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Watershed Sustainability Project Centers Place-Based Research

EOS - Thu, 12/04/2025 - 14:14
Source: Community Science

The Xwulqw'selu Sta'lo' (Koksilah River) is a culturally important river to the Cowichan Tribes, located on traditional Quw'utsun land on Vancouver Island, British Columbia. The land, which was never ceded to Canada, is part of a watershed that faces challenges including decreasing salmon populations, low river flow, flooding, and land use changes.

Gleeson et al. are working with the Cowichan Tribes and the provincial government to collaborate on the first water sustainability plan in British Columbia. About halfway through their 5-year project, the researchers are sharing how their work is guided by five “woven statements,” representing their intentions and values. These statements include a commitment to uphold Quw'utsun rights and laws, an intention that community-based monitoring and modeling will inform water and land decisions about the river, and a commitment by researchers to share their practices and outcomes. Just like the horizontal wefts and vertical warps in traditional Coast Salish weaving practices, these statements overlap and connect with their research goals, projects, and partnerships.

The research project has three goals: to improve understanding of current and future low flows in the Xwulqw'selu Sta'lo' through community science; to promote community engagement with water science, water governance, and Indigenous Knowledge; and to examine how this community science work can be useful to shared watershed management.

To accomplish these goals, the researchers use traditional scientific practices deeply grounded in the river itself. The community science project includes hydrological monitoring, modeling of low river flows, and quantification of groundwater flows into the river. In 2024, 44 volunteers participated in the community science project.

The 5-year project is part of the larger Xwulqw'selu Connections program, which supports a shift toward water cogovernance between the Cowichan Tribes and the provincial government through the Xwulqw'selu Water Sustainability Plan. The program could inform other community science collaborations between governments and Indigenous peoples, the authors say. (Community Science, https://doi.org/10.1029/2024CSJ000120, 2025)

—Madeline Reinsel, Science Writer

Citation: Reinsel, M. (2025), Watershed sustainability project centers place-based research, Eos, 106, https://doi.org/10.1029/2025EO250439. Published on 4 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.

Changes in Slab Dip Cause Rapid Changes in Plate Motion

EOS - Thu, 12/04/2025 - 14:00
Editors’ Highlights are summaries of recent papers by AGU’s journal editors. Source: Journal of Geophysical Research: Solid Earth

Reconstructing the direction and rate of motion of tectonic plates is essential for understanding deformation within and between plates and for evaluating the geodynamical drivers of plate tectonics. One debate concerns the relative importance of flow in the asthenosphere versus processes at plate boundaries in controlling the motion of tectonic plates.

Wilson and DeMets [2025] present the most detailed reconstruction of changes in motion of the Nazca Plate to date. Remarkably, their results show periods of constant motion separated by geologically short periods of rapid acceleration or deceleration. These changes coincide with changes in the dip of the Nazca plate where it subducts beneath South America, with decelerations occurring when multiple regions of the slab shallowed to anomalously low dips (“flat slab subduction”), and accelerations occurring when the slab deepened to normal dips.  These results imply that changes in the forces acting between plates are an important control on plate motion.

Citation: Wilson, D. S., & DeMets, C. (2025). Changes in motion of the Nazca/Farallon plate over the last 34 million years: Implications for flat-slab subduction and the propagation of plate kinematic changes. Journal of Geophysical Research: Solid Earth, 130, e2025JB031933. https://doi.org/10.1029/2025JB031933

—Donna Shillington, Associate Editor, JGR: Solid Earth

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

Why the Amazon's ability to make its own rain matters more than ever

Phys.org: Earth science - Thu, 12/04/2025 - 13:17
Dr. Magali Nehemy stood on the banks of the Tapajós River in the Amazon rainforest when the community's chief—a man in his seventies who had lived there his whole life—looked out over the bare shoreline and shook his head.

K'gari's world famous lakes could be at risk of drying

Phys.org: Earth science - Thu, 12/04/2025 - 12:42
K'gari is the world's largest sand island and known for its world-famous lakes, but research from the University of Adelaide has discovered its largest lakes could be vulnerable to drying.

Sargasso Sea shift reveals dramatic decline in some historic seaweed populations

Phys.org: Earth science - Thu, 12/04/2025 - 10:00
A study led by researchers at the University of South Florida's College of Marine Science has found that certain populations of the seaweed sargassum have experienced a significant decline over the past decade, even as increased abundance of sargassum in the tropical Atlantic has caused large mats of the seaweed to inundate beaches across the Caribbean and Gulf regions.

Degraded peatlands emit nearly twice as much greenhouse gas as previously thought, study finds

Phys.org: Earth science - Thu, 12/04/2025 - 02:00
For the first time, researchers have produced a detailed, high-resolution map of peatlands in the EU, showing that these areas emit twice as much greenhouse gases than previously thought. The research, led by eco-hydrologist Quint van Giersbergen of Radboud University, has been published in Nature Communications.

Enhanced Scholte-wave characterization of marine sediments through dispersion-spectrum McMC inversion

Geophysical Journal International - Thu, 12/04/2025 - 00:00
SummaryThis study proposes a dispersion-spectrum inversion method for improved estimation of shear-velocity (VS) profiles in marine sediments using underwater multichannel analysis of surface waves (UMASW). The method leverages an efficient forward modeling algorithm combined with a Markov chain Monte Carlo (McMC) global search to address the nonlinearity inherent in the inversion process. Comparisons with field and synthetic data demonstrate that the VS profiles inverted using the full dispersion spectrum (in terms of the frequency-phase velocity spectrum, FVS) exhibit greater stability and reliability than those obtained through traditional fundamental-mode (FM) inversion. Pseudo two-dimensional VS profiles are constructed by interpolating one-dimensional profiles obtained from the FVS-McMC inversion, showing more continuous subsurface interfaces that align with borehole data. Parametric studies further highlight the influence of Poisson’s ratio, water layer thickness, and VS contrast on the dispersion behavior, underscoring the robustness of the proposed approach for offshore site characterization.

Trump Proposes Weakening Fuel Economy Rules for Vehicles

EOS - Wed, 12/03/2025 - 21:09
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 the White House today, President Donald Trump announced his administration would “reset” vehicle fuel economy standards. Trump said the administration plans to revoke tightened standards, also known as Corporate Average Fuel Economy (CAFE) standards, set by President Joe Biden in 2024.

“We’re bringing back the car industry that was stolen from us.”

“We are officially terminating Joe Biden’s ridiculously burdensome—horrible, actually—CAFE standards that imposed expensive restrictions and all sorts of problems, all sorts of problems, to automakers,” Trump said. “We’re bringing back the car industry that was stolen from us.”

Automobile executives from Ford, General Motors (GM), and Stellantis joined federal officials, including Department of Transportation Secretary Sean Duffy, at the announcement. The administration said, without providing evidence during today’s announcement, that the current CAFE standards have increased vehicle prices and estimated that changing those standards would save American families $109 billion in total.

Vehicle fuel efficiency standards, which set the average gas mileage that vehicles must achieve, have been in place since 1975. The standards were most recently tightened in June 2024 by the Biden administration, and required automakers to ensure vehicles achieved an average fuel efficiency of about 50.4 miles per gallon by model year 2031. The Biden administration estimated that the rule would lower fuel costs by $23 billion and prevent the emission of more than 710 million metric tons of carbon dioxide by 2050. 

Fuel economy standards have significantly reduced greenhouse gas emissions from vehicles, which are one of the largest sources of carbon emissions in the United States. According to one estimate, fuel economy improvements spurred by the standards have avoided 14 billion tons of greenhouse gas emissions since 1975. 

However, Duffy said, the current standards are “completely unattainable” for automakers.

The announcement did not specify the degree to which the administration would lower the standards.

 
Related

Weakening fuel economy rules for vehicles is the latest step in President Trump’s continued efforts to slow the adoption of electric vehicles and boost the fossil fuel industry. 

Trump’s One Big Beautiful Bill, the omnibus spending bill that became law in July, also eliminated fines for automakers that did not comply with fuel economy standards. The Environmental Protection Agency is also expected to weaken limits of greenhouse gas emissions from vehicles by finalizing the repeal of the 2009 Endangerment Finding, which underpins important federal climate regulations, early next year. 

Policy advocates said weakening the standards would slow the transition to electric vehicles and make the U.S. vehicle market less competitive. “While Trump tells G.M., Ford and others that they needn’t make gas-saving cars, China is telling its carmakers to take advantage of the lack of U.S. competition and accelerate their efforts to grab the world’s burgeoning clean car market,” Dan Becker, director of the Safe Climate Transport Campaign at the Center for Biological Diversity, told The New York Times

However, automakers supported the proposal. “As America’s largest auto producer, we appreciate President Trump’s leadership in aligning fuel economy standards with market realities,” Jim Farley, Ford’s CEO, told Fox News.

“Today is a victory of common sense and affordability,” Farley, who attended the announcement, said. 

The Transportation Department will solicit public comments about the rule and is expected to finalize it next year.

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

Editorial Board

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s):

Correlative isotope excursions driven by transport, not global environmental change

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Connor S. van Wieren, Blake Dyer, Jon M. Husson

A whole-rock geochemistry-based semi-quantitative proxy for magmatic oxygen fugacity

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Ze Liu, Oliver Jagoutz, Hervé Rezeau, Hong-Luo L. Zhang, Benjamin Klein, Zoe Molitor, Xu-Yang Meng, Di-Cheng Zhu

Modeling magma viscosity and ascent dynamics of the 472 CE sub-Plinian eruption of Somma-Vesuvius (Italy)

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Serena Dominijanni, Laura Calabrò, Emily C. Bamber, Gabriele Giuliani, Dmitry Bondar, Pedro Valdivia, Fabio Arzilli, Giuseppe La Spina, Alexander Kurnosov, Alessandro Vona, Alessandro Longo, Danilo Di Genova

Trace element proxies in seamount olivine reveal the ‘missing pyroxenite’ and refertilized peridotite mantle beneath the East Pacific Rise

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Peng Jiang, Michael R. Perfit, Molly K. Anderson, George Kamenov, Andres Trucco

Mechanism of incorporation of fallout <sup>7</sup>Be, <sup>210</sup>Pb and <sup>210</sup>Po in sediment-laden ice from Lake St. Clair, SE Michigan, during snowstorms: Analogy to that in the Arctic Ocean

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Mark Baskaran, Lathan Saperstein, Max Denny

Dynamics and thermal survival of delaminated orogenic lithosphere in deep mantle

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Zhenhui Cao, Huilin Wang, Jiakuan Wan, Chen Yang

The lithosphere - asthenosphere system seen by surface waves: New insights from radial anisotropy

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): S. Durand, E. Debayle, Y. Ricard

Non-equilibrium behavior of trace elements during zircon crystallization from the melt

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Ilya Bindeman, Oleg Melnik

Neon isotopes in individual vesicles of Icelandic basaltic glasses: Insights into the origin of light volatile elements on earth

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Romain Sauvalle, Manuel Moreira, Bruno Scaillet

Significant crustal uplift attributed to contemporary glacier loss over laterally heterogeneous mantle

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Zhengyang Wang, Wei Feng, Zhongshan Jiang, Zhou Wu, Baoming Tian, Haipeng Luo, Min Zhong, Hao Wei

Density and viscosity variations due to plume melting of a bilithologic mantle: Implications for asthenosphere and hotspot swell root dynamics

Earth and Planetary Science Letters - Wed, 12/03/2025 - 19:11

Publication date: January 2026

Source: Earth and Planetary Science Letters, Volume 673

Author(s): Jia Shao, Jason P. Morgan

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