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Rapid characterization of the 2025 Mw 8.8 Kamchatka, Russia earthquake Rapid characterization of the 2025 Mw 8.8 Kamchatka, Russia earthquake

The 29 July 2025 Mw 8.8 Kamchatka, Russia, earthquake was the sixth largest instrumentally recorded earthquake. This event was seismically well observed at regional and teleseismic distances, but publicly available near‐source data were sparse at the time of the event, presenting unique challenges for rapid source and impact characterization. The U.S. Geological Survey (USGS) National...
Authors
Harriet Zoe Yin, Kate E. Allstadt, William D Barnhart, Samantha Ann Clapp, Paul S. Earle, Dara Elyse Goldberg, Alex R. Grant, Matt Herman, Kishor S. Jaiswal, Sara K. McBride, Adam T. Ringler, Max Schneider, Eric M. Thompson, Nicholas van der Elst, David Wald, Dun Wang, Charles Worden, William L. Yeck

Capturing the uncertainty of seismicity observations in earthquake rate estimates: Implications for probabilistic seismic hazard analysis and the USGS National Seismic Hazard Model Capturing the uncertainty of seismicity observations in earthquake rate estimates: Implications for probabilistic seismic hazard analysis and the USGS National Seismic Hazard Model

The rate of earthquakes in a region is a fundamental input to Probabilistic Seismic Hazard Analysis. We present a Monte Carlo method for computing that rate from seismicity catalogs while including a range of data and analysis uncertainties. This method is applied to regions for which the b value is assumed to be spatially invariant. Each region is broken down into epochs for which each...
Authors
Andrew J. Michael, Andrea L. Llenos

Using gridded seismicity to forecast the long-term spatial distribution of earthquakes for the 2025 Puerto Rico and U.S. Virgin Islands National Seismic Hazard Model Using gridded seismicity to forecast the long-term spatial distribution of earthquakes for the 2025 Puerto Rico and U.S. Virgin Islands National Seismic Hazard Model

Gridded (or background) seismicity models are a critical component of probabilistic seismic hazard assessments, accounting for off‐fault and smaller‐magnitude earthquakes. They are typically developed by declustering and spatially smoothing an earthquake catalog to estimate a long‐term seismicity rate that can be used to forecast future earthquakes. Here, we present new gridded...
Authors
Andrea L. Llenos, Andrew J. Michael, Kirstie Lafon Haynie, Allison Shumway, Julie A. Herrick

High frequency and region-scale simulations of large (Mw7+) earthquakes on the southern Whidbey Island fault, Washington, USA High frequency and region-scale simulations of large (Mw7+) earthquakes on the southern Whidbey Island fault, Washington, USA

We simulate ground shaking in western Washington State from hypothetical Mw7.0–7.5 earthquakes on the southern Whidbey Island fault (SWIF). Ground motions are modeled considering kinematic source distributions on a complex fault plane, a 3D seismic velocity model, and region‐specific soil velocity models. We run simulations with varying model resolutions, including regional‐scale...
Authors
Ian P. Stone, Erin A. Wirth, Alex R. Grant, Arthur D. Frankel

Memory and jamming in fault zone sediments Memory and jamming in fault zone sediments

Many subsurface processes involve transitions in granular material states, from arrested to creeping to flowing. Experiments and frameworks for idealized systems reveal that granular fabrics develop during shearing, co-evolve with applied stress, and govern such transitions. We use microtomography to test whether fabrics at two San Andreas fault sites reflect slip history and whether...
Authors
Jhardel Dasent, Vashan Wright, Katherine M. Scharer, Michael Manga, Richard Kilburn

Ultramafic float rocks at Jezero crater (Mars): Excavation of lower crustal rocks or mantle peridotites by impact cratering? Ultramafic float rocks at Jezero crater (Mars): Excavation of lower crustal rocks or mantle peridotites by impact cratering?

Based on observation and data from meteorites and in situ scientific missions, experiments as well as models, the Martian mantle is assumed to share some compositional and mineralogical affinity with the terrestrial mantle. However, there might be subtle differences like the Martian mantle being more ferroan. Yet, we do not have any direct analysis of a Martian mantle rock to confirm...
Authors
O. Beyssac, E. Clave, O. Forni, A. Udry, A.C. Pascuzzo, E. Dehouck, P.S.A. Beck, L. Mandon, C. Quantin-Nataf, N. Mangold, G. Lopez-Reyes, C. Royer, O. Gasnault, Travis S.J. Gabriel, L.C. Kah, S. Schroder, J.R. Johnson, T. Bertrand, B. Chide, T. Fouchet, J.I. Simon, F. Montmessin, A. Fau, S. Maurice, R.C. Wiens, A. Cousin

Summer snow determines the depth to ice-cemented ground under dry permafrost in Antarctica Summer snow determines the depth to ice-cemented ground under dry permafrost in Antarctica

Dry permafrost underlain by ice-cemented permafrost has been reported in several locations in Antarctica. Initially thought to be relic ice, it is now understood that this subsurface ice is in equilibrium with the surface conditions, although it is not in equilibrium with the atmosphere. We use year-round data from University Valley in the Dry Valleys and Elephant Head in the Ellsworth...
Authors
C. P. McKay, M. Marinova, Kaj E. Williams, M. Mellon

Long‐period ground motions from dynamic rupture simulations of large earthquakes on the creeping Hayward–Calaveras–Rodgers Creek fault system Long‐period ground motions from dynamic rupture simulations of large earthquakes on the creeping Hayward–Calaveras–Rodgers Creek fault system

he Hayward, Calaveras, and Rodgers Creek faults in the San Francisco Bay region of California have a high probability of producing a large earthquake in the next decades. Although these faults creep, the creep is insufficient to keep up with their relatively rapid slip rates on their deepest sections, so they have been storing tectonic strain since their last large earthquakes, with the...
Authors
Ruth A. Harris, Michael Barall, Grace Alexandra Parker, Evan Tyler Hirakawa

Rare earth elements on the Moon Rare earth elements on the Moon

Rare earth elements (REEs) are a scarce but vital resource for our modern economies and lifestyles. Since the late 1990s, China has supplied the vast majority of the world’s refined REEs. Increasing global demand has broadened the search for REE deposits to unconventional places, including the Moon. Although most lunar rocks have very low REE concentrations, Apollo samples showed that...
Authors
Laszlo P. Keszthelyi, Joshua A. Coyan, Lori M. Pigue, Kristen A. Bennett, Travis S.J. Gabriel

Fiber-optic sensing for earthquake hazards research, monitoring and early warning Fiber-optic sensing for earthquake hazards research, monitoring and early warning

The use of fiber‐optic sensing systems in seismology has exploded in the past decade. Despite an ever‐growing library of ground‐breaking studies, questions remain about the potential of fiber‐optic sensing technologies as tools for advancing if not revolutionizing earthquake‐hazards‐related research, monitoring, and early warning systems. A working group convened to explore these topics...
Authors
Jeffrey J. McGuire, Andrew J. Barbour, Zack J. Spica, Verónica Rodríguez Tribaldos, Zhongwen Zhan, Bradley P. Lipovsky, Robert J. Mellors, Ettore Biondi, Clara Yoon, Martin Karrenbach, Adam T. Ringler, James William Atterholt, Avinash Nayak, Theresa Marie Sawi, Loic Viens, Eileen R. Martin, Allen L. Husker, Paul Bodin, Morgan P. Moschetti, Qibin Shi, Nathaniel C. Miller, Prisha Puri

Lessons from 40 years of communicating volcanic risk during crises Lessons from 40 years of communicating volcanic risk during crises

Since the 1985 Nevado del Ruiz eruption that killed over 23,000 people in Armero, Colombia, risk communication has become central to volcanic crisis management. Despite the development of effective tools and programmes for volcanic risk communication, considerable challenges remain.
Authors
Lara Mani, Jenni Barclay, Carina Fearnley, Richard E.A. Robertson, Blaise Mafuko Nyandwi, Sara Barsotti, Amy Donovan, Wendy K. Stovall

Potential for continental scientific drilling to inform fault mechanics and earthquake science Potential for continental scientific drilling to inform fault mechanics and earthquake science

Our understanding of fault mechanics and earthquake processes remains limited, largely due to minimal direct observations near active faults at seismogenic depths. This lack of data restricts our ability to accurately assess and mitigate both natural and human-induced seismic hazards. However, recent advancements in drilling capabilities and downhole sensing technologies offer an...
Authors
Elizabeth S. Cochran, Natalia Zakharova, Brett Carpenter, Folarin Kolawole, Nicholas W. Hayman, Hiroki Sone, Douglas R. Schmitt, Peter Eichhubl, William Ellsworth, Yves Guglielmi, Stephen H. Hickman, Harold J. Tobin
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