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SummaryThe extension of direct current resistivity methods to induced polarization methods has enriched the tools available for subsurface exploration. This enrichment involves an increase in the number of parameters used in the models, as well as addressing different physical phenomena than those observed with direct current. Accounting for non-linearities, if they exist, can further enhance the sophistication of our models. Non-linearities are often observed, particularly in laboratory experiments. However, we question their origin, and the experiment described here suggests that the non-linearities observed under typical experimental conditions may be artifacts related to the electrodes, rather than reflecting the actual response of the subsurface. Indeed, we first replaced the polarizable injection electrodes with non-polarizable electrodes. The non-linearities observed due to the presence of harmonics were significantly reduced. Then, we replaced the voltage control with a current control, which completely eliminated the non-linearities still present.We know that it is impossible to prove the non-existence of a phenomenon that does not exist. This fundamental epistemological principle (as pointed out by Russell and Popper) means that we are not claiming that nonlinearity does not exist. We are simply describing an experiment that can raise doubts about its existence.

For years, we believed the Himalayas were a climatic sanctuary—untouched, pristine, and resilient to the turbulence of modernization. But what happens when mountain cities begin to mimic the dynamics of megacities in the plains?

Burning fossil fuels has elevated atmospheric carbon dioxide, causing massive changes in the global climate including extreme temperatures and weather events here in the Midwest. Meanwhile, human activities have increased the amount of nutrients like nitrogen and phosphorus in grasslands and forests. These are the elements in fertilizer that make lawns greener and farmland more productive.

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.

Major floods in Alaska have caused the death of at least one person and displaced thousands more over the course of the last two weeks. Many of the displaced may not be able to return home for 18 months or longer, according to Alaska Gov. Mike Dunleavy.

Tropical Storm Halong formed in the Northern Philippine Sea on 5 October, and had become a category 4 typhoon by 7 October. Though it was considered an ex-typhoon by the time it reached western Alaska, the storm brought wind speeds of up to 113 miles per hour (181 kilometers per hour), along with severe flooding across the Yukon Delta, Kuskokwim Delta, and Norton Sound.

 
Related

•  Hundreds evacuated, homes destroyed as Alaska communities reel from devastating flooding
•  Gov. Dunleavy’s Request for Federal Assistance
•  Alaska Representatives’ Letter of Support
•  Murkowski: FEMA ‘on the ground’ as west coast Halong evacuations continue
 

Among the hardest hit population centers were the villages of Kipnuk and Kwigillingok, home to a combined 1,000 people, mostly Alaska Native or American Indian. At this time of year, the remote villages can only be reached by water or by air.

In Kipnuk, water levels rose 5.9 feet (1.8 meters) above the normal highest tide line. In Kwigillingok, water levels measured 6.3 feet (1.9 meters) above the normal highest tide line—more than double the previous record set in 1990. According to a letter from the governor’s office to President Trump, 90% of structures in Kipnuk and 35% of structures in Kwigillingok have been destroyed.

The Alaska Air and Army National Guard, the U.S. Coast Guard, and Alaska State Troopers evacuated hundreds of residents to the regional hub of Bethel, then to the capital of Anchorage in what the Alaska National Guard called the state’s largest airlift operation in history.

“It’s been an all-hands-on deck endeavor, and everybody is trying to support their fellow Alaskans in their time of need,” said Col. Christy Brewer, the Alaska National Guard director of joint operations, in a 19 October statement.

Silence From FEMA

But calls for assistance from the Federal Emergency Management Agency seem to have so far gone unanswered, leaving some people asking, “Where is FEMA?”

An urgent question. According to the FEMA Daily Briefing a presidential disaster declaration was requested on October 16th. To the best of my knowledge it hasn’t been granted. Any event of this size should be an easy and immediate yes.

— Dr. Samantha Montano (@samlmontano.bsky.social) 2025-10-18T23:13:44.421Z

As reported by the New York Times, the EPA revoked a $20 million grant in May that was intended to protect Kipnuk from extreme flooding. The grant cancellation was likely part of a larger effort by the administration to shift the burden of disaster response to states.

On 16 October, Dunleavy submitted a request to President Trump to declare a major disaster for the state.

The letter notes that Alaska has seen 57 state-declared disasters since November 2018, 14 of which have been approved for federal disaster assistance. There have been 14 state-declared disasters in Alaska in the last 12 months alone, including fires, freezes, landslides, and floods.

“It is anticipated that more than 1,500 Alaskans will be evacuated to our major cities, many of whom will not be able to return to their communities and homes for upwards of 18 months,” Gov. Dunleavy wrote. “This incident is of such magnitude and severity that an effective response exceeds state and local capabilities, necessitating supplementary federal assistance to save lives, protect property, public health, and safety, and mitigate the threat of further disaster.”

On 17 October, Alaska’s senators and state representative (all Republicans) also submitted a letter to President Trump, urging him to approve the governor’s request for a major disaster declaration.

Also on 17 October, Vice President JD Vance said on X that he and the president were “closely tracking the storm devastation,” and that the federal government was working closely with Alaska officials. On 18 October, Lisa Murkowski (R-AK) said she believed FEMA representatives were “totally on the ground.”

However, as of 20 October, the incident is not listed in FEMA’s disaster declaration database.

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

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

The ocean has helped mitigate global warming by absorbing about a quarter of anthropogenic carbon dioxide (CO2) emissions, along with more than 90% of the excess heat those emissions generate.

When farmland is abandoned and allowed to return to nature, forests and grasslands naturally regrow and absorb carbon dioxide from the atmosphere—helping fight climate change.

Imagine you're walking along a beach, talking to your friend, enjoying the sunshine. Time goes by and it's time to head back. But as you approach the headland you had walked around previously, you realize that's not possible anymore: the tide has come in and there is no path around it now. You're trapped in a bay with the tide continuing to submerge the beach.

A new review led by the MARUM—Center for Marine Environmental Sciences at the University of Bremen—highlights how hydrothermal vents on the seafloor shape iron availability and influence the global oceanic element cycles. The review study, titled "Iron's Irony," has been published in Communications Earth & Environment.

Ten years ago, close to 200 nations signed the Paris Agreement, an international treaty designed to cut greenhouse gas emissions and curtail global warming. Under the treaty, most nations made a 15-year promise to reduce emissions.

Source: AGU Advances

The ocean has helped mitigate global warming by absorbing around a quarter of anthropogenic carbon dioxide (CO2) emissions, along with more than 90% of the excess heat those emissions generate.

Many efforts, including assessments by the Intergovernmental Panel on Climate Change, have looked at how the oceans may continue to mitigate increasing emissions and global warming. However, few have looked at the opposite: How will the oceans respond if emissions and associated atmospheric heat levels begin to decrease in response to net negative emissions?

Frenger et al. examined what might happen in the Southern Ocean if after more than a century of human-induced warming, global mean temperatures were to be reduced via CO2 removal from the atmosphere. The Southern Ocean is a dynamic system, with large-scale upwelling and a robust ability to take up excess carbon and heat. To better understand how the Southern Ocean will behave in net negative carbon conditions, the researchers modeled how the ocean and the atmosphere would interact.

They used the University of Victoria climate model, UVic v. 2.9, to simulate multicentury timescales and carbon cycle feedbacks. UVic uses a combination of an atmospheric energy–moisture balance model, an ocean circulation and sea ice model, a land biosphere model, and an ocean biochemistry model. The researchers used UVic to model an idealized climate change scenario commonly used in climate modeling: Emissions increase until atmospheric CO2 levels double after 70 years, followed by a steep emissions cut and subsequent sustained net negative emissions.

The results showed that after several centuries of net negative emissions levels and gradual global cooling, the Southern Ocean abruptly released a burst of accumulated heat—an oceanic “burp”—that led to a decadal- to centennial-scale period of warming. This warming was comparable to average historical anthropogenic warming rates. The team said that because of seawater’s unique chemistry, this burp released relatively little CO2 along with the heat.

Frenger and colleagues note that their work uses a model with intermediate-level complexity and an idealized climate change scenario, but that their findings were consistent when tested with other modeling setups. They say the Southern Ocean’s importance to the global climate system, including its role in heat release to the atmosphere in a cooling climate, should be studied further and contemporary changes closely monitored. (AGU Advances, https://doi.org/10.1029/2025AV001700, 2025)

—Sarah Derouin (@sarahderouin.com), Science Writer

Citation: Derouin, S. (2025), The Southern Ocean may be building up a massive burp, Eos, 106, https://doi.org/10.1029/2025EO250385. Published on 20 October 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.

Tropical inland waters don't produce as many greenhouse gas (GHG) emissions as previously estimated, according to the results of an international research collaboration led by Charles Darwin University (CDU).

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

The Community Science Exchange was founded in 2021 to elevate the work of scientists, scholars and community members collectively engaged in participatory science and to broaden the reach of their discoveries, results and science-based solutions. Now more than ever, we would like to recognize the importance of the work of the Community Science Exchange in fostering an inclusive scientific community and strengthening public trust in science. Here, we highlight the publication outlets offered by the Community Science Exchange and encourage the AGU community to contribute.     

The Community Science Exchange aims to encourage, foster, and promote co-production between science and community.

Within equitable participatory science, or a collective scientific endeavor giving significant voice and weight to both science and publics, the Community Science Exchange defines “community” variously as place-based, a group defined by a shared culture or heritage, and/or a group defined by a shared experience. From environmental concerns to public health, anthropology to engineering, the Community Science Exchange aims to encourage, foster, and promote co-production between science and community. To aid in the integration of local knowledge and lived experience, the Community Science Exchange specifically includes community voice in its publications: as authors, in sections devoted to community description and community impact, and in quotes from community members involved in and/or affected by the work. Scientists and academic scholars with an interest in elevating their community partners within their publications instead of hiding them in an acknowledgment should consider publication within the Exchange.

The American Geophysical Union hosts the Community Science Exchange with further support and guidance from five partnership organizations: the American Anthropological Association (AAA), the American Public Health Association (APHA), the Association for Advancing Participatory Sciences (AAPS), the Unión Geofísica Mexicana (UGM), and Wiley. To broaden the publication venues for community members and organizations, practitioners, boundary spanners, and others who may not receive career benefits from scientific journal publication, the Community Science Exchange has created two new avenues for those who want to publish and share their work: the journal Community Science and the online publication venue managed by AGU, the Hub.

Since its first issue in June 2022, Community Science has published articles discussing a variety of topics of interest to communities and scientists, including water quality, plastic pollution, language as a barrier to equitable access to scientific literature, and integration of Indigenous knowledge in shellfish monitoring. Community Science has also participated in several special collections, including on air quality, equitable co-production, and sustainable agriculture. Growing steadily in submissions, Community Science received the PROSE Award for Journals from the Princeton University Press in 2024. The journal is open access, allowing anyone to read the work published for free.

As a peer-reviewed journal, manuscripts go through an evaluation and revision process to ensure that research published in the journal rigorously advances both science and community outcomes. Like the other journals within the AGU journal portfolio, those who review for Community Science are welcome to invite a co-reviewer. This endeavor can help early career researchers to become thorough and constructive reviewers, and can invite experienced community organizers, boundary spanners and those with relevant lived expertise to engage in thoughtful reviews complementary to scientific review. Publications in both Community Science and the Hub are periodically featured in Editor’s Highlights, in which editors explain what they found exciting about a work, or in Research Spotlights, which are written by Eos’ professional science writers and feature recent newsworthy work. These features offer a more approachable point of entry to explore the science.

Unlike any other journal in the AGU portfolio, the Community Science Exchange also supports an alternate publication venue – the Hub – which is hosted on the Community Science Exchange website. Broadening the definition and understanding of scientific research, work, and resources, the Hub seeks to deepen the connection between science and community.

The Hub is home to a wide variety of content, including stand-alone submissions that are intentionally written outside of the strictures of a scientific journal format.

The Hub is home to a wide variety of content, including stand-alone submissions that are intentionally written outside of the strictures of a scientific journal format, to “complementary materials” allowing journal paper authors to enrich their articles with linked materials furthering community voice. Although the Hub isn’t a scholarly journal in the traditional sense, all submissions are editor-vetted before potential revision and publication. Any new, original content published on the Hub is now eligible to receive a permanent digital object identifier (DOI) allowing it to be cited in the references of scholarly publications and other content.

Authors can submit materials to the Hub that fall into one of four categories:

Project Descriptions are narratives of work done, or even more formalized case studies. They should include a description of the community involved, an explanation of the community knowledge utilized, and a summary of the work done. Example: Climate Safe Neighborhoods [Project Description] (doi.org/10.1029/2024CSE000101)

Protocols and Methods are for describing how the community science work was done. These could be practiced approaches, descriptions of relevant policies to be considered, or outlines of project development.

Tools and Resources are items that can help others along on their own community science work, such as datasets or visualization tools. Even descriptions of useful apps that would be helpful would be welcome.

Educational Materials are items geared toward educating or training about community science practices. These could include instruction manuals, guidebooks, or even workshop or webinar curricula.

Because the Hub is a living initiative, evolving with the needs and desires of the community, submissions that don’t cleanly fit into any one of these categories will still be considered.

If you are interested in joining in the Community Science Exchange’s efforts to expand how we view, publish, and share science, please email us at communitysci@agu.org. Whether you have a resource to submit to the Hub, an article to submit to the journal, want to be a reviewer, or even want to apply to be an editor – we’d love to hear from you.

Finally, we want to thank all of those who have served as editors of this initiative so far, both past and present (starred are original editorial board members):

• Julia Parrish*, current Editor-in-Chief
• Kathryn Semmens*, current Deputy Editor of the Hub
• Claire Beveridge*, current editor
• Gillian Bowser, current editor
• Muki Haklay*, current editor
• Rajul Pandya, current editor
• Jean Schensul*, founding Deputy Editor, current editor
• Kevin Noone*, founding Editor-in-Chief, past editor
• Paula Buchanan*, founding Deputy Editor, past editor
• Shobhana Gupta*, past editor
• Heidi Roop*, past editor
• Roopam Shukla*, past editor

—Allison Schuette (aschuette@agu.org, 0009-0007-1055-0937), Program Coordinator, AGU Publications; Julia Parrish (0000-0002-2410-3982), Editor-in-Chief, Community Science Exchange; Kathryn Semmens (0000-0002-8822-3043), Deputy Editor, The Hub; Kristina Vrouwenvelder (0000-0002-5862-2502), Assistant Director, AGU Publications; and Sarah Dedej (0000-0003-3952-4250), Assistant Director, AGU Publications

Citation: Schuette, A., J. Parrish, K. Semmens, K. Vrouwenvelder, and S. Dedej (2025), Publishing participatory science: the Community Science Exchange, Eos, 106, https://doi.org/10.1029/2025EO255032. Published on 20 October 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.

SummaryWe present and validate an efficient GPU-accelerated solver for seismic wave propagation in three-dimensional elastic media. The solver achieves up to a 372× speedup relative to a CPU implementation and supports forward simulations on grids ranging from 100 million to 1 billion cells. It is based on a velocity-stress, first-order formulation of the elastodynamic wave equation and supports kilometer-scale models with layered isotropic and anisotropic structure. We validate the solver by comparing synthetic seismograms to analytical solutions from a propagator matrix method in axisymmetric media. Simulations include moment-tensor sources for a 2017 nuclear explosion and collapse in North Korea, and a magnitude ∼4 earthquake near Linthal, Switzerland (6 March 2017). Anisotropic effects for the Swiss event are modeled using rotated orthorhombic stiffness tensors derived from laboratory measurements of gneiss. Projection onto orthorhombic symmetry enables solver compatibility. We find that anisotropy changes waveform polarity, amplitude, and phase at near-source stations. Unscaled laboratory values produce polarity reversals, while velocity-rescaled tensors correct them. These results demonstrate the impact of anisotropy on waveform modeling and indicate that simplified 1D isotropic models may be insufficient for complex crustal settings. We review how structural effects, including anisotropy and 3D heterogeneity, contribute to transverse-component energy in the 2017 DPRK explosion and discuss implications for seismic source classification.

Publication date: 15 October 2025

Source: Advances in Space Research, Volume 76, Issue 8

Author(s): Muhammed Yusuf Ozturk, Ismail Colkesen

Publication date: 15 October 2025

Source: Advances in Space Research, Volume 76, Issue 8

Author(s): Mahdi Sadeghi Pour Marvi, Somayeh Moharami

Publication date: 15 October 2025

Source: Advances in Space Research, Volume 76, Issue 8

Author(s): Tian Liang, Yinyin Chen, Xueting Lu, Yu Zhou, Yanli Mao, Fei Yang

Publication date: 15 October 2025

Source: Advances in Space Research, Volume 76, Issue 8

Author(s): Yingping Long, Hongwei Ding, Yuanjing Zhu, Zhijun Yang, Bo Li

Publication date: 15 October 2025

Source: Advances in Space Research, Volume 76, Issue 8

Author(s): Ozge Gunes, Cuneyt Aydin

Publication date: 15 October 2025

Source: Advances in Space Research, Volume 76, Issue 8

Author(s): Abdelhalim S. Mahmoud, Adel Fathy, Ahmed A. Masoud, Ahmed M. Abdelhameed, Mokhles K. Azer

Climate models suggest that climate change could reduce the Southern Ocean's ability to absorb carbon dioxide (CO2). However, observational data actually shows that this ability has seen no significant decline in recent decades.