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Earth is taking in more energy than it releases back to space—a growing "energy imbalance" that is fueling global warming. A new study led by scientists at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science finds that recent changes in air pollution are not the main reason this imbalance has increased.

Scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and collaborators have developed a new type of lidar—a laser-based remote-sensing instrument—that can observe cloud structures at the scale of a single centimeter. The scientists used this high-resolution lidar to directly observe fine cloud structures in the uppermost portion of laboratory-generated clouds. This capability for studying cloud tops with resolution that is 100 to 1,000 times higher than traditional atmospheric science lidars enables pairing with measurements in well-controlled chamber experiments in a way that has not been possible before.

With modern seismic tomography, Earth scientists have discovered that above Earth's core-mantle boundary (CMB), about 2,900 kilometers beneath our feet, there is a thin layer about 300 kilometers thick with remarkable structural complexity and compositional heterogeneity. Among these features are small-scale structures known as ultralow velocity zones (ULVZs) that have attracted intense scientific interest.

A new regional assessment shows that Southeast Asia is a major net source of greenhouse gases, with land-use change and rising fossil fuel use overwhelming natural carbon sinks, reservoirs that store carbon-containing chemical compounds for a long period.

Women and gender minorities, especially in lower-income countries, generally bear a greater burden than men do with regard to the impacts of climate change. For example, women are more often responsible for hauling water in drought-stricken areas, more often the targets of weather- and climate-driven violence, and more likely to find their education discontinued so they can work inside or outside the home, fulfill domestic tasks, or be married off to alleviate the cost to their birth families.

But just because they bear the brunt of climate burdens does not necessarily mean that they are more likely to think that climate change is human driven.

A recent analysis, published in World Development, showed that in countries with lower gross domestic product (GDP), greater access to education increased the percentage of women and gender minorities who think that climate change is driven by human activity. What’s more, in low-income countries with greater civil liberties, including a free media, people of all genders were more likely to think that human activity drives climate change.

“Having better knowledge on climate change increases propensity to be more engaged and build more resilience against climate change.”

“We have significant gender gaps in climate literacy in the developing world,” said Marija Verner, a climate communication researcher at the Yale Program on Climate Change Communication in New Haven, Conn., and lead researcher on the study. “As countries are advancing both economically and democratically, these gender disparities in climate literacy, they shrink.”

“Having better knowledge on climate change increases propensity to be more engaged and build more resilience against climate change,” Verner said. “But it’s important to know that there are important gaps in foundational knowledge about climate change.”

Polling the World

Past research has shown that women and gender minorities generally express greater concern about climate change and its impacts and more readily recognize that climate change is driven by human activity.

However, most of this research has focused on women in high-income, developed countries with generally broad access to education. The lack of research in lower-income countries, especially those in the Global South, is due in part to the fact that research hubs are concentrated in higher-income countries, Verner said. What’s more, it’s typically easier to collect sociodemographic and opinion data in more developed areas than in less developed ones.

“This just speaks to our biases and access in academia.”

“This just speaks to our biases and access in academia,” Verner noted. However, “I’d say in the [past] 5 years or a decade or so, we’ve been getting more and more good public opinion data, especially about environmental attitudes or climate change, from the Global South.”

Verner and her team turned to social media to overcome these challenges. They developed a survey that asked people’s belief about the causes of climate change as well as demographic information about gender, age, education level, and how urbanized the area in which they live is. The team partnered with Meta to administer the survey to Facebook users in 103 lower-income countries and territories.

They received more than 92,000 responses, with an almost even split between men and women plus gender minorities and different age groups. Verner said that respondents skewed slightly toward those with more education and those living in urban environments, which is reflective of Facebook’s user base.

“It’s a trade-off,” she said, “because in this way, you can reach more people, it’s quicker, it’s more efficient, you have a bigger coverage.…But the con is that you are sacrificing an extent of representativeness.”

Gaps in Climate Literacy

People were asked “Assuming climate change is happening, do you think it is…” and were offered four options ranging from denial of climate change to some level of natural causation to acknowledgement of human causation.

The team found that countries with the smallest economies have the greatest gender gap in climate knowledge: More than 50% of men believed in anthropogenic climate change, while less than 40% of women and gender minorities did. This gender knowledge gap disappeared in higher-GDP countries, driven entirely by more women and gender minorities believing in anthropogenic climate change—men’s beliefs remained unchanged.

“When it comes to a well-established democracy that starts backsliding, oftentimes it starts with restricting media freedoms [and] academic freedoms.”

The researchers looked into potential causes for this trend and homed in on education level and metrics related to a country’s civil liberties, like the ability to choose a government, speak freely, and access free media.

The team’s data showed that for all genders, greater access to education and greater civil liberties increased a person’s belief in anthropogenic climate change. In more democratic countries and those with more educated populations, the climate knowledge gender gap disappeared or reversed, with more women than men believing in human-driven climate change.

The connection between democratic freedom, education, and climate literacy noted in this research could have broad implications, as political scholars have noted that many countries around the world have experienced democratic backsliding over the past 2 decades.

“When it comes to a well-established democracy that starts backsliding, oftentimes it starts with restricting media freedoms [and] academic freedoms,” Verner noted, pointing to both Hungary and the United States as examples. “You are getting less access to all sorts of things, including climate change knowledge.”

Making a Difference

“This paper provides a test and empirical evidence to support the importance of gender disparities in understanding about the anthropogenic causes of climate change in less developed country contexts,” said Jennifer Givens, an environmental sociologist at Utah State University in Logan who has studied the relationship between gender and climate literacy.

Givens, who was not involved in the new study, found its education finding to be useful “because as [the researchers] note, policies could be implemented to address this specifically, in addition to policies that target inequalities in education more generally.”

“Once women gain better understanding, will it lead to social change?”

Verner said that data like these could help international groups create education programs tailored for regions where the gender knowledge gap is particularly wide. Future work might seek to disaggregate the data and examine the gender gap country by country.

Data like these could be a useful starting point for policymakers and educators, but Givens questioned whether simply increasing women’s climate literacy would be enough to shift the needle, especially if they remain politically marginalized.

“Once women gain better understanding, will it lead to social change?” she asked. More research is needed, she said, to understand the effectiveness of potential climate awareness campaigns in lower-income and less democratic countries.

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

Citation: Cartier, K. M. S. (2025), Democracy and education increase women’s belief in climate change, Eos, 106, https://doi.org/10.1029/2025EO250485. Published on 23 December 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.

Due to its thick, vast ice sheet, Antarctica appears to be a single, continuous landmass centered over the South Pole and spanning both hemispheres of the globe. The Western Hemisphere sector of the ice sheet is shaped like a hitchhiker's thumb—an apt metaphor, because the West Antarctic ice sheet is on the go.

When the first salmon return to Oregon’s Coquille River in the spring, thousands of fish congregate, and an important ceremony for the Coquille Indian Tribe (CIT) unfolds.

“You come out and you welcome them,” said Jason Younker, former Coquille Indian Tribe chief and assistant vice president of sovereign government-to-government relations at the University of Oregon. Neighbors share the first salmon of the season, and fish bones are returned to the river. “We’re giving thanks. And if you give thanks regularly and with intent, then you’re less likely to abuse the resources that are there in front of you,” said Younker.

But the region’s salmon have not always been treated with such care. The CIT is intimately familiar with the history of both the Coquille River and the Coos Bay estuary, located roughly 24 kilometers (15 miles) to the north. In the 1800s, logging practices and grazing animals introduced by settlers wreaked havoc on the salmon population in the estuary. These historical accounts are backed by recent research from the University of Oregon conducted in collaboration with CIT members, which was presented on 16 December at AGU’s Annual Meeting 2025 in New Orleans.

The research began when scientists studying the area’s vegetation were discussing plants and fish over dinner with Younker. During the conversation, Younker shared the importance of salmon to the region and to settlement history. Tribal knowledge pointed to the idea that salmon do not merely pass through Coos Bay but also deliver nutrients such as nitrogen from the ocean to rivers and wetlands.

“The bells in my head started ringing,” said Katya Podkovyroff, a doctoral student studying biogeochemistry and paleoecology at the University of Oregon. “If I’m looking at vegetation, salmon periods of migration at different points in time would impact the plant communities.”

Of Salmon and Soil Soil cores gathered by researchers suggested that salmon likely play a key role in nutrient cycling in the Coos Bay estuary. Credit: Katya Podkovyroff

University of Oregon researchers teamed up with CIT members, including university faculty members Younker and Ashley Cordes, a professor of Indigenous media studies. Together the group proposed that the rapid decline in salmon had removed nutrients from the river that supported plants and other animals.

To test their hypothesis, the researchers extracted meter-long soil cores from dry ground near the waters of the estuary, providing a physical timeline of the land, with the oldest soil at the bottom and newest soil at the top. They looked at elemental indicators, such as carbon-to-nitrogen ratios, to understand how available nutrients fluctuated over time.

Preliminary results showed that sites with previous restoration efforts—such as the removal of dikes and the addition of trees to stabilize stream banks—had lower carbon-to-nitrogen ratios and higher nitrogen-15 levels, aligning with those found in areas with more salmon. The patterns indicated that when salmon were more abundant, they likely played a critical role in the river’s nutrient cycling.

“I think that when we talk about science, you have to talk about Indigenous science, Indigenous ways of knowing, too.”

There are limitations to using cores to learn about an area. Most notably, a soil core represents only one very specific spot and is unable to show how its chemical or biological contents arrived at that location. To help address this limitation, the researchers plan to conduct more testing of regional environmental DNA, which could provide further evidence of when and where salmon have lived in the area.

“That seems like a really interesting and unique way of using this kind of tool, to try to look back through time, through cores,” said Katharyn Boyer, a restoration ecologist at San Francisco State University who was not involved in the research.

The team hopes their work will inform future restoration efforts. Regardless of the outcome, though, the research will remain collaborative. “I think that when we talk about science, you have to talk about Indigenous science, Indigenous ways of knowing, too. They, too, can augment science,” said Younker. “I think that Indigenous ways of knowing complement a lot of the science that exists.”

—Stella Mayerhoff (@stellamayerhoff.bsky.social), Science Writer

Citation: Mayerhoff, S. (2025), Blending science and Indigenous Knowledge to tell an estuary’s story, Eos, 106, https://doi.org/10.1029/2025EO250484. Published on 23 December 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.

SummaryThe aim of this study is to assess the potential of rotational and strain measurements to provide complementary information on seismic wave scattering, in addition to the conventional seismological observables. We begin by evaluating the accuracy of numerical solutions to the elastic wave equation, solved via the Spectral Element Method, for modeling wave propagation in 3D complex heterogeneous media. These simulations are benchmarked against predictions from the Radiative Transfer Equation (RTE), which models energy transport in scattering media. The comparison focuses on key scattering parameters: mean free path, diffusion onset, and temporal evolution of P/S energy partitioning. Three levels of velocity heterogeneity (10%, 17%, and 25%) are tested in both full-space and half-space configurations. The analysis highlights how scattering strength, numerical accuracy, and theoretical assumptions, such as those underlying the Born approximation, affect the agreement between the two modeling approaches. This comparison helps define the conditions under which RTE and wave equation-based simulations produce consistent results. Following this assessment, we analyze the energy envelopes of the displacement wavefield and its spatial gradients. The results demonstrate that rotational measurements preserve source-induced polarization longer than other observables. This persistence can provide valuable information for better constraining the source mechanism. Furthermore, analysis of the rotational components can provide complementary constraints on the medium’s elastic and scattering properties.

Despite its tropical climate and floodplain location, Bangladesh—one of the world's most densely populated nations—seasonally does not have enough freshwater, especially in coastal areas. Shallow groundwater is often saline, a problem that may be exacerbated by rising sea levels.

Aviation's climate impact is partly due to contrails—condensation that a plane streaks across the sky when it flies through icy and humid layers of the atmosphere. Contrails trap heat that radiates from the planet's surface, and while the magnitude of this impact is uncertain, several studies suggest contrails may be responsible for about half of aviation's climate impact.

The low-latitude highlands region of southwestern China experienced two major climate events in recent years: a severe drought in 2009–2010 and an extreme heat wave in 2019. Though both sprang from similar large-scale atmospheric circulation patterns, the events produced different responses, raising questions about how multiple stressors can push ecosystems toward contrasting outcomes.

Though ice sheet melting is widely talked of and debated, there is limited knowledge about what happens after the period of melting. Researchers dig into this "after" period and see how it relates to previous patterns.

An existing body of research indicates that climate change is making tropical cyclones wetter and more powerful. Now, a new study is indicating the same thing may be happening to the precursors of these storms: the wet weather systems that sometimes give rise to destructive hurricanes and often cause hazardous rain and flooding. The findings are published in the Journal of Advances in Modeling Earth Systems.

A multinational scientific team led by UiT has uncovered the deepest known gas hydrate cold seep on the planet. The discovery was made during the Ocean Census Arctic Deep–EXTREME24 expedition and reveals a previously unknown ecosystem thriving at 3,640 meters on the Molloy Ridge in the Greenland Sea. The groundbreaking findings regarding the Freya Hydrate Mounds, which hold scientific significance and implications for Arctic governance and sustainable development, have recently been published in Nature Communications.

A 400-mile blanket of fog has socked in California's Central Valley for weeks. Scientists and meteorologists say the conditions for such persistent cloud cover are ripe: an early wet season, cold temperatures and a stable, unmoving high pressure system.

When it comes to landslides, some of our planet’s largest have occurred underwater. But out of sight shouldn’t mean out of mind—submarine landslides can be both damaging and dangerous.

Researchers have now mapped the Stad Slide, an underwater megaslide that occurred in the Norwegian Sea several hundred thousand years ago. Material raining out of ancient glaciers set the stage for this event, and an earthquake might have been the ultimate trigger, the team surmised. And with a smaller nearby landslide known to have created a significant tsunami, the hunt is on for evidence of the waves that the Stad Slide might have unleashed. These results were published in the Journal of Quaternary Science.

Follow the Chaos

In many places around the world, jumbled layers of sediment lurk beneath the seafloor.

“The next best thing is to map these deposits.”

Such sedimentary chaos is evidence of one or more ancient underwater landslides that occurred on a grand scale. Humans have never witnessed such an event, but these megaslides are apt to damage undersea infrastructure like communications cables and trigger tsunami, said Bridget Tiller, a geographer at Newcastle University in the United Kingdom. By studying what’s left behind, it’s possible to better understand these events and potentially prepare for similar ones in the future, she added. “The next best thing is to map these deposits.”

Tiller and her colleagues recently focused on the Stad Slide, which occurred off the coast of Norway roughly 400,000 years ago. It’s one of at least five landslides that took place in the region over the past 3 million years. But given its hidden nature—the deposits of the Stad Slide lie roughly 1 kilometer beneath the seafloor, which is, in turn, capped by several hundred meters of water—it was first identified just a decade ago. That earlier investigation mapped less than 5% of the Stad Slide’s deposits, however.

Contrasting Sediments

Tiller and her team have now mined observations that cover nearly the entirety of this Switzerland-sized megaslide. Those data were collected from 2014 to 2018 by TGS, a company that amasses geological and geophysical data for energy exploration. The observations are seismic reflection data, meaning that they were generated by launching sound waves downward from a ship-based platform and measuring how those waves were reflected.

These measurements reveal not only the properties of the seabed but also the nature of the sediment layers beneath the seafloor, said Tiller. “Any time there’s a change in the properties of the sediment below the seabed, you can see these different reflections.”

The researchers discovered interspersed layers of sediment, some measuring up to hundreds of meters thick. Those layers appeared to be composed of either coarse material or fine-grained, sand-dominated material. That layering of contrasting sediments likely predisposed the region to sloughing off in a landslide, the team concluded.

The coarser sediments probably built up over time as a result of ancient glacial activity in the region, the team surmised. Glaciers literally scrape the landscape, depositing sediments entrained within them, explained Rob McKay, a sedimentologist at the Antarctic Research Centre at Victoria University of Wellington in New Zealand not involved in the research. “They basically bulldoze a lot of sediment,” said McKay. “In some places, it can be meters per year of sediment coming out.”

The finer, sand-rich sediments naturally accumulated over the eons because of erosion, the researchers found. Those sediments could well contain biological material, added McKay, which might predispose their layers to sliding down the continental shelf. Aquatic microorganisms known as diatoms create slippery mats when they settle out of the water column, and McKay and his team have suggested that such layers could predispose a region to sliding. “That creates a slide plane,” said McKay.

But a trigger of some sort was probably likely to send those layers moving downslope, the researchers concluded. “It wouldn’t fail just on its own,” said Tiller. An earthquake is a likely culprit, the team noted. However, ground movement due to isostatic rebound might also have done it, said McKay.

Stairs Beneath the Seafloor

“We think it formed in multiple stages.”

Tiller and her collaborators inferred that the sediments that composed the Stad Slide failed in several stages. Finding multiple scarps in a kind of stair-step profile indicated that material had let loose sequentially, said Tiller. “We think it formed in multiple stages.”

The current dataset doesn’t reveal anything about how closely in time those failures might have occurred, however, said Tiller. “It could be almost instantaneous, it could be up to several hundred years apart.”

The team estimated that roughly 4,300 cubic kilometers of sediment were displaced by the Stad Slide. That’s roughly 1,000 times the volume of material ejected by the largest volcanic eruption of the 20th century, the team calculated. And all that material in motion would have displaced seawater, potentially resulting in a tsunami.

Another underwater landslide in the area, the much younger Storegga Slide, is known to have produced a tsunami whose waves reached more than 10 meters above sea level. The Stad Slide is about 30% larger by volume than the Storegga Slide, so it’s highly plausible that it too triggered a large tsunami. But finding evidence of waves from that long ago is a tall challenge, said Tiller. “It’s nearly half a million years ago now. It’s possible they wouldn’t have been preserved.”

But don’t give up yet, said McKay, because there’s good evidence for far older tsunamis. In New Zealand, unusual rock outcroppings originally attributed to tectonic activity are now believed to be due to the tsunami waves that rolled up on shorelines 65 million years ago following the dinosaur-killing asteroid impact marking the end of the Cretaceous.

—Katherine Kornei (@KatherineKornei), Science Writer

Citation: Kornei, K. (2025), New eyes on one of the planet’s largest submarine landslides, Eos, 106, https://doi.org/10.1029/2025EO250469. Published on 22 December 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.

This is an audio story from Eos, your trusted source for Earth and space science news. Do you like this feature? Let us know in the comments or at eos@agu.org.

TRANSCRIPT

Emily Gardner: Justin Higa is a geologist, a postdoctoral researcher at the University of Hawaiʻi at Mānoa, where he studies landslides.

But like most of us, he does more than just work. He has hobbies. When he was in high school, he started taking lessons on the sanshin, a three-string lute that has been called “the soul” of the music tradition in the Ryukyu Islands, a chain of southern Japanese islands that include Okinawa. Higa himself is Okinawan, and he wanted to learn more about his culture. So he joined the Ryukyu Koten Afuso Ryu Ongaku Kenkyu Choichi Kai USA, Hawaiʻi Chapter. His instructor was June Uyeunten, or, as he calls her, June Sensei.

At AGU’s Annual Meeting in New Orleans this December, Higa presented research that aimed to bridge the worlds of geoscience and Indigenous Ryukyuan music.

Justin Higa: This started because when I was an undergrad at the University of Hawaiʻi, there was a lot of focus on place-based science and Indigenous Knowledge and Hawaiian knowledge in geology. So because of this background in the arts that I had, and I knew that we’d sung songs about nature and animals and plants, I thought, “Oh, you know, we could do similar things with the songs that we sing and interpret science from lyrics.”

Gardner: Higa went to California for grad school, but when he came back to Hawaii for his postdoc, he had a little more freedom to pursue different research interests, and he was back in a place with a strong Okinawan diaspora presence. Maybe he could use this music to teach the public, and people interested in music, about the geosciences. His mentor, Uyeunten, was excited for the inverse reason: Maybe this could be a way to get the public, and scientists, interested in Ryukyuan music.

June Uyeunten: I got superexcited, cause I’m like, if Justin can get that excitement out into the public, maybe we can tap other people who are not interested in this type of music to learn more about it, right? And so you don’t know which audience we’re going to appeal to. And so we just have to try different ways to educate others. And music is universal. You don’t need to understand the lyrics, but you could feel it when a performer sings it, right? 

Gardner: Higa teamed up with Uyeunten and Kenton Odo, who are both instructors in the same chapter, to look at how Indigenous Ryukyuan music could be used to teach about geoscience and the climate.

They focused their analysis on a pair of sailing songs, both composed in the 18th century. One is called “Nubui Kuduchi”; Kuduchi is a subgenera of Ryukyuan classical music. And nubui means “climbing up.” The song starts with a description of a group of envoys walking from the Ryukyu capital to the main port on Okinawa, stopping at temples along the way to pray, and then saying goodbye to their families. Then, they set sail to the Kyushu islands:

 (sample of “Nubui Kuduchi” plays)

The lyrics here say, “Sailing across the rough seas off the coast of Iheya, we look out over the route of many islands. To see the Tokara Islands and Strait, and pass without mishap. How lucky we are.”

The south-southwesterly winds described in the song, taking place between May and September, match with observations from the 20th and 21st centuries, which have documented the same wind patterns at the same time of year. The researchers further looked at historical records, which showed that during this period of history, about 20 such envoy departures took place each year between approximately May and August. It all lined up perfectly.

They also analyzed another song called “Kudai Kuduchi.” Kudai means “climbing down.” In this song, the envoy returns to Okinawa island via north-northeasterly winds.

 (sample of “Kudai Kuduchi” plays)

The lyrics here say, “The winds are directly from the north-northeast, with Cape Sata behind us. Sailing comfortably over the seas of the Tokara Islands and Strait.”

Once again, it all lines up: The northeasterly boreal winter monsoon typically occurs from September to May, and historical records show the envoys returning to port at that time of year.

Higa: We could make implications and a discussion about how this kind of implies a reliance on a very constant monsoon season for travel, and when that breaks down, that’s a problem for them. 

Gardner: In another line, the sailors observe an active volcano.

Higa: It’s kind of cool in that this volcano that they observed as active during their boat journey, it was kind of in a location that’s a little outboard from the main Japanese islands that had a lot of written historical records.

So maybe the earliest record was from, I think the 12th century, and then we have our song from the 18th century and then modern instrumented science. So it’s these three points of volcanic activity and ours is kind of bridging that in the middle, kind of implying that, yeah, this volcano has been active for continuously for a very long time and that aligns with geochronologic dating, geologic mapping of this area.

Gardner: James Edwards is an ethnomusicologist at the SINUS Institute, an institution for market and social research in Germany. He wrote his dissertation on the Okinawan performing arts, tracking its development from the 17th century to today. He focuses in part on ecomusicology, a field that examines, among other things, how music mediates the relationships between humans and the environment.

Edwards was not involved in this work, but he said the project was really interesting and could be a launching point for potential interdisciplinary collaboration.

James Edwards: Traditional ecological knowledge can be a valuable intervention contra the overreach of Western scientism and the privileging of Western knowledge systems, right? In this case, you have the opposite. You have a traditional ecological system and Western scientific knowledge synergizing and complementing each other in a really beautiful way.

Gardner: On top of the research presented at AGU25, the authors have published a paper about their work in Geoscience Communication and shared the work in the science and art worlds, including at the Geological Society of America conference and an Okinawan festival in Hawaii. September of 2025 marked 125 years since the first Okinawan immigrants arrived in Hawaii. Especially during such a landmark year, Higa and Uyeunten have high hopes for the work. Incorporating such music into science lessons, for instance, could help educators demonstrate the value of Indigenous Knowledge throughout history.

Uyeunten: If you can blend your career with your culture and with some art form, I think that’ll just, you know, be a good thing to just broaden everyone’s lenses.

Higa: I guess it, I hope it really shows the legitimacy of Indigenous Knowledge from all cultures and it inspires other people to….think of themselves as you can be a scientist and you can be an artist.

Reading List

Paper in Geoscience Communication: Place-based science from Okinawa: 18th-century climate and geology recorded in Ryukyuan classical music

AGU25 abstract: Transforming Indigenous Ryukyuan Music into Geo- and Climate Science Lessons for the Ryukyuan-Okinawan Diaspora in Hawaiʻi

Ryukyu Koten Afuso Ryu Ongaku Kenkyu Choichi Kai USA

University of Hawaiʻi press release

(“Kudai Kuduchi” fades in)

Gardner: Thank you to Justin Higa and June Uyeunten for speaking with me and to their coauthor, Kenton A. Odo. All are members of Ryukyu Koten Afuso Ryu Ongaku Kenkyu Choichi Kai USA, Hawaiʻi Chapter. Thank you also to James Edwards for providing an outside perspective. Credits for the music are as follows:

Translation and interpretation: Hooge Ryu Hana Nuuzi no Kai Nakasone Dance Academy, Clarence T. Nakosone

Singing and Sanshin by Kenton Odo

Tēku (the drums) and fwansō (the bamboo flute) by June Uyeunten

Thanks for listening to this story from AGU’s Eos, your source for Earth and space science news. As always, you can find a transcript of this story, as well as links to the relevant research, at Eos.org.

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

Citation: Gardner, E. (2025), What Okinawan sailor songs might teach us about the climate, Eos, 106, https://doi.org/10.1029/2025EO250486. Published on 22 December 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.

A swarm of at least a dozen earthquakes reaching up to magnitude 3.9 rattled San Ramon near San Francisco, the U.S. Geological Survey reports.

SummaryThis study develops a Bayesian optimisation method of coseismic slip distributions and the correlation lengths of the von Kármán autocorrelation function, which can realize more reliable regularisation grounded in geophysical analysis (VKR). To validate VKR and its dependence on the observation, synthetic tests using data from inhomogeneously distributed Global Navigation Satellite System (GNSS) stations and Synthetic Aperture Radar (SAR) were conducted. When observation stations surround the source fault, the assumed slip distribution and the correlation length were well recovered with some artificially extended slip due to the inhomogeneity of the observation network. Moreover, when observation stations exist only on one side of the fault, the method recovered the slip and other parameters with accuracy comparable to that of the surrounding-case scenario, albeit with slightly increased uncertainty of the parameters. This highlights the importance of uncertainty evaluation for slip and correlation length parameters, especially under biased observation networks. Applying existing Laplacian smoothing methods to the same experiments produced models globally consistent with VKR, demonstrating that the proposed method, despite additional non-linear parameters, achieves comparable estimation accuracy. Existing method showed isotropic correlations of slip variables, whereas VKR exhibited correlations elongated along the strike direction, reflecting its ability to independently regularise along strike and dip via correlation length parameters. These correlation patterns were most pronounced in deeper fault regions, where regularisation dominated over observational constraints. Cluster analysis of the Markov samples revealed that VKR captured a more diverse set of slip distribution models, with cluster differences most evident in deeper fault regions. These analyses underscore the importance of regularisation choice and its impact when evaluating and interpreting slip distributions. We also applied VKR to the actual data of the 2024 Noto Peninsula earthquake in Japan, observed by dense GNSS networks and SAR. The estimated slip distribution featured multiple slip areas in the eastern and western peninsula, consistent with previous studies and Laplacian smoothing-based results. The correspondence between estimated slip distribution and correlation length was confirmed, although it did not match previous empirical findings. To further examine the effect of observation network configuration, we performed additional inversions using a reduced set of actual data. The resulting slip distribution was smoother, and the estimated correlation lengths were larger and more uncertain. Our results reconfirm that simultaneous estimation of slip distribution and correlation length produces mutually consistent values, both of which depend on the spatial distribution of observation points. The results also demonstrate the strong dependence of estimated slip distribution and correlation lengths on the observation network. Therefore, future studies of coseismic slip self-similarity, using observed data, should incorporate parameter analyses that account for network resolution effects.

SummaryThe precise extraction of tidal signals from non-stationary gravity observations is a central challenge in geophysics, where accuracy is often limited by mode mixing in data preprocessing algorithms. This study evaluates the performance of the Time-Varying Filter-based Empirical Mode Decomposition (TVF-EMD) method to address this issue. We employed a progressive validation pipeline: the method was first verified on simulated signals, then rigorously tested against a high-fidelity benchmark from a superconducting gravimeter (SG), and finally applied to one month of continuous data from an Atom Gravimeter (AG) at the Yilan station. Results demonstrate that TVF-EMD dramatically suppresses mode mixing, with the energy of transient spikes in its residual being an order of magnitude lower than that from the conventional Ensemble Empirical Mode Decomposition (EEMD) method. The tidal signal reconstructed by TVF-EMD achieved the highest cross-correlation coefficient and the smallest root mean square error when compared to the theoretical gravity tide. Subsequent harmonic analysis confirmed that TVF-EMD yielded the lowest errors across all major tidal constituents. These findings validate TVF-EMD as a superior preprocessing framework for tidal analysis, particularly for enhancing the reliability of geophysical parameter inversion from short-duration records obtained with next-generation quantum sensors.