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What leads to lower atmospheric CO2 during ice ages is a question that has puzzled scientists for decades, and it is one that UConn Department of Marine Sciences Ph.D. student Monica Garity and co-authors are working to understand. By looking at patterns of carbon storage in the deep ocean, the researchers shed new light on this decades-old question. Their results are published in Proceedings of the National Academy of Sciences.

Environmental scientists are increasingly using enormous artificial intelligence models to make predictions about changes in weather and climate, but a new study by MIT researchers shows that bigger models are not always better.

New research has revealed New Zealand is on track for a major spike in extreme heat, with heat waves that currently hit once a decade potentially striking every other summer.

From Devastation to Data

Some effects of wildfire are immediately apparent: burned vegetation, smoldering ruins, dissipating smoke. As such, the massive Palisades and Eaton Fires cut charred wakes through western Los Angeles County that remain long after firefighters contained the blazes earlier this year.

This month, we shadow geoscientists investigating the fires’ less tangible, if no less serious, consequences for regional air, soil, and water quality.

“Where There’s Fire, There’s Smoke,” writes Emily Dieckman in her profile of air quality following the fires—and where there’s smoke, there are particulates, including organic compounds, toxic chemicals, and hazardous dust and ash.

For Earth scientists, the liminal space between what is urban and what is wild is crucial for understanding postfire debris flows and the ground below. As profiled by Kimberly Cartier, these researchers consider the L.A. fires to be a case study of “how this urban-rural interface is changing and what…recovery looks like.”

Watersheds, those ever-changing interfaces between earth and water, are no less fraught, writes Grace van Deelen in “Scrambling to Study Smoke on the Water.” Scientists are documenting how ash-laden runoff is changing, if only ephemerally, both freshwater and marine ecosystems.

Perhaps the most elusive and powerful consequences of the fires are their effects on human health. And in places like Los Angeles, writes Dieckman, “Access to Air-Conditioning May Affect Wildfire-Related Health Outcomes.” The L.A. fires are yet another test case for extreme events augmented by a warming climate. The importance of thoughtful, science-based policy has never been more relevant for the health of both our planet and ourselves.

—Caryl-Sue Micalizio, Editor in Chief

Citation: Micalizio, C.-S. (2025), Fallout from the fires, Eos, 106, https://doi.org/10.1029/2025EO250311. Published on 26 August 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

From Devastation to Data

Over 24 days in January, the Eaton and Palisades fires burned nearly 38,000 acres of Los Angeles County. Whole neighborhoods were destroyed, 29 people died, and thousands were displaced. The conditions that led to the fires were estimated to be 35% more likely because of climate change, and damage to public and private infrastructure made the blazes among the costliest wildfire disasters in U.S. history.

In the wake of the fires, multiple local, state, and federal disaster response agencies mobilized to contain the flames, document dangers, and communicate those findings to the public. Agencies’ emergency response playbooks are tried and tested and often require interagency cooperation.

Within this massive, coordinated effort in postfire monitoring and response, where have non-agency scientists with relevant skills and a desire to help fit in?

This is a question Michael Lamb has wrestled with this year. Lamb is a geomorphologist at the California Institute of Technology (Caltech) in Pasadena who was evacuated from his home and left without power for several days when the Eaton Fire tore through Altadena.

Lamb, who researched debris flow patterns after the 2009 Station Fire in the Angeles National Forest, wondered how to apply his knowledge to help with this latest disaster, and whether he should. He worried that members of his lab group, by inserting themselves into the disaster response apparatus, might inadvertently confuse official communications or make it harder for first responders to do their jobs.

“We don’t want to take time away [from agency scientists], especially when they’re in the middle of the emergency management part of work,” Lamb said.

Lamb wasn’t alone in his concern, or in his desire to help. The areas of Los Angeles County affected by the Palisades and Eaton fires are home to a high concentration of scientists who work or study at the area’s many scientific institutions. Some of them study fires and fire impacts and realized they could help, while many outside that niche were surprised to find that their work might have new, immediate applications close to home.

Scientists Spot Need

When the Palisades Fire was still burning in early January, Adit Ghosh watched the coverage at home on television. Ghosh, an Earth science graduate student at the University of Southern California (USC) in Los Angeles, had helped evacuate his in-laws and some of his friends from at-risk areas and couldn’t go in to work because campus was closed.

“They were showing the fires nonstop,” Ghosh recalled of news reports. In one broadcast, the camera zoomed in on a house in Mandeville Canyon near Topanga State Park. “I saw it on TV catching fire and then burning to the ground.”

“He took us to this house. Then it clicked. This is the house that I saw burning on TV.”

By the third week in January, Ghosh was back in his geochemistry class. His adviser, who works closely with the professor teaching the course, suggested a way for Ghosh and his fellow graduate students to contribute to the ongoing efforts to understand contamination in water runoff. They were eager to help in whatever ways they could.

That weekend, Ghosh went out with a team of other USC students to collect water runoff in burned areas. They hoped to analyze the samples for chemicals that might prove harmful to human and environmental health. A helpful resident showed the team around the burned area, pointing out places they might collect samples from.

A home burned by the Palisades Fire. Credit: Adit Ghosh

“He took us to this house,” Ghosh said. “Then it clicked. This is the house that I saw burning on TV.”

The postfire landscape and environmental conditions can change rapidly. Many scientists felt a sense of urgency to collect samples of ash, dust, soil, and water, as well as to study sediment and debris built up along the mountainside, because much of these data are considered “perishable,” Lamb explained.

In an area burned by the Palisades Fire, a University of Southern California student collects water runoff from a drainpipe. Credit: Adit Ghosh

Lamb’s team rushed to obtain flight permits and conduct drone flyovers of debris channels along the San Gabriel Mountains above Altadena. Knowing that weather reports anticipated rain soon after the fires, debris flow researchers wanted to obtain postfire, prerain lidar scans of the channels’ topographies to better understand how debris accumulates and what conditions can trigger dangerous flows.

If measurements weren’t taken quickly enough, information about immediate postfire impacts could be washed away. They shared their results with disaster response agencies and affected communities.

Serendipitous Science

In the wake of such a disaster, doing something, anything, to help others can be a powerful tool of healing and recovery.

“As soon as they were safe, people really wanted to contribute,” said Kimberley Miner, a climate scientist and representative of NASA’s Disasters Response Coordination System (DRCS) at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif. NASA and JPL coordinated to fly the Airborne Visible/Infrared Imaging Spectrometer 3 (AVIRIS-3) instrument to survey damage immediately after the fire.

The first AVIRIS-3 flight on 11 January was serendipitous, explained Robert Green, principal investigator for AVIRIS-3 at JPL. The instrument had already been installed on a plane and approved to fly over a completely different area. The team was able to divert the flight path to cover the Eaton burn area instead.

“There were folks working out of hotel rooms [on all of that imagery] while they were evacuated.”

“There were folks working out of hotel rooms while they were evacuated,” Miner said. On some science teams, only one or two people had not been displaced.

The AVIRIS team has been on the scene after some of the most infamous disasters in modern U.S. history. The team flew an earlier version of the instrument over the ruins of the World Trade Center after the terrorist attack on 11 September 2001 to look for asbestos and residual hot spots burning under the rubble. After the 2010 Deepwater Horizon disaster, AVIRIS-3 data yielded the first estimates of how much oil had been released into the Gulf of Mexico.

Even in the context of those disasters, Green said that flying over the L.A. burn scars was “heartbreaking and poignant.”

“It’s especially poignant, I would say, because it is a local disaster,” Green said. “But for 9/11, the Gulf oil spill, or wherever we contribute, our team is committed to offer information via this unique spectroscopy to be helpful.”

The first AVIRIS-3 flyover provided some of the first aerial data assessing the scope of the fires. NASA’s DRCS provided those data to federal and state disaster response teams, and those data helped justify and expedite approval for subsequent flyovers.

Getting Involved but Not Being in the Way

As official emergency responders worked to contain the fires and rapidly document the damage, collecting samples from the air, ground, rivers, or ocean outside of those efforts presented logistical quandaries.

The USC team that Ghosh worked with to collect water runoff samples had been organized within his department and went out on its own volition. But getting to sample sites was a challenge.

“We’re trying to focus on whatever we can get our hands on, essentially, because access is really hard,” he said earlier this year. In some burned areas where runoff sampling would have yielded important science results, for example, the National Guard had restricted access to prevent looting.

“Even in sites that are open, the residents still didn’t really want us hanging around over there. And understandably, because their house almost burnt down,” Ghosh said. When members of his team encountered resistance from residents, he said, they respectfully moved to another location.

“Something that we can try to help with more as research scientists is to think about real forward-looking measurements.”

Lamb said that his research group considered a broad range of science that they might contribute before contacting government agencies operating in the area. “We reached out via email to people…leading debris flow hazard teams and just said, ‘We are interested in helping. These are some of the capabilities we have. We also don’t want to get in the way. Please let us know if this can be of help.’”

Lamb’s team was told it could help by monitoring the accumulation of sediment and debris in ravines on the slopes of the San Gabriel Mountains, and they gained approval to fly drones over certain landslide-prone areas. Those aerial lidar measurements will be helpful in assessing the ongoing risk of debris flows and landslides and also in monitoring for future hazards.

“Emergency managers and the federal agencies are mostly tasked with trying to deal with the immediate situation,” Lamb said. “Whereas something that we can try to help with more as research scientists is to think about real forward-looking measurements.”

Their lidar flights focused on areas of burned mountainside rather than on urban areas. “It’s sad to say, but in some of the areas that were really devastated by the fires, there aren’t homes there [anymore] to be damaged by the debris flows,” Lamb said.

Working with Their Communities

The public messaging that agencies provide is critical for residents to find out about the immediate risks they face, but non-agency scientists also have found ways to engage these communities deeper in the scientific discoveries that are helping them stay safe.

As crews started containing the fires, scientists at the Natural History Museum of Los Angeles County (NHMLA) recognized the need to collect and analyze samples of the ash, not only for the immediate emergency response but also to curate a catalog that scientists could use for longer-term and future studies. Because they have a small staff, the museum’s team solicited community members for ash samples rather than going in to the field themselves.

“They just lost their homes. They want to be treated with respect.”

“We didn’t want to reach out right away, because that would appear as insensitive and not really caring about the people but rather more caring about the science,” said Aaron Celestian, curator of mineral sciences at NHMLA. But once it started raining, they couldn’t wait any longer.

The museum’s community science team approached their existing community partners about collecting ash and found that people were already doing it themselves. The team pivoted, instead showing people how to collect ash without risking personal health or contaminating the samples.

“We didn’t want anybody to do anything that would have any kind of health effects on them long term,” Celestian said. “We had to develop a protocol that could be understood by the community at large, and so that we get the best kind of science out of it in the end.”

Celestian analyzed his first sample on 27 January, measuring the chemical composition of forest ash. He plans to compare the results with those from urban ash.

Natural History Museum of Los Angeles County mineral sciences curator Aaron Celestian prepares one of the collected ash samples for total element analysis to reveal its chemical composition. The whole process takes about 2 hours. Credit: Aaron Celestian/Natural History Museum of Los Angeles County

Then came the question of how to communicate the results. Celestian and the museum’s communications team came up with a two-pronged approach. First and foremost, they consulted with the community member who sent in the ash sample. “They get to decide on how they want their samples to be treated and communicated with everybody else,” Celestian said.

With a resident’s permission, the ash sample was entered into a museum collection for other scientists to check out and analyze. They received 11 samples for the collection.

“Even though I’m collecting the data, it really is their property,” Celestian said. “That’s a big part of making them feel comfortable, making them feel confident in the results.”

“They just lost their homes,” he emphasized. “They want to be treated with respect,” he said, adding that the samples “are really like a family member’s ashes.”

At the same time, Celestian recognized the importance of transparency and that timely information can not only protect people but also help them feel confident in their safety. He began live-streaming his analysis on social media and his blog using anonymized samples.

“People want to know,” Celestian said.

Lamb’s group took a similar approach. They shared their lidar data directly with emergency response managers so they could be incorporated into official responses. They also communicated directly with the public. Lamb had been scheduled to give a public science talk in late January, and he decided to center the science of postfire debris flows.

“I was going to talk about something completely different, and I changed the topic last minute because of this very heightened community interest in understanding what’s happening in the mountains,” Lamb said. Nearly 900 people showed up to listen.

Strong, and Mixed, Emotions

Having a way to help after a disaster—whether through distributing supplies or figuring out whether playground soil has elevated lead levels—can aid community recovery and empower personal healing. In some, it can also evoke a sense of duty.

“I think we have a responsibility to use our skill sets to help the greater Los Angeles area where we live,” Ghosh said. Logically, he knew that sampling water runoff and analyzing it for harmful chemicals is an important part of postfire recovery. But sometimes, it didn’t feel like enough.

“You go up there and you’re collecting water, and people have almost lost their homes,” Ghosh said. “It feels like, ‘Why the hell are you collecting water?’ It may not seem in the moment as important a thing to do. I definitely felt that.”

Studying the risks from these fires “does feel more personal.”

Some residents questioned what the sampling team was doing and whether they were focusing on the right problems. “But we also had neighbors who were like, ‘Thank you so much for doing this, coming out and helping us understand whether we can drink our water, or whether it’s safe to be out,’” Ghosh said. “In fact, some people even let us in to their house, and [we] collected tap water from their house.” Ghosh and his colleagues shared the results of those in-home water tests directly with the homeowners when they got them.

“It’s a lot of mixed emotions,” he added.

Studying the risks from these fires “does feel more personal” for local scientists, Lamb said. “We know people that live in those areas. There’s faculty from Caltech and graduate students that live there, and postdocs and friends. It’s very close to where we live and work. It certainly adds more motivation to try to do anything that we can to help.”

—Kimberly M. S. Cartier (@AstroKimCartier), Staff Writer

Citation: Cartier, K. M. S. (2025), When disaster science strikes close to home, Eos, 106, https://doi.org/10.1029/2025EO250315. Published on 26 August 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

From Devastation to Data

Gale Sinatra and her husband fled their Altadena, Calif., home on 7 January with little more than overnight bags, taking just one of their two cars.

“We thought we were going to be gone overnight,” Sinatra said. “We thought they’d get the fire under control and we’d get back in.”

When the couple did return, weeks later, it was to dig through the rubble of their former home, burned to the ground by the Eaton Fire.

Though they escaped with their lives, health hazards were not behind Sinatra, her husband (who chose not to be named for this story), and others from their neighborhood. The Eaton and nearby Palisades fires filled the Los Angeles Basin with a toxic haze for days, and cleanup efforts threatened to loft charred particles long after the fires were out.

Teams of scientists from across the country, along with community members, monitored air quality in the weeks following the fire, seeking to learn more about respiratory health risks and inform community members about how to protect themselves.

Urban Fires Versus Wildfires

Inhaling smoke from any fire can be harmful. Smoke contains hazardous components, including volatile organic compounds (VOCs), emitted by burning vegetation and products such as paint and cleaning supplies; and particulate matter, such as dust and soot.

About 90% of the particulate matter (PM) in wildfire smoke is PM2.5, or particles smaller than 2.5 micrometers in diameter—small enough to enter the bloodstream and deep areas of the lungs.

These instruments are used by Michael Kleeman to monitor air quality from the back of a car in Victory Park in Altadena, as far north as he can go in the area without entering the evacuation zone. Credit: Michael Kleeman

Urban wildfires present their own dangers, because they burn not just through trees and other vegetation but through homes and infrastructure as well.

When Sinatra returned to her former home, she was struck by everything the fire had burned, from her jewelry to her car. “I just found it very eerie standing in my kitchen, going, ‘Where’s my refrigerator?’” she said. “How do you melt an entire refrigerator?”

In January 2025, the Palisades and Eaton fires ravaged more than 150 square kilometers across cities and wildlands in Los Angeles County. Even as they were personally affected, LA-area scientists worked diligently to understand how fires at the urban-wildland interface create unique hazards via air, land, and water.

In the future, hot and dry conditions enhanced by climate change will continue to raise the risks of fires like these. The work of these scientists can provide a blueprint for rapid hazard assessment, health risk mitigation, and urban planning in other fire-prone communities.

In January 2025, the Palisades and Eaton fires ravaged more than 150 square kilometers across cities and wildlands in Los Angeles County. Even as they were personally affected, LA-area scientists worked diligently to understand how fires at the urban-wildland interface create unique hazards via air, land, and water.

In the future, hot and dry conditions enhanced by climate change will continue to raise the risks of fires like these. The work of these scientists can provide a blueprint for rapid hazard assessment, health risk mitigation, and urban planning in other fire-prone communities.

“From mattresses to carpets to paint to electronics, everything like that burns,” said Roya Bahreini, an environmental scientist at the University of California, Riverside (UCR). Bahreini is also co–principal investigator of the Atmospheric Science and Chemistry Measurement Network (ASCENT), a long-term air quality monitoring project led by the Georgia Institute of Technology, UCR, and the University of California, Davis (UC Davis).

ASCENT, which launched in 2021, has stations across the country, including three in Southern California. During the January fires in Los Angeles, which tore through not only Altadena (an unincorporated inland community) but also neighborhoods along the coast, these stations detected levels of lead, chlorine, and bromine at orders of magnitude higher than usual.

Older houses sometimes have lead paint, asbestos ceilings, or wooden decks and fences treated with preservatives containing arsenic. PVC piping contains chlorine. And flame retardant often contains brominated organic compounds. In these forms, such materials don’t necessarily pose a high risk to human health. But when they are burned and released to the air, they can be dangerous.

Smoke plumes from the Palisades Fire (left) and the Eaton Fire are seen from space on 9 January. Credit: ESA, contains modified Copernicus Sentinel data, CC ­BY-SA 3.0 IGO

Michael Kleeman, a civil and environmental engineer at UC Davis, explained that the short-term mortality associated with high PM2.5 events such as wildfires often comes in the form of a heart attack. But inhaling urban wildfire smoke or the particles kicked up from dust and ash during remediation efforts can present risks that aren’t immediately apparent. “It’s not a heart attack a day or three after the exposure. It’s, like, a cancer risk way down [the road],” Kleeman said. “The long-term exposure [risk] can be insidious.”

Air Quality Maps

Southern California is no stranger to wildfires. (Neither is Sinatra, who has evacuated several times during her 15 years in Altadena.) Frequent droughts in the Los Angeles Basin result in large swaths of parched vegetation. The infamous Santa Ana winds, which blow into the basin from the east and northeast, can cause fires to quickly grow out of control, as was the case in the Palisades and Eaton blazes.

Real-time air quality maps, such as those hosted by the South Coast Air Quality Management District (AQMD) and U.S. EPA, pull from several sources to provide data year-round. More detailed data come from sophisticated instruments set up by the agencies themselves; South Coast AQMD hosts 32 permanent air monitoring stations throughout Los Angeles, Orange, Riverside, and San Bernardino counties.

The Air Quality Management District has permanent installations for monitoring air quality, but in the wake of the January 2025 Los Angeles wildfires, it launched supplemental efforts, gathering real-time air quality data from mobile monitoring vans. Credit: South Coast AQMD

Less detailed but more widespread data on particulate matter come from networks of off-the-shelf air quality measuring tools, such as PurpleAir monitors and Clarity Sensors, that are set up by residents or community organizations.

“It turns out that the areas that the fires were in had [a] really, really dense network of these low-cost sensors,” said Scott Epstein, planning and rules manager at South Coast AQMD. “When you combine that with our regulatory network, we had very good coverage of fine particle pollution.”

This density meant researchers could watch the Eaton and Palisades wildfire plumes as they traveled toward the coast.

An existing AQMD station in Compton, about 23 miles (37 kilometers) south of the Eaton Fire, showed highly elevated levels of toxic metals, including arsenic and lead, between 7 and 11 January as the plume passed over the area. These levels returned to normal within a few days. ASCENT instruments in Pico Rivera, about 14 miles (23 kilometers) south of the Eaton Fire, recorded a 110-fold increase in lead levels from 8 to 11 January.

Permanent air quality measuring stations like these offer one source of public information that residents like Sinatra could consult to make decisions about when to stay indoors or return to a burned area. But when the Palisades and Eaton fires broke out, researchers from AQMD and other institutions set out to supplement these efforts with more granular monitoring.

Mobilizing Quickly Melissa Bumstead (left) and Jeni Knack volunteered to gather air and ash samples in the wake of the Eaton and Palisades fires. Credit: Shelly Magier

In January, researchers from Harvard University; the University of California, Los Angeles (UCLA); the University of Texas at Austin; the University of Southern California (USC); and UC Davis launched the Los Angeles Fire Human Exposure and Long-Term Health Study, or LA Fire HEALTH.

While many Los Angeles residents, including Sinatra, were still under evacuation orders, LA Fire HEALTH researchers were traveling into evacuation zones.

One such researcher was Nicholas Spada, an aerosol scientist who headed down to Los Angeles from UC Davis on 14 January to set up four cascading impactors in Santa Monica (near the Palisades Fire), Pasadena (near the Eaton Fire), Hollywood, and West Hills. These briefcase-sized instruments act like coin-sorting machines, Spada said: They take an air sample, then sort particles into eight different size categories. They take an air sample, then sort particles into eight different size categories, ranging from 10 micrometers (about 1/9 the average width of a human hair) to 90 nanometers (about 1/1,000 the width of a human hair). The instruments collected eight samples every 2 hours until 10 February.

A cascading impactor allows scientists to “associate the particle size profiles with time,” Spada said. The instrument “picks up the changes in the smoke plumes as the fire progresses from active to smoldering to being put out, and then to the mitigation effects.”

The measurements showed that not only were toxic elements such as lead and arsenic present in the air throughout the sampling period but also a high proportion of their mass—about 25%—was in the form of ultrafine particles (on the order of nanometers). Such particles aren’t filtered by N95 masks and can penetrate deep into the body when inhaled, Spada explained.

A team of University of Texas researchers arrived in a van that doubled as a mobile laboratory on 2 February, at which point the fires were out but dust-disturbing remediation efforts had begun. They found that outdoor air quality in the weeks after the fires was back to prefire levels and within EPA guidelines. Indoor samples—especially from homes within the burn zones—showed higher levels of VOCs compared with the outdoor samples.

Neighbors Lend a Hand

Community members got in on the efforts to monitor air quality.

Southern California community members got in on the efforts to monitor air quality, too. Melissa Bumstead and Jeni Knack, codirectors of Parents Against Santa Susana Field Laboratory, worked with researchers to create and distribute flyers about appropriate measures regarding personal protective equipment, as well as a self-sampling protocol for residents who wanted to gather ash samples from their own properties.

About twice a week from 14 January to 19 February, they gathered air and ash samples in Pasadena, Altadena, Santa Monica, Topanga, and Pacific Palisades, then sent them to laboratories, including Spada’s, for testing. Arsenic in all of the ash samples and lead in about a third of them exceeded EPA regional screening levels. Spada noted in communications to residents that these screening levels are based on what’s safe for ingestion by a child and are relatively conservative.

“This is going to help people in the next iteration of fires to know what to do,” Bumstead recalled telling residents in sampling areas.

After the Ashes Sinatra lost her Altadena home in the January 2025 Eaton Fire. When she returned to dig through the rubble, she drove past “chimney after chimney after chimney with no house attached.” Credit: Gale Sinatra

The next fire, Sinatra said, is something that weighs on her as she and her neighbors consider the prospect of rebuilding.

When rain finally arrived in Southern California on 26 January, it helped extinguish the fires and tame the dust disturbed by remediation efforts, reducing the risk that people would inhale toxins.

Still, those toxins were also present in the soil and water. When Sinatra and her husband returned to the charred site of their home, they took every precaution they’d heard about from the news, the EPA, community leaders, and neighbors: They wore respirators, hazmat suits, goggles, and two pairs of gloves each to protect themselves.

Concerns about potential long-term consequences of the air they had already breathed, as well as the soil beneath them, linger as they wait for more data.

“Everyone feels there’s a significant chance of a future fire,” Sinatra said. We’re “wondering about whether it would be safe to live up there, [in] regards to the soil quality and the air quality, and whether it’s going to happen again.”

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

Citation: Dieckman, E. (2025), Where there’s fire, there’s smoke, Eos, 106, https://doi.org/10.1029/2025EO250308. Published on 26 August 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

From Devastation to Data

The 2025 Palisades and Eaton Fires torched scrub-lined slopes of the San Gabriel and Santa Monica Mountains, as well as buildings, streets, cars, and infrastructure.

Before the flames were even contained, scientists from throughout the Los Angeles (LA) metro area turned to the skies, their labs, and their communities to study the extent of the damage. Their work is informing residents and other researchers about how hazards from the fires have shifted in the weeks and months after containment, and how they could change in the years to come.

Scientists are learning how the fires, which burned along the urban-wildland interface, were distinct from strictly urban or rural fires in terms of chemistry, topographic changes, and follow-on hazards.

During Containment

While firefighters were still battling flames on the ground, an airborne surveyor team took stock of the damage, mapping the scope and extent of the fires and assessing which areas needed immediate remediation.

On 11 January 2025, NASA’s Airborne Visible/Infrared Imaging Spectrometer 3 (AVIRIS-3) flew over Los Angeles County mounted on a B200 research plane. The instrument provided some of the first aerial data assessing the scope of the Palisades Fire while it was still smoldering. It flew over the Eaton Fire soon thereafter.

“We immediately looked for methane or natural gas,” said Robert Green, principal investigator for AVIRIS-3 at NASA’s Jet Propulsion Laboratory in Pasadena. Natural gas leaks can pose health and safety risks to first responders. The instrument did not detect any abnormalities.

“But then we realized we had this dataset and could do advanced spectroscopic mapping of the burn severity and the burn products—the char and the ash,” Green said.

One of AVIRIS-3’s quick-turnaround data products is this aerial map of the fraction of burn material, char, and ash within the spectrum of each pixel. Values from 0 (no burn, dark) to 1 (entirely burned, red) describe the burn fraction of the exposed surfaces. Nearly all structures have moderate to severe surface burning (yellow), and few pockets of vegetation (green) survive. Credit: AVIRIS-3/NASA/JPL, via Rob Green

AVIRIS-3 data showed that the Eaton Fire burned more wildland area than urban area, largely because fire managers focused prevention efforts on areas in which people were endangered, Green explained. Initial maps of burn severity, which were provided to first responders, showed that within the burn area, nearly all structures suffered moderate to severe surface-level burns. Very few patches of urban vegetation survived.

“We’ve never had an urban fire like this to collect datasets.”

The instrument completed subsequent surveys of the Eaton and Palisades burn scars in late May.

“We’ve never had an urban fire like this to collect datasets,” Green said. “There’s a whole bunch of new spectroscopic compounds established by burning these [urban] materials, which are different than those you would find in a natural environment.” These surveys will help scientists track combustion products and how long they persist in the soil.

Lead Laden

After the fires were contained, many local scientists mobilized with the tools and people they had at hand—themselves, their students, and even their children—to collect ash, dust, and soil samples. They and fellow residents wanted to know what chemicals enter the environment when wildland-urban fires burn, how bioavailable they are, and how long they present a danger.

“We were scrambling to get ready for the rain. A lot of these data, from a scientific point of view, are perishable.”

Many scientists homed in on lead contamination. Of the more than 7,000 homes and structures that burned, most were built before 1975, when lead-based paint was commonly used. Lead that enters the body is easily absorbed into blood and can cause significant neurological harm, especially in children. It is particularly dangerous when inhaled or ingested as fine dust, and fire ash and dust are key exposure routes. Residents wondered when it would be safe for children and pets to play outside and whether it was safe to eat vegetables from their gardens.

Time was of the essence to collect samples, explained Joshua West of the University of Southern California (USC) in LA, not only because of the potential health impact but also because imminent wind and rain threatened to redistribute or wash away the fires’ by-products.

“We were scrambling to get ready for the rain,” West said. “A lot of these data, from a scientific point of view, are perishable.”

USC researcher Seth John used a handheld X-ray fluorescence machine to test the lead concentration in roadside dust near the Eaton Fire burn scar in early February. Credit: Cecilia John

A team of USC scientists, including West and Earth scientist Seth John, tested dust and ash along the edges of the Altadena burn scar in late January. Over several weekends, the scientists used handheld instruments to measure the lead concentrations in dust that had accumulated on streets and playgrounds. They also collected samples for further analysis in the lab.

EPA’s thresholds for levels of lead in residential soil and playgrounds are 200 parts per million generally and 100 parts per million for sites with multiple sources of exposure. The researchers found that a few roadside spots exceeded those thresholds but no playground samples did.

The team also found a strong correlation between lead levels and proximity to burned structures but not to wildland.

“It seems very clear that there is higher lead in the areas with destroyed structures,” John said.

Wildland ash had low concentrations of lead.

A team from the California Institute of Technology (Caltech) in Pasadena similarly found that ash closest to burned structures contained higher concentrations of lead. The Caltech analysis could differentiate wildland and urban ash and found that wildland ash had low concentrations of lead.

Researchers at the University of Southern California tested lead concentrations in dust samples from streets (circles) and playgrounds (triangles) along the Eaton Fire burn scar. They found higher concentrations of lead (darker blue) in dust near burned and damaged structures (black dots). Credit: map: Seth John, Josh West, and Sam Silva; data collection: Mia Bradshaw, Katherine Thomas, and Cecilia John

“No amount of lead is safe,” John cautioned. “That said, these levels are elevated, but I wouldn’t say they’re elevated to extremely toxic levels.” The researchers found similar trends in dust near the Palisades burn scar.

The USC team returned to the same locations every few weeks to collect more roadside dust samples. As of June, lead concentrations were slowly going down but were still elevated in most of the sample locations in Altadena, John said.

Another Caltech team measured lead concentrations in dust—a fine mix of ash particles, soot, and aerosols—that accumulated on indoor and outdoor surfaces. Many dust samples had lead concentrations exceeding EPA limits. Although simple cleaning with water was often enough to remove that lead, cleanup efforts can disturb new dust and prolong exposure risk.

A survey of garden soil samples found that about 35% had lead concentrations exceeding California’s recommended lead limit, but only about 7% exceeded the EPA’s limit (which is higher). They also found that soil lead levels could vary significantly within a single residential yard and that finer soil particles (smaller than 250 micrometers) had higher lead levels than a mixed soil sample.

The Risks of Rain

As cleanup efforts began in earnest and residents started returning, they were aware of the lingering hazard of debris flows and landslides from the charred slopes of the San Gabriel and Santa Monica Mountains.

The mountains are steep, and gravity slowly moves soil, rocks, and sand downhill, explained Emily Geyman, a graduate student researching climate and surface processes at Caltech. Low brush and scrappy mountainside shrubs typically interrupt that flow and accumulate that debris before it reaches foothill neighborhoods.

“Once you incinerate that [vegetation], those sand grains that are perched at this angle that should be unstable come cascading down,” Geyman said.

What’s more, fires can mobilize contaminants and change soil chemistry so that it repels, rather than absorbs, water and loosens soil so it’s more likely to fall downslope, explained West, who also studied the potential for debris flows in the San Gabriels. Gravity funnels sand and debris into natural channels where it builds up, compounding runoff and erosion risks.

“These are probably some of the first fires in which we have the post-fire, pre-rain topography at really high resolution.”

Studies of past wildfires in the San Gabriels have shown that between 20 and 50 years’ worth of soil erosion happens during the first 2 years following a wildfire. Sudden erosion can damage infrastructure, fill debris basins, and strip ecosystems of critical soil nutrients and structure.

Between 25 January and 24 March, Geyman and other Caltech researchers conducted 10 uncrewed aerial vehicle (UAV) lidar surveys above the Eaton Fire burn scar. They surveyed mountain catchments and debris basins—artificially dug repositories to contain flows—before and after every major rain since the fires.

“These are probably some of the first fires in which we have the post-fire, pre-rain topography at really high resolution,” West said. “Being able to capture that time sequence going forward is one of our big goals.”

A significant rainfall on 13 February triggered debris flows in almost every mountain catchment in the Eaton Fire burn area, Geyman said. Using pre-rain and post-rain lidar scans, the researchers estimated that 680,000 cubic meters of material cascaded downhill, “equivalent in volume to about 270 Olympic-sized swimming pools,” Geyman added.

Debris basins captured most of the flow before it affected residential neighborhoods. “The debris basin infrastructure largely did its job,” Geyman said. Debris flows have not caused any additional loss of life.

Similar UAV lidar work by geomorphologist Seulgi Moon and her colleagues at the University of California, Los Angeles (UCLA), resulted in digital elevation maps of debris channels in Topanga Canyon, an area in the Santa Monica Mountains affected by the Palisades Fire, before and after the February rains. They continue to assess debris flow hazards in the canyon.

On 19 February, a debris flow in Topanga Canyon blocks roads west of the Palisades burn area. Credit: Seulgi Moon The Paths Ahead

UAV surveys continue, and scientists are monitoring debris channels to assess the ongoing risk of landslides and debris flows.

“We plan to continue the surveys before and after each major rain event [through] winter 2026 or until…the loose sediment released from the hillslopes during the fire is cleared out,” Geyman said.

Moon and her colleagues plan to install a geophone and five debris flow monitoring stations in the canyon to monitor ongoing hazards in the area for 2 years. Any ground motion, whether from a skittering animal or an imminent debris flow, will create vibrations. A geophone converts them into a measurable voltage.

“We want to make the connection between how much rain is coming and how much sediment will come downstream,” she said.

Data from both groups will help scientists understand which debris flow mechanisms are most likely, track the volume of material at which flows become imminent, and help inform hazard maps to aid emergency response.

After the initial rush of dust, ash, and soil collection, many research groups shifted to community-led sampling efforts. John and West, for example, set up a free community sampling program for lead in soils and received more than 1,000 samples by mid-May. Some groups are reaching out to residents who want their soil tested or who want to contribute to scientific efforts. Other teams at UCLA and Loyola Marymount University created similar lead soil testing programs for communities.

The AVIRIS-3 team is working with laboratory scientists to match the aerial spectral signatures to those of burn products in ash samples. Green said that every burn compound the team catalogs will help efforts to protect first responders during future urban fires and inform future instruments that could identify when burnable material builds up in fire-prone areas.

Additional flyovers may happen when AVIRIS-3 flies to or from its home base in LA, Green said. Those data could be used to track how environmental damage such as toxic ash contamination and soil erosion change over time.

“That might inform our understanding [of] how this urban-rural interface is changing and what the recovery looks like,” Green said.

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

Citation: Cartier, K. M. S. (2025), Burning urban and wild land alike, Eos, 106, https://doi.org/10.1029/2025EO250309. Published on 26 August 2025. Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

From Devastation to Data

As multiple fires raged through Los Angeles in January 2025, Bernadeth Tolentino had one more thing to worry about: kelp.

Tolentino, a marine biologist and graduate student at the University of Southern California, is part of a lab that runs a gene bank of kelp spores. The repository preserves genetic diversity and allows scientists to bolster struggling populations.

As the roaring fires turned homes, cars, and businesses into chemical-laden ash, Tolentino realized that runoff from postfire rains would eventually carry that ash to the sea.

In the ocean, the ash threatened to block sunlight and pollute the water surrounding one particular kelp population in Santa Monica Bay—a population not represented in the gene bank. She needed to reach the kelp before runoff damaged viable spores.

The dive team, including Tolentino, scrambled to apply for permits, gather their equipment, and coordinate dives before rainstorms carried too much toxic runoff to the site. “It was a little bit of a rush job,” she said. Accelerated permitting from the California Department of Fish and Wildlife allowed the team to reach the kelp population just in time.

They dove four times, collecting spores from southern sea palm, feather boa, and golden kombu kelp, which may be used to restore regional ecosystems in the future.

AltaSeeds Conservancy curator Michael Marty-Rivera places kelp spores into biobank storage. Credit: Taylor Griffith

Tolentino was one of many water quality and marine scientists who collected valuable, time-sensitive information after the LA fires. “It felt great to be able to apply what I know to jump on this really urgent matter,” she said.

Ash in the Water

On 8 January, a day after the Eaton Fire began, scientists from the California Cooperative Oceanic Fisheries Investigations (CalCOFI) were about 80 kilometers (50 miles) away on a routine monitoring cruise. CalCOFI has been monitoring the state’s coastal waters for more than 75 years, collecting oceanographic and ecological data.

But as the fires raged, scientists on the deck of the CalCOFI vessel—and their colleagues on land—recognized the unique opportunity posed by the disastrous event. Here was a chance to collect real-time data on the environmental impacts of an urban fire without needing to plan and launch a separate expedition. They pivoted, used a planned crew exchange to gather more equipment, and increased their sampling.

Even kilometers off the Pacific coast, those on board a CalCOFI (California Cooperative Oceanic Fisheries Investigations) monitoring cruise observed ash in the air on 9 January. Credit: Rasmus Swalethorp/Scripps Institution of Oceanography, University of California, San Diego

The event provided “a perfect opportunity to study the ocean impact of this very devastating urban fire,” said Julie Dinasquet, a marine microbiologist at the Scripps Institution of Oceanography, University of California, San Diego, who works closely with the CalCOFI team. Dinasquet was not on board the monitoring cruise but helped to coordinate the work during the fires.

Those on board were shocked at the effect the fires were having on the ocean, Dinasquet said. She and her colleagues had to wear masks and goggles when the smoke became too potent.

On board the CalCOFI cruise on 9 January, researchers from NOAA Fisheries’ Southwest Fisheries Science Center hold up a plankton net full of ash and debris collected from the ocean surface. Credit: Rasmus Swalethorp/Scripps Institution of Oceanography, University of California, San Diego

Some particles that landed on the water were big enough to see with the naked eye. The largest chunks the group measured were 5 centimeters wide—quite unusual given how far from the fires the samples were taken, said Douglas Hamilton, an Earth systems scientist at North Carolina State University who collaborates with the CalCOFI team.

Closer to shore, the onboard team pulled up a plankton net that was full of black ash. And water samples, typically filled with plankton, were filled instead with soot and debris.

Hamilton thinks that particles traveling from the primarily urban fires to the ocean contained more toxic material than those from blazes burning primarily biological fuels (such as brush).

Scientists know that falling ash and runoff from wildfires that burn mostly vegetation add nutrients to the ocean, sometimes spurring primary production and altering ocean biogeochemistry. The samples from the CalCOFI cruise will shed light on how urban fires can also affect ocean biogeochemistry—a rather new field, Hamilton said.

“This is really the first time this has been able to be observed.”

Ash from urban fires contains very different chemicals than ash from burned areas of less developed land, and therefore might have very different effects on the ocean. “We’re adding this extra layer of complexity,” Hamilton said. “How does this urban wildfire change the narrative of the way that we’ve been thinking about how wildfires might be impacting ocean ecosystems? This is really the first time this has been able to be observed.”

In April, a very large bloom of the toxic phytoplankton Pseudo-nitzschia unfolded along the California coast, killing sea lions and dolphins. Though the event is not unusual under La Niña conditions, scientists are questioning whether material that entered the ocean from the fires may have contributed to the bloom.

Dinasquet plans to analyze the composition of the ash and water samples collected on board the CalCOFI cruise and compare them with ash transported from fires in less developed areas. Hamilton will create models that could be used to project how future urban fires may affect the ocean.

The January fires were the first large coastal urban fires to have affected the ocean at such a scale. “This is an absolutely tragic event, but it’s the first of its kind,” Hamilton said. “So we need to learn from that.”

Rushing for Runoff

Fires’ effects on marine ecosystems don’t come from just the air: As rainwater percolates through burned neighborhoods, runoff carries pollutants through the watershed and into the ocean, too.

When rainstorms hit after the fires, Adit Ghosh was ready. More rainfall meant more runoff and a chance to collect samples that might shed light on how toxic metals such as lead, arsenic, iron, and vanadium, as well as organic pollutants, move through the watershed.

Rain events after the January Los Angeles wildfires caused debris flows, like this one in Mandeville Canyon on 13 February, 2025.Credit: Rain Blankenship

Ghosh, a geobiologist at the University of Southern California, and his colleagues monitored the forecast in the weeks after the fires. No matter the hour, when they expected rain, they headed out to four field sites to collect runoff.

The team especially wanted to sample runoff from the first storms to hit the area after the fires,as that water, they hypothesized, would contain the highest amounts of pollutants. During the first storm, which occurred in late January, the team stayed out until nearly midnight, filling bottles and vials with runoff. Since then, Ghosh has ventured out into rainstorms more than 2 dozen times, trying to capture runoff each time there’s enough flow to sample.

At one point during the sampling, a University of California, Los Angeles professor led the research team around a burned neighborhood in Mandeville Canyon. Ghosh did a double take at the remains of one of the houses—he’d seen it burn down, live, on television.

“You see it on TV, but when you walk up to it, you see the devastation,” he said. “It really hit home. It was really sad.”

Ghosh said he feels that as a member of the Los Angeles community, he has a responsibility to use his skill set to help area residents understand how the fires may be affecting their water.

“It’s important that we do this work, that we try to find these things out quickly and let the public know what we found.”

“It’s important that we do this work, that we try to find these things out quickly and let the public know what we found.”

As this article was written, the team had not finished analyzing all of the samples, but preliminary results show that lead and arsenic are elevated in runoff from burned urban areas, though not above EPA limits. Lead and arsenic may have been elevated in the area already, as they are regularly derived from several natural and urban sources.

Ghosh and his team want to collect streamflow samples from the unburned watersheds during next year’s winter storms to see how the contamination they’ve found compares with background levels.

Ghosh hopes that a full analysis of the data will help scientists and the public understand how chemicals in runoff differ between burned and unburned, and urban and less developed, areas. Ghosh and his collaborators also plan to create time series analyses for each of the pollutants they sampled to show how concentrations of pollutants in runoff change over time after a fire and over the course of multiple rainstorms.

“If there’s another fire somewhere, we can have a better understanding of how those [water quality] risks are going to linger after the event,” he said.

Spotting Plumes from Above

One public agency is helping coordinate much of the aquatic research. After the fires, the Southern California Coastal Water Research Project started to keep track of what samples scientists were collecting to reduce redundancies and help everyone involved know what data are available.

“We’re going to learn some great things from this.”

“We’re going to learn some great things from this,” said Michelle Gierach, an oceanographer at NASA’s Jet Propulsion Laboratory (JPL) working on ocean monitoring projects.

Gierach has been struck by that high level of collaboration in the postfire research. As just one example, she’s been in conversation with the CalCOFI team to determine whether their samples of ash-laden water can help her team at JPL validate satellite observations and derive new algorithms to assess the impact of future urban fires on the ocean. Her team at JPL is also working with colleagues at the University of California, Los Angeles and the University of California, Merced to assess the impacts of the fires on aquatic ecosystems.

“If our data can support the efforts of state agencies, municipalities, NGOs [nongovernmental organizations], academic groups, and others conducting fieldwork and analyses, and ultimately enhance understanding of urban wildfire impacts on nearshore and coastal aquatic environments, then sharing [them] is not only valuable—it’s essential,” Gierach wrote in an email.

She finds a “glimmer of hope” in seeing the scientific community rallying together so rapidly and coordinating so well. “It’s inspiring that in the face of this horror, something positive can happen.”

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

Kimberly M. S. Cartier also contributed to this reporting.

Citation: van Deelen, G. (2025), Scrambling to study smoke on the water, Eos, 106, https://doi.org/10.1029/2025EO250310. Published on 26 August 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.

Cities are particularly vulnerable to heat stress because paved and densely built-up areas tend to store heat. More frequent and intense heat waves are a growing challenge for public health and urban infrastructure.

Volcanoes that blast gases high into the atmosphere not only change global temperatures but also influence flooding in unusual ways, Princeton researchers have found.

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

Seismic monitoring has served as one of the most common and reliable tools for volcanic eruption forecasting. While seismic networks have many advantages over other types of monitoring, the data can be complex to interpret because they include signals from a large variety of sources.

Carleo et al. [2025] analyze 84 eruptions from the South-East Crater of Mount Etna between 2012 and 2023 using data from a 200-meter-deep borehole strain meter. To complement the low frequency strain signals associated with the eruptions, the authors produce a strain tremor record from the higher frequency strain data that is consistent with signals from a nearby seismometer. This large dataset permits analysis using an automated clustering approach.

Interestingly, classification of the strain data comes much closer to matching those made by volcanologists based on the eruption behavior, than does the tremor-based classification. So, while tremor may reflect both deep and shallow magmatic fluid processes, which can be complex and time varying, the strain data may better capture the amount of magma flowing out of the reservoir. This implies that broader implementation of real-time strain monitoring could provide important information for eruption early warning.

Citation: Carleo, L., Currenti, G., Bonaccorso, A., & Sicali, A. (2025). Relation between volcanic tremor and geodetic strain signals during basaltic explosive eruptions at Etna. Journal of Geophysical Research: Solid Earth, 130, e2025JB031564. https://doi.org/10.1029/2025JB031564

—Gregory P. Waite, Associate Editor, JGR: Solid Earth

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

Author(s): A. A. Shelkovoy and S. A. Uryupin

Without imposing additional restrictions on the magnitude of induced scattering of waves by ions, the numerical solution of the nonlinear integral equation for the ion-acoustic waves distribution function over the angles of the wave vector is obtained. This solution complements the analytical and nu…

[Phys. Rev. E 112, 025210] Published Tue Aug 26, 2025

Author(s): J. A. S. Lima and M. H. Benetti

An extension of Maxwell's original prescription for an ideal gas is adopted to derive a broad class of kappa-type velocity distributions, encompassing both fat and short-tailed forms. Within this general framework, a physically consistent fat-tailed kappa distribution is identified that accurately f…

[Phys. Rev. E 112, 025211] Published Tue Aug 26, 2025

In May 2025, I recorded 66 fatal landslides worldwide, resulting in 313 fatalities. The number of fatal landslides is significantly above the long term mean.

Somewhat later than planned, resulting from other workload challenges, this is my latest update on fatal landslides in 2025, covering the month of May. I hope to be able to post data for June in the next few days.

As always, allow me to remind you that this is a dataset on landslides that cause loss of life, following the methodology of Froude and Petley (2018). At this point, the monthly data is provisional.

In May 2025, I recorded 66 fatal landslides worldwide, resulting in 313 fatalities. This is very significantly above the 2004-2016 average number of landslides (n=28.3) and slightly above the average number of fatalities (n=308.8).

This is the histogram by month for the number of fatal landslides in 2025 through to the end of May:-

The number of fatal landslides to the end of May 2025 by month.

The figure, with the higher monthly total in May than for the previous months, primarily reflects the increases in rainfall that start to occur in many Northern Hemisphere areas in May, most notably pre-monsoonal precipitation in large parts of Asia. As such, the trend is quite typical.

This is the graph of the cumulative total number of landslides, organised by pentads. This goes to pentad 30, which ends on 30 May:-

The number of fatal landslides to 30 May 2025, displayed in pentads. For comparison, the long term mean (2004 to 2016) and the exceptional year of 2024 are also shown.

As the above graph shows, at the end of May, 2025 was trending very much above the long term average, and it was remarkably similar to the exceptional year of 2024. This is quite surprising, but may reflect continued high atmospheric temperatures. The EU Copernicus atmospheric temperature note says the following:

“May 2025 was the second-warmest May globally, with an average ERA5 surface air temperature of 15.79°C, 0.53°C above the 1991-2020 average for May.“

As a teaser for the June data, this trend of exceptional landslide occurrence did not continue into the following month.

Reference

Froude M.J. and Petley D.N. 2018. Global fatal landslide occurrence from 2004 to 2016. Natural Hazards and Earth System Science 18, 2161-2181. https://doi.org/10.5194/nhess-18-2161-2018

Return to The Landslide Blog homepage Text © 2023. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

SummaryThe quantitative interpretation of geological structures relies on multi-parameter models (MPMs) inversion. However, conventional full waveform inversion that matches simulated seismic data to observed seismic data cannot accurately obtain high-resolution MPMs because of the implicit inter-parameter coupling relations in the multi-parameter wave equation. Additionally, conventional supervised deep learning approaches that require a significant number of annotated labels cannot predict precise MPMs, as only a limited number of sophisticated synthetic MPMs are available as labels. To address this issue, we propose a self-supervised multi-parameter inversion (SS-MPI) to provide high-resolution MPMs from the prior first-arrival-based tomography and reflection-based migration image. SS-MPI creates representative MPMs from the prior information as pseudo-labels to pre-train the deep learning algorithm, which then predicts MPMs as feedback to update these training pseudo-labels iteratively. Synthetic examples of elastic and anisotropic models indicate that SS-MPI outperforms the conventional elastic full waveform inversion (EFWI) and delivers highly accurate and high-resolution MPMs.

Some 390 million years ago in the ancient ocean, marine animals began colonizing depths previously uninhabited. New research indicates this underwater migration occurred in response to a permanent increase in deep-ocean oxygen, driven by the above-ground spread of woody plants—precursors to Earth's first forests.

Throughout the first half of 2020, average monthly temperatures in Siberia reached 6°C above the norm. The situation climaxed on 20 June, when the temperature in the town of Verkhoyansk climbed to 38°C (100.4°F), the highest temperature ever recorded north of the Arctic Circle. With the extreme heat came wildfires, insect outbreaks, and thawing permafrost.

A new international study published in Earth and Planetary Science Letters reveals that the boundaries between geological epochs and periods, even though randomly distributed, follow a hidden, hierarchical pattern. Co-authored by Prof. Andrej Spiridonov from Vilnius University (VU) Faculty of Chemistry and Geosciences, the research shows that these time boundaries cluster in a way that reflects Earth's system's deepest fluctuations. This finding could reshape how we understand our planet's past and its possible futures.

So-called "100-year weather events" now seem almost commonplace as floods, storms and fires continue to set new standards for largest, strongest and most destructive. But to categorize weather as a true 100-year event, there must be just a 1% chance of it occurring in any given year. The trouble is that researchers don't always know whether the weather aligns with the current climate or defies the odds.

How did freshened water end up beneath the New England Shelf miles offshore, how long has it been there, and how much of it exists?