EOS

Good digital data is now being published that presents the scale of landscape change that occurred as a result of the Matai’an landslide hazard cascade. There is also interesting information about the root causes of the vulnerability of the town of Guangfu, where the fatalities occurred.

Some interesting information is now emerging about the Matai’an landslide and dam breach, much of it published in Taiwan in Mandarin. A very interesting post has appeared on the website of the Aerial Survey and Remote Sensing Branch that uses aerial imagery before and after the hazard cascade to analyse terrain changes. It is based upon this figure that they have published:-

Vertical elevation change before and after the Matai’an landslide and dam breach. Published by ASRS in Taiwan.

This uses LIDAR data from before and after the sequence of events, which has been turned into one metre Digital Elevation Model, which have then been digitally compared. Note this gives vertical change.

In the source area of the landslide, where the topography is extremely steep, there is over 300 metres of elevation reduction. Downslope and in the area of the dam and lake, the elevation change is over 200 m of accumulation – this is the landslide debris, whivch will now be mobilised in successive rain storm events. In the main channel, the river bed has aggraded (increased in elevation) by over ten metres, although the analysis shows that at point C this was 52 metres! This is going to cause very substantial issues in the future unless a large scale mitigation exercise is undertaken.

The cross-section through the landslide is fascinating:-

A cross-section showing vertical elevation change before and after the Matai’an landslide and dam breach. Published by ASRS in Taiwan.

This shows extremely well the rupture surface of the failure, which clearly had a rotational element, and the infilling of the bedrock topography by the landslide debris. Meanwhile, there is a good helicopter video on Facebook that shows the aftermath of the dam breach.

On a different matter, there is a huge amount of discussion in Taiwan as to why so little effort was made to mitigate the hazard associated with a breach of the Matai-an landslide dam. Writing in the Taipei Times, Michael Turton has a great article exploring the socio-political reasons why this disaster played out as it did. The bottom line is that Guangfu was built on a floodplain – a problem in so many places, but particularly acute in the almost uniquely dynamic physical geography of Taiwan. Levees were built to protect the town, which caused the river to aggrade even before the dam break event. And thus, the scene was set.

Hazards can be natural, disasters are not.

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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 12:01 a.m. this morning, the U.S. federal government shut down. This shutdown comes after weeks of negotiations and pressure tactics failed to bring Congressional Republicans and Democrats together on a budget for the 2026 fiscal year or a continuing resolution to fund the government for a few more weeks.

The federal government has experienced numerous shutdowns over the past decade, the longest of which happened during the first Trump administration and lasted 35 days.

This shutdown, however, may be different, and far more devastating, for the federal workers, including scientists, who live and work across the nation.

In a typical shutdown, employees and contractors who are deemed nonessential to government function, including most workers at science and science-adjacent agencies, are furloughed (temporarily suspended) without pay. Those whose jobs are deemed essential work without pay. Employees receive backpay when the shutdown lifts, but contractors do not.

As of this morning, the shutdown has been proceeding as before.

“The plan to exploit a shutdown to purge federal workers is illegal, unconstitutional, and deeply disturbing.”

But experts are watching how the Trump administration proceeds, as, earlier this week, it ordered all agencies to prepare plans for mass firings and reductions in force (RIFs), not furloughs, should a shutdown occur. According to the White House’s Office of Personnel Management, RIF plans must work within the budget outlined by the President’s Budget Request (PBR). On top of this, thousands of federal workers took offers of deferred resignation earlier this year and have been on paid leave for months. With the shutdown, they may be officially out of jobs.

Exceptions to the shutdown include departments that align with the president’s agenda and received money from his domestic policy megabill, such as the Department of Defense and the Department of Homeland Security, along with a few essential services like Medicare and Social Security.

Trump had doubled down on the threat to fire federal employees yesterday afternoon, which spurred a set of federal employee unions to file a lawsuit alleging that the threats are an unlawful abuse of power.

“The plan to exploit a shutdown to purge federal workers is illegal, unconstitutional, and deeply disturbing,” Tim Whitehouse, the executive director of Public Employees for Environmental Responsibility, said in a statement. “To weaponize it as a tool to destroy the civil service would mark a dangerous slide into lawlessness and further consolidate power in the Executive Branch.”

 
Related

•  From the Prow: AGU Statement on the U.S. Government Shutdown
•  How the Shutdown Is Affecting Federal Services and Workers
•  U.S. Scientists Gird for Yet Another Government Shutdown
•  Government Shutdown Threatens Further Destruction of Environment and Science Agencies, Advocates Warn
•  Get Involved: AGU Science Policy Action Center
 

These mass firing plans, poised to radically downsize and reshape the federal government, have not yet been implemented and it’s unclear if or when that will change. In preparation for possible firings, the Interior Department instructed employees to take home government laptops and cellphones to be able to receive updates.

Nonetheless, until this shutdown is resolved many federal science agencies have largely ceased operations or are working with very limited capacity. Some agencies that have submitted revised shutdown plans, like NOAA and the U.S. Geological Survey, have not yet received approval for the plans, leaving significant uncertainty about what parts of an agency will be allowed to legally operate.

Below is a nonexhaustive list of science-related agencies and how they are being affected by the shutdown.

• Environmental Protection Agency (EPA): An updated contingency plan from the EPA, posted 30 September, is much the same as in past years. Research at the EPA was already suffering: Staff cuts to the agency’s research arm, the Office of Research and Development, are expected to set back much of the agency’s research into environmental hazards, for example.
  • Under the plan, about 89% of EPA staff are now furloughed.
  • The plan calls for a cessation of new grants, updates to the EPA website and communications, all Superfund cleanup activities not necessary to safeguard human lives, inspections of industrial sites, and issuance of permits. Any research and publication activities not deemed necessary to maintain critical operations (such as care for lab animals, plants, and maintenance of instrumentation) must cease as well. Although not mentioned in the current plan, The New York Times notes that during past shutdowns, most employees responsible for monitoring pollution and ensuring industry compliance were furloughed.
  • Past EPA employees think the shutdown could also derail administrator Lee Zeldin’s plans to restructure the agency and revoke landmark EPA rules, such as the 2009 Endangerment Finding.
• National Aeronautics and Space Administration (NASA):
  • Per NASA’s shutdown plan, less than 17% of essential personnel will remain at work, tasked with protecting mission-critical assets such as spacecraft in orbit, astronauts aboard the International Space Station, and other safety operations. Research activities, educational support, and NASA Center tours will cease. NASA Television and the NASA.gov website will not be updated. The agency has requested an exemption from furlough for operations related to upcoming Artemis missions. Although a bipartisan group of lawmakers included a request in a proposed continuing resolution that NASA follow funding guidelines set in the appropriations bill passed by the House of Representatives, for now NASA is following the more severe PBR. Federal whistleblowers recently reported that NASA was illegally implementing the PBR before now, so this shutdown might lead to many spacecraft and their operators being terminated.
  • Proposals for the next observing cycle of the James Webb Space Telescope are due 15 October. The Space Telescope Science Institute has extended the deadline for scientists affected by the shutdown.
• National Oceanic and Atmospheric Administration (NOAA) and National Weather Service (NWS): NWS was chronically understaffed before January 2025 and staffing problems have only gotten worse this year. The current shutdown will likely deepen the existing strain on NWS staff and slow down the hiring process for new meteorologists and forecasters.
  • NWS will continue to issue weather warnings and watches, including those related to developing Atlantic storms. NWS and NOAA tours, outreach, and educational activities will cease. Hurricane Hunter crew and maintenance workers are exempted from being furloughed. Flights are expected to continue. Many employees who operate NOAA satellites are exempted from being furloughed. NOAA satellite data should continue to flow. Most NOAA research activities will cease.
  • If NOAA implements firings in line with the PBR, research related to climate, weather and air chemistry, habitat conservation, ocean science, coastal conservation, and the Great Lakes would be eliminated, as would the Office of Oceanic and Atmospheric Research (OAR).
• National Park Service (NPS): The most recent NPS shutdown contingency plan is from March 2024.
  • Activities related to law enforcement, emergency response, fire suppression and monitoring, and public safety should continue. Most national parks are not expected to close. However, some former park superintendents have asked people not to visit due to safety concerns and bad public behavior during past shutdowns. Visitor centers, bathrooms, trash collection, and park ranger services are now unavailable in most locations. No staff are maintaining trails, clearing brush, or monitoring wildlife. The majority of NPS staff are furloughed and some may soon be laid off.
  • Access to some wildlife refuges has been restricted.
• National Science Foundation (NSF):
  • According to a 2023 contingency plan for the agency, no new grants, cooperative agreements, or contracts are being awarded, and no new funding opportunities issued. The agency’s plan also calls for responses to any questions about upcoming grant deadlines to pause, so calls and emails won’t be answered. Scientists are still free to complete work that has already been funded, and the Award Cash Management Service, responsible for disbursing already-awarded funds, will still operate. However, funding decisions have been halted or delayed. Websites such as Grants.gov and Research.gov remain operational and will accept materials, but processing of those materials will be delayed.
  • NSF scientists temporarily working at the agency but paid by their home institutions are continuing to work.
• U. S. Forest Service (USFS):
  • A 2024 contingency plan from the agency calls for more than half its staff to remain active, as thousands of employees have been deemed necessary to protect life and property. Some USFS work to manage forests, such as reducing hazardous fuels, running fire training, planting new trees, or supervising controlled burns, will continue. However, the 2024 plan states that an extended shutdown could delay these activities, possibly impacting fire risk over hundreds of thousands of acres of forest as windows of favorable burn conditions dwindle.
  • Per the 2024 plan, USFS science, including experiments that rely on specific timing, such as prescribed burn studies, may face delay or cessation.
• U.S. Geological Survey (USGS):
  • In the past, USGS shutdown plans have called for all employees who are not deemed necessary to protect human lives and property to be furloughed, resulting in about half of the agency’s staff temporarily losing their paychecks. According to past contingency plans, some research activities at USGS are supported by supplemental funding from laws such as the Infrastructure Investment and Jobs Act and the Inflation Reduction Act. Such projects can continue. However, much of the USGS’s monitoring and analyzing of Earth systems and natural resources will cease.
  • Online access to USGS maps, publications, and data may be limited, including water quality data and Landsat data critical for emergency response, agriculture, Earth science research, and more.

“It’s incredibly difficult to predict what the federal research enterprise might look like on the other side.”

We don’t know how long this shutdown will last. But the Office of Management and Budget’s posture means “there are likely to be more questions than answers about the operating status of science agencies,” Cole Donovan, associate director of science & technology ecosystems at the Federation of American Scientists, wrote in an email to Eos. “It’s incredibly difficult to predict what the federal research enterprise might look like on the other side.”

Eos will be following news related to this shutdown and monitoring impacts to the federal workforce and larger scientific community. If you have a tip, suggestion, or personal story to share about how this shutdown has affected you, please email us at eos@agu.org.

–Grace van Deelen (@gvd.bsky.social) and Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writers

These updates are made possible through information from the scientific community. Do you have a story about how changes in law or policy are affecting scientists or research? Send us a tip at eos@agu.org. Text © 2025. AGU. CC BY-NC-ND 3.0
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Almost a decade after NASA’s InSight mission put the first working seismometer on the Martian surface, researchers are still combing through its records of faint ground vibrations to reveal secrets of the planet’s deep interior.

In a recent analysis, scientists reported seismic evidence that Mars has a solid inner core, an unexpected finding that challenges earlier studies that suggested the planet’s core was entirely molten.

Like Earth—and onions and ogres—the interior of Mars has layers. These layers have different densities and can be solid or liquid. As seismic waves move through the layers, they are bent or reflected, especially at boundaries where density changes sharply. By analyzing how these waves propagate, scientists can trace their paths and infer the structure and properties of the materials they pass through.

Previous analyses of InSight data had already mapped the structure of the Martian crust and mantle and also revealed that the planet has a surprisingly large molten metallic core, spanning nearly half its radius. Such a large core, combined with measurements of the planet’s relatively low density, suggested that it must contain a lot of light elements such as sulfur, carbon, hydrogen, and oxygen. These light elements lower iron’s melting point, making it less likely to crystallize to form a solid inner core, which partly explains why the new finding caught InSight scientists off guard.

“None of us really believed that you would have a solid inner core,” said Amir Khan, a geophysicist at ETH Zurich who is part of the InSight science team but wasn’t involved in the new study.

A Long Way to the Core

Still, seismologist Daoyuan Sun of the University of Science and Technology of China in Hefei and his colleagues decided to look for signs of a solid core in the publicly available InSight data. Specifically, they reexamined data from a set of 23 marsquakes with seismic waves that passed through the planet’s core before returning to the surface.

To enhance the faint signals from the seismometer, the team combined—or stacked—recordings from these quakes. This revealed two types of compressional (P) waves that crossed the core. One set, known as P′P′ waves, traveled through the outer core to the farside of the planet, reflected off the surface there, and then passed back through the core to reach the seismometer. The other set, called PKKP waves, passed through the outer and inner core before being reflected back to the surface and encountering the core-mantle boundary on the way out.

“To me that’s the most exciting thing. That’s basically saying that you see this inner core structure. ”

Initially, the researchers could not find the PKKP waves at their expected arrival times. Instead, the waves were arriving 50–200 seconds earlier than predicted if the core was fully molten. The early arrivals suggested the waves had traveled through solid material, which transmits seismic P waves faster than liquids.

While looking for these early-arriving signals, the team also picked up a third set of seismic waves, called PKiKP. These are P waves that reflect back to the surface right at the boundary between the inner and outer core. This is the same type of seismic phase that seismologist Inge Lehmann used to reveal the existence of Earth’s solid inner core in 1936.

Finding these PKiKP waves in InSight data offered scientists a strong clue that Mars, too, may have a solid core.

“To me that’s the most exciting thing,” Sun said. “That’s basically saying that you see this inner core structure.”

By measuring the travel times of the seismic phases, Sun’s team estimated that Mars has a solid inner core with a radius of about 613 kilometers—roughly 18% percent of the radius of the planet itself. That ratio is very similar to that of Earth’s inner core, which is about 19% of Earth’s radius, and much larger than many researchers anticipated Mars could have. The new findings were published in Nature.

The team posited that their seismic observations could be explained by an outer core made up mostly of liquid or molten iron and nickel, as well as smaller amounts of sulfur and oxygen, and no more than 3.8% carbon, encasing a solid inner core enriched in more oxygen.

“It’s like Mars has lifted just the corner of its veil and allowed us to peek inside, but only a sneak peek—we could not get the full picture.”

These levels of light elements remain difficult for scientists to explain, Khan said. As light elements prefer to stay liquid, the existence of a solid inner core means that the outer core around it would have to be even richer in light elements than in previous models, which were already pushing the limits of what seemed plausible. On top of that, the building blocks from which scientists think Mars formed don’t contain enough of these elements to account for the abundance required by a solid core, Khan added.

The finding is also at odds with two studies published 2 years ago, one of them led by Khan, that proposed that a layer of molten rock sits at the bottom of the mantle, just above the core, insulating it like a thermal blanket. Such a layer would keep the core hotter, making it more difficult for it to crystallize and solidify.

“It’s like Mars has lifted just the corner of its veil and allowed us to peek inside, but only a sneak peek—we could not get the full picture,” Khan said. “We are not there yet.”

A Hibernating Dynamo

The new finding also renews questions about the absence of a global magnetic field on Mars. Earth’s magnetic field is sustained by the slow crystallization of the core, which drives magnetism-inducing convective motions in the liquid outer core. We know that Mars once had a magnetic field, but it died out billions of years ago.

If Mars does have a solid inner core, why is its magnetic dynamo inactive?

The likely reason is that core crystallization, and thus convection in the outer core, is too slow to power a global magnetic field on Mars, said Douglas Hemingway, a planetary scientist at the University of Texas at Austin and a coauthor of the new study. Mars’s early magnetic field was likely powered by primordial heat escaping from its core. As the planet cooled over billions of years, this convection weakened, and the magnetic field eventually disappeared.

Finding a solid core on Mars, however, opens up the intriguing possibility of a global magnetic field eventually reigniting, Hemingway said. The process of crystallization happens at the boundary of the outer core and the inner core, and if this surface grows larger over time, it could reach a point where there’s enough convective motion to kick-start the dynamo and revive the global magnetic field.

In earlier work, Hemingway predicted that if the Martian core is crystallizing from the center outward, the magnetic field could turn on sometime within the next billion years. “So, you know, if we wait a billion years and it doesn’t happen, then we were wrong,” he joked.

There may be no definitive confirmation of the existence of a solid core on Mars for a long time. The InSight mission ended in 2022, after dust piling up on the lander’s solar panels drained the device’s power supply, and new seismic data from Mars won’t be available for decades, most likely.

“Maybe when we send humans, we would be motivated to bring a few seismometers,” Hemingway said.

—Javier Barbuzano (@javibar.bsky.social), Science Writer

Citation: Barbuzano, J. (2025), Scientists may have finally detected a solid inner core on Mars, Eos, 106, https://doi.org/10.1029/2025EO250367. Published on 1 October 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Source: Journal of Geophysical Research: Machine Learning and Computation

Long-term weather forecasting is a difficult task, partly because weather systems are inherently chaotic. Though mathematical equations can approximate the underlying physics of weather, tiny inaccuracies that grow exponentially as a model progresses in time limit most physics-based forecasts to 2 weeks or less.

Estimated values called parameters, which are used to represent the effects of specific physical processes, are important ingredients in these equations. Parameters are inferred by physical data and affect model outcomes by, for example, multiplying or giving different weights to measurements of temperatures, winds, or other factors.

In recent years, artificial intelligence (AI)–based models such as GraphCast and FourCastNet have transformed weather prediction with their ability to learn from large amounts of weather data and produce highly accurate predictions of future weather. However, AI-based models typically contain tens of millions to hundreds of millions of parameters that do not directly translate to underlying physical processes. Because these parameters are not interpretable by researchers, such AI models make only limited contributions to the scientific understanding of weather.

Minor et al. address this limitation by demonstrating the capabilities of a Weak form Scientific Machine Learning (WSciML) algorithm known as Weak form Sparse Identification of Nonlinear Dynamics (WSINDy). Like other AI methods, WSINDy learns from data. But instead of using a highly parameterized approach, it discovers mathematical equations that represent complex, real-world physical processes, such as how air pressure, density, and vorticity interact to determine wind speed and direction.

The researchers applied WSINDy to both simulated and real-world turbulent atmospheric fluid data, which include measurements of temperature, pressure, and wind speed. WSINDy used the artificial data to identify the known equations from the simulation. Most important, WSINDy was also able to successfully identify the governing equations of the known atmospheric physics from a global-scale set of assimilated data incorporating real-world weather observations.

These findings suggest that WSINDy could not only aid in weather forecasting but also help uncover new physical insights about weather, the researchers say. They also note that WSINDy is especially well suited for application to data with high levels of observational noise.

However, further work will be needed to refine WSINDy so it can identify more accurately certain kinds of known atmospheric equations, such as realistic models for atmospheric wind, the researchers say. The algorithm is also being explored for use across a wide range of other scientific areas, including unexplained phenomena in fusion, population behaviors driving epidemics, and communication between cells that leads to collective motion in wound healing. (Journal of Geophysical Research: Machine Learning and Computation, https://doi.org/10.1029/2025JH000602, 2025)

—Sarah Stanley, Science Writer

Citation: Stanley, S. (2025), Unveiling what’s under the hood in AI weather models, Eos, 106, https://doi.org/10.1029/2025EO250365. Published on 30 September 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.

Our planet’s tectonic plates have been grinding against and diving below one another since time immemorial. However, the earthquakes that result from all the geological jostling have been actively monitored for less than 2 millennia. Researchers have now proposed how liquefaction features known as sand dikes can be used to both pinpoint and precisely date ancient earthquakes. The team published their findings in Earth and Planetary Science Letters.

The Calling Card of Liquefaction

One of the relatively little known dangers of earthquakes is liquefaction, in which strong shaking causes water-rich sediments to lose their structural integrity and behave almost like a liquid. When the ground is no longer solid, the results can be catastrophic—buildings can tilt substantially or even sink, and buried infrastructure like pipes can rise to the surface.

Liquefaction is therefore one fingerprint of a strong earthquake. And fortunately for researchers hoping to better understand past earthquakes, liquefaction leaves behind a calling card: sand dikes. These subsurface intrusions of fine-grained sediments resemble upward-pointing icicles. Sand dikes form in a matter of seconds when mixtures of sand and water are squeezed into cracks opened by ground shaking and the water later drains away. “They give undisputed evidence that an earthquake has occurred,” said Devender Kumar, a scientist at the National Geophysical Research Institute, a research laboratory of the Council of Scientific and Industrial Research, in Hyderabad, India.

Determining when a sand dike formed would therefore reveal when its parent earthquake occurred. And understanding such timing has long been a research goal, said Kumar. “That’s the most important question we need to answer in paleoseismology.”

“This is the million-dollar question.”

To get a handle on the timing of ancient earthquakes, previous studies turned to radiocarbon dating of organic matter found near sand dikes. But that technique comes with its own uncertainties, said Ashok Kumar Singhvi, a geoscientist at the Physical Research Laboratory in Navrangpura, India, and Shantou University in Shantou, China. It’s impossible to know whether the organic material was laid down contemporaneously with the sand dike and therefore the earthquake, said Singhvi. “This is the million-dollar question.”

Younger, but Why?

Another technique, known as optically stimulated luminescence, can be used to date sand dike sediments directly. This method relies on measuring the energy stored up over time in quartz grains from the natural radioactive decay of elements like thorium, uranium, and potassium. Earlier investigations using optically stimulated luminescence showed that sand dike sediments tend to be younger than their host rocks, a tantalizing clue that the luminescence signals in sand dike sediments could be reset, or zeroed out, by an earthquake. But no one had ever conclusively demonstrated this zeroing out effect.

Anil Tyagi, a physicist also at the Physical Research Laboratory, and his colleagues, including Kumar and Singhvi, set out to do just that. Heat, light, and pressure can all reset a material’s luminescence signal, the team knew. But sand dikes form underground, meaning light couldn’t be the culprit, and in sediments that are too soft to generate sufficient pressure, Tyagi and his collaborators concluded. That left heat.

Using a theoretical model developed in the 1970s, the researchers calculated the increase in temperature associated with the formation of a sand dike. Heating occurs simply because of friction, said Kumar: Sediment grains run into each other as they pour upward into a crack in excess of several tens of meters per second. The team estimated that temperatures of up to 450°C were attainable, particularly in the centers of dikes, where sediment grains would be inflowing the fastest.

Tyagi and his colleagues experimentally verified that temperature estimate by analyzing sediment samples taken from five sand dikes in northeastern India. The team calculated that most of the samples had experienced heating to at least 350°C. Such temperatures are sufficient to reset the luminescence signal of quartz grains, earlier work has shown.

“We have a direct method to date sand dikes, and hence past earthquakes.”

These findings demonstrate that quartz grains do indeed zero out their ages when sand dikes form. That fact makes sand dikes valuable and accurate tracers of past ground shaking, said Singhvi. “We have a direct method to date sand dikes, and hence past earthquakes.”

These results are convincing and pave the way for paleoseismological investigations, said Naomi Porat, a luminescence dating scientist who recently retired from the Geological Survey of Israel and who was not involved in the research. In 2007, Porat and her colleagues published a paper that suggested that sand dikes’ luminescence signals were being reset, but the team didn’t posit a mechanism. “We left it as an open question,” said Porat. “It’s so nice to see this paper,” she added. “I waited for 20 years.”

—Katherine Kornei (@KatherineKornei), Science Writer

Citation: Kornei, K. (2025), Spiky sand features can reveal the timing of ancient earthquakes, Eos, 106, https://doi.org/10.1029/2025EO250364. Published on 30 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

CubeSats on The Rise

When Devin Phyllides graduates from college next year, she’ll be able to boast something few students can: She’ll have helped launch a satellite into space.

“It’s probably my favorite job I’ve ever had,” she said.

Phyllides, a senior undergraduate physics student at the University of New Hampshire (UNH) in Durham, is a research assistant for the 3UCubed CubeSat project, a collaboration between UNH, Howard University in Washington, D.C., and Sonoma State University in Rohnert Park, Calif.

CubeSats are small satellites first developed in 1999 as a platform for education and space exploration. They are measured in “units” or U, where a 1U CubeSat is a cube measuring 10 centimeters per side. A 2U CubeSat is equivalent to two 1U CubeSats stacked together, a 3U CubeSat is three cubes stacked together, and so on. The NASA-funded 3UCubed satellite is the size of a 1-quart milk carton.

Dozens of people from the three universities have helped design, build, and test the satellite ahead of its planned October 2025 launch, and most of them are university students.

“The goal from the get-go of this CubeSat is to give students hands-on experience, not just in building…but in the full life cycle of a mission,” said Noé Lugaz, a space scientist at UNH and colead of the 3UCubed project.

Students around the world—high schoolers, undergraduates, and graduate students—have participated in CubeSat missions. Student-focused satellite programs not only provide important science in multiple fields but also inspire and engage the next generation of space scientists and engineers.

Why Build a CubeSat?

An entire aerospace industry has been developed around CubeSats, but the tiny satellites also remain a cornerstone of science, technology, engineering, and mathematics (STEM) education for all ages. Today, many of the satellites’ components, such as the chassis, navigation systems, cameras, and scanners, can be purchased off-the-shelf, and most don’t require advanced technical skills to assemble.

Building a CubeSat “still provides the challenge of putting everything together, and making sure the software works, and making sure that it does exactly what needs to be done,” said Floor Bagchus, a master’s student in aerospace engineering and the educational manager for the Da Vinci satellite at Delft University of Technology (TU Delft) in the Netherlands. But because so many of the components come ready to install, “it’s really a very accessible way for engineering students to learn how to make an actual satellite,” she said.

Some CubeSats are space-ready and are launched into orbit or released from the International Space Station. Others are not designed to leave the atmosphere and are lofted by atmospheric balloons for a short time before descending. Their small size and light weight make CubeSats ideally suited for doing science in the upper atmosphere or in low Earth orbit, such as studying Earth’s magnetosphere, atmosphere, and surface conditions.

CubeSats aren’t the only type of small, budget-friendly space mission in the game, Lugaz said, but in his opinion, they offer the most science per dollar and a realistic space mission experience.

In comparison with a CubeSat, “a balloon, for example, would be cheaper, faster, and maybe scientists can do faster turnover and reach more students,” Lugaz said. “A CubeSat is obviously a longer program. But the positive side of this is that the science you can do with a CubeSat is much more [varied and] is also better training for some of the jobs in industry.”

Their size also helps make the idea of space and satellites approachable, especially for younger students, Bagchus said.

“I think people are a bit scared of space, and teachers are scared of space, because they think that space is so gigantic, dark, vast, and complex,” she said. “How can you make sense of such a difficult thing? How can you make students not be so scared of it, and show them that you can actually work in space, do things in space, and overcome very difficult hurdles by very basic principles? I think it’s a very important thing to do in primary schools and high schools to show that you can actually do challenging things.”

Building STEM Pathways for High Schoolers

The simplicity of a CubeSat means that students with limited or no technical experience can learn how to select the satellite components, install the scientific payloads and navigation systems, design the software, and analyze data. In this way, CubeSats can be an entry point into STEM careers.

“I never really thought I’d be able to say that I launched a satellite to space in my high school years.”

In 2022, the Israel Space Agency launched the TEVEL CubeSat constellation, a program designed to provide high school students with a chance to build and launch satellites. Avigail Anidjar learned about the program when she was in eighth grade. When she started at Ulpanat AMIT Givat Shmuel High School near Tel Aviv the following year, she was excited to learn that the school was participating in the program’s second iteration. She joined TEVEL 2 in 2023, at 15 years old.

“I never really thought I’d be able to say that I launched a satellite to space in my high school years,” Anidjar said.

TEVEL 2 gave nine teams of Israeli high school students the opportunity to build and launch a 1U CubeSat. Building a satellite exposes students to an array of STEM fields, including atmospheric science, computer science, engineering, physics, and robotics.

The child of two engineers, Anidjar had taken introductory classes in physics and coding. Still, she learned a lot of hands-on skills in data analysis, computer programming, and problem-solving while working on her school’s CubeSat.

“I’ve always known that I want to go into this kind of field…but now I know that dealing with more space things and satellites is something that’s very interesting, and maybe I want to focus more on that,” she said.

Nine TEVEL 2 satellites, one from each participating school, launched in March 2025 and will operate together to measure the flux of high-energy particles and solar cosmic rays over roughly the next 2 years. The satellites also feature a transponder for ham radio communication.

Anidjar said the launch was “really stressful” but also very rewarding. “We saw our whole work actually come to life. And after a few days, we also got a beacon from it [showing] that it actually works and that it’s alive, and not just a piece of metal in space. It was really exciting.”

Anidjar recently graduated but remains on the satellite’s data analysis team.

Student-built CubeSats can be a tool for educational empowerment, said Maryam Sani, a STEM educator and advocate, and the education lead for the Space Prize Foundation, a U.S.-based nonprofit dedicated to promoting space education and innovation.

In October 2024, Space Prize sponsored the NYC CubeSat challenge, during which 38 high school– and college-age girls and gender minority students from Colombia, Saudi Arabia, the United Kingdom, and the United States spent three intensive days in New York City (NYC) learning what it takes to create a satellite.

The students were split into teams with others they had never met. Some had interest and prior knowledge about space or engineering from school or programs such as Space Camp. Others joined out of curiosity.

“And that was brilliant,” Sani said. “To quote one student, she said, ‘I just thought it would be something nice to do…I can’t believe how much I learned and how much this has made me more interested in finding out about the space industry.’ Which is exactly what we wanted.”

Participants of the 2024 Space Prize NYC CubeSat challenge gather data from their satellites—and pose for photos—while standing on the deck of the museum ship USS Intrepid in New York City. Credit: Space Prize

Throughout the program the students learned basic physics, circuitry, and coding. Each team brainstormed a problem in New York City that a CubeSat could help solve, designed the system, and then built it. Weather prevented the launches, but the participants collected and analyzed data from their creations on the ground.

Sani said that some of the students from Saudi Arabia extended their project after they went home, eventually launching their CubeSat and incorporating the data into an undergraduate project for electrical and computer engineering degrees.

The CubeSat challenge “was a surreal experience,” wrote one participant in her feedback form. “It made me feel more confident that being a woman in STEM was a possibility.”

Space for All

CubeSats can lower the barrier to entry for students around the world who can’t join rocketry programs or other STEM opportunities. CubeSat education programs can foster international participation and collaboration in science, even when pandemic lockdowns prevent in-person meetups.

In 2021, FIRST Global, a U.S.-based nonprofit that promotes international youth STEM education and engagement, hosted a CubeSat Prototype Challenge that enabled students from 176 countries to build and launch CubeSats. Among its initiatives, FIRST Global has organized annual Olympic-style robotics competitions for national youth teams since 2017. The competitions are typically held in-person, but the COVID-19 pandemic prevented the 2021 gathering. Organizers realized that a CubeSat challenge, which they had never done before, could be the answer if it were held remotely.

“We’re trying to connect the world, but we couldn’t do that physically,” said Matt Stalford, the communications director of FIRST Global. “We certainly could do that symbolically, and CubeSats were a huge part of that.”

Each FIRST Global CubeSat challenge team received a standardized CubeSat prototype assembly kit, from which they built their CubeSats. Credit: FIRST Global

For the challenge, each national team—made up mostly of teenagers—defined a mission of importance to their community and designed a CubeSat to collect the data needed to solve it. For example, team Japan studied residual airborne radiation near the Fukushima nuclear site, Team Seychelles collected environmental data to improve local weather forecast accuracy, and Team Argentina studied how local atmospheric conditions obstruct radio transmissions. FIRST Global shipped each team a standardized CubeSat prototype assembly kit.

“Then they had to do the hard part of building it, launching it, taking that data, and writing a report on what that data produced,” Stalford said. Using balloons, the teams launched 90 CubeSats into the lower atmosphere.

Stalford said that asking students to design a satellite that could help solve a problem in their community made the CubeSat challenge more meaningful to them.

“Kids were built to care about the world,” he said. “When you can spark the imagination, when you can get them asking questions like, ‘How can I be part of the solution?’, that’s where kids come alive, and that’s how you spark that love of STEM.”

Reaching Even More Students

FIRSTGlobal’s CubeSat Prototype Challenge inspired the creation of other CubeSat programs, including one run by STEMbees in Accra, Ghana. STEMbees is a nonprofit organization whose mission is to increase the visibility and participation of girls and women in STEM in Ghana and to close the STEM gender gap across Africa.

A STEMbees expert mentored the eight girls from Team Ghana in the 2021 FIRST Global challenge. Team Ghana members built and launched their CubeSat during the challenge and wanted to launch another one after the contest ended. They took their blueprints, customized them with 3D printing, and built a new one. The group went to nearby Academic City University for a launch that attracted the attention of the university students and local community.

“We saw the impact that it created,” said Benedict Amoako, a robotics engineer and STEM instructor with STEMbees. “We had basically half the university students come out to see what these high school girls were trying to do on their large football pitch, and [they] were very impressed.”

Seeing the success of Team Ghana’s second launch made the STEMbees team want to expand its CubeSat program to reach even more students across Ghana, Amoako said. The organization partnered with AIMS Ghana and the U.S. Embassy in Ghana to create the Infinity Girls in Space Project. By August 2023, more than 110 girls from 37 schools across the country had learned about and helped build CubeSat prototypes.

Aerospace engineering and satellite imagery analysis are not commonly taught in primary or high school in Ghana, explained Lady-Omega Hammond, STEMbees product and start-up growth strategist. Unless a student goes into one of a few specific careers—for example, the military, telecommunications, or land surveying—“you might not find yourself, as a young person, wanting to think about what’s going on beyond the skies,” Hammond said. “CubeSats gave us a very interesting angle to pique the interest.”

As part of the Infinity Girls in Space Project, cohorts of high school girls across Ghana build and launch CubeSat prototypes. Credit: STEMbees

During Infinity Girls in Space, STEMbees provided CubeSat prototype training modules, lesson plans, assembly kits, and technical resources to teachers and students at more than 3 dozen high schools across Ghana. Students learned 3D printing, satellite assembly, coding, and basic physics and atmospheric science. Cohorts from several nearby schools, joined in person by STEMbees experts, worked together for the builds and launches. The eight cohorts lofted 10 CubeSat prototypes into the lower atmosphere by balloon, and they collected images and basic atmospheric readings before their teams retrieved them.

Although some students struggled initially because the concepts were new to them, “I think it all came together when they were working as a team” and supporting one another through the learning process, Amoako said.

“The pride and joy that you see when the parents are coming to see the end result of what their girls have created is always very heartwarming.”

“The pride and joy that you see when the parents are coming to see the end result of what their girls have created is always very heartwarming,” Hammond said. Some participants have graduated and gone on to study engineering.

At the university level, students who participate in CubeSat missions can explore more complex technical and science skills such as payload design, spacecraft assembly, launch testing, and data pipeline development. They can then leverage this hands-on experience into academic or aerospace industry jobs. Postdoctoral researchers and senior graduate students gain experience mentoring newer team members and also experience a space mission’s life cycle.

3UCubed has been in development for several years. After launch into low Earth orbit, the satellite will measure how particle precipitation affects the polar thermosphere and the lifetime of satellites at this altitude.

To date, 68 undergraduate students and two graduate students have been part of the 3UCubed team. They have gone through all stages of mission development, Lugaz said, from concept and design reviews, to building, programming, and testing. After launch, students will be involved with collecting and analyzing data and publishing the results.

The 3UCubed satellite, shown here in an artist’s rendering, is only 30 centimeters long. Credit: University of New Hampshire Teaching Future Teachers

TU Delft’s Da Vinci CubeSat offers those same experiences and skill development opportunities to its student team members, Bagchus said, and it also provides opportunities for those who want to become STEM educators.

“The goal of the satellite is, very simply put, purely educational,” Bagchus said. “We want to provide STEM education to inspire the future generation for STEM and also make them aware that space is literally all around them.”

Da Vinci is planned to launch in 2027 through a partnership with the European Space Agency. The 2U CubeSat will have two educational payloads: one geared toward primary schoolers and one for secondary schoolers. The team is writing and testing free lesson modules for each payload so that teachers and independent learners around the world can learn from the satellite. Members of the satellite team who want to become teachers themselves are gaining experience in developing lesson plans that incorporate satellite technology.

We asked the students, ‘What would you like to do in space?’ And the answer was, ‘I want to play in space.’”

“We did a primary school competition, and we asked the students, ‘What would you like to do in space?’” Bagchus explained. “And the answer was, ‘I want to play in space.’”

The team designed a payload that will allow students to roll dice in space. The satellite will send them pictures and videos of the dice rolling, so they can make statistical calculations and play chance games. The design involved figuring out the technical aspects of controlling a space-based dice roll from the ground and delivering the results in a way that’s accessible to primary schoolers.

The payload for secondary schoolers teaches them about how radiation in the space environment degrades digital photos when cosmic radiation strikes a pixel. One lesson plan for this payload guides students in developing computer code to restore image quality, similar to the Hamming codes used to process space telescope images—another practical lesson for students interested in space science.

The lesson plans and master classes for both modules will be available in-person and virtually.

“Not all people have the same access to education or can have their true potential achieved through education, because of where they were born, or maybe some personal issues they are facing,” Bagchus said. The Da Vinci satellite is “a beautiful initiative to at least try to help a little bit in that aspect.”

The Da Vinci CubeSat will have an educational payload tailored for primary school students that will allow them to roll dice in space. Credit: Da Vinci Satellite/TU Delft Launching into the Future

Some CubeSat prototypes are quick to develop. Others take years to complete. Case studies have found that lack of student training, time commitment constraints, and turnover from graduation can be challenges to CubeSat programs with longer lifespans. But using prototype kits and satellite simulators as well as dedicating time to hands-on training can overcome time and training issues, and turnover can provide an opportunity to get more students involved.

“You don’t find this in your everyday secondary school or even in university.”

“You don’t find this in your everyday secondary school or even in university,” Hammond said. The long-term influence of a CubeSat on its student team members might not be immediately clear, she said, “but I believe in a couple of years, it will definitely influence their thinking into why they chose a career in STEM or not.”

Phyllides, who joined 3UCubed last year, said she got involved with the program through a friend and had no experience with satellites when she started. Now, after more than a year calibrating the onboard instruments and analyzing test data, she’s eagerly awaiting the satellite’s launch.

“I want to see if the code that I’ve been writing will work and actually show our data,” she said. She hopes to analyze 3UCubed data as part of her senior project. “That would be like a huge, huge goal of mine.”

Last year, she presented on the 3UCubed mission at AGU’s annual meeting and found networking with other students involved with space missions to be a valuable experience. She’s still figuring out what she wants to do after graduation, but her work with 3UCubed has expanded her horizons.

“It’s really, really awesome,” she said. “I’m very, very lucky.”

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

Citation: Cartier, K. M. S. (2025), Small satellites, big futures, Eos, 106, https://doi.org/10.1029/2025EO250359. Published on 29 September 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.

CubeSats on The Rise

CubeSats, those boxy satellites that float above Earth alone or in miniature constellations, are emerging as little engines (without engines) of accessible education and affordable engineering.

“The goal from the get-go” of CubeSat education programs “is to give students hands-on experience, not just in building…but in the full life cycle of a mission,” says space scientist Noé Lugaz in Kimberly Cartier’s forward-looking feature “Small Satellites, Big Futures.” Such programs have reached those goals with successfully launched missions designed by STEM students from Saudi Arabia to Seychelles. And international CubeSat projects (as well as readily available hardware and innovative engineering) have expanded career opportunities for budding space scientists from Africa to Southeast Asia.

Other goals of CubeSat programs include the pursuit of economic and ecological sustainability. Wooden satellites, like the ones profiled in Grace van Deelen’s “A New Satellite Material Comes Out of the Woodwork,” might just do the trick.

In more terrestrial matters, a scientist-authored opinion considers the implications of land management in the Himalayas in “Beyond Majesty and Myths: Facing the Realities of Mountainside Development.”

This month’s articles offer a good reflection of Earth and space scientists in these uncertain times: excavating down-to-earth opportunities, reaching for the stars. I think I can, I think I can…

—Caryl-Sue Micalizio, Editor-in-Chief

Citation: Micalizio, C.-S. (2025), Squaring up in space, Eos, 106, https://doi.org/10.1029/2025EO250358. Published on 29 September 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.

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

Only big impactors can punch their way through Venus’s atmosphere. When they do, the impact lofts dust which is then blown downwind as it drifts back to the surface. The resulting parabola-shaped dust deposits are unique to Venus and indicate the wind direction at the time of impact.

In a clever study, Austin et al. [2025] show that the parabolas that appear oldest and most degraded depart most strongly from the expected wind direction. This suggests that wind directions on Venus have changed over time – but why? Because of Venus’s slow spin, its rotation axis is unstable. The authors suggest that the parabolas are recording winds from a period when Venus’s rotation axis was somewhere else. Future Earth-based or spacecraft observations might be able to test this theory.

Citation: Austin, T. J., O’Rourke, J. G., Izenberg, N., & Silber, E. A. (2025). Survey and modeling of windblown ejecta deposits on Venus. AGU Advances, 6, e2025AV001906. https://doi.org/10.1029/2025AV001906

—Francis Nimmo, Editor, AGU Advances

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

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

AGU Publications is committed to supporting early career professionals and provides many opportunities for developing scientists. One of these opportunities is our annual summer publications internship, where someone early in their career is given an inside look at many different aspects of publishing at a scientific society.

Our summer 2025 publications intern, Mackenzie Flynn, joined our team with several unique opportunities and perspectives in between her Master’s and Doctorate studies. Here, Mackenzie shares her background, reflects on the internship, and discusses how the internship will help her moving forward.

What is your academic background?

When I was in the fifth grade, I was asked to do a project on my future career of choice: from contacting potential universities to “dressing the part” for my presentation. Back then, I insisted that I would be a mineralogist and prepared my flannel shirt and field pants. While I did not end up going to Harvard as originally planned, nor did I become a mineralogist, I maintained my passion for geology. This led me to obtain my Bachelor of Science in Geology from Bucknell University with a minor in Classics and Ancient Mediterranean Studies.

While attending Bucknell, I was given a number of opportunities. As a Presidential Fellow, I was able to take part in summer research from the first semester of my freshman year, during which I studied a passive remediation system targeting abandoned coal mine drainage under Dr. Molly McGuire and Dr. Ellen Herman. By my second semester, I was a teaching assistant (TA) for introductory geology labs. The Geology Department also hosts spring break trips to the western United States, which function as a sort of miniature field camp and happens to be where I met the alumni who introduced me as a contender for a spot in the University of Oklahoma’s (OU) graduate program.

Figure 1. A) Late nights in the McGuire-Herman lab processing mine drainage samples with Hannah Schultheis. B) Double rainbow over the valley seen during a Bucknell Geology 2020 spring break trip stop in Globe, AZ. C) Views from on top of The Whaleback at the Bear Valley Strip Mine field trip during my first time as a Teaching Assistant (Coal Township, PA).

This past spring, I finished my Master of Education in Instructional Leadership and Academic Curriculum with a focus in Science Education from OU. My thesis—advised by Dr. Kelly Feille—focused on climate change education for secondary (grades 6-12) science teachers, for which I developed and taught two-week professional development programs that targeted both academic and pedagogical content knowledge through an Earth systems perspective. I’m also currently completing my Master of Science in Geology, characterizing mineral dust aerosols across the Great Plains Ecoregion of Oklahoma under Dr. Lynn Soreghan.

Figure 2. A) My boots overlooking the sunset in White Sands National Park, New Mexico; one of many stops taken on a field trip during my graduate carbonates. B) Sunset views from the Oklahoma Mesonet site located in Tishomingo, OK. Also, one of the sites used in my master’s research in geology studying mineral dust aerosols. C) Taking a break and appreciating the scenery on Mount Fløyen during my study abroad in Norway, which had graduate and undergraduate classes focused on outdoor education and the psychology of adventure therapy.

How have you engaged with AGU since you were first introduced to it?

I first joined AGU as a member during my senior year of my undergraduate degree for two reasons: my advisors suggested I present a poster at the 2022 annual meeting in New Orleans, and I was actively looking for jobs. Having AGU as my first (non-school-sponsored) conference was a little overwhelming and I ended up pulling my poster to focus on writing my thesis, which was due the week after. However, this allowed me to explore more of the conference with my fellow students. I remember being particularly attentive during a session on government jobs and visiting almost every university’s table in the exhibition hall to ask about their graduate programs.

While I maintained my membership since then, my second true interaction with AGU was presenting my preliminary data at the 2024 annual meeting in Washington D.C. I didn’t realize it then, but I actually met my future coworkers there at the publications table. They were kindly telling me about all their journals and pointing to ones of particular interest for my research area while I robbed them blind of no less than five journal stickers (one for each of the journals they recommended). Ever since then, my job notifications have been turned on for AGU.

Figure 3. A) Outside of AGU 2021 with (from left to right) Allison Bergeron, Molly O’Halloran, me, and Bayasgalan Erdene-Ochir. B) A quick group picture right before the “Everything You Ever Wanted to Know About Federal Science Jobs, Fellowships, and Internships” Town Hall. C) Reuniting with Molly O’Halloran at AGU 2024 after the Presidential Forum Lecture with Sharon Lavigne.

Why did you decide to apply as an intern?

I applied to this internship, first and foremost, because of my positive past experiences with AGU as an organization. Additionally, I greatly appreciate the work that they are doing to support scientists in the United States that are struggling in the current political climate, specifically climate scientists. Finally, as someone who is normally on the other side of the journal submission form, I thought it would be a great opportunity to gain a new perspective on scientific publishing and further develop science communication skills.

What have you worked on during the internship?

During my time at AGU, I’ve split my time in the publications department between journal operations and promotions. In operations, my work primarily took place in Earth’s Future and Water Resources Research, but I also occasionally lent a hand in GeoHealth, JGR: Planets, and JGR: Solid Earth. There, I helped with initial quality control; checking newly submitted manuscripts to ensure that they met our standards and abided by our publication policies. I also worked with journal editors to secure peer reviewers for manuscripts and followed up to maintain journal timeliness standards.

For my work with promotions, I primarily assisted with outlining and editing Eos Editor’s Highlights and Editor’s Vox pieces. However, I was also recently given the opportunity to create posts for our social media accounts on BlueSky, X, Facebook, and Instagram. This work allowed me to apply my geoscience background and science communication skills, while working with editors and authors to feature recent research using accessible language for diverse audiences.

My work at AGU was rounded out with meeting attendance. I was asked to jump right in during my first week and attend several journal Editorial Board meetings to take minutes. As a part of the Research Impact Team, I was presented with opportunities to provide a student and early career perspective on upcoming conference materials, project planning, and marketing campaigns. Finally, I was also invited to take part in the marketing and editorial meetings with AGU’s publishing partner, Wiley.

How will this internship help you going forward?

Gaining an inside perspective on scientific publishing and the life of a manuscript has been an invaluable experience.

As someone who is currently situated within academia, gaining an inside perspective on scientific publishing and the life of a manuscript has been an invaluable experience for when I go on to publish my own research. Additionally, this internship allowed me to work with scientists from around the world and has exposed me to a variety of methods for science communication in terms of both mediums (Vox, Highlights, social media, etc.) and how people adjust their language within those varying contexts for the appropriate target audiences. During my time, I was able to explore cutting-edge research in a variety of fields, testing and applying my understanding of areas outside of my primary focus as a graduate student to assist authors and editors in creating promotional material that would make their work more accessible to different audiences.

I was also exposed to a variety of pathways in the field of scientific publishing. From books to community science to data analysis, my supervisors set up quick introductory meetings with a variety of my publications colleagues so that I could gain a more complete understanding of AGU and everything behind the scenes.

What are your next steps and hopes for the future?

While I finish up my M.S. in Geology, I’ve also just started the first semester of my PhD in Instructional Leadership and Academic Curriculum with a focus in science education under Dr. Kelly Feille. Additionally, I’m participating in the first cohort of OU’s newly established Sustainable Energy Systems certificate program. I hope that my next few years in these programs will afford me the opportunity to continue my research in climate change and environmental science education, pursue more outdoor and informal educational studies, present more chances to improve my science communication skills, and — if I’m lucky — catch up on sleep every once in a while.

No matter what form it takes, my primary goal is to make Earth science as accessible as possible to diverse groups.

After finishing up with my education (optimistically before I turn 30, for my mother’s sake), I’d like to work somewhere where I can utilize my geoscience and education background. At this point, my dream job would be an education outreach coordinator for a science-related organization. No matter what form it takes — whether it is a non-profit, scientific society, state geologic survey, science museum, or government body — my primary goal is to make Earth science as accessible as possible to diverse groups.

—Mackenzie Flynn (m.e.flynn.research@gmail.com; 0009-0000-6942-8636) University of Oklahoma, United States

Citation: Flynn, M. (2025), All publish, no perish: three months on the other side of publishing, Eos, 106, https://doi.org/10.1029/2025EO255031. Published on 29 September 2025. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 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.

It is likely that the final death toll from the collapse of the Matai’an landslide dam will be 25 people.

The dust is literally settling in the aftermath of the breach of the Matai’an landslide dam in Taiwan. The current estimates for the loss are life are 18 fatalities with seven more missing, and a further 107 injuries. This would seem to be a high level of loss for an event that was forecast, so there is considerable upset in Taiwan. Questions are being raised as to why no major attempt was made to mitigate the hazard at the site of the landslide.

I will discuss the site of the landslide itself in the coming days, but in the meantime this pair of Planet images gives an idea of the scale of the impact of the Matai’an landslide dam breach. First, this is PlanetScope image from 30 August, before the breach:-

A satellite image of Guangfu township in Taiwan before the breach of the Matai’an landslide dam. Image copyright Planet, used with permission. Image dated 30 August 2025.

And here is the same site after the breach:-

A satellite image of Guangfu township in Taiwan after the breach of the Matai’an landslide dam. Image copyright Planet, used with permission. Image dated 27 September 2025.

And here is a slider to compare the two images:-

Images copyright Planet: https://www.planet.com/.

As the images show, there is an extremely high level of inundation of Guangfu, especially on the eastern side of the town.

Reference

Planet Team 2024. Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/

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.

A new, precisely detailed map of the continental United States puts data from more than a hundred different geologic maps into one interactive interface.

“Mineral resources or major infrastructure projects, even urban planning or disaster management, they all rely on maps.”

The Cooperative National Geologic Map from the U.S. Geological Survey (USGS) is the result of 3 years of development but builds on decades of mapping by geoscientists. Those efforts have yielded a multifunctional tool cataloging the complex rock strata that make up the conterminous United States: vast swaths of glacial till across the Great Plains, bands of ancient metamorphic rocks in the Appalachian Mountains, overlapping layers of volcanic rocks covering the Pacific Northwest, and more.

The audience for the new geologic map is broad: USGS encourages its use by everyone from the curious general public to professionals involved in searching for natural resources or identifying potential natural hazards.

The Cooperative National Geologic Map allows users to toggle between disparate map layers (including age and map source) for a single location, in this case the Eagle Valley Formation in Colorado. Credit: USGS, Public Domain

“Geologic maps and topographic maps are the first stop for so many large-scale efforts,” said Juliet Crider, a geologist at the University of Washington who wasn’t involved in the map’s creation. “Mineral resources or major infrastructure projects, even urban planning or disaster management, they all rely on maps.”

The Cooperative National Geologic Map places a premium on such approachability. Rock layers are delineated by color, and users can click on them to learn more. Users can switch between views that differentiate rocks by source material or age or bounce between different geologic layers in one location. Citations to the original maps integrated into the Cooperative National Geologic Map and stored by the National Geologic Map Database let users dig into the source material.

“I view this as a very effective educational tool,” said David Soller, senior program scientist for the National Geologic Map Database at USGS and part of the map’s development team. “It’s an exciting way for people to begin to understand the geology and to see the similarities and the differences between how the geology was mapped in different areas at different times.”

Decades of Work, Brand-New Technology

The new map draws upon decades of surveying work categorizing the types and origins of the rocks and sediments that compose the geology of the United States.

These data come from many sources, including state geologic surveys and university geologists. These sources don’t always use the same units, a key challenge USGS mapmakers had to address. In fact, the new map is in part the product of a recent push by the Association of American State Geologists and the National Geologic Map Database to standardize geologic maps from across the country, said Sam Johnstone, a research geologist at USGS involved in the map’s creation.

“This map shows some of what we can do by harnessing the power of having that community standard,” Johnstone said.

USGS mapmakers also benefited from a new, largely automated process for adding disparate geologic maps into a single database. It relies on taxonomic categories like rock type and geologic age to standardize data from different maps, building on a process geologists have established over decades of work, Johnstone said.

“What we did is formalize some of that through this process that relies on taxonomies to select broad categories of units,” Johnstone said.

The new tool can integrate a new map in about a minute with little user input, according to Johnstone, meaning adding new and updated maps will be much easier and much faster than before.

A Work in Progress

Though the new map integrates data from different states, Crider noted it still reveals disparities in how geologic data are collected and published. The Idaho-Washington border, for example, stands out clearly in the new map, not because the geology changes suddenly, but because each state provided different information about the rock layers near the border.

The underlying geology of Washington (left) and Idaho doesn’t recognize state borders, but historically, the state geologic societies have used different reporting structures. Credit: USGS, Public Domain

Such disparities are unavoidable on the new map, said Johnstone, because the goal was to integrate data without altering the original maps’ interpretations. The disparities point to opportunities for future collaboration across state agencies and with USGS, Crider suggested.

Future updates to the Cooperative National Geologic Map will include the addition of Alaska, Hawaii, Puerto Rico, and other U.S. territories. Further updates may include improved functionality in the map legend, as well as the ongoing addition of new geologic maps as they become available.

—Nathaniel Scharping (@nathanielscharp), Science Writer

Citation: Scharping, N. (2025), New USGS map offers an interactive look at the rocks beneath our feet, Eos, 106, https://doi.org/10.1029/2025EO250356. Published on 26 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Wastewater from agricultural runoff and human waste contains nutrients such as nitrogen and phosphorus, which can pollute natural waters and cause harmful algal blooms. These nutrients may persist at low levels even after wastewater has been biologically and chemically treated.

In southern Florida, many wastewater treatment facilities inject the treated water into wells 60–120 feet deep. As the water percolates underground, it is diluted by rainwater and groundwater. Chemical interactions with Key Largo Limestone—the rock that makes up the subsurface in the upper and middle Keys—and with microbes living in the groundwater filter out residual nutrients, such as the nitrogen-bearing compounds nitrate and nitrite.

“The idea is that the microbial nitrogen cycle will transform nitrate and nitrite to ammonium and nitrogen gas, which is then released to the atmosphere, before the effluent reaches coastal waters,” explained Miquela Ingalls, a sedimentary geochemist at Pennsylvania State University (Penn State). Similarly, phosphorus is removed from wastewater via a chemical reaction that attaches it onto the limestone bedrock.

But a new study, coauthored by Ingalls, shows that shallow injection doesn’t entirely eliminate nitrogen, raising the possibility that the nutrient may be contaminating coastal ecosystems.

The study’s authors analyzed water from monitoring wells near a wastewater injection site in the Florida Keys. They found that nitrogen and phosphorus levels decreased as water moved away from the site, but were still detectable at a depth of 6 meters (20 feet) and a distance of 350 meters (~1,150 feet) from the injection site, close to the Florida Bay shoreline.

In an earlier study targeting phosphorus, also in the Florida Keys, Ingalls and other researchers at Penn State concluded that up to 10% of initially present soluble reactive phosphorus (the form of phosphorus that can be directly taken up by plants) remained in injected water and was ultimately discharged into the ocean.

The new study aimed to determine how effectively shallow injection eliminates nitrogen.

Some Nitrogen Persists

The study focused on a wastewater injection site in Marathon, located on Vaca Key. The city of Marathon currently pumps treated wastewater between 18 and 27 meters (59–89 feet) into the underlying Key Largo Limestone. In 2021 and 2022, Penn State scientists installed nine monitoring wells 3–27 meters (10–89 feet) deep near the injection site. The researchers then measured levels of nitrate, dissolved nitrogen, and other chemicals at the monitoring wells from 2021 to 2023 and compared them with the levels found in the injected wastewater.

Nitrate levels were elevated at a monitoring well 350 meters (~1,150 feet) from the injection site and close to the Florida Bay.

At most wells, nitrate was completely eliminated from wastewater 2 weeks after injection. However, nitrate levels remained elevated 3–6 meters (10–20 feet) deep in a monitoring well 350 meters (~1,150 feet) north of the injection site and close to the Florida Bay.

This monitoring well is farthest from the injection site and is probably in the path of injected wastewater, according to the previous study, which found that wastewater injected in Marathon mostly travels north and east. As it travels, the water rises toward the surface. This may explain why nitrate is elevated at the most distant well: Close to the injection site, wastewater remains at its initial depth, but after traveling hundreds of meters, it has risen far enough to contaminate shallow groundwater. The contaminated well’s location on the Florida Bay shoreline suggests that along with phosphorus, some wastewater-derived nitrogen may be washing out to sea.

The authors attributed the imperfect filtering of nutrients to the unique setting of the Florida Keys. For wastewater injection, timing is important: The longer wastewater remains underground, the more time there is for microbial and chemical processes to filter out contaminants. But the Keys are mostly composed of small, narrow islands, so the injected wastewater doesn’t travel very far before reaching the ocean.

Groundwater in the Keys also mixes with seawater, making an especially salty and dense mixture. The injected wastewater has a lower density, causing it to buoy up toward the surface and limit the time spent underground.

Nitrogen Pollution Harms Coastal Ecosystems

The discharge of nitrogen into the Florida Bay may have consequences for marine life. The researchers found total nitrogen concentrations of 18 micromoles per kilogram just offshore of the contaminated monitoring well, surpassing the local threshold of 16.1 micromoles per kilogram defined by the Florida Department of Environmental Protection.

Such pollution from wastewater and other human activities is harmful to wildlife, said Brian Lapointe, a marine scientist at Florida Atlantic University who was not involved in the research, because “increased nutrient concentrations support not only algal blooms and microbial pathogens, including coral diseases, but also myriad water quality problems.”

“Nutrient pollution from shallow injection wells has been a major local pollution source driving eutrophication in coastal waters of the Florida Keys for decades.”

“Nutrient pollution from shallow injection wells has been a major local pollution source driving eutrophication in coastal waters of the Florida Keys for decades,” Lapointe said. But both Lapointe and Ingalls highlighted that nutrient pollution in certain parts of the Florida Keys has decreased in recent years, largely due to advances in wastewater treatment. “The effluent being injected into the subsurface starts with a lower concentration of nutrients, so there is less to remediate by biological and chemical processes within the Key Largo Limestone,” Ingalls said.

Nonetheless, Lapointe recommended eliminating shallow injection of wastewater as a way to reduce nutrient pollution. The city of Marathon is set to phase out shallow injection following a 2022 lawsuit filed by the environmental group Friends of the Lower Keys (FOLKs). Instead, the city will transition to deep well injection, which is used in other parts of the Florida Keys. Deep wells inject wastewater more than 2,000 feet underground, lowering the chances that wastewater will rise to the surface before microbes and chemical reactions can filter out contaminants.

—Caroline Hasler (@carbonbasedcary), Science Writer

Citation: Hasler, C. (2025), Shallow injection imperfectly filters Florida wastewater, Eos, 106, https://doi.org/10.1029/2025EO250357. Published on 26 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

Seismologists have long detected unusual structures deep beneath continents at mid-lithospheric depths (80–120 kilometers), but their cause has remained uncertain.

In a new study, Zhang et al. [2025] use state-of-the-art computer simulations that combine first-principles (or fundamental assumption) calculations with machine learning to discover a new form of calcium carbonate, an important carbon-bearing mineral in Earth’s deep interior. This newly identified phase undergoes remarkable elastic softening under mid-lithospheric conditions, greatly reducing seismic wave speeds. Even trace amounts of such carbonate could explain the puzzling seismic signals and anomalous electrical properties observed beneath ancient continental regions.

These findings suggest that carbonates play a far more important role in shaping continental structure than previously recognized. Moreover, the results demonstrate that advanced computational methods can uncover unexpected aspects of the deep carbon cycle and the long-term stability of continental roots.

Citation: Zhang, P., Man, L., Yuan, L., Wu, X., & Zhang, J. (2025). Ultra-low-velocity disordered CaCO3 may explain mid-lithospheric discontinuities. Journal of Geophysical Research: Solid Earth, 130, e2025JB031906. https://doi.org/10.1029/2025JB031906

—Jun Tsuchiya, 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.

body {background-color: #D2D1D5;} Research & Developments is a blog for brief updates that provide context for the flurry of news that impacts science and scientists today.

Unchecked greenhouse gas emissions could cause the world’s income to fall by nearly a quarter within the century, projects a new study published in PLOS Climate.

“Climate change reduces income in all countries, hot and cold, rich and poor alike.”

“Climate change reduces income in all countries, hot and cold, rich and poor alike,” the study’s authors wrote in a press release.

Gross domestic product, or GDP, is the total value of goods and services produced in a given year. A country’s per-capita GDP is a measure of the average income of a person living there. 

In the new study, researchers turned to information about the previously studied link between rising temperatures and GDP, along with possible scenarios of future warming, called Shared Socioeconomic Pathways. They used this data to simulate more precisely how rising temperatures might impact global GDP over time.

Their projections show warming could cause widespread economic losses as higher temperatures and climate variability impact the activities of industries including agriculture and manufacturing. But reducing greenhouse gas emissions could soften the effect, the authors write. 

In a moderate emissions scenario (SSP2-4.5), global GDP decreased by about 2.5% by 2100. In a high-emissions scenario with minimal adaptation (SSP3-7.0), the projections showed global per-capita GDP dropping by up to 11%. And in a more extreme emissions scenario (SSP5-8.5) without any climate mitigation or adaptation, the researchers projected per-capita income losses of up to 24%.

Under this extreme scenario, the United States would lose nearly a third of its per-capita GDP by 2100. 

The estimated changes in global income compared to the 1960-2014 warming trend, as well as a world without climate change, varied depending on the warming scenario that the researchers used. Credit: Mohaddes and Raissi, 2025, https://doi.org/10.1371/journal.pclm. 0000621

The results are in line with previous research from 2024, which indicated a likely decrease in global income by 11% to 29%, depending on future emissions scenarios. However, the new study finds that if the world’s governments abide by Paris Agreement goals—that is, limiting temperature increases to 0.01°C (0.02°F) per year—global GDP could slightly increase by 0.25% by 2100.

 
Related

•  Read the paper: “Rising temperatures, melting incomes: Country-specific macroeconomic effects of climate scenarios”
•  Climate Change Is Likely to Slash Global Income
• Get Involved: AGU Science Policy Action Center
 

In both the new study and previous research, low-income and hotter countries fared the worst: In the new study’s projections, countries located in hot climates and classified as low-income faced income losses between 30% and 60% of the global average. 

The publication comes on the heels of a speech at the United Nations General Assembly in which President Trump called climate change the “greatest con job ever perpetrated on the world.” That denialism won’t preserve global income, according to the authors: “Urgent action is needed to address climate change and protect economies from further income losses,” they wrote.

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

These updates are made possible through information from the scientific community. Do you have a story about science or scientists? Send us a tip at eos@agu.org. 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: Community Science

This is an authorized translation of an Eos article. 本文是Eos文章的授权翻译。

在中国，通过大规模耕作实现农业现代化的努力，将许多参与了全国大部分粮食生产的小农户推到了边缘。一个颇具前景的解决方案是“循环农业”，它通过鼓励大规模和小规模农业经营之间的合作，重点关注可持续性、生产力和农村经济发展。

在Community Science期刊关于可持续农业跨学科合作的特刊中，Li 和 Nielsen[2025]研究了中国西南部一个将柚子种植与养猪相结合的循环农业项目。作者对小农户、政府官员、金融机构员工以及其他各类利益相关者进行了35次访谈，了解了该模式面临的各种利益和风险。

他们的研究结果表明，地方政府在搭建合作平台方面发挥着关键作用，而农业合作社则是商务管理的核心。该研究还揭示了政府参与往往出于政治动机，小农户在决策过程中可能失去自主权和公平代表权等挑战。作者建议，要使循环农业真正惠及每个人，小农户需要有话语权和权力来决定自己的未来，而不能让自己的利益受到侵犯。

Citation: Li, H., & Nielsen, J. Ø. (2025). Smallholders, capital, and circular agriculture—The case of combined pomelo and pig farming in southwest China. Community Science, 4, e2025CSJ000127. https://doi.org/10.1029/2025CSJ000127

—Claire Beveridge, Editor, Community Science

Text © 2025. The authors. CC BY-NC-ND 3.0
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A stalagmite in a Yucatán cave has provided new insight into the role drought may have played in Maya sociopolitical shifts more than 1,000 years ago. A recent analysis of a rainfall proxy in the Maya lowlands revealed that several episodes of severe, prolonged drought occurred during the Maya Terminal Classic Period (roughly 800–1000 CE), a time when large urban centers experienced major sociopolitical shifts.

The researchers suggest that just as climate change acts as a threat multiplier today, drought may have amplified existing troubles in Maya political centers like Chichén Itzá and Uxmal and added climate stress to societies already under pressure.

“These climate events would have affected each individual site in a very specific way depending on the resilience of that site at that time,” said lead researcher Daniel James, who studies paleoenvironmental reconstruction at University College London. “Hopefully the precision of this record allows that [analysis] to be done at individual sites…then we can really start to build up a picture of what I am certain will be a wide variety of societal responses to climate change across this time and across the region.”

Extended Droughts During Wet Seasons

During the Maya Terminal Classic Period, several Maya city-states in the southern lowlands (in modern-day Mexico, Belize, and Guatemala) experienced sociopolitical upheaval, site abandonment, and depopulation. Political and cultural centers shifted northward. Although the societal changes are clear in the archaeological record, there is still widespread debate about the potential drivers of these shifts as well as why some city-states survived while others did not.

This map of the Maya lowlands in Yucatán marks sites of prior paleoclimate studies with white squares, with this study’s site, Grutas Tzabnah, marked with an X. White circles denote Northern Maya Lowland sites, and stars denote sites of interest to this study. The land is shaded on the basis of its elevation in meters above sea level (m asl). Blue contours outline modeled mean annual total rainfalls from 1979 to 2022 in millimeters per year. Credit: James et al., 2025, https://doi.org/10.1126/sciadv.adw7661, CC BY 4.0

Drought comes up often in these debates as a potential destabilizer: Insufficient or unpredictable rainfall can lead to food instabilities, trade disruptions, disease, and even military conflicts. But previous paleoclimate studies failed to precisely pin down the timings and durations of droughts in the Maya lowlands during the Terminal Classic Period, James said.

James and his colleagues trekked to a cave called Grutas Tzabnah, in the state of Yucatán, Mexico, located near several large Classic Maya sites, including Chichén Itzá and Uxmal. This cave has been sought out before for paleoclimate studies of the region because of its accessibility and well-preserved cave formations. What’s more, Grutas Tzabnah is also a relatively shallow cave, which means that water does not take long to drip into the cave from ground level.

The researchers chose a stalagmite that has been growing for thousands of years and shows distinct annual growth layers. This particular stalagmite grew fast in the layers that dated back to the Maya Terminal Classic Period, James said, so the team was able to collect 10–20 data points within each annual layer to determine subannual, seasonal rainfall.

Researchers Daniel James (left), Ola Kwiecien (center), and David Hodell (right) install a drip water autosampler in Grutas Tzabnah to analyze seasonal changes in drip chemistry. Credit: Sebastian Breitenbach, 2022

“You can see wet seasons and dry seasons in our record, whereas previous records from the same cave are looking at annual average rainfall,” James said. “Wet season rainfall is what determines the success or failure of agriculture, as opposed to annual average.”

They measured the ages of the layers using uranium-thorium radiometric dating and rainfall quantity using a stable oxygen isotope ratio, δ18O, within calcite. Stalagmite samples that recorded a lower δ18O indicate more rainfall, while higher δ18O indicates less rainfall. The team calibrated their paleoclimate calculations with modern rainwater and cave drip measurements over a few years to ensure that they could convert the stalagmite’s δ18O measurements to rainfall.

From 871 to 1021, the stalagmite recorded eight extreme droughts during wet seasons, each lasting at least 3 years. A 4-year drought that started in 894 was interrupted by a single wet year and was followed by another 5 years of wet-season drought. A few decades later, the region had experienced 13 consecutive years of wet-season drought (929–942), longer than any multiyear drought in local historical records. This research was published in Science Advances in August.

“The chronology makes this one of the most detailed paleoclimate records available for understanding human-climate interactions during the Maya collapse period.”

“This new study represents a significant advancement in our understanding of Terminal Classic drought patterns, primarily due to its exceptional temporal resolution and robust age control with uncertainties of just a few years,” said Sophie Warken, who studies speleothems and climate variability at Universität Heidelberg in Germany and was not involved with this research.

“This high-resolution approach enables the authors to examine the timing and duration of individual drought episodes very precisely, which previous studies could only identify as broad periods of drying,” Warken added. “The chronology makes this one of the most detailed paleoclimate records available for understanding human-climate interactions during the Maya collapse period.”

One Piece of the Puzzle

While this rainfall record is a big step forward, Warken said that she would like to see it verified using additional proxies like trace elements, as well as a longer modern calibration period. She would also like to see this record extended to before and after the Terminal Classic Period to gauge whether those droughts were truly exceptional for the region.

“Such expanded paleoclimate networks could also provide crucial baselines for assessing recent and future climate changes in this vulnerable region,” she added.

Despite the fact that the extended droughts coincide with major societal shifts, James cautioned that this does not mean that drought caused these changes or were even the most important factor.

“I would love for this data to be used to pick apart individual stories from individual sites of resilience and survival, as well as the stories of disintegration of systems and abandonment and loss of population.”

“Other hardships like famine, disease, and internal violence could have been caused by drought or indeed could have been ongoing beforehand and made the society more susceptible to and less prepared for climate hardship,” James said.

Importantly, archaeological evidence suggests that two Maya cities near this cave, Chichén Itzá and the regional capital of Uxmal, did not decline at the same rate. (Uxmal declined much more rapidly.) Understanding the pressures that the two cities experienced, including drought, will be key to creating a holistic picture of how the cities functioned during the Terminal Classic Period.

“While climate stress likely played an important role in the Terminal Classic transformations,” Warken said, “the Maya’s response to drought was probably mediated by existing social, political, and economic vulnerabilities that varied between different centers and regions.”

“It could be how well were they ruled, how rigid or flexible was their political system, how good was their water management at the time,” James said.

“I would love for this data to be used to pick apart individual stories from individual sites of resilience and survival, as well as the stories of disintegration of systems and abandonment and loss of population,” he added.

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

Citation: Cartier, K. M. S. (2025), Major droughts coincided with Classic Maya collapse, Eos, 106, https://doi.org/10.1029/2025EO250361. Published on 24 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

By the end of the 19th century, most of the estimated 30 million to 60 million bison roaming North America’s Great Plains had been eradicated, forever changing the landscapes that they lumbered across. Today, only about 400,000 bison remain in North America, and 95% of those animals are raised and managed for meat production. The remaining bison live in carefully controlled conservation settings, such as Yellowstone National Park.

Though existing research suggests that grazing bison can diversify habitats and drive nutrient cycling and productivity, studying how they shape larger, ecosystem-scale landscapes has been difficult. A new study conducted in Yellowstone does just that, showing how bison grazing boosts nitrogen cycling and improves plant health to create resilient grasslands.

Yellowstone offers a unique national laboratory for the study because the 5,000 bison who call the park home range freely along a 50-mile (80-kilometer) migration route. Their migration is a reminder of a time when millions of these massive herbivores roamed the continent.

Grazing Helps the Grass Grow

Researchers measured the plant productivity of 16 Yellowstone sites between 2015 and 2022. These sites spanned across lawn-like valley bottoms, which were grazed throughout grass-growing seasons; dry hillsides, which were grazed in spring, fall, and winter (depending on snowpack); and high-elevation wet areas, which were grazed from early summer until frosts arrived.

“Bison are true grazers. They put their heads down and just do their thing.”

Though other species subsist on these grasses, cameras and GPS data from tracking collars showed bison were the primary grazing animals in these locations. “Bison are true grazers. They put their heads down and just do their thing, whereas elk and mule deer and pronghorn are a little more selective in what they eat,” said study author Bill Hamilton, an ecologist at Washington and Lee University.

To compare areas of vegetation that were and were not grazed by bison, researchers constructed a series of movable “exclosures” that kept bison out of 9-square-meter areas. Some of the exclosures remained fixed in place from April, when snowpack melts and new plants emerge, to October, the time when grasses stop growing. Moveable exclosures, shifted every 30 days, followed the bison along their migration path.

By comparing fenced and unfenced areas, researchers were able to estimate how much biomass had been eaten. The missing biomass was added back into the productivity total to give a fuller picture of plant production. “It would be like if each time you mow your lawn and put it into a bag and then you weighed that pile at the end of the summer, you would know how much your grass you actually grew,” said Hamilton.

Having thousands of large animals grazing at once may seem like it would inhibit plant growth, but the study showed the opposite effects. As bison graze, they speed up the nitrogen cycle in the plants and soil around them. Urine is one concentrated source of nitrogen, and as it enters the soil, enzymes and microbes break it down into ammonia, which is then converted to ammonium. Some plants absorb the ammonium directly, and microbes further convert some of the ammonium into nitrate that is absorbed by other plants.

Populations of ammonium-oxidizing bacteria were concentrated more highly in heavily grazed areas, leading to more available nitrogen for plant growth. Researchers determined nitrogen levels by burying reverse osmosis membranes in the ground and measuring the amount of ammonium and nitrate collected on the membrane after 30 days.

The large amounts of bison urine and feces entering the soil weren’t the only cause of increased nitrogen, Hamilton explained. “We found differences in the amount of nitrogen in the leaf tissue above ground. But where’s it coming from? It’s coming from the nitrogen cycle that’s being stimulated by the grazing.”

Mutually Beneficial

When a bison chomps off the top of a patch of grass, the plants quickly release carbon into the soil through their roots to regrow their lost tissue. The carbon stimulates the microbes belowground to accelerate decomposition and nutrient cycling. “In 7 days, there’s more nitrogen in the leaf tissue of that [grazed] plant than a comparable ungrazed plant,” said Hamilton. “The key is that plants are not passive in this process.”

“Animals, through their natural behavior of congregating and eating and hanging out, are changing the way plant communities grow and respond.”

Increased nitrogen in the grasses means more nutritious food for Yellowstone’s migrating bison herds and resident ruminants: The rise in nitrogen translated to a 156% crude protein increase in lawn-like grasslands, a 155% increase in high-elevation habitats, and a 119% increase in dry areas.

“What this study tells me is that what’s happening in Yellowstone is very special,” said Tyler Kartzinel, an ecologist at Brown University who was not part of the study. “Animals, through their natural behavior of congregating and eating and hanging out, are changing the way plant communities grow and respond. And that has cascading effects on nutrient cycling and the functioning of the entire ecosystem.”

Yellowstone and Beyond

Yellowstone’s free-roaming bison herds provide a glimpse at the past, but they also might offer insight into how to preserve and improve grasslands in the future, the study authors suggest. When large groups of herbivores move freely across landscapes—like wildebeest in the Serengeti and caribou in Alaska—they can influence the broader ecosystem in a positive way.

Restoring bison in large-scale settings allows them to fulfill not only significant ecological roles but cultural roles as well. “That’s important for Indigenous tribes that have spiritual and cultural connections to these animals,” said Hamilton.

Besides Yellowstone, few places exist in North America to study how large grazing animals affect the land that sustains them. The nonprofit American Prairie aims eventually to connect 3.2 million acres (about 1.3 million hectares) of grasslands and host thousands of free-roaming bison in Montana—offering another venue where bison could migrate and interact with plants and soil on a large scale. “This study says it could work,” said Hamilton.

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

Citation: Owen, R. (2025), Free-roaming bison graze life into grasslands, Eos, 106, https://doi.org/10.1029/2025EO250355. Published on 24 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

For decades, as Jill Kenny drove around her hometown of Tāmaki Makaurau Auckland, Aotearoa New Zealand, the now-retired geologist and geomorphologist wondered about the shape of the landscape. Auckland, the country’s largest urban area, is located on a volcano-studded isthmus on the North Island. Obvious volcanic mounds aside, why does the city have the shape it does?

Kenny noticed similar flat, eroded surfaces at different heights above sea level and one day in 2004 had an aha moment: Maybe these surfaces were at different elevations because they had been offset by faults. In other places, scientists can trace the echo of fault lines in the landscape or through seismic data, but Auckland has few earthquakes and is covered over by a patchwork of small lava flows and ash deposits, as well as by a modern concrete jungle.

Were there faults hidden beneath the city, and could any of them still be active?

A Passion Project

For years, Kenny trawled through paper and digital records detailing data culled from boreholes drilled through the lava and into Auckland’s underlying sedimentary rock. The boreholes were part of geotechnical investigations conducted for construction purposes and resulted in a total of 2,000 logs.

In those records was evidence of Miocene epoch layers of sandstone and mudstone called the Waitematā Group. The top of this layer, which eroded between 15 million and 5 million years ago, is the “only potential marker horizon that can be followed with any certainty across the Auckland region,” wrote Kenny and University of Auckland volcanologist Jan Lindsay in a 2012 paper describing the borehole research. That study identified a number of previously hidden faults under Auckland, as indicated by adjacent boreholes showing the surface suddenly raised or lowered along a consistent line.

In the years since Kenny and Lindsay’s 2012 paper, Auckland borehole data have proliferated. Logs that were once closely guarded by companies and organizations have been brought together in the New Zealand Geotechnical Database.

“Every little extra piece of information adds to the overall jigsaw puzzle,” said Lindsay.

Now, in a new study published in the New Zealand Journal of Geology and Geophysics, Kenny, Lindsay, and colleagues have used information from 8,200 boreholes in addition to new remote sensing and geophysical data to provide a revised model of post-Miocene faulting in the Auckland region. The model includes a new geospatial database, fault maps, and a suggested standard methodology for classifying obscured urban faults. The research identifies 10 likely and 25 possible faults in the region and erases some nonfaults that have been incorrectly propagated through the literature for decades.

Jill Kenny and colleagues trawled through data from 8,000 urban boreholes to identify 10 likely and 25 possible faults under Auckland. Credit: Kenny et al., 2025, https://doi.org/10.1080/00288306.2025.2519722, CC BY-NC-ND 4.0

“This paper is really a passion project,” said Lindsay. “It was a long, painstaking process, but we think we’ve ended up with a really robust catalog of buried faults in Auckland with a range of different confidences attached to them.”

Finding Urban Faults

While earthquakes are among the deadliest threats to urban areas, cities are tricky places to find faults, said Nicolas Harrichausen, who studies crustal deformation at the University of Alaska Anchorage but was not involved in the New Zealand research. Surface offsets can be just a few meters across, and when a shopping center, road, high-rise, or house is built, evidence of the fault is erased.

Another problem is access. “Say you do find something that is interesting—you can’t go dig a trench in somebody’s yard or dig up a street in the name of finding a potential fault,” said Harrichausen, who recently discovered an active fault in the city of Victoria on Vancouver Island, Canada.

Finally, seismic surveying is one of the most common fault-finding methods, and cities are just seismically noisy places. Vibrations from construction and highways consistently interfere with seismic signals. Some cities restrict or even ban seismic surveys for ecological reasons.

However, cities do have some advantages when compared to places like the extremely remote Alaskan fault he’s currently investigating, Harrichausen said: People are already digging lots of holes.

The new Auckland borehole database is a great starting point for research into the geomorphology of the region, Harrichausen said, but because of the ancient age of the marker horizon, “for earthquake hazard, it’s just kind of a baseline.” The United States considers a fault active if it’s ruptured in the past 12,000 years. In New Zealand, it’s 125,000 years. So far, the faults Kenny and Lindsay have identified can be constrained only to the past 5 million or so years.

“It may be that none of [the suggested Auckland faults] are active,” Lindsay acknowledged. “But we need to better understand our faults and how active they are in order to work out what our actual seismic risk is.”

The study has revealed several compelling candidates for further investigation, she said, including one fault near the peninsula suburb of Bucklands Beach, where offset evidence from the boreholes lines up with a visible scarp through a golf course. “If I were studying faults in Auckland, that’s where I would start,” said Harrichausen.

Where Magma Meets Fault

Even if none of the Auckland faults turn out to be active, for Lindsay, a volcanologist who leads the transdisciplinary Determining Volcanic Risk in Auckland project, the fault maps and database are also the starting point for another line of inquiry with significant implications for the people of the city.

“We need to know as much as we can about the rocks beneath our feet.”

The new maps show that the region’s volcanoes consistently erupted near the faults and associated structures, but not right along them. “Volcanologists are not in agreement as to whether magma prefers to move along faults or whether it prefers to move between faults,” said Lindsay. There seems to be some relationship between the structural fabric of the region and its volcanism, she and her coauthors wrote.

“In order to better understand the active volcanoes in Auckland, we need to know what the subsurface looks like,” Lindsay said. “We need to know the structure, we need to know where the faults are—we need to know as much as we can about the rocks beneath our feet.”

—Kate Evans (@kategevans.bsky.social), Science Writer

Citation: Evans, K. (2025), “Passion project” reveals Auckland’s hidden urban faults, Eos, 106, https://doi.org/10.1029/2025EO250354. Published on 23 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Kelp forests are underwater jungles and some of Earth’s most productive ecosystems, absorbing carbon, providing refuge for a myriad of marine life, and buffering vulnerable shoreline communities and infrastructure. But kelp ecosystems are under increasing climate stress and have been whittled down by overgrazing urchins as key food webs have collapsed.

“Our results suggest that kelp canopy can be a useful indicator of ecosystem resilience within MPAs under climate stress.”

New research led by a team from the University of California, Los Angeles (UCLA) and published in the Journal of Applied Ecology examines the effects of marine protected areas (MPAs) on giant and bull kelp forests off the coast of California. When comparing kelp in protected and unprotected waters, researchers found only modest differences in the surface layer of fronds. Following climate disturbances like marine heat waves, however, kelp within MPAs proved far more resilient, especially in Southern California.

“Our results suggest that kelp canopy can be a useful indicator of ecosystem resilience within MPAs under climate stress,” said Emelly Ortiz-Villa, a graduate student at UCLA and lead author of the study.

California as a Bellwether

California’s kelp forest ecosystems are threatened by factors such as marine heat waves and imbalanced food webs. As sea surface temperatures get hotter, researchers say, California’s experience may be a bellwether for temperate ecosystems globally.

During a catastrophic marine heat wave that struck the California coast between 2014 and 2016, Northern California lost more than 90% of its kelp canopy, which wreaked havoc on marine food webs as well as coastal economies that rely on tourism and fishing.

Compounding the threat posed by marine heat waves is the purple sea urchin, an animal that can devour kelp faster than the seaweed can reproduce. Predators of the sea urchin, including sea stars and sea otters, face pressures, including disease and habitat loss. When urchins outnumber their predators, once lush and verdant kelp forests can become spindly outcrops nicknamed “urchin barrens.”

In the future, said Ortiz-Villa, “research should examine how multiple stressors interact to influence kelp forest recovery, so we can better pinpoint where and when MPAs are most effective at enhancing resilience.”

“What We Mean by Protected”

Marine managers have long sought tools to buy time for kelp forests to recover.

MPAs are one such tool. Many MPAs limit or ban extractive activities, including fishing, but until now, their effectiveness for kelp conservation remained understudied. Using 4 decades of Landsat imagery of the California coast, researchers compared 54 kelp forests in MPAs to those with similar environmental features in unprotected waters.

Following climate disturbances like the 2014–2016 marine heat wave, researchers found an 8.5% increase in kelp coverage in fishing-restricted MPAs. In these protected areas, healthy populations of predator species like California sheepshead and spiny lobsters helped control sea urchin populations that might otherwise have overwhelmed compromised kelp forests.

There’s “a growing body of evidence that we need to be more targeted in terms of what we mean by protected.”

Previous research established the value of MPAs for preserving biodiversity, but this study is among the first to document their advantage to kelp forests. “It’s important to demonstrate that there is an additional benefit of MPAs, and they can be an extra part of the toolbox for protecting kelp forests,” said Aaron Eger, director of the Kelp Forest Alliance and a postdoctoral fellow at the University of New South Wales in Australia who was not involved in the study.

While MPAs tend to follow guidelines established by the International Union for Conservation of Nature, their levels of protection and management can differ greatly. Reserves range from strictly protected “no-take” areas, where all extractive activities are prohibited, to “multiple-use” zones that accommodate fishing and industrial operations. Some MPAs even allow controversial bottom-trawling practices.

The differing standards are “part of a growing body of evidence that we need to be more targeted in terms of what we mean by protected,” said Eger.

—Amelia Macapia (@ameliamacapia), Science Writer

Citation: Macapia, A. (2025), Marine protected areas show promise for kelp forest recovery, Eos, 106, https://doi.org/10.1029/2025EO250350. Published on 23 September 2025. Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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

Ice sheets can have a large impact on the surrounding land and sea where they form, which can create many different landforms. One such landform is called a “glacial forebulge,” which is a long hill that forms in front of an ice sheet. These glacial forebulges are important to understand since they influence sea level and earthquake activity in North America and Europe.

A new article in Reviews of Geophysics digs deeper into the characterization of glacial forebulge dynamics. Here, we asked the authors to give an overview of glacial forebulges, how scientists study them, and what questions remain.

How would you define a glacial forebulge to a non-specialist?

Figure 1: Conceptual model of a glacial forebulge. The glacial forebulge is the upheaval of the lithosphere in front of the ice sheet. This model is based on Stewart et al. [2000], Grollimund and Zoback [2003], Keiding et al. [2015], and R. Steffen et al. [2021]. Lithostatic strength distribution based on Bürgmann and Dresen [2008]. Credit: Brandes et al. [2025], Figure 1

A glacial forebulge is an upheaval of the Earth’s surface that is formed in front of an ice sheet and runs parallel to the ice margin. These form because the ice mass bends the lithosphere and deforms the Earth’s surface. Below the ice load, a depression is formed, whereas outside the ice sheet, there is a gentle upward bending of the surface that forms the forebulge. This bending is supported by Earth’s lithosphere and mantle material that flows away from the area pushed down by the ice sheet.

For the large ice sheets that covered northern Europe and North America during the last glacial period, state-of-the-art numerical models show that the crest, or the highest point, of the forebulge has a maximum height of approximately 50 meters and 90 meters in these areas, respectively. Additionally, the crest can be one or two hundred kilometers away from the ice margin’s maximum extent around 20,000 years ago.

Why is it important to understand glacial forebulges?

The formation, geometry, and motion of the glacial forebulge affects sea level, river flow paths, and earthquake activity in North America and Europe. Though the large ice sheet of the last glaciation is already gone, remnants of the forebulge still exist. With the ice load gone, the area that was below the ice is uplifting and, consequently, the area of the forebulge now subsides. This process is slow and still ongoing, because the lithosphere cannot move independently from the underlying mantle. The mantle has a high viscosity and flows slowly. The subsidence in the forebulge area is on the order of a few millimeters per year. At coastlines, this subsidence can result in a rising sea level. The subsidence of the forebulge area also changes the stress state of the lithosphere, which could lead to a reactivation of pre-existing faults that can cause earthquakes.

Figure 2: Stresses in the lithosphere related to the glacial forebulge. The ice sheet loads the lithosphere and causes a depression below the ice sheet and an upheaval outside the ice sheet. The bending causes stresses in the lithosphere indicated by the arrows. Arrows that point towards each other indicate compressional stresses (material is pushed together), whereas arrows pointing in opposing directions indicate extensional stresses (material is pulled apart). These stresses change, when the ice melts. The figure is based on Stein et al. [1989], Stewart et al. [2000], Grollimund and Zoback [2003], and Keiding et al. [2015]. Credit: Brandes et al. [2025], Figure 14

How do scientists observe and measure glacial forebulges?

In the early years of forebulge research, the existence of a glacial forebulge was predicted by theoretical considerations and calculations assuming that the Earth’s surface before the onset of glaciation was “more-or-less flat,” and the deformation was due to the loading and unloading of a single ice sheet. These models were used to interpret the observed relative sea level data in the near field of the ice centers in Northern Europe and North America. In particular, these correspond to a transition zone between a zone showing pure land emergence and a zone showing pure land submergence in the pattern of global sea level change. These zones are carefully explained in our study.

Figure 3: Visualization of the different zones of relative sea level, predicted by state-of-the-art numerical models that simulate glacial isostatic adjustment processes like surface uplift/subsidence, changes in the rotation of the Earth, changes in the gravitational attraction due to the ice mass loss etc. Melting of the large ice sheets in both the northern and southern hemispheres after the Last Glacial Maximum led to changing sea levels around the world. However, changes are not uniform, and the different zones are visualized in different colors here, with zones II to V being affected by the dynamics of the glacial forebulge. Credit: Brandes et al. [2025], Figure 13

How have these methods evolved over time?

Today, high-quality sea level data are used in the study of glacial forebulges and the numerical models used to simulate Earth deformation and relative sea level change are more refined and realistic. For example, the change in ice-thickness history and the migration of ice margins for all the globally important ice sheets and their interactions on Earth deformation are included. Earth material properties can now change both radially and laterally. Mantle flow-law can be linear, nonlinear, and composite.

In the computation of sea level change, effects such as time-dependent coastlines (land-sea boundaries that change geographically over time) and rotational feedback (the concept that the redistribution of Earth’s surface and internal mass can change its rotational or spin motion and thus sea levels) are included. Besides sea level data, other measurements from modern geodetic techniques are also used. For example, forebulge decay is inferred from the Global Navigation Satellite System (GNSS).

What are some of the major controlling factors of glacial forebulge behavior/evolution?

The most important controlling factors for the geometry and behavior of a glacial forebulge are the structure and material properties of the lithosphere and the viscosity, as well as the flow pattern, in the underlying mantle (including the asthenosphere). A thick and rigid lithosphere leads to a lower forebulge crest that is located at a greater distance from the ice margin. If the lithosphere is thinner and less rigid, the forebulge crest is higher and lies closer to the ice margin. In addition, the forebulge can migrate through time. The flow behavior of the material in the mantle determines how the forebulge migrates when the ice sheet decays. When the ice melts, the forebulge can either retreat with the ice margin, move away from the ice margin, or decay in place.

Figure 4: Schematic view showing the controlling factors for forebulge evolution. The height and width of the forebulge depends on properties of the lithosphere. A thick lithosphere makes the forebulge lower and further away from the glacier. If the lithosphere is thinner, the forebulge is higher and closer to the glacier. The highest part of the forebulge can migrate through time. The type of material flow in the mantle controls how the forebulge moves when the ice melts. This figure is based on the work of Wu and Peltier [1983], Wu [1993], Kaufmann et al. [1997], O’Keefe and Wu [1998]. Credit: Brandes et al. [2025], Figure 3

What are some of the recent advances in our understanding of glacial forebulges?

GNSS data have allowed researchers to map the position of the now decaying forebulge with a higher accuracy. GNSS data for North America and Europe show that there is a belt of subsidence parallel to the former ice margin. This subsiding area is the decaying forebulge.

In North America, it can be found in the southern parts of the central Canadian provinces and the northern United States, making a north-east turn just south of the Great Lakes, then following the northeastern US east coast states into the Maritimes. In Central Europe, there is a subsidence zone that runs from the Netherlands across northern Germany into Poland and southern Lithuania.

This knowledge about today’s forebulge behavior can help to better predict future sea level positions along the US east coast and the coasts of northern Central Europe, the Baltic countries and southern Scandinavia.

What are the major unsolved or unresolved questions and where are additional research, data, or modeling efforts needed?

Because of its small magnitude today, the forebulge in Europe is difficult to observe. Moreover, there are overlapping processes from sediment compaction and large-scale tectonics that hamper a clear determination with geodetic techniques in northern Central Europe. In northeastern Europe, the forebulge cannot be traced yet because of insufficient geodetic data.

To solve these questions, more high-quality data and improved modeling of glacial isostatic adjustment are needed. An integrated study should interpret all the observations and modeling results related to the glacial forebulge (including, for example, height and direction of bulge movement, uplift pattern, relative sea level changes, stress changes and seismicity, etc.) to get a more coherent view of the glacial forebulge dynamics. Precise terrestrial GNSS measurements and satellite data should be utilized to enhance the understanding of forebulge evolution and help to distinguish its subsidence signal from the subsidence caused by groundwater extraction or natural gas recovery.

—Christian Brandes (brandes@geowi.uni-hannover.de, 0000-0003-2908-9259), Leibniz Universität Hannover, Germany; Holger Steffen (0000-0001-6682-6209), Lantmäteriet, Sweden; Rebekka Steffen (0000-0003-4739-066X), Lantmäteriet, Sweden; Tanghua Li (0000-0003-0501-0155), Nanyang Technological University, Singapore; and Patrick Wu (0000-0001-5812-4928), University of Calgary, Canada

Citation: Brandes, C., H. Steffen, R. Steffen, T. Li, and P. Wu (2025), How glacial forebulges shape the seas and shake the earth, Eos, 106, https://doi.org/10.1029/2025EO255030. Published on 23 September 2025. This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s). Text © 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.