Feed aggregator

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

The devastating floods that killed nearly 200 people in Germany four years ago could have been even more damaging, new research suggests. The floods in July 2021 were among the worst disasters in German history. At least 196 people died in Germany, 43 people died in Belgium and the total damage to Central Europe amounted to €46 billion.

Any home gardener knows they have to tailor their watering regime for different plants. Forgetting to water their flowerbed over the weekend could spell disaster, but the trees will likely be fine. Plants have evolved different strategies to manage their water use, but soil moisture models have mostly neglected this until now.

SummaryReliable earthquake forecasts depend on modellers making suitable choices regarding data selection and model implementation. We explore some of these choices in order to construct short-term forecasts for independent background events in Italy, using a Log-Gaussian Cox Process to describe the spatial intensity of seismicity as a function of physical spatial covariates and a random field. We explore correlations between a range of physical covariates available for Italy, and investigate how they might contribute to observed spatial seismicity patterns. We find that historic smoothed seismicity, strain rates and elevation are most useful in describing instrumentally-observed seismicity. We use point process intensity models constructed with combinations of these covariates with past seismicity to generate Bayesian earthquake forecasts, constructing simulated catalogue forecasts of future earthquake catalogues in Italy, discussing modelling choices we make along the way. Finally, we test the performance of these forecasts in a pseudo-prospective manner for the 2010-2021 period and using historical data to assess how well they might perform for extreme events. While the inclusion of historic events improves forecasts, models without historic seismicity also perform well, indicating a degree of stationarity in the process. We demonstrate that combinations of covariates can add predictive power over modern catalogue data alone, and provide a framework for future modelling.

SummaryThe rapid development of the global economy brings frequent artificial seismic events related to industrial activities. The identification of faults revealed by natural earthquakes, along with the temporal and spatial distribution of b-values derived from these seismic events, is influenced by their occurrence. Correcting identification of seismic events has significant influence on seismic risk assessment. In this paper, we present a tri-branch convolutional neural network (CNN) model, known as EQTypeNet, to automatically classify three classes of events (natural earthquakes, explosions, and collapses) in China, using waveform, spectrogram, and amplitude ratio features as inputs. The EQTypeNet has developed in two steps: 1. Binary classification: Mitigating data imbalance by supplementing non-natural events outside the test set area. In the classification of explosions and earthquakes, we obtained an individual station macroF1 of 0.99 and a classification accuracy of 98.7 per cent. In the classification of collapses and earthquakes, we obtained an individual station macroF1 of 0.99 and a classification accuracy of 99.5 per cent. 2. Ternary classification of natural earthquakes, explosions, and collapses: Enhancement of the model's classification in small areas by transfer learning. In the transfer learning of Shanxi and Northeast China, the F1-score of individual stations reached 0.98 and 0.97, with corresponding accuracies of 98.6 per cent and 96.8 per cent. The EQTypeNet applies to different magnitude ranges for seismic event discrimination and shows a satisfactory application performance in a large area. It will be expected to achieve higher performance in the ternary classification by further supplementing the training with suitable physical features.

SummaryIn February 2025, a strong seismic crisis occurred 35 km northeast of Santorini, an active volcano located in South Cyclades, Greece, a region of distributed extensional active faulting. The GNSS data shows an inflation of the volcano since August 2024. We model it with a magma source of 7.7 106 m3 located 3.1 km under the north-central floor of the caldera, near the inflation centre of 2011–2012. After 24 January 2025, the seismic activity, until then localised within the caldera, shifted offshore Santorini and increased with eight Mw ≥ 5 events and ground motion exceeding 5 mm at Syros at 110 km from the epicentres. The GNSS data is consistent with a model of dislocation involving a south-east dipping normal fault located between the Kolumbo submarine volcano and the Anydros islet, 18 km long, 12 km wide, with a tip at 7.5 km depth and ~3 m of slip. The ~17.5 1018 Nm corresponding seismic moment, much greater than the ~1.5 1018 Nm of the recorded earthquakes, reveals the probable occurrence of a slow-slip earthquake of equivalent magnitude 6.8. This event might have been triggered by a small dyke injected from the inferred source beneath Santorini. However, the subsidence recorded at Santorini and Anydros is incompatible with the hypothesis of a large dyke injected beneath Kolumbo-Anydros.

Melting glaciers may be silently setting the stage for more explosive and frequent volcanic eruptions in the future, according to research on six volcanoes in the Chilean Andes.

A joint project which saw two boreholes drilled in northern Singapore has revealed subsurface temperatures reaching up to 122°C at a depth of 1.76 km in Sembawang, significantly higher than earlier findings recorded in Admiralty, where 70°C was measured at a depth of 1.12 km.

A new study conducted at Reichman University's School of Sustainability presents an innovative tool to help decision-makers better understand the condition of streams and thereby advance their restoration and rehabilitation. The tool, called SESBI—the Stream Ecosystem Services and Biodiversity Index—is designed to measure what is called "stream health," meaning the degree to which a stream functions ecologically and contributes to public welfare.

Sea level on Earth has been rising and falling ever since there was water on the planet. Scientists were already able to use sediments and fossils to roughly reconstruct how sea levels changed over time steps of a million years or more.

Due to the radiative thermal conductivity of the mineral olivine, only oceanic plates over 60 million years old and subducting at more than 10 centimeters per year remain sufficiently cold to transport water into Earth's deep mantle. This was found by scientists from the University of Potsdam and from the Helmholtz Center for Geosciences (GFZ) Potsdam, together with international colleagues, by measuring the transparency of olivine under conditions in Earth's mantle for the first time. Their results are published in the journal Nature Communications.

A new autonomous underwater vehicle (AUV) imaged a previously unexplored portion of the seafloor in ultra-deep waters near the Mariana Trench. Operationalizing this technology for the first time was part of a mission led by the Ocean Exploration Cooperative Institute (OECI), based at the University of Rhode Island's Graduate School of Oceanography, with support from the National Oceanic and Atmospheric Administration (NOAA), the Bureau of Ocean Energy Management (BOEM), and the U.S. Geological Survey (USGS).

We are going back 55 million years. That was when Greenland and Norway began to drift apart, causing the Atlantic Ocean to open up. The Earth's crust between them became thinner and thinner, and enormous amounts of lava poured forth.

Peak water flows in parts of India's largest river basin have been falling by more than one-sixth every decade, according to a study published in npj Natural Hazards that highlights a similar trend across the country, impacting irrigation, domestic water, and hydropower in the world's most populous nation.

Solar Maximum 2025 is the expected peak of solar activity in Solar Cycle 25, characterized by heightened sunspots, solar flares, and coronal mass ejections. This peak is anticipated around mid to late 2025, coinciding with the sun's magnetic field flip. Such solar activity may influence Canadian climate patterns by potentially affecting weather systems.

New research from a Southampton scientist has identified the causes of changes affecting river deltas around the world—warning of an urgent need to tackle them through climate adaptation.

Earth formed about 4.6 billion years ago, during the geological eon known as the Hadean. The name "Hadean" comes from the Greek god of the underworld, reflecting the extreme heat that likely characterized the planet at the time.

Research involving the University of Liverpool has discovered a trend of increasing surface meltwater in East Antarctica. In an ambitious new study, they produced the first Antarctic-wide, high-resolution monthly dataset of surface meltwater using satellite images.

Scientists have discovered hundreds of giant sand bodies beneath the North Sea that appear to defy fundamental geological principles and could have important implications for energy and carbon storage.

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
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.