EOS

A new paper (Kharismalatri, Gomi & Sidle 2025) in the journal Natural Hazards uses the concepts of the inflow angle and the channel gradient to examine the behaviour of large landslides after failure.

Large landslides in areas with steep terrain that either block the valley or turn into a long runout debris flows are an increasing problem globally as the impacts of climate change accelerate. A key question for any large, potentially unstable slope is whether it will block the valley or transition into a long runout flow. Neither is good, clearly, but the risks and management approaches differ.

There is a very interesting paper (Kharismalatri, Gomi & Sidle 2025) in the journal Natural Hazards that uses a database of 188 large landslides from around the world to examine this issue. The paper has been published open access and using a creative commons licence (hurrah!), so please do take a look.

This diagram, from the paper, explains a key and very interesting metric in the study – the inflow angle:-

Key concepts, including the inflow angle, in the study of large landslides by Kharismalatri, Gomi & Sidle (2025).

There are two key ideas here – one is the inflow angle, which is the angle between the main axis of the landslide and the main axis of the channel, and the other is the channel gradient – the gradient of the river valley into which the landslide is moving, measured using a consistent distance scaled to the landslide length.

The most important diagram in the paper is this one, which shows the inflow angle plotted against channel gradient:-

The relationship between the inflow angle, and the channel gradient , from the study of large landslides by Kharismalatri, Gomi & Sidle (2025).

This is quite remarkable. The inflow angle plays a key controlling role in what happens when the landslide reaches the valley. If that angle is greater than about 60o, the landslide nearly always blocks the valley. If it is less, then it generally turns into a debris flow.

Similarly, if the channel gradient is less than about 10o, the landslide almost always blocks the valley. If it is less, it generally turns into a debris flow.

There are some overlaps, but the number of these cases is remarkably low.

It is also very interesting that there are no cases of landslides with both a high inflow angle and a high channel gradient (i.e. where inflow angle is >60o and channel gradient is >15o). I am not sure why this is the case.

This will be a very useful finding for those who are having to manage developing failures in large slopes. It allows a first order prediction of likely behaviour of the slope upon failure. So, for example, I wrote yesterday about a study of the potential failure of the large landslide at Joshimath in India. It would be interesting to see where on the graph that slope plots – it appears to me that the inflow angle is c.90o?

Reference

Kharismalatri, H.S., Gomi, T. & Sidle, R.C. 2025. Geomorphic thresholds for cascading hazards of debris flows and natural dam formation caused by large landslides. Natural Hazards. https://doi.org/10.1007/s11069-025-07402-0

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Source: Journal of Geophysical Research: Biogeosciences

When sunlight hits clouds or other atmospheric particles, it scatters and becomes diffuse light. Unlike direct sunlight, diffuse light can reach deeper into shaded plant canopies, where plants have dense, layered leaves. The diffuse-light fertilization effect theory suggests that diffuse light in such environments can promote carbon uptake and influence canopy temperature and evapotranspiration. Prior research suggests that some diffuse light can also boost photosynthesis, but after an optimal point, the overall reduction in total radiation will decrease photosynthesis.

However, diffuse light is not typically measured at ground-based sites. Previous studies used indirect methods to infer its effects on plants, including running computer models and measuring atmospheric properties such as clearness. So questions remained about the optimal amount of this filtered sunlight for vegetation.

Since 2017, the National Ecological Observatory Network (NEON) has collected data on diffuse sunlight, evapotranspiration, and other ecological variables across 32 sites in the continental United States, including forests, grasslands, shrubs, and cultivated crops. Schwartz et al. used the NEON dataset combined with satellite records from the Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) to determine how diffuse sunlight connects to evapotranspiration and net ecosystem exchange, or the carbon exchange between ecosystems and the atmosphere.

Their findings suggested that across NEON sites between 2018 and 2022, evapotranspiration decreased as diffuse radiation increased, and no optimal point was observed, contrary to what previous modeling suggested. Evapotranspiration, the researchers found, may be more strongly affected by available moisture than by either direct or diffuse light.

However, diffuse sunlight did enhance net ecosystem exchange in some locations, including forests and areas with shrub or scrub vegetation. Nineteen of the 32 sites showed a positive net ecosystem exchange response to diffuse light, meaning that more carbon can be absorbed when sunlight is scattered. (Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG008757, 2025)

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

Citation: Owen, R. (2025), How plants respond to scattered sunlight, Eos, 106, https://doi.org/10.1029/2025EO250249. Published on 14 July 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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Shoppers may use a plastic bag for only a few minutes before tossing it in the trash. Inefficient waste disposal, however, may allow that bag to find its way into streams and, ultimately, coastal ecosystems. There, plastic pollution can imperil marine plants and animals as well as the economic value of beachfront businesses.

“Plastic bags are designed to be single use. They’re designed to be lightweight. Even if we’re trying to properly manage them, they just get into the environment more easily than other plastics,” said Erin Murphy, ocean plastics science and research manager at the Ocean Conservancy.

“These [plastic bag bans] are effective policies, regardless of the scale of governance in which you implement them.”

While many states and municipalities have plastic bag bans or require fees for customers who want a bag, there is no national policy that aims to reduce the number of plastic bags used in the United States.

But a study published last month in Science shows some promising results: In places with bag bans and fees, the number of plastic bags found on local beaches and shorelines has dropped significantly.

“A lot of the time, communities don’t feel like they can implement policy that will directly impact their communities and directly benefit their communities. This study showed that whether it’s a town or state, these [plastic bag bans] are effective policies, regardless of the scale of governance in which you implement them,” said Murphy, who was not involved in the research.

Analyzing the Trash

Study authors Anna Papp and Kimberly Oremus examined data collected from 45,067 shoreline cleanup events between 2016 and 2023. During these events, organized by the Ocean Conservancy, participants collected trash along a beach and logged their findings into the Trash Information and Data for Education and Solutions (TIDES) database.

Plastic bags are the fifth most common item found during these shoreline cleanups, making up 4.5% of all cataloged trash. (Some of the more unusual items logged include golf balls, Mardi Gras beads, and fake nails.)

Papp and Oremus cross-checked the cleanup data with 182 plastic bag policies around the United States that were enacted between 2017 and 2023. The discrepancy between the dates of the cleanup data (starting in 2016) and the policy data (starting a year later) allowed the researchers to use the 2016 data as a control to evaluate how trends in plastic bag litter may have changed in response to local or state-level regulation.

“Comprehensive data on plastics in the environment can be challenging to find, so the cleanup data offered a new way of measuring plastic bag litter in the environment. This, combined with the wide reach of bag policies in the U.S. in recent years, made our study possible,” said Papp, an environmental economist at the Massachusetts Institute of Technology.

A Broad Spectrum of Bans

Across the country, a hodgepodge of legislation exists to manage plastic bag waste, from strict bans (like the ones implemented in New Jersey, where single-use paper bags are also limited), to partial bans (like the ones in California, targeted at large retailers), to required fees (as in Oregon, where retailers must charge at least 5 cents for a thick, presumably reusable plastic bag). In addition to statewide legislation, hundreds of municipalities have their own plastic bag policies.

“During our data collection phase, I was initially surprised by the reach of plastic bag policies. We estimate that now one in every three Americans lives in an area with some bag policy,” said Papp.

Papp and Oremus were able to document the effectiveness of such policies, regardless of their reach. In places where some form of plastic bag legislation exists, data showed a 25%–47% decrease in the proportion of plastic bags recovered in coastline cleanups. Although all policies aimed at reducing plastic bag litter were effective, researchers found that those implemented at the state level correlated most strongly to reducing the amount of plastic bag waste found during beach cleanups.

“In some ways it’s like, well, of course, if you use fewer plastic bags, you’re going to find fewer plastic bags on the beach, but it’s good that [researchers] documented that in a quantitative way,” said Susanne Brander, an ecotoxicologist at Oregon State University who was not involved in the study. “We need those data in order to convince additional lawmakers and agencies to take this seriously and to think not just about plastic bags, but about other single-use items as well.”

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

Citation: Owen, R. (2025), Policy success: Fees and bans on plastic bags reduce beach trash, Eos, 106, https://doi.org/10.1029/2025EO250247. Published on 14 July 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
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A new paper (Dalal et al. 2025) in the journal Engineering Geology examines movement of a major landslide complex in India. It shows that the slope reactivated in 2018, probably as a result of the loss of vegetation and poor management of water.

Loyal readers will remember a series of posts that I made back in early 2023 regarding accelerated movement of the complex landslide system located beneath the town of Joshimath located in the Himalaya in Uttarakhand, India. At this time, there was a significant increase in the movement rate of the landslide, causing substantial damage to structures within the town.

Joshimath is located at [30.5526, 79.5628]. This is a Google Earth image of the town in 2022. The complex landslides in the area are quite easy to see:-

Google Earth image of the town of Joshimath in northern India.

A very nice paper (Dalal et al. 2025) has been published in the journal Engineering Geology. The authors have used InSAR to examine the long term movement pattern of the landslides – the InSAR data extends back to 2017. In it, they demonstrate that the slope did indeed undergo a phase of rapid movement in early 2023, and they link this to heavy rainfall that occurred in October 2022, which increased the pore water pressure in the slope.

But there are some interesting details in this piece of work. First, the slope actually started to move in 2018, and showed a seasonal pattern of deformation until the rapid movement even in 2023. The authors link this reactivation of the landslide at Joshimath to progressive urbanisation and removal of the vegetation canopy – modelling indicates that the factor of safety of the slope has been notably reduced by this effect. This is quite surprising as the failure at Joshimath is deep-seated, where vegetation does not normall play a major role.

Second, the analysis also highlights that “mismanaged groundwater seepage and blocked drainage paths further exacerbated slope weakening.” This is a common problem in rapidly developing Himalayan communities.

Finally, and most worryingly, Dalal et al. (2025) indicate that the slope could be undergoing progressive failure towards a catastrophic collapse. They have modelled runout scenarios for the slope, which indicate that such an event would threaten the Tapovan Vishnugad hydropower project downstream.

All of this indicates that action is needed at Joshimath. If a large-scale mitigation project is not possible (and I recognise that this would be extremely expensive and very challenging), efforts should be made to manage water (and drainage) across the whole area, and the slope should be monitored in real time.

Reference

Dala, P. et al. 2025. Deformation dynamics and hazard of slow-moving landslides: The 2023 Joshimath event, Uttarakhand Himalaya. Engineering Geology, 354, 108201. Doi: https://doi.org/10.1016/j.enggeo.2025.108201

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Source: Global Biogeochemical Cycles

Whether from a forest on fire or gasoline powering a car, organic matter rarely combusts completely: Remnants such as char and soot can persist in the environment for decades. Over time, as physical and biological processes break down the scorched leftovers, some of the carbon they contain leaches into groundwater, lakes, and rivers, eventually making its way to the ocean.

This carbon, known as dissolved black carbon (DBC), represents the ocean’s largest identified reservoir of stable dissolved organic carbon. Yet the isotopic signature of DBC in the ocean does not match what rivers alone supply. This discrepancy suggests there are one or more unknown sources of DBC entering the ocean that are not accounted for in the global carbon budget.

To address this knowledge gap, Zhao et al. conducted six field surveys along China’s eastern coast, in the Jiulong, Changjiang (Yangtze), and Pearl River estuaries. By gathering samples during all four seasons, the researchers aimed to quantify changes in DBC and shed light on how it moves through coastal ecosystems toward the sea. Prior research focused only on individual estuaries and didn’t always account for how processes may vary across seasons and tide cycles.

The findings from the new study reveal submarine groundwater discharge (SGD) as a likely missing source of DBC. The scientists observed that as seawater pushed into estuaries during flood tides, DBC levels rose. Conversely, when water flowed out of the estuaries during ebb tides, DBC concentrations fell. They suggest that this pattern occurs because the salty ocean water that mixes into the estuaries during flood tides promotes the release of DBC from groundwater into the water column.

The researchers estimate that globally, SGD contributes approximately 20% of the riverine discharge of DBC that enters the ocean each year. Given the role that DBC plays in carbon sequestration and biogeochemical cycling in the ocean, the findings underscore the importance of including estuarine processes in global carbon models. (Global Biogeochemical Cycles, https://doi.org/10.1029/2025GB008532, 2025)

—Aaron Sidder, Science Writer

Citation: Sidder, A. (2025), Tracing black carbon’s journey to the ocean, Eos, 106, https://doi.org/10.1029/2025EO250248. Published on 11 July 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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Marine scientist Matthew Mulrennan was piggybacking on a tourist vessel around the Antarctic Peninsula’s coasts, surveying a seabed teeming with life, when his underwater cameras came across a gray seafloor scarred with ridges.

Anchoring had churned up the sediment, leaving lifeless patches strewn with crushed sponges. The damage had narrowly missed three giant volcano sponges, which can live for up to 15,000 years and grow larger than the divers who study them.

“We saw a lot of life on the seafloor and not a lot of regulation around its protection,” said Mulrennan, founder of KOLOSSAL, an ocean exploration and conservation nonprofit in California.

Anchoring churns up the seabed, destroying life and leaving regular furrows, akin to plow marks. Credit: Matt Mulrennan/KOLOSSAL

Mulrennan’s footage, which was released alongside a recent study in Frontiers in Conservation Science, provides evidence that the seafloor impacts of anchoring now extend to remote polar waters.

A Vulnerable Ecosystem

Retreating sea ice is opening Antarctica’s coast to increasing amounts of ship traffic, including tourist cruises. “Most visitors want to see the penguins, seals, and whales,” Mulrennan said, but the seafloor, which is home to 95% of the continent’s biodiversity, “is where the real action is.”

With large areas of the Southern Ocean unexplored, scientists estimate that as many as 17,000 species might live on the seabed.

Colorful life lies on the Antarctic seabed, including the 50-armed death star starfish and the giant volcano sponge, the oldest animal on the planet. Credit: Matt Mulrennan/KOLOSSAL

Many Antarctic species, such as the giant volcano sponge, are uniquely adapted to extreme cold and play an important ecological role, Mulrennan said. “They filter water, sequester carbon, provide food and habitat.”

“These are probably some of the most vulnerable ecosystems to anchor in in the world.”

“These are probably some of the most vulnerable ecosystems to anchor in in the world,” Mulrennan said. Although relatively fast-growing tropical reef communities may start to recover from anchoring in roughly a decade or so, “it could take hundreds or potentially thousands of years for Antarctic ecosystems to grow in the exact same way,” he said.

Mulrennan surveyed 36 sites around the Antarctic Peninsula between 2022 and 2023, finding anchor damage only at Yankee Harbour on Greenwich Island.

He showed the footage to Sally Watson, a geophysicist at Earth Sciences New Zealand and a study coauthor, who matched the characteristically uniform, curved gouges to anchor damage observed elsewhere.

Anchors can dig through 80 centimeters of sediment, but most damage is caused by the connected chain, which sweeps sideways because of winds and currents and can excavate 50 centimeters of sediment where it lies on the seafloor. From above, the scars resemble a broomstick, explained Watson, composed of one main scour stemming from the anchor connected to a series of branching gouges dug as the chain shifts in the sediment.

“Most of the really important life is within the uppermost 10 centimeters,” Watson said. “Anchoring blasts through that.”

In 2022, Watson and her colleagues published the first estimate of anchoring’s global footprint, putting its damage on par with bottom trawling.

Anchors and Icebergs

Anchoring isn’t the only thing churning up the Antarctic seafloor. Icebergs can drift into shallow water and drag along the seabed—causing well-documented impacts around the Antarctic Peninsula’s coastline, said Lloyd Peck, a marine biologist from the British Antarctic Survey who was not involved in the study.

Diver surveys show that iceberg scouring can destroy up to 99% of life on the shallow seabed. Regularly uprooted by icebergs, shallow-living species recover relatively quickly, in around a decade.

Waters deeper than 30 meters are struck less often, Peck said, allowing complex, slow-growing organisms to establish themselves. The slow growth also means these deeper areas take longer to recover.

At Yankee Harbour, Mulrennan observed the scours in waters 70 meters in depth, so he is confident they were caused by anchoring rather than by icebergs. Peck agreed, noting the large, slow-growing volcano sponges nearby. “That suggests the iceberg scouring is going to be very rare here,” he explained.

“Activities in Antarctica are bound by strict conservation rules, yet ship anchoring goes almost completely unregulated.”

Peck said that compared to iceberg scouring, anchoring will have a minor imprint across the Antarctic Peninsula. But the location of an anchoring impact is as important as its scope, he noted. “This is about disrupting sheltered areas that icebergs can’t reach.”

Species-rich areas in deeper waters, such as Yankee Harbour, could be acting as refugia, Peck explained, reseeding surrounding areas with life after they are scoured by icebergs. To avoid wider ecosystem impacts, he said, “we should be making every effort to avoid anchoring in areas of undisturbed biodiversity.”

In addition to tourist cruises, research vessels, shipping fleets, and private yachts operate in Antarctic waters. “Activities in Antarctica are bound by strict conservation rules” for all visitors, Mulrennan said, “yet ship anchoring goes almost completely unregulated.”

Watson and Mulrennan have several suggestions to mitigate anchoring impacts, including limiting time vessels spend on anchor and the use of designated anchorages, where ecological impact can be monitored and limited.

Above all, anchoring needs wider recognition as a conservation concern, not just in Antarctica but globally, Watson said. “I think we could do better, by changing the way we anchor, the gear we use, but at least understanding that this is not a no-consequences game.”

—Erin Martin-Jones, Science Writer

Citation: Martin-Jones, E. (2025), Anchoring is damaging the fragile Antarctic seabed, Eos, 106, https://doi.org/10.1029/2025EO250246. Published on 11 July 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
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Mud volcanoes may be less imposing and less familiar than their distant cousins, lava volcanoes, but they come with hazards of their own, and their presence can signal hidden geologic processes shaping a landscape.

A team of geologists has now made a global map of submarine mud volcanoes, which they hope will help further the understanding of these little-known landforms. The study, published earlier this year in Scientific Data, mapped more than a thousand mud volcanoes in shallow seas. A million more may sit undiscovered deep in the world’s oceans.

No one had put all the mapped mud volcanoes in a single dataset until now, said study author Daniele Spatola, a marine geologist at Sapienza Università di Roma. Patterns that Spatola and his colleagues spotted in the dataset were published in another study appearing in the Journal of Marine Science and Engineering.

Hazards and Emissions

Mud volcanoes erupt when the pressure of gas trapped in rock becomes so strong that the rock is not able to hold it anymore, Spatola explained. Instead of lava, mud volcanoes spew a mix of gas, sediment, dissolved minerals, organic matter, water, and other fluids.

Fields of mud volcanoes are found in different geologic settings around the world, including in oil and gas fields, above mantle hot spots, near active faults, and at the edge of tectonic plates. Their presence and activity can give scientists important clues about tectonic and volcanic activity, said Nils Asp, a marine geologist at the Universidade Federal do Pará in northern Brazil who was not involved in the research.

“Mud volcanoes can be really dangerous.”

The unstable ground mud volcanoes create can put oil rigs, telecom cables, and other subsurface infrastructure at risk. “Mud volcanoes can be really dangerous,” Spatola said, particularly those on land.

They are also a not-insignificant source of methane and can also spew oxide-rich material and gases like carbon dioxide. “Carbon balances and climate models don’t take these emissions into account, and locally, they can be a problem in terms of increasing water acidity,” Asp said.

Having a global inventory of what submarine mud volcanoes look like and where they occur could help scientists estimate how much methane is bubbling through these vents and reveal where hazards lie.

Digging Through Records

Spatola and his colleagues gathered data from earlier published studies for roughly 1,100 submarine mud volcanoes—the majority in water no deeper than about 200 meters (650 feet). For 700 of them, the researchers either had full size, shape, and location information or had location information and were able to estimate geometry.

From these data, Spatola’s team created a freely available and downloadable database.

Most of the mud volcanoes in the database (65%) are located in the Mediterranean Sea. This distribution may reflect sampling bias, according to the authors. Areas in the eastern Mediterranean are often prospected for oil and gas, for example, and had more data available for the researchers to mine.

Other regions are less well mapped. “Probably, the number of mud volcanoes in the Atlantic is higher than what [appears in] the database, for example,” Spatola said.

Roughly 60% of mud volcanoes in the database are medium sized, with an area of 0.5–9 square kilometers. Small (<0.5 square kilometer) and large (>9 square kilometers) volcanoes together make up less than a third of the mapped volcanoes.

Giant mud volcanoes (defined as those covering an area larger than 20 square kilometers) are the rarest features in the database, making up about 4.5% of the mapped and classified total. Most of the very large or giant mud volcanoes are found in an area southeast of Japan where the Pacific and Philippine tectonic plates meet.

An initial analysis of the database showed that the more small-sized volcanoes a region has, the fewer large or giant volcanoes there are. This kind of pattern, known as a power law, is recognizable in many geologic processes, including earthquake distribution. The researchers also found that the size of a mud volcano is not necessarily related to how deep it sits below the sea surface.

The database could help inform regional health and safety measures, the study suggests, as the morphology of a mud volcano influences its geohazard potential. Tall and narrow volcanoes, for instance, are the most hazardous because they are more prone to instability.

Deep Challenges

Asp said that the database is “a solid starting point to be extended upon in further studies.”

Researchers don’t know how many submarine mud volcanoes there are because only a small portion of the ocean floor has been mapped.

“We need the help of the scientific community to improve this dataset. The more information we put into it, the better it will be.”

“In many areas, there might be a dozen kilometers of distance between one mapped stretch and another,” Asp said. “So we have no information of what is in that [unmapped] part of the seafloor.”

Some satellite imagery can penetrate a few dozen meters below the surface but not the deep ocean floor. To look that deep, marine researchers need ships capable of bathymetric mapping, but such instrumentation, including sonar and lidar equipment, is often prohibitively expensive.

The new study is a first attempt to create a database of submarine mud volcanoes, one that can be refined as more data are contributed. “We need the help of the scientific community to improve this dataset,” said Spatola. “The more information we put into it, the better it will be.”

—Meghie Rodrigues (@meghier.bsky.social), Science Writer

Citation: Rodrigues, M. (2025), Mapping mud volcanoes in shallow seas, Eos, 106, https://doi.org/10.1029/2025EO250245. Published on 10 July 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
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Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Perspectives of Earth and Space Scientists

Our modern society is increasingly reliant on multiple technologies that are vulnerable to the adverse effects of space weather. This necessitates effective public communication and awareness of various space weather phenomena as well as increased public engagement and preparedness for risk mitigation.

Chabanski et al. [2025] advocate for the development and implementation of a standardized naming convention of geomagnetic storms, along the lines of existing naming conventions in meteorology, astronomy, and geography.

The authors surveyed the top 50 geomagnetic storms over the past 47 years (since 1978), of which only five had names assigned by the scientific community. Drawing on lessons learned in other scientific disciplines, they propose the possible formation of an international working team comprised of International Space Weather Coordination Forum participants. This international team would implement a theoretical framework and a unified international standard for defining the criteria, protocols, and procedures for naming and cataloguing geomagnetic storms based on their minimum Disturbance Storm Time (Dst) indices and their solar origins.

This proposed initiative is about not only assigning names to geomagnetic storms but also empowering the public with the knowledge necessary to navigate the challenges of the 21st-century space environment.

Citation: Chabanski, S., de Montety, F., Lilensten, J., Poedts, S., & Spogli, L. (2025). The power of a name: Toward a unified approach to naming space weather events. Perspectives of Earth and Space Scientists, 6, e2025CN000285. https://doi.org/10.1029/2025CN000285

—Andrew Yau, Editor, Perspectives of Earth and Space Scientists

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The Independent Review Board has released its report into a 6 million cubic metre landslide in Canada. It indicates that an initial rotational failure triggered a flow slide that travelled 1,400 metres.

On 24 June 2024, a very large landslide affected a heap leach facility (HLF) at the Eagle Gold Mine in Yukon, Canada. I wrote about this event at the time. The failure was of sufficient scale to force the mine into administration – creating a very big pile of problems (if you’ll excuse the pun) for the government. The administrator is PWC, which has now released a report by the Independent Review Board established to understand what happened. The report can be downloaded as a PDF and makes interesting reading. As expected, it is a comprehensive piece of work.

This was a large landslide – the IRB report indicates a volume of 5,946,000 m3 (about 12.3 million tonnes) with a runout distance of 1,400 m. The report includes some nice imagery of the failure, including this picture of the main body of the landslide:-

Figure 1: The main flow slide at the Eagle Gold Mine. Image from the IRB report.

Also included is this image of the upper portions of the landslide:-

Figure 2: The upper portions of the landslide at the Eagle Gold Mine. Image from the IRB report.

The IRB report provides a detailed understanding of the sequence of events that led to the failure. In creating the HLF, the operators created an oversteepened section of ore (locally the slope angle as 36.5o), which was vulnerable to failure. The system for collecting the fluids that were being circulated through the HLF was deficient, allowing the water table to rise within the ore body, and this section of the HLF had low permeability, impeding drainage. Starting in mid-April, the operator increased the level of irrigation within the HLF, allowing the water table to rise until the factor of safety reduced to one.

On 24 June 2024, a rotational failure occurred in the oversteepened section of the HLF at the Eagle Gold Mine. This can be clearly seen in Figure 1. This was a rotational failure which remained within the HLF – see the intact benches in Figure 2.

Within 10 seconds, this triggered a flow slide through static liquefaction, which rapidly moved down the slope (as shown in Figure 2). In Appendix A2, it is estimated that the landslide moved at 9 to 18 metres per second, suggesting that the total time duration of the failure was 1.5 to 2.5 minutes.

I speculated at the time that this was a rotational failure that transitioned into a flowslide.

The IRB report into the Eagle Gold Mine landslide makes a series of recommendations (see page 123 and the following pages). These seem sensible – I can only hope that they are adopted. There has been a long succession of investigations into mining landslides that have also made very sensible recommendations, but failures continue to occur.

But, I would also highlight from an external perspective that some of these recommendations seem surprising. Thus, for example, the IRB recommends that the such facilities should have independent review boards; that a single individual (a “Responsible Person”) should be in place to monitor on-site activities; that there should be a detailed monitoring and surveillance system in in place to ensure that design assumptions are correctly satisfied; and that there should be active monitoring of the performance of the HLF.

All very sensible indeed, and it is impossible to disagree, but it is deeply shocking that such recommendations are needed for a large-scale mining facility in a properly regulated country with very extensive experience of mining.

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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.

At least 2,145 high-level NASA employees are set to leave as the agency faces pressure from the Trump administration to reduce its staff, Politico reported on 9 July. More than half of these employees, all of whom hold GS-13 to GS-15 positions, work within core NASA mission sets including science and human spaceflight. Staff were offered early retirement, buyouts, and deferred resignations.

The departures are spread across NASA’s 10 regional centers, with the largest loss of staff (607) concentrated at the Goddard Space Flight Center in Greenbelt, Md.

The president’s budget request for NASA calls for an overall staff reduction of more than 5,000. One departing staffer told Politico that their decision to leave was out of fear for NASA’s uncertain future.

“Things just sound like it’s going to get worse,” they said.

 
Related

•  Over 2,000 senior staff set to leave NASA under agency push
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•  Get Involved: AGU Science Policy Action Center
 

The Trump administration has made loud noises about sending humans back to the Moon and then to Mars. These priorities were made clear in its budget request to NASA, which cut nearly 50% of the budget for NASA’s Science Mission Directorate while boosting funding for its human spaceflight program (this is within a 25% reduction in NASA’s overall budget). The proposed budget would shut down 41 space missions. The budget reconciliation bill that was signed on 4 July also included about $10 billion for NASA’s human spaceflight efforts.

Despite the boost in funding, it’s hard to see how the Moon-to-Mars goals are achievable in a reasonable timeframe with the massive drain of experience these departures represent.

“You’re losing the managerial and core technical expertise of the agency,” said Casey Dreier, chief of space policy at The Planetary Society. “What’s the strategy and what do we hope to achieve here?”

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

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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.

The Trump administration can act on its planned restructuring of the federal government, the United States Supreme Court announced in an 8 July decision.

In the decision, the court stayed an order prohibiting the Trump administration from proceeding with mass layoffs of federal workers including scientists at agencies like NOAA and the EPA. The decision, while temporary, means the administration is free to continue with reductions in force (RIFs) and restructuring efforts at federal agencies.

The decision is the latest action in the case of Trump v. American Federation of Government Employees. In the case, a coalition of plaintiffs including labor unions, municipal and regional governments, nonprofits and other organizations assert that President Trump’s February executive order directing federal agencies to carry out large-scale reductions in force is illegal in that it “goes far beyond the authority of the President to direct, and that such a massive reorganization of federal agencies must be planned in accordance with law and approved by Congress.” AGU is a co-plaintiff in the case.

“That temporary, practical, harm-reducing preservation of the status quo was no match for this Court’s demonstrated enthusiasm for greenlighting this President’s legally dubious actions in an emergency posture.”

In a ruling in May, a federal judge in California extended a two-week pause on federal layoffs by granting a preliminary injunction, which would continue that pause through the conclusion of the case.  The Trump administration appealed the decision, but it was upheld on 30 May by the Ninth Circuit U.S. Court of Appeals. The Trump administration then filed an emergency application with the Supreme Court.

With the 8 July ruling, the Court is allowing the administration to move forward with its restructuring plans outlined in the February executive order. In the unsigned decision, the Court did not express an opinion on the legality of the RIFs, but reasoned that the Trump administration “is likely to succeed” in its argument that the executive order is lawful.

In a lone dissent, Justice Ketanji Brown Jackson argued that any attempt by a president to reorganize the federal government requires authorization from Congress, which President Trump did not obtain.

Referring to the pause established in May, Jackson wrote: “That temporary, practical, harm-reducing preservation of the status quo was no match for this Court’s demonstrated enthusiasm for greenlighting this President’s legally dubious actions in an emergency posture.”

“This ruling will give Trump’s wrecking crew more awful ideas about sacking critical federal workers, like regional meteorologists with the National Weather Service and climate scientists at NOAA,” wrote Rep. Jamie Raskin, D-Md., on Bluesky.

 
Related

•  8 July Opinion
•  Statement from Coalition of Plaintiffs
•  AGU Files New Lawsuit to Protect Hundreds of Thousands of Federal Workers
• Supreme Court Allows Trump to Resume Mass Federal Layoffs For Now
•  Get Involved: AGU Science Policy Action Center
 

The plaintiffs expressed disappointment. “This decision does not change the simple and clear fact that reorganizing government functions and laying off federal workers en masse haphazardly without any congressional approval is not allowed by our Constitution.”

Justices Elena Kagan and Sonia Sotomayor, the other two members of the court’s liberal wing, sided with the conservative majority in this case. Sotomayor wrote a concurrence in which she agreed with Jackson that President Trump could not restructure federal agencies “in a manner inconsistent with congressional mandates,” but found the executive order in question does not direct federal agencies to defy the law when carrying out reorganization plans and that the case did not require the Court to consider the legality of the plans themselves. 

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

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Scientists have traditionally described long-term changes to Earth’s marine ecosystems by measuring biodiversity—the number of different species that show up in ancient rock samples.

Until now, no one had measured how marine biomass—the sheer amount of organic material—fluctuated over hundreds of millions of years. A new study published in Current Biology does just that, using limestone samples to show for the first time that marine biomass and biodiversity trends aligned over the past 541 million years. The results may help answer questions about how ecosystems evolve over geologic time and how humans are driving a mass extinction in the modern world.

“[Biomass] patterns really followed the biodiversity curve, at least on macroevolutionary timescales.”

“[Biomass] patterns really followed the biodiversity curve, at least on macroevolutionary timescales,” said Pulkit Singh, a paleobiologist at Stanford University and coauthor of the new study. Singh’s graduate research forms the basis of the new study. 

“This provides a new type of data that allows us for the first time to test some very influential ideas about the causality of long-term biodiversity changes,” said Seth Finnegan, a paleobiologist at the University of California, Berkeley, who was not involved in the new study. 

Counting Skeletons and Shells

As organisms living in shallow marine environments die and settle to the seafloor, their calcium carbonate shells and skeletons are preserved as fossil-filled limestone. The successive layers of this limestone serve as an inventory of the diversity and abundance of life in the oceans over millions of years and are especially valuable to paleontologists because of their high shell content as well as the fact that limestone deposition rates likely stay stable over time, even in the absence of shells and skeletons.

To get a comprehensive picture of biomass over the Phanerozoic eon, Singh and the research team collected troves of data from previous studies that included counts of skeleton and shell fragments in marine limestone samples. In all, the team found data for more than 7,000 samples from 111 studies and conducted point counts for 73 new samples, too. 

The data collection required a lot of “intellectual courage” from Singh, said Jonathan Payne, a paleobiologist at Stanford University and coauthor of the new study. “It took a lot of hard work with no guarantee that we’d get anything informative in the end.”

The gamble paid off: Results showed that “shelliness,” as Payne calls it—a proxy for biomass—generally increased over the past 541 million years alongside recorded trends in marine biodiversity, with dips in biomass aligning with known major extinction events. 

The study “provides a link that has been missing until now” that connects long-term biodiversity processes to biomass trends, Finnegan said. The data appear to confirm an idea many paleobiologists expected but had not had the data to demonstrate—that marine animal biomass and biodiversity aligned over Earth’s history, he said.

Singh and the team performed a series of analyses to ensure the trends they were seeing weren’t due to other factors such as depositional environment, latitude, ocean depth, and ecosystem type. No matter how they sliced up the data, the results showed the same trends.

“It’s really rare to get the first chance to document a pattern about life across long histories of time,” Payne said. “There’s theory, but in the end, theory is meaningful when you can compare it to real data.”

The patterns the team uncovered in the limestone were reflected, too, in language past researchers used to describe their samples: An analysis of nearly 16,000 abstracts including descriptions of sedimentary carbonate rock over geologic time showed that the “shelliness” of words used to describe limestone samples increased alongside biomass trends. Words like “skeletal” and “fossiliferous” showed up at higher ratios compared to nonskeletal words in descriptions of samples from times in Earth’s history when biomass was higher.

“It was an interesting, independent confirmation of the rest of the study,” Payne said.

What Biomass Tells Us

Biomass indicates how much energy is available in an ecosystem. For animals, the ultimate source of that energy is created via the primary productivity of photosynthetic organisms such as plants and algae. Understanding the relationship between biomass and biodiversity can provide insight into how ecosystems evolve, how diversity arises and collapses, and what the ultimate factor that limits biodiversity in an ecosystem is.

“When there is more stuff to eat at the base of the food chain, ecosystems can support more and larger individuals, and maybe they can also support more different kinds of organisms.”

“It has been suggested for a long time that the long-term increase in biodiversity is a response to higher primary productivity,” Finnegan said. “When there is more stuff to eat at the base of the food chain, ecosystems can support more and larger individuals, and maybe they can also support more different kinds of organisms.”

In the ecology of the modern world, scientists have evidence that this is true. But modern scientists live in a “thin little time slice” in which any observations of ecosystems occur on very short timescales relative to Earth’s history, Finnegan said. 

Scientists don’t know whether ecosystems work the same now as they did for all of Earth’s history. Long ago, biodiversity may have dictated biomass instead, or the relationship may have been a feedback loop. “Really understanding biodiversity processes means understanding them on the million-year timescale,” he said.

Since humans started to dominate ecosystems, biodiversity has plummeted. Biomass, however, has increased significantly, mostly as a result of animal husbandry and pet ownership. “We have a lot of humans, and a lot of cats and dogs, but not a lot of diversity,” Singh said. The world’s oceans are also “very likely in the early stages of a significant extinction event,” Finnegan said.

Deeper knowledge of how biomass and biodiversity relate over geologic time could help scientists better understand the effects of human-caused ecosystem changes and the drivers of this sixth mass extinction. Humans are altering the planet in a “massive experiment,” Payne said. And the only way to understand planetary-scale experiments is to use the geologic record, he said. “It is the only source of information at the same temporal and spatial scales.”

At least during the Phanerozoic, biomass and biodiversity seem to have been coupled, according to the new study. The results provide a coarse, but robust, picture, Payne said, though “there’s a lot more to learn.”

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

Citation: van Deelen, G. (2025), Biomass and biodiversity were coupled in Earth’s past, Eos, 106, https://doi.org/10.1029/2025EO250243. Published on 9 July 2025. Text © 2025. 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

Over two-thirds of Earth’s surface lies underwater, and the boundary of the hydrosphere and the lithosphere at the seafloor represents an important area of study of both materials–rock, sediment, fluid, and gas– and ecosystems for scientists studying Earth and ocean processes.

In a new commentary, FUTURE 2024 PI-team et al. [2025] report on the U.S. Seafloor Sampling Capabilities 2024 Workshop, which assessed the current state and future needs for U.S. oceanographic assets, including the evolution and design of multiscale science infrastructure. A key finding of the workshop is that future study of science at the seafloor interface will be severely limited by recent reductions in the oceanographic infrastructure available in the U.S. 

Such infrastructure includes, among others, scientific deep drilling platforms, which enable human access to ice-covered seas in the polar regions; an expansion of ships in the U.S.-Academic Research Fleet that can handle heavy over-the-side shipboard coring and deeper rock dredging; and sample repository infrastructure that maximizes the value of returned samples by better supporting discoverability and accessibility of archived materials. The authors also emphasize the importance of workforce training and knowledge transfer through inclusive educational and professional development opportunities, particularly for early-career researchers.

Citation: FUTURE 2024 PI-team, Appelgate, B., Dugan, B., Eguchi, N., Fornari, D., Freudenthal, T., et al. (2025). The FUTURE of the US marine seafloor and subseafloor sampling capabilities. AGU Advances, 6, e2024AV001560. https://doi.org/10.1029/2024AV001560

—Alberto Montanari, Editor-in-Chief, AGU Advances

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

Baroclinic instability, which converts vertical wind shear into energy in storms, is the main driver of the growth of midlatitude storms. However, previous investigations of the relationship between baroclinicity and storm growth have been limited to case studies, idealized simulations, or region-specific analyses.

Hadas and Kaspi [2025] use 83 years of ERA-5 data to analyze the growth and tracks of midlatitude storms. The ERA-5 dataset provides a much wider dataset for analysis, including an estimated 100,000 cyclones and 50,000 anticyclones. The authors find that while storm intensity increases linearly with baroclinicity under mild conditions, under more extreme conditions the traditional linear relationship between baroclinicity and storm activity becomes nonlinear. They attribute this shift to a decrease in the storm growth time with baroclinicity. Based on a Lagrangian analysis, the authors then propose a nonlinear correction better accounting for the relationship of baroclinicity and storm activity under extreme conditions. Such a correction is found to be crucial for advancing our understanding of midlatitude climate.

Citation: Hadas, O., & Kaspi, Y. (2025). A lagrangian perspective on the growth of midlatitude storms. AGU Advances, 6, e2024AV001555. https://doi.org/10.1029/2024AV001555

—Alberto Montanari, Editor, AGU Advances

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Yesterday, catastrophic flood swept down the Bhote Kosi river through Tibet and Nepal. At least 28 people have been killed. There is speculation that this might have been a GLOF.

On 8 July 2025, a catastrophic mudslide / flood suddenly struck the Rasuwagadhi border crossing point between Tibet and Nepal, causing extensive damage. The Himalayan Times reports that there are nine confirmed victims, with a further 19 people missing, in Nepal. Xinhua reports that eleven people are missing in Tibet, but it is unclear as to whether the Nepal figures include these people.

The scale of the event is impressive. All India Radio has posted this video to Youtube:-

Meanwhile, the Nepali Times has reported that the bridge at the at the Rasuwagadhi border crossing point was destroyed, along with a significant part of the infrastructure at that location. Four hydroelectric schemes have been damaged or destroyed (Rasuwagadi, Trisuli III, Trisuli and Benighat), removing 8% of Nepal’s generation capacity.

Rasuwagadhi is located at [28.27875, 85.37808], on the Bhote Kosi river. It is going to be important to understand what has happened to cause this flood. There is speculation that this was a glacial lake outburst flood (GLOF), which is very possible. It could also have been the collapse of a landslide dam or a high altitude landslide that transitioned into a debris flow. I’ll keep an eye on the satellite imagery over the coming days, but at the peak of the monsoon, it may take some time to get a clear image.

Kirsten Cook of the Université Grenoble Alpes has posted to Bluesky some seismic data from a station near to Kathmandu (a long distance downstream of Rasuwagadhi), which shows the flood:-

thehimalayantimes.com/nepal/rasuwa…Another destructive Himalayan flood, this time transboundary. And like most of these, we can see the seismic signals created by the flood at a DMG station near Kathmandu. The flood is visible seismically about an hour before it arrived at the Nepali border…

— Kristen Cook (@kristencook.bsky.social) 2025-07-08T21:07:08.342Z

The annual time period in which cross-border trade between Tibet and Nepal is possible is short, so the damage to the border infrastructure is likely to have significant implications for Nepal. The loss of the electricity generating capacity is likely to be a greater issue in the long term.

I have highlighted previously that I am concerned that the risks associated with these catastrophic landslides / floods in Himalayan valleys are not being adequately considered. This is the third time in four years that such an event has caused massive damage to power generation infrastructure (after the 2021 Chamoli event and the 2023 Sikkim event). The investment cases for these projects much be increasingly difficult to justify, which will have a range of significant wider economic implications.

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

Atmospheric models describing climate change rely on accurate depictions of chemical transport. Prather [2025] examines the different ways to define the troposphere, a highly chemically heterogeneous domain influenced by a range of chemical sources and sinks, from lightning, wildfires, and pollution to convection and rainfall.

The author builds on previous work proposing the use of the artificial age-of-air tracer e90. After calibrating the e90 tracer, Prather demonstrates its application in calculating the mass of the troposphere and troposphere ozone values, using output from UC Irvine’s chemical transport model, ozonesondes representing northern and southern mid-latitudes and the tropics, and satellite ozone profiles. This work presents a practical demonstration of the calibration of an age-of-air tropopause that could potentially be applied more widely in other models or other age-of-air tracers.  

Citation: Prather, M. J. (2025). Calibrating the tropospheric air and ozone mass. AGU Advances, 6, e2025AV001651. https://doi.org/10.1029/2025AV001651

—Kristina Vrouwenvelder, Executive Editor, AGU Advances

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

Incoming radiation from the Sun is balanced by reflected and emitted radiation from Earth, but greenhouse gases trap radiation in Earth’s atmosphere, causing energy to accumulate in the atmosphere, oceans, and land.

Mauritsen et al. [2025] discuss how recent work analyzing Earth’s energy imbalance reveals that it is increasing much faster than predicted and is now almost double what has been predicted by climate models. The current discrepancy between the measured energy imbalance and that predicted by climate models is likely caused by a decrease in Earth’s solar reflectivity, possibly because models have not correctly accounted for sea surface temperature patterns or effects of aerosol particles.

Understanding these changes in Earth’s energy imbalance and their effects on global warming is critical to science and policy. However, these measurements rely heavily on several satellites scheduled for decommissioning, threatening our understanding of our climate future.

Citation: Mauritsen, T., Tsushima, Y., Meyssignac, B., Loeb, N. G., Hakuba, M., Pilewskie, P., et al. (2025). Earth’s energy imbalance more than doubled in recent decades. AGU Advances, 6, e2024AV001636. https://doi.org/10.1029/2024AV001636

—Kristina Vrouwenvelder, Executive Editor, AGU Advances

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Source: Global Biogeochemical Cycles

The ocean absorbs carbon from the atmosphere, but exactly how much is uncertain. For instance, estimates from the 2023 Global Carbon Budget ranged from 2.2 billion to 4 billion metric tons of carbon per year. One source of this uncertainty may be that the effects of bubbles have not been incorporated into air-sea carbon flux estimates, according to Rustogi et al.

When waves break, they create multitudes of tiny bubbles that carry gases such as carbon dioxide back and forth between the atmosphere and water. Models used to evaluate how fast this exchange occurs typically rely on measurements of wind speed, assuming that wind speed directly relates to the prevalence of bubble-forming waves. However, waves can be affected by other factors as well, meaning this assumption doesn’t always hold.

To assess the role of bubbles in air-sea carbon exchange in more detail, scientists applied a recently developed “bubble-mediated gas transfer theory” to the ocean. As with other models, the bubble-mediated approach incorporates wind strength, but uniquely, it also accounts for wave conditions that form gas-carrying bubbles. The researchers compared the results from their new model to a simpler, wind-only model that ignores the effect of bubbles.

The two models yielded similar estimates for total annual ocean carbon storage, but the bubble-mediated model showed much higher variability, both seasonally and regionally; in some instances, local fluxes it indicated differed by 20%–50% from the wind-only model. The bubble-mediated model also suggested that intense wave activity in the Southern Hemisphere leads to much higher carbon storage than in the relatively calm Northern Hemisphere—a difference that’s not obvious in the wind-only model.

That north-south difference could have implications for interpreting and projecting carbon cycle dynamics in a changing climate. With average wind speeds and wave heights likely to increase with global warming, it is essential to anticipate accurately how these changes will influence ocean carbon storage, the authors say.

The work is also important for marine carbon dioxide removal projects aiming to enhance carbon uptake to mitigate climate change effects, they note. A prerequisite for these efforts is quantifying how much carbon the ocean takes up naturally. Without a comprehensive understanding of the processes affecting uptake, the impacts of such interventions may be vastly under- or overestimated. (Global Biogeochemical Cycles, https://doi.org/10.1029/2024GB008382, 2025)

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

Citation: Sidik, S. M. (2025), More bubbles means more variation in ocean carbon storage, Eos, 106, https://doi.org/10.1029/2025EO250244. Published on 8 July 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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This story was originally published by Grist. Sign up for Grist’s weekly newsletter here.

When wildfires devastated a wide swath of Los Angeles last winter, officials warned residents of several ZIP codes not to drink the water, or boil it first if they must. They worried that soot, ash, and other debris from the blazes might have infiltrated the groundwater, or that damaged pipes might allow toxins into the supply. The last of these “do not drink” orders was lifted last month.

At their peak, those pollutants can be found at levels up to 103 times higher than before the fire. There also can be 9 to 286 times as much sediment in water after a fire. 

But the first large-scale study of post-wildfire water quality has found that pollution created by such a blaze can threaten water supplies for eight years—far longer than previous studies indicated. Researchers at the Cooperative Institute for Research in Environmental Science, or CIRES, at the University of Colorado Boulder analyzed 100,000 samples from 500 watersheds across the western United States. They found “contaminants like organic carbon, phosphorus, nitrogen, and sediment” throughout those that had burned. At their peak, those pollutants can be found at levels up to 103 times higher than before the fire. There also can be 9 to 286 times as much sediment in water after a fire.

The findings have great implications for water systems as they prepare for a world in which fires like those that burned in Los Angeles and, more recently, North Carolina and a great swath of Canada, grow more common. One in six people in the United States lives in a wildfire risk zone, and forested watersheds provide water to almost two-thirds of municipalities in the U.S., making water systems everywhere vulnerable.

“I’ve had a lot of conversations with different utilities and water managers in the West, and every single one of them are concerned about wildfire impacts,” said Carli Brucker, lead author of the study, published on 23 June. But, she added, what they don’t have is longer-term data. “I’m hoping that this research provides these concrete numbers that can really back up water managers’ concerns, and turn those concerns into real funding that they can start putting towards climate resilience. Strong evidence can be really helpful in securing funding.”

Water utilities in the LA area addressed the threat posed by the fires that burned in January in the short term by flushing water mains and pipes. Officials with the Los Angeles Department of Water & Power said they are conducting ongoing water testing in the Palisades area, and are offering free water quality testing to any resident that wants it.

“These urban fires are creating these unprecedented challenges that treatment plants can’t really deal with,” Brucker said. “Burning buildings and businesses and roads and cars, it creates all these contaminants that are just way more dangerous and way more difficult to deal with.”

Even years after a fire, a major rainfall can trigger a mudslide, unearthing contaminants.

Across the locations the researchers analyzed, contamination levels varied widely. In general, post-fire pollution was worse in heavily forested or heavily urbanized areas. The “most dramatic spikes” in pollutants like phosphorus, nitrate, organic carbon and sediment generally occurred in the first few years after a fire, according to researcher Ben Livneh.

“We found the impacts to be really persistent,” Livneh wrote in The Conversation. “We saw significantly elevated levels of nitrogen and sediment for up to eight years following a fire.” Even years after a fire, a major rainfall can trigger a mudslide, unearthing contaminants. Beyond polluting groundwater, that can cause unexpected environmental issues. “Nitrogen and phosphorus act like fertilizer for algae. A surge of these nutrients can trigger algal blooms in reservoirs, which can produce toxins and create foul odors,” Livneh said.

There are several ways to fight these threats to water supply.

“The first line of defense is just diversifying water sources,” Brucker said. Ideally, a utility would draw from several watersheds, so it has a backup in the event one of them is impacted by a fire, she said. They also can build additional sedimentation basins to increase their capacity for sediment handling.

“But all of these things cost a lot more,” Brucker said. And it’s difficult to convince strained utilities in Western states—already dealing with things like water shortages—to spend money on wildfire mitigation without numbers. Rural communities, in particular, often rely on single-source water systems and limited funding, which makes responding to emergencies much more challenging.

“Utilities don’t usually have these sorts of process improvements in place, unless they have a good reason,” she said. “I’m hoping this research can point to—this is a pretty good reason to start planning for and trying to budget for those resilience improvements.”

—Sophie Hurwitz (@hurwitz.bsky.social), Science Writer

This article originally appeared in Grist at https://grist.org/wildfires/pollution-from-wildfires-can-contaminate-our-water-for-up-to-eight-years-new-study-finds/.

Grist is a nonprofit, independent media organization dedicated to telling stories of climate solutions and a just future. Learn more at Grist.org

Takao Doi’s dream is to go to the Moon and plant a tree. The former astronaut is inspired by ancient wooden shrines and temples in Kyoto, Japan, that have lasted more than a thousand years.

“If we can use wood in space, we might be able to have sustainable space development forever,” said Doi, a professor at Ryukoku University.

The idea of a wooden space age gained traction last year with the launch of LignoSat, the world’s first wooden satellite to reach orbit. LignoSat, developed by Doi, a group of Kyoto University scientists, and logging company Sumitomo Forestry, is a CubeSat—a type of minisatellite that is relatively inexpensive and easy to construct. LignoSat’s structure is meant to reduce its environmental impact because wood is a renewable material and creates less pollution when it burns up on reentry into Earth’s atmosphere.

“We think wooden satellites orbiting around the Earth are the future.”

LignoSat was deployed from the International Space Station (ISS) last year by the Japan Aerospace Exploration Agency (JAXA) and stayed in space for 116 days.

Doi and his colleagues are using what they learned to develop LignoSat-2, which they expect to launch in 2028. And they’re not alone—at least one other group is also developing a wooden satellite.

“We think wooden satellites orbiting around the Earth are the future,” Doi said.

Raphaela Günther, an aerospace engineering Ph.D. student at Technische Universität Dresden in Germany who is not involved in the LignoSat project, said she considers the work from the Kyoto University team to be a “small breakthrough” in renewable space materials research.

Lessons Learned

The first LignoSat was a 10-centimeter cube made of magnolia wood panels assembled with traditional wooden joinery. An aluminum frame reinforced the structure.

LignoSat used a traditional joinery method called the blind miter dovetail joint. Credit: Kyoto University

The LignoSat mission had five goals: to measure strain on the wooden structure, to measure temperature inside the satellite, to demonstrate how permeable wood is to magnetic fields in space, to analyze the effects of space radiation on wood, and to establish two-way communication with scientists on the ground.

After the satellite was deployed from the ISS on 9 December 2024, though, scientists in Kyoto weren’t able to communicate with it.

Orbital data from the U.S. Department of Defense show the satellite stayed in one piece during its time in space, proving wooden satellites can work, Doi said. But without the ability to communicate with the satellite, the other four missions weren’t able to be completed, either.

“Unfortunately, we didn’t receive any of the information we wanted to know about,” Doi said.

An analysis indicated that the loss of communication could have been caused by two failures: First, any or all of the three switches needed to activate the satellite system and deploy its antenna may not have turned on, and second, the computer program used in the system may not have started up as expected, Doi said. “We are still analyzing what happened, but we now have two reasons to further investigate.”

Despite the lack of communication, Doi recognized two achievements in the LignoSat mission. First, it demonstrated that a wooden satellite can exist in orbit without falling apart. Second, it streamlined the review process for wooden spacecraft. NASA must complete a safety review of all satellites that head to the ISS, he explained, and now that such a review was completed for LignoSat, reviews for subsequent wooden satellites will be simpler.

LignoSat-2 will have both an external antenna and an internal antenna and will be twice the size of the first LignoSat. Credit: Kyoto University

The Kyoto University team plans to build LignoSat-2 to be twice the size of LignoSat, with two communication systems (one inside the structure and another attached to its surface). Installing the antenna inside the satellite body reduces the drag of the structure as it orbits Earth, Doi said.

“Even if the antenna is not deployed, which might have been the cause of LignoSat 1’s communication problems, we may be able to use this second communication system to communicate with [LignoSat-2],” Doi said.

Finnish space technology company Arctic Astronautics is also thinking about wood in space. In 2021, they and Finnish company UPM Plywood developed the WISA Woodsat, a 10-centimeter birch plywood CubeSat. The satellite contains a suite of sensors meant to gather information about how outer space affects wooden spacecraft. It has a deployable camera, a “selfie stick” meant to take photos of itself in space and allow the team on the ground to monitor it visually.

The WISA Woodsat contains a suite of sensors meant to measure how outer space will affect its materials. It also has a selfie stick. Credit: Arctic Astronautics/Flickr, CC BY 2.0

“There is a niche for these kinds of satellites, and the basic research is extremely interesting,” said Jari Mäkinen, cofounder of Arctic Astronautics and initiator of the WISA Woodsat project. “It’s totally possible that when we see these satellites flying, we realize important information [about how plywood acts in space].”

The WISA Woodsat itself is nearly ready for launch, Mäkinen said, but Arctic Astronautics still needs permitting from Finnish space authorities to proceed. He’s hopeful the launch will take place next year. “We will fly as soon as possible,” he said.

A Sustainable Space Industry

For Doi, the wooden CubeSats are just the beginning. “Let’s create a space timber industry” reads the translation of the bio of the research team’s X (formerly Twitter) account. Doi said he imagines a future where wood overtakes aluminum as the primary material for satellites.

Wood is cheaper, easier to use, and lighter than conventional spacecraft materials. Its use as a potential material could both push the space industry toward using more wood and make space development more accessible to countries with fewer resources, Günther said.

A wooden space age could shrink the environmental footprint of the space industry, too. When aluminum satellites fall back into Earth’s atmosphere, they burn, creating aluminum oxide particles. These particles, sometimes smaller than 1 micrometer, may destroy ozone, disrupt atmospheric processes, and even alter Earth’s magnetic field, some scientists suggest. When wood burns, it generates only carbon dioxide, biodegradable ash, and water vapor.

And though scientists don’t fully understand all the possible ways that particles from decomposing metal or wooden spacecraft interact with the upper atmosphere, the decomposition products of wood are easier to assess because they are already major drivers of atmospheric processes, Günther said.

“It’s not a question if we do or if we don’t” begin to use more sustainable spacecraft materials, she said. “I think we have to.”

With a few hundred tracked objects returning to Earth each year, reentering metal spacecraft are not currently a major environmental problem. But as the space industry quickly grows, it’s crucial to look for more ecofriendly materials, Doi said. Replacing even a small portion of parts on future satellites with wood could significantly reduce pollution, Mäkinen said.

Wood poses challenges for spacecraft engineers, too. Because it’s grown naturally, it has defects and doesn’t behave homogeneously, meaning “the behavior of the material in three different directions is not the same,” Günther said. Her own research is working to create spacecraft materials made of wood fibers and binding material that behave more consistently.

“It’s not a question if we do or if we don’t” begin to use more sustainable spacecraft materials, she said. “I think we have to.”

Mäkinen agreed that wood provides many environmental and technical advantages but said large space companies have likely invested enough in their current manufacturing processes that a large-scale shift to wood as a satellite material is unlikely without pressure from space authorities. “I hope that I’m wrong,” he said.

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

Citation: van Deelen, G. (2025), A new satellite material comes out of the woodwork, Eos, 106, https://doi.org/10.1029/2025EO250241. Published on 7 July 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
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