. Compared to other ecosystems, little is known about the ecology of the ocean floor or how these ecosystems support marine life. Disturbing these ecosystems could have wide-ranging consequences.

“Once nodules are removed by mining, all biodiversity and functions directly dependent on the minerals will be lost for millions of years at the mined location, as nodules need millions of years to re-form,” Sabine Gollner, a deep-sea marine biologist at the Royal Netherlands Institute for Sea Research told Eos in 2024. 

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

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This story was originally published in the Louisiana Illuminator.

A new study says river deltas around the world aren’t just disappearing because of rising seas, but also because the land itself is sinking down into the waters, either as fast or faster than the rising oceans.

Researchers found some of the most rapid sinking is happening along the Mississippi River Delta in Louisiana. The study aims to better guide coastal restoration in disappearing river deltas around the globe, helping leaders, scientists and people living in coastal communities with hard decisions on what can— and should—be saved.

“Coastal areas account for less than 1% of the entire land area we have,” said Leonard Ohenhen, a professor at the University of California, Irvine and the lead author of the study. “But a whole significant population, more than 600 million people, live in those areas.”

“You have a sort of a hodgepodge of different reasons why deltas are sinking.”

The study, published this week in the academic journal Nature, found the contributions of  subsidence, or slowly submerging land, to disappearing coasts is often overlooked.

The fight to preserve rapidly sinking land has been a decades-long battle in the Mississippi River Delta, as well as a source of contention between scientific and political figures in the state. But deltas across the world are sinking, too, and fast.

“You have a sort of a hodgepodge of different reasons why deltas are sinking,” Ohenhen said.

He said river deltas naturally sink to some degree, with sediment carried downstream by rivers piling up and pushing down on the spongy, soft land already there. Humans can accelerate this natural process by engineering rivers such as the Mississippi and by extracting groundwater or oil.

“Relative sea level rise in the area is also really important. That’s the sea level rise plus subsidence,” said Alisha Renfro, a coastal scientist with the National Wildlife Federation. “It really helps us understand where we can make investments in restoration long-term that we might actually be able to hold on to.”

This map from the report shows which areas of the Mississippi River Delta are sinking. Areas in red and yellow are areas of land sinking more rapidly, while spots in blue and purple are building land upwards. Credit: University of California, Irvine

Lack of sediment is the main driver of subsidence in the Mississippi River Delta, Ohenhen said, creating hotspots of rapidly sinking pieces of land amid slightly more stable areas. Most of the deltas studied in the paper, around 70%, have subsidence problems primarily the result of groundwater withdrawal. But some, like the Amazon and Mississippi deltas, had subsidence issues driven by the disappearance of river-carried sediment to replenish the delta’s land.

Putting hard numbers to and pinpointing causes of subsidence—like human activity—is invaluable to restoring coastal land.

“I would say that really validates what, not just my organization, but what a lot of people have recognized for a long time—that this was a significant contributing factor in subsidence,” said James Karst with the nonprofit advocacy group Coalition to Restore Coastal Louisiana, referring specifically to the lack of sediment sent to the Mississippi River Delta.

Decisions about what pieces of the coast can be saved are even more urgent with the cancellation of two large-scale restoration projects in Louisiana.

Known as sediment diversions, the Mid-Barataria and Mid-Breton plans would have diverted freshwater from the Mississippi River into surrounding wetlands. They were scrapped by the state because of the prospective impact on fisheries for oysters, crabs and other marine species. Fish and oyster harvesters celebrated the projects’ demise, while scientists and coastal restoration advocates warned that time is running out to save the coast.

Boaters fish in the canals and wetlands just outside of New Orleans, Louisiana. Coastal restoration projects spearheaded by the state hope to preserve areas of subsiding land that are at risk of disappearing. Credit: Elise Plunk/Louisiana Illuminator

“In light of the cancellation of Mid-Barataria, I think what we, everybody, should be thinking of is, ‘What is the next best thing?’” Karst said. “Clearly it is not going to move forward, but we can’t do nothing.”

“People should be aware that we are in a part of the world that is changing and that is changing rapidly.”

“People should be aware that we are in a part of the world that is changing and that is changing rapidly,” he added. “If we want to position ourselves as individuals and as communities, we should be anticipating these changes and anticipating how they will affect us.”

While the average rate of subsidence for the Mississippi River Delta is around 3.3 millimeters per year, Ohenhen said, some areas of Louisiana are sinking at a rate of 3 centimeters per year, one of the fastest rates of all the deltas studied. That is paired with sea level rising by at least 7 millimeters per year along the Gulf Coast, he said, also one of the highest rates in the world. This puts some areas of Louisiana’s land at higher risk of loss than anywhere else.

“In the Mississippi River Delta, for example, that is one of the only deltas in the world where you have active relocation of people from the delta due to land loss,” Ohenhen said. “The time that we need to respond to these changes is now before the situation gets significantly worse.”

—Elise Plunk (@plunk.bsky.social), Louisiana Illuminator

This story is a product of the Mississippi River Basin Ag & Water Desk, an independent reporting network based at the University of Missouri in partnership with Report for America, with major funding from the Walton Family Foundation.

A new paper (Jia et al. 2026) has found that the 8 February 2025 Junlian rock avalanche was caused by progressive weakening of the rock mass through wetting and drying cycles.

On 8 February 2025, the major Junlian rock avalanche landslide occurred at Jinping Village in Sichuan Province, China. A paper (Jia et al. 2026) has now been published in the journal Landslides that provides more details about the possible causes of this event. This link should provide access to the paper.

An earlier paper (Zhao et al. 2025), which I noted in June, has already described this landslide. This is a photograph of the aftermath of this event:

The aftermath of the 8 February 2025 Junlian rock avalanche in Sichuan, China. Image by Xinhua.

Unfortunately, the paper does not give a lat / long for this landslide, but I have previously noted that it is at [27.99885, 104.60801].

As a reminder, Zhao et al. (2025) determined that the initial failure was 370,000 m3, increasing to 600,000 m3 through entrainment. The landslide had a runout distance of 1,180 metres and a vertical elevation change of 440 m. In total, 29 people were killed.

The slightly odd thing about this failure is that the rainfall event that appears to have triggered it was unexceptional (c. 85 mm over the previous 30 days). I hypothesised that a progressive failure mechanism could have been in play.

Jia et al. (2026) have made some really interesting observations. First, this site was subject to previous landslides, most notably in February 2013. The paper notes that:

“all 173 people from 29 households under threat [from this earlier event] were included in the geohazard risk avoidance relocation subsidy program. Some farmers self-demolished their houses, but as some occasionally returned during the farming season, the Mu’ai Town Government, with support from the county government, organized mandatory demolition of unremoved houses in the area in 2018. ”

Further failures occurred in 2021 and 2022, whereupon all the households immediately below the unstable slope were relocated. However, homes located at a greater distance from the cliff were left in place – these were the people affected by the 2025 event.

Jia et al. (2026) suggest that initial movement of the landslide in the years before 2025 weakened the rock mass and opened pathways for the movement of water into the shear zone. Critically, their work suggests that successive wetting and drying cycles led to degradation of the the sandstones and mudstones forming the slope, moving the mass towards failure.

This weakening was sufficient to render the slope vulnerable to the effects of the rainfall in February 20925, triggering the Junlian rock avalanche.

We might take away to key messages from this work. The first is the need to understand the likely runout characteristics of a slope in determining the safety of the population. This is devilishly difficult. That there was an ongoing programme to relocate the most vulnerable people is (on the face of it) good, but it depends on this calculation.

Second is the need to understand the complexities of the processes occurring in a slope. In the case of the Junlian rock avalanche, it was the progressive weakening of the rock mass through wetting and drying cycles that meant that the slope could fail under the influence of unexceptional rainfall. As we drive climate change, similar processes will be occurring in many more slopes in China and elsewhere. That is going to pose a major challenge in terms of keeping people safe.

References

Jia, W., Wen, T., Chen, N. et al. 2026. Dry–wet cycle may trigger the catastrophic landslide in Junlian on February 8, 2025. Landslides. https://doi.org/10.1007/s10346-026-02692-2

Zhao, B., Zhang, Q., Wang, L. et al. 2025. Preliminary analysis of failure characteristics of the 2025 Junlian rock avalanche, China. Landslides. https://doi.org/10.1007/s10346-025-02556-1.

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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.

Humanity has overspent and depleted freshwater in the world’s aquifers, glaciers, wetlands, and other natural reservoirs to an irreversible degree, according to a new United Nations report.

The report, published by United Nations University’s Institute for Water, Environment and Health, argues that “water bankruptcy” is the only appropriate way to describe the reality of Earth’s water resources. 

The authors define water bankruptcy as a state of irreversible damage to human-water systems in which long-term water use has exceeded renewable inflows and safe depletion limits. “Water crisis,” which indicates a reversible condition, is no longer an accurate description of the world’s water situation, they write: “What appears on the surface as a crisis is, in fact, a new baseline.”

Water stress, water crisis, and water bankruptcy all refer to different states of concern in water-human systems. Credit: United Nations University Institute for Water, Environment, and Health

“Many critical water systems are already bankrupt,” lead author Kaveh Madani, director of UNU-INWEH, said in a statement.“Enough critical systems around the world have crossed these thresholds. These systems are interconnected through trade, migration, climate feedbacks, and geopolitical dependencies, so the global risk landscape is now fundamentally altered.”

This water bankruptcy is particularly evident in the Middle East and North Africa, where climate vulnerability, decreasing agricultural productivity, and sand and dust storms also threaten livelihoods and economies, the report states.

Widespread groundwater depletion, water overallocation, land and soil degradation, deforestation, and pollution are all contributing to depleted freshwater stores. Climate change has exacerbated these issues by worsening droughts and upending typical weather patterns.

The authors write that 70% of major aquifers worldwide are showing long-term decline, 75% of humanity lives in a water-insecure or critically water-insecure country, and 4 billion people face severe water scarcity for at least one month each year. 

Overall water risk, reflecting the value of physical water quantity, water quality, and regulatory and reputational risks, is greatest in North Africa, the Middle East, and Central Asia. Credit: United Nations University Institute for Water, Environment, and Health

“Millions of farmers are trying to grow more food from shrinking, polluted, or disappearing water sources,” Madani said. “Without rapid transitions toward water-smart agriculture, water bankruptcy will spread rapidly.”

 
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Though water bankruptcy is irreversible, the report spells out possible ways to mitigate the crisis and protect against worsening water deficits, including implementing better wetland protections, reforming irrigation practices, and rebalancing water rights and expectations to match the degraded capacity of the world’s aquifers.

The report is intended to inform discussions at the 2026 UN Water Conference in the United Arab Emirates in December.

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

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

El mundo se está calentando, pero las temperaturas de verano en la ladera sur del monte Everest, medidas continuamente por el Laboratorio Pyramid desde 1994, han descendido en los últimos 15 años.

¿El motivo? Los vientos fríos descendentes, causados por el aumento de las diferencias de temperatura entre el aire más cálido que se encuentra por encima del glaciar y la masa de aire en contacto directo con la superficie helada del glaciar.

Estos vientos catabáticos crean un efecto de enfriamiento alrededor de los glaciares de montaña, explicó Thomas Shaw, glaciólogo del Instituto de Ciencia y Tecnología de Austria. “Se derriten más lentamente de lo que lo harían si hubiera una correspondencia uno a uno entre la temperatura atmosférica y la temperatura de la capa límite del glaciar”.

Los científicos han tomado nota de este fenómeno desde finales de 1990, pero hasta ahora los estudios se han limitado a glaciares específicos.

Para comprender el alcance del fenómeno y los factores que influyen en él a escala global, Shaw y sus colegas recopilaron y analizaron un conjunto de datos de 62 glaciares a través de 169 campañas glaciares, lo que asciende a un volumen sin precedentes de 3.7 millones de horas de datos de temperatura del aire.

Mientras muchos de los datos eran fácilmente accesibles, algunos eran “casi como si estuvieran escritos en la parte de atrás de una servilleta”, dijo Shaw, que fue capaz de incluir datos sin publicar de otros investigadores. “Hay que enviar muchos correos electrónicos, hacer clic, buscar, investigar y pensar: Ah, recuerdo que alguien publicó algo sobre esto”.

Cambio en las proyecciones

El estudio, publicado en Nature Climate Change, encontró que la capa límite del glaciar se calienta una media de 0.83 °C por cada grado de calentamiento ambiental.

“Este no es el único proceso que afecta al deshielo de los glaciares, pero es uno importante del que antes no teníamos pruebas”, mencionó Inés Dussaillant, glacióloga del Centro de Investigación en Ecosistemas de la Patagonia en Chile, que no participó en el estudio.

“Esto podría cambiar nuestras proyecciones…y los informes del IPCC sobre la evolución futura de los glaciares o la contribución al nivel del mar.”

Actualmente, este efecto no se tiene en cuenta al momento de modelar cómo cambiarán los glaciares con el tiempo, según Harry Zekollari, glaciólogo de la Universidad Libre de Bruselas (Bélgica), que no participó en el estudio. “Puede cambiar nuestras proyecciones y cómo las elaboramos, y puede cambiar las proyecciones y los reportes [Grupo Intergubernamental de Expertos sobre el Cambio Climático] sobre la evolución futura de los glaciares o la contribución al nivel del mar”.

De acuerdo con el análisis de Shaw, los principales factores que impulsan el efecto de enfriamiento son la diferencia de temperatura entre la capa límite del glaciar y el aire circundante, el tamaño del glaciar y la humedad. La capa de escombros que cubre el glaciar y los fuertes vientos sinópticos dificultan el efecto.

Este fenómeno significa que el aumento de la temperatura ambiente en realidad aumenta el efecto de enfriamiento en los glaciares grandes, pero solo hasta cierto punto. “Los glaciares no están protegidos por esto; no se están enfriando. Es un término un poco engañoso”, afirmó Shaw. Aunque se están derritiendo más lentamente de lo que cabría esperar con un calentamiento lineal, el efecto sigue siendo considerable. El estudio proyecta que, a nivel mundial, estos efectos de enfriamiento cerca de la superficie alcanzarán su punto máximo a finales de la década de 2030, a medida que aumenten las temperaturas.

A medida que los glaciares se reduzcan de tamaño, dejarán de generar vientos catabáticos y su ritmo de calentamiento comenzará a reflejar las temperaturas ambientales. Según el estudio, esto provocará un deshielo acelerado a partir de mediados de siglo.

Se va, se va, se fue

Shaw y sus coautores notaron grandes variaciones regionales en los datos. Si bien no se espera que el efecto de enfriamiento alcance su punto máximo hasta la década de 2090 en los glaciares de Nueva Zelanda y el sur de los Andes, es probable que los glaciares de Europa central ya hayan superado este punto y se estén deteriorando a un ritmo cada vez mayor.

Los resultados del estudio coinciden con otros hallazgos. A principios de este año, un estudio sobre los cambios en la masa glaciar mundial encontró que Europa central perdió el 39% de su masa de hielo entre 2000 y 2023, lo que la convierte en la peor de las 19 regiones estudiadas.

Un ejemplo claro es el Pasterze, un glaciar austriaco en el que se iniciaron las investigaciones sobre el fenómeno del enfriamiento en la década de 1990. “ Este glaciar era antes mucho más grande y presentaba un efecto de enfriamiento catabático mucho más intenso. Ahora se está desintegrando muy rápidamente”, afirmó Shaw, notando que probablemente no seguirá siendo el glaciar más grande de Austria durante mucho tiempo. “Ya se está mostrando evidencia de lo rápido que pueden reaccionar los glaciares al clima cuando empiezan a desaparecer”.

Pero, aunque se dispone de gran cantidad de datos confiables a largo plazo para zonas como los Alpes europeos, Islandia, Svalbard y el oeste de América del Norte, la vigilancia de los glaciares no está distribuida de manera uniforme en todo el mundo. Dussaillant quisiera que se prestara más apoyo a las regiones cuyos gobiernos no pueden mantener una vigilancia continua de los glaciares. “No podemos decir realmente que este sea el panorama global, cuando en realidad algunas regiones siguen teniendo enormes huecos que debemos llenar y comprender mejor”.

Con alrededor de 200 000 glaciares en todo el mundo, aún queda mucho trabajo por hacer antes de que se obtenga una imagen verdaderamente global, afirmó Zekollari. “Pero es un gran paso adelante en comparación con lo que teníamos”.

—Kaja Šeruga, Escritora científica

This translation by Saúl A. Villafañe-Barajas (@villafanne) was made possible by a partnership with Planeteando and Geolatinas. Esta traducción fue posible gracias a una asociación con Planeteando y Geolatinas.

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In the summer of 2020, Friends of Palm Beach, a nonprofit that cleans the shores of Palm Beach, Fla., noticed something unusual among the typical debris—many bottles and rubber bales were washing up covered in a black residue. Diane Buhler, the group’s founder, cataloged the time and location of the arrival of each piece of debris and kept an expertly photographed record.

No oil spills had been reported locally, and the high amount of residue-coated debris created a mystery: Where was all this black sludge coming from?

Christopher Reddy, a chemical oceanographer at the Woods Hole Oceanographic Institution, had been working with an international team of scientists on a separate mystery: the origins of a 2019 oil spill in Brazil, the largest in the country’s history. When he saw the debris posted on the Friends of Palm Beach Instagram page, he reached out. “I was like, ‘Please, please send [the debris] to us,’” he said. The details Buhler was providing about the debris, he said, were “remarkably informative.”

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Reddy and the team had a hunch: They thought the 2020 Florida debris and the 2019 Brazil spill were linked. Because of weathering, oil residues rarely travel more than 300 kilometers (186 miles)—but perhaps they’d used plastic pollution to hitch a ride to the Sunshine State.

“This project wouldn’t have happened unless there was this knowledge of the way the currents move.”

A thorough analysis, published in Environmental Science and Technology, confirmed the residue likely originated from the Brazil spill. The findings reinforce scientists’ hypothesis that oil can travel far greater distances when attached to plastic debris in the ocean.

Matching Mysterious Oil Samples

Multiple lines of evidence informed the team’s conclusion that the Brazil spill and Palm Beach debris were related. First, previous experiments that tracked drifting bottles in the western tropical Atlantic and Caribbean Sea in the 1960s and 1970s showed it was possible for plastic debris to drift thousands of kilometers in the time that elapsed between the spill and the appearance of the debris. Second, computer simulations of the movement of oiled debris in the ocean also showed that it was possible for such debris to have reached Florida’s shores from the coast of Brazil. 

“This project wouldn’t have happened unless there was this knowledge of the way the currents move,” said Reddy, a coauthor on the new study. 

In the summer of 2020, oiled debris was found on Florida beaches. The oil likely traveled 8,500 kilometers (about 5,300 miles) from a 2019 oil spill off the coast of Brazil. Credit: James et al., 2026, https://doi.org/10.1021/acs.est.5c14571, CC-BY 4.0

The researchers also scraped oil residue from 10 samples of the Palm Beach debris, then performed a series of chromatography tests and molecular analyses to compare it to oil samples from the Brazilian spill. Researchers found the samples to be forensically identical to oil from the spill; compounds that the team expected to be present were, while ones that should have been lost as oil degraded were not.

“It was such crystal-clear evidence that I got nervous.”

The team was astounded at the similarities, particularly the chromatography results. “It was such crystal-clear evidence that I got nervous,” Reddy said. “Oh my gosh, this really did happen,” he remembered thinking. 

The data are “pretty striking,” agreed Bryan James, a chemical engineer at Northeastern University and coauthor on the new study. 

The research team reasoned that the oiled debris traveled about 8,500 kilometers (about 5,300 miles) from the coast of Brazil to Palm Beach over about 240 days. That much oil has never been documented traveling so far, said Michel Boufadel, an environmental engineer at the New Jersey Institute of Technology who was not involved in the study. 

Researchers think the oiled debris may also have reached Caribbean islands but wasn’t cataloged. Credit: Diane Buhler, Friends of Palm Beach

The authors think it’s likely that similar debris washed up on Caribbean shores as well as Florida’s but simply wasn’t collected or cataloged. “Southeast Florida was where there was a person thinking and looking, who had this database in her head” and reported it, too, Reddy said. 

While the “science is solid,” Boufadel said, additional evidence from elsewhere in the Caribbean would add confidence to the results. 

A Plastic Problem

Typically, oil spilled in the ocean is removed by natural processes before it reaches very far, James said. But plastic debris can travel much farther, sometimes washing ashore after traveling thousands of miles over decades.

James said this raises a colocation problem. Many sources of oil and sources of plastic overlap, creating a “greater possibility for these two to find each other…and continue to move oil farther from where it originated,” he said. 

The results are further proof of a known risk of plastic pollution: It can be a vector for other toxic substances, Boufadel said. 

The research team is investigating why plastic debris can carry oil residues so far. Boufadel said it’s likely the plastic helped to maintain the physical integrity of the oil, preventing some of the fragmentation and degradation that would otherwise have occurred.

Colleagues in Brazil, Reddy added, are continuing to investigate the origin of the still-mysterious 2019 spill there, as well. It may be oil that leaked from the SS Rio Grande, a German supply boat sunk by the U.S. Navy in 1944, but more research is needed to confirm that hypothesis, Reddy said.

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

This news article is included in our ENGAGE resource for educators seeking science news for their classroom lessons. Browse all ENGAGE articles, and share with your fellow educators how you integrated the article into an activity in the comments section below.

Citation: van Deelen, G. (2026), Plastic debris helps oil residues reach farther across the ocean, Eos, 107, https://doi.org/10.1029/2026EO260033. Published on 20 January 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: AGU Advances

Technologies for Earth observation by satellites have been used to give advance warning of potentially imminent crop failure due to drought conditions. These risks are increasing with climate change and are especially concerning for middle- and low-income countries that are vulnerable to food insecurity.

Nakalembe [2026] reports on the effectiveness of Uganda’s Disaster Risk Financing Program, which pioneered satellite-triggered financing for drought disaster relief operating at scale. The $14 million program yielded $40.7 million in total benefits, including $11.1 million in immediate emergency aid cost savings. In addition to offering lessons learned, this commentary concludes that institutional and financial barriers, rather than technical limitations, now constrain the scaling of this satellite-driven climate resilience mechanism. Similar programs may reduce vulnerabilities worldwide, as climate disasters become increasingly frequent and severe.

Anomalies in the Normalized Difference Vegetation Index (ANDVI) from satellites and the Standardized Precipitation Index (SPI-3) during the peak growing season (June – September) of each year from 2000 to 2015 across the Karamoja Region of Uganda. The solid-colored lines show ANDVI (left axis) for six Ugandan districts, with negative values indicating reduced crop health. A horizontal dashed line at -0.02 ANDVI represents the trigger threshold for activating financial assistance by Ugandan government agencies. The dashed black line illustrates precipitation anomalies from SPI-3 (right axis), with classification of drought severity indicated by horizontal lines D1-D4 at negative SPI-3 values. Note that the in years when the SPI-3 index dropped below the drought severity lines (D1-D4), many of the ANDVI values for the six districts (colored lines) also become negative, often below the threshold of -0.02, indicating a crop response to drought that warns of potential crop failure and proactively triggers governmental disaster relief. Credit: Nakalembe [2026], Figure 1

Citation: Nakalembe, C. (2026). Lessons From Uganda’s Earth Observation-Based Disaster Risk Financing Program. AGU Advances, 7, e2025AV002224. https://doi.org/10.1029/2025AV002224

—Eric Davidson, Editor, AGU Advances

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A new study (Akhila et al. 2025) in the the journal Development in Practice examines the mental health impacts of the 30 July 2024 Wayanad landslides in India.

In this blog, I generally provide a commentary on recent landslide events and a review of subsequent studies of landslides. I regularly discuss the impacts on the local population at the time of the disaster, but in 18 years I have almost never written about the long term effects on those people. This is primarily because of a lack of literature that covers this issue for landslides. This is particularly true of mental health impacts.

However, it is logical to assume that the mental health impacts must be profound. Landslides are deeply traumatic events even setting aside the loss of friends and family. They are violent and unpredictable in their behaviour, and people are often buried alive, which is a fundamental human fear.

In that context, a faascinating study (Akhila et al. 2025) has been published in the journal Development in Practice that examines the mental health impacts of the 30 July 2024 Wayanad landslides in India, which are believed to have killed 454 people and injured 397 more. Back at the time, I posted this image of the aftermath of these channelised debris flows:-

Planet Labs image of the 30 July 2024 landslide at Wayanad in Kerala, India. Image copyright Planet Labs, used with permission, captured on 12 August 2024.

The first author was present in some of the 53 camps established in the immediate aftermath of the landslides to house and care for the 6,759 people displaced by the landslides. The paper provides a reflection on their experiences.

The short term impacts of the landslide on survivors decumented by Akhila et al. (2025) are perhaps unsurprising but valuable. They describe emotional breakdown:-

“The very grounds they once called home had turned into graveyards of their people. Many survivors now carry the weight of survivor’s guilt, asking why they survived when others didn’t. This leads to feelings of self-blame, helplessness, and in some cases, post-traumatic stress symptoms.”

Survivors lost cherished places and livelihoods, and their “sense of security, identity, and hope was disrupted”. This triggered “heightened anxiety, sleep disturbances, a lingering sense of fear and uncertainty about the future.” The picture that emerges is one of profound collective trauma.

The longer term mental health impacts are also deeply troubling. Akhila et al. (2025) describe how the communities were left in a constant state of fear of a repeat of the event. This was heightened by anxiety about rehabilitation, livelihoods and relocation. The population lost their homes and the fabric of their communities; some inevitably turned to alcohol or substance abuse, leading to high risk behaviours. Financial crises further exacerbated the challenges for many.

Akhila et al. (2025) also highlight the particular mental health impacts for children, older people, those with disabilities and those who were from outside of the area. The ways that landslide disasters have particular impacts on different groups is a really interesting topic.

But the authors also look at the impact on first responders, noting that many of these individuals were themselves survivors, and some lost loved ones. They note that the responders were “forced to work under extreme stress during the disaster relief efforts. Many were deployed without prior debriefing and continue to carry the emotional distress from that period into their daily lives.”

Finally, Akhila et al. (2025) briefly consider the provision of long term mental health support for survivors. They note that there were many gaps in provision of such services, leading to many people failing to receive the support that they needed, but also to some duplication of effort due to poor coordination. Providing such services affectively would stretch any community, but the authors recommend better planning and integration of services.

This is an incredibly valuable piece of work that explores an issue so rarely considered for landslides. The picture described in the paper must be replicated again and again around the world. It would be great to see both more studies of this type and, of course, better provision of mental health support in the aftermath of landslide disasters.

Reference and acknowledgement

Akhlia, V et al. 2025. Mental health aftershocks following the high-intensity landslide in Southern India. Development in Practice, https://doi.org/10.1080/09614524.2025.2551850.

Thanks as ever to the kind people at Planet Labs for providing access to their amazing imagery.

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New research indicates that over 100,000 landslides were triggered by a single rainstorm.

Back in July 2023, the remnants of Typhoon Doksuri swept across northern China, bringing exceptional rainfall. I briefly covered this at the time, but there was a lack of clear information about the impacts.

A technical note has been published in the journal Landslides in the last few days (Xie et al. 2026) [this link should allow you to access the paper behind the paywall), which provides greater clarity on what occurred. And the picture is remarkable.

The authors have undertaken detailed mapping of the landslides triggered by Typhoon Doksuri, identifying 104,555 landslides. The authors describe this as “the largest rainfall-induced landslide event in North China to date”.

To give an idea if the scale of this event, the image below shows just a small part of the affected area, centred on [39.9530, 116.04518]. This is a Planet Labs image captured on 25 July 2023, just before the rainfall:-

Satellite image of a part of northern China before Typhoon Doksuri. Image copyright Planet Labs, captured on 25 July 2023, used with permission.

And here is the same area after Typhoon Doksuri:-

Satellite image of a part of northern China after Typhoon Doksuri. Image copyright Planet Labs, captured on 16 August 2023, used with permission.

And here is a slider to allow the images to be compared:-

Images copyright Planet Labs, used with permission.

The situation will be familiar to regular readers of this blog – intense rainfall has triggered multiple shallow landslides in steep terrain, which have then coalesced to form channelised debris flows with high mobility and a long runout. Note the way that these debris flows have entered the populated area – in some cases the damage looks very serious:-

Satellite image of a part of northern China after Typhoon Doksuri showing debris flows in populated areas. Image copyright Planet Labs, captured on 16 August 2023, used with permission.

These landslides were triggered by extreme rainfall – Xie et al. (2026) suggest that some areas received over 400 mm in a seven day period, and over 200 mm in 24 hours.

It was not the aim of this paper to consider the cost of these landslides, but this must have been substantial. A paper in Mandarin (Yang et al. 2023) on the meteorology of this event notes that:

“According to incomplete statistics (as of August 10, 2023), the continuous heavy rainfall affected 3.8886 million people in 110 counties (cities, districts) of Hebei Province, causing direct economic losses of 95.811 billion yuan, 29 deaths, and 16 missing persons. It is necessary to review and summarize the precipitation characteristics and weather causes of this event to provide a reference for forecasting extreme torrential rainstorms in North China.”

This translates to US$13.7 billion.

References
Xie, C., Huang, Y., Xu, C. et al. 2026. Over 100,000 landslides triggered by typhoon-induced rainfall in North China in July 2023. Landslides. https://doi.org/10.1007/s10346-026-02698-w

Yang, X. et al. 2023. Evolution characteristics and formation of the July 2023 severe torrential rain on the eastern foothills of Taihang mountains in Hebei Province.
Meteorological Monthly, 49, 1451-1467. (in Chinese). https://doi.org/10.7519/j.issn.1000-0526.2023.102301

Thanks as ever to the kind people at Planet Labs for providing access to their amazing imagery.

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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: AGU Advances

Asteroids, moons, and comets near Earth act like fossils from the time when our solar system first formed. In a new article, de Kleer et al. [2025] explain how a powerful telescope called the Atacama Large Millimeter/submillimeter Array (ALMA) has changed the way scientists study these small worlds. ALMA can detect very weak thermal emission (heat) signals, allowing researchers to map the surface features of asteroids and accurately measure the masses of distant objects beyond Neptune, known as Kuiper Belt Objects.

ALMA is also used to study gases released by volcanic eruptions on Jupiter’s moon Io and probe the thick atmosphere of Saturn’s moon Titan. The review emphasizes the study of isotopes, which are slightly different forms of the same chemical element. These isotopes act like chemical fingerprints, helping scientists track how elements such as nitrogen and sulfur have changed over time. By comparing these local measurements with observations of young planetary systems around other stars, scientists can better understand how the ingredients for life survived the violent process of planet formation.

Citation: de Kleer, K., Brown, M. E., Cordiner, M., & Teague, R. (2025). Satellites and small bodies with ALMA: Insights into solar system formation and evolution. AGU Advances, 6, e2025AV001778. https://doi.org/10.1029/2025AV001778

—Xi Zhang, Editor, AGU Advances

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Source: Journal of Geophysical Research: Biogeosciences

Human activities add large quantities of nitrogen to the environment, much of which gets washed into streams and rivers. These waterways transport some of that nitrogen to the oceans, but they also remove a significant portion of it through a process called denitrification: Microbes facilitate a series of chemical reactions that turn nitrate into dinitrogen gas, which is then released into the atmosphere.

Existing research, largely in streams, shows a wide range of denitrification rates, but the factors affecting this process aren’t fully quantified, especially in rivers. Pruitt et al. compared denitrification rates in a stream and a river across three seasons to study how the process varies across waterway scales.

The researchers took hourly water samples from the Tippecanoe River and the Shatto Ditch in Indiana over 36-hour periods in spring, summer, and fall. They used open-channel metabolism and a membrane inlet mass spectrometry–based model to study how rates of denitrification fluctuated in both waterways as the seasons changed. They found the stream had higher denitrification rates per square meter than the river in all seasons. They attribute this in part to higher nitrate levels in the stream, as well as a proportionally greater contribution of microbial activity on the streambed. However, when the researchers scaled up, the denitrification rate in rivers per kilometer of channel length was equal to or even higher than that of streams.

The researchers also observed different seasonal denitrification patterns. In the stream, denitrification rates were highest in spring and lower in summer and fall, whereas in the river, denitrification rates were highest in the fall, followed by spring, and very low in summer. Fertilizer application and higher precipitation rates in spring likely drive the stream dynamics, they suggest, whereas higher rates of ecosystem respiration increasing denitrifier activity in the fall may explain the pattern seen in the river.

Additionally, nitrogen gas concentrations varied by hour, the authors report, which could help explain the large range of rates found by previous studies. They recommend that future work use both the open-channel method and an in situ chamber assay and compare the two sampling methods. The authors also suggest that separating incomplete from complete denitrification could be valuable to explore the release of nitrous oxide, a potent greenhouse gas, to the atmosphere. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG009044, 2025)

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2026), Denitrification looks different in rivers versus streams, Eos, 107, https://doi.org/10.1029/2026EO260029. Published on 16 January 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Global Biogeochemical Cycles

A critical part of Earth’s carbon cycle is the sinking of particulate organic material from the ocean’s surface to its depths. Much of that material is classified as “marine snow,” which is primarily made of snow-sized (>0.5 mm) detrital organic matter and phytoplankton.

Siegel et al. participated in a field campaign in the northeast Atlantic Ocean during the demise of the spring phytoplankton bloom during May 2021. They set out to observe how both physical processes, such as turbulence created by storms, and biological processes, such as consumption by animals and microbes, affected marine snow dynamics. The researchers used three research vessels, three instrumented gliders, a Lagrangian float, and 10 water-following surface drifters to measure the size distribution and characteristics of marine snow particles in the upper 500 meters of the water column.

The researchers found that near the ocean’s surface, turbulence induced by intense storms caused the breakdown of marine snow particles that later aggregated during calmer conditions. The succession of multiple storm events helped to foster the downward movement of marine snow through the water column. Below a depth of 200 meters, consumption by zooplankton and other organisms drove the removal of the snow particles and their breakdown into smaller ones. The combination of these processes affected how quickly particles sank through the water column and therefore the timescales over which the sinking organic carbon was sequestered from the atmosphere.

Over the course of the experiment, the researchers found that the marine snow particles became fluffier, larger, and more porous, and more marine snow appeared in the water column overall. Additionally, the average particle sinking velocity above 200 meters of depth increased from roughly 17 meters per day to almost 100 meters per day, likely attributable to the increase in the particle size of the marine snow aggregates.

The results highlight how both abiotic and biotic processes affect how marine snow moves through the water column. That understanding could have implications for how scientists quantify the effects of the ocean’s biological pump within the planet’s carbon cycle, the researchers say. (Global Biogeochemical Cycles, https://doi.org/10.1029/2025GB008676, 2025)

—Madeline Reinsel, Science Writer

Citation: Reinsel, M. (2026), Marine snow grows faster and fluffier as it sinks, Eos, 107, https://doi.org/10.1029/2026EO260030. Published on 16 January 2026. Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

Advancing our understanding of climate change and its impacts requires a multidisciplinary effort to generate, evaluate, and integrate reliable climate records at appropriate spatiotemporal scales. Reliable and traceable climate observations are essential for evidence-based climate governance.

Essential Climate Variables (ECVs) serve as the foundation for monitoring the Earth system. For instance, ECVs such as the Earth Radiation Budget and Total Solar Irradiance (TSI) provide critical information on energy exchanges within the Earth system, underpinning assessments of long-term variability and anthropogenic influences.

These variables are estimated from satellites, ground networks, and models, producing vast datasets whose usefulness depends not on size, but on quality, consistency, and careful integration. As measurement coverage is uneven, instruments differ in calibration, and techniques can yield conflicting results. Thus, transforming raw data into reliable information requires rigorous quality control and collaboration across scientific and technical disciplines.

International frameworks such as the WMO Integrated Global Observing System (WIGOS) set standards for measurement, documentation, uncertainty reporting, and open data sharing. These systems promote traceability and reliability—ensuring the ability to track how each data point was produced and processed—so that scientists can reproduce analyses and policymakers can trust the results. In addition, emerging approaches, including physics-informed Machine Learning (ML) and Deep Learning (DL), enable enhanced detection of patterns, anomaly identification, and quality control in large, heterogeneous datasets. Thereby they are strengthening the role of ECVs in monitoring system integrity.

Moreover, geodetic observations of sea-level rise, cryospheric changes, and solid Earth deformation illustrate the key role of multidisciplinary ECV analysis. By providing a holistic understanding of environmental change, these data streams are foundational for developing next-generation predictive tools, including Earth’s Digital Twin, to monitor global and local dynamics.

In this context, the Global Climate Observing System (GCOS) plays a key role by fostering global collaboration to develop interdisciplinary ECVs that are traceable and reliable. GCOS supports efforts to advance climate science by ensuring high-quality data, which is vital for informed climate action and adaptive policy development. Through innovation and interdisciplinary approaches, this framework enables more effective responses to the challenges posed by climate change.

This special collection serves as a venue for contributions that shed light on the role of continuous monitoring of ECVs, coupled with rigorous quality assurance, as a foundation for policy decisions, ultimately bridging the gap between technical observation and actionable climate governance. We especially welcome novel research that advances the methodologies required to demonstrate how robust, traceable data can empower society to build resilience against a changing climate. Contributions will include (but not be limited to) research into: best practices in observation, collection, and processing and curation of data. It can also include physics-informed machine and deep learning methods to identify relationships and feedback loops between atmosphere, hydrosphere, biosphere, and lithosphere, as well as evidence-based policies and remediation measures.

This is a joint special collection between Earth and Space Science, JGR: Machine and Computation, and Earth’s Future. Manuscripts can be submitted to any of these journals depending on their fit with each journal aims and scope. Submissions are now open and welcome until 7 March 2027.

—Jean-Philippe Montillet (Jean-Philippe.Montillet@pmodwrc.ch, 0000-0001-7439-7862), Physikalisch-Meteorologisches Observatorium Davos World Radiation Center, Switzerland; Graziella Caprarelli (Graziella.Caprarelli@usq.edu.au, 0000-0001-9578-3228), University of Southern Queensland, Australia;  Gaël Kermarrec (0000-0001-5986-5269), Leibniz Universitat Hannover, Germany; CK Shum (0000-0001-9378-4067), Ohio State University, United States; Ehsan Forootan (0000-0003-3055-041X), Aalborg University, Denmark; Jan Sedlacek (0000-0002-6742-9130), Physikalisch-Meteorologisches Observatorium Davos World Radiation Center, Switzerland; Elizabeth Weatherhead (0000-0002-9252-4228), University of Colorado at Boulder, United States; Orhan Akyilmaz (0000-0002-8499-2654), Istanbul Technical University, Turkey; Wolfgang Finsterle (0000-0002-6672-7523), Physikalisch-Meteorologisches Observatorium Davos World Radiation Center, Switzerland; Yu Zhang, Ohio University, United States; Enrico Camporeale (0000-0002-7862-6383), University of Colorado Boulder, United States; and Kelly K. Caylor (0000-0002-6466-6448), University of California, Santa Barbara, United States

Citation: Montillet, J-P., G. Caprarelli, G. Kermarrec, CK. Shum, E. Forootan, J. Sedlacek, E. Weatherhead, O. Akyilmaz, W. Finsterle, Y. Zhang, E. Camporeale, and K. K. Caylor (2026), Bridging the gap: transforming reliable climate data into climate policy, Eos, 107, https://doi.org/10.1029/2026EO265001. Published on 16 January 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.