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Comparison of earthquake early warning systems and the national volcano early warning system at the U.S. Geological Survey

IntroductionEvery year in the United States, natural hazards threaten lives and livelihoods, resulting in thousands of casualties and billions of dollars in damage. The U.S. Geological Survey (USGS) Natural Hazards Mission Area works with many partners to monitor, assess, and research a wide range of natural hazards, including earthquakes and volcanic eruptions. These efforts aim to enhance commun
Aleeza Wilkins, Charlie Mandeville, John Power, Doug Given

Scaling microseismic cloud shape during hydraulic stimulation using in-situ stress and permeability

Forecasting microseismic cloud shape as a proxy of stimulated rock volume may improve the design of an energy extraction system. The microseismic cloud created during hydraulic stimulation of geothermal reservoirs is known empirically to extend in the general direction of the maximum principal stress. However, this empirical relationship is often inconsistent with reported results, and the cloud g
Y. Mukuhira, M. Yang, T. Ishibashi, K. Okamoto, H. Moriya, Y. Kumano, H. Asanuma, S.A. Shapiro, Justin Rubinstein, T. Ito, K. Yan, Y. Zuo

Converted-wave reverse time migration imaging in subduction zone settings

We use a newly developed 2-D elastic reverse time migration (RTM) imaging algorithm based on the Helmholtz decomposition to test approaches for imaging the descending slab in subduction zone regions using local earthquake sources. Our elastic RTM method is designed to reconstruct incident and scattered wavefields at depth, isolate constituent P- and S-wave components via Helmholtz decomposition, a
Leah Langer, Fred Pollitz, Jeffrey McGuire

Accuracy of finite fault slip estimates in subduction zone regions with topographic Green's functions and seafloor geodesy

Until recently, the lack of seafloor geodetic instrumentation and the use of unrealistically simple, half-space based forward models have resulted in poor resolution of near-trench slip in subduction zone settings. Here, we use a synthetic framework to investigate the impact of topography and geodetic data distribution on coseismic slip estimates in various subduction zone settings. We calculate s
Leah Langer, Théa Ragon

Slip deficit rates on southern Cascadia faults resolved with viscoelastic earthquake cycle modeling of geodetic deformation

The fore‐arc of the southern Cascadia subduction zone (CSZ), north of the Mendocino triple junction (MTJ), is home to a network of Quaternary‐active crustal faults that accumulate strain due to the interaction of the North American, Juan de Fuca (Gorda), and Pacific plates. These faults, including the Little Salmon and Mad River fault (LSF and MRF) zones, are located near the most populated parts
Kathryn Zerbe Materna, Jessica R. Murray, Fred Pollitz, Jason R. Patton

A detailed view of the 2020-2023 southwestern Puerto Rico seismic sequence with deep learning

The 2020–2023 southwestern Puerto Rico seismic sequence, still ongoing in 2023, is remarkable for its multiple‐fault rupture complexity and elevated aftershock productivity. We applied an automatic workflow to continuous data from 43 seismic stations in Puerto Rico to build an enhanced earthquake catalog with ∼180,000 events for the 3+ yr sequence from 28 December 2019 to 1 January 2023. This work
Clara Yoon, Elizabeth S. Cochran, Elizabeth A. Vanacore, Victor Huerfano, Gisela Báez-Sánchez, John D. Wilding, Jonathan D. Smith

Witnessing history: Comparison of a century of sedimentary and written records in a California protected area

We use a combination of proxy records from a high-resolution analysis of sediments from Searsville Lake and adjacent Upper Lake Marsh and historical records to document over one and a half centuries of vegetation and socio-ecological change—relating to logging, agricultural land use change, dam construction, chemical applications, recreation, and other drivers—on the San Francisco Peninsula. A rel
R. Scott Anderson, M. Allison Stegner, SeanPaul La Selle, Brian L. Sherrod, Anthony D. Barnosky, Elizabeth A. Hadly

Introduction to the digitization of seismic data: A user’s guide

Modern seismic data are collected, distributed, and analyzed using digital formats, and this has become a standard for the field. Although most modern seismometers still make use of analog electronic circuits, their data are converted from an analog voltage output to time‐tagged counts by way of digitization. Although much of the digitization process is not complicated to conceptualize, there is a
Adam T. Ringler, Robert E. Anthony, Patrick Bastien, Adam Pascale, Bion J. Merchant

Rapid characterization of the February 2023 Kahramanmaraş, Turkey, earthquake sequence

The 6 February 2023 Mw 7.8 Pazarcık and subsequent Mw  7.5 Elbistan earthquakes generated strong ground shaking that resulted in catastrophic human and economic loss across south‐central Türkiye and northwest Syria. The rapid characterization of the earthquakes, including their location, size, fault geometries, and slip kinematics, is critical to estimate the impact of significant seismic events.
Dara Elyse Goldberg, Tuncay Taymaz, Nadine G. Reitman, Alexandra Elise Hatem, Seda Yolsal-Çevikbilen, William D. Barnhart, Tahir Serkan Irmak, David J. Wald, Taylan Öcalan, William L. Yeck, Berkan Özkan, Jessica Ann Thompson Jobe, David R. Shelly, Eric M. Thompson, Christopher DuRoss, Paul S. Earle, Richard W. Briggs, Harley M. Benz, Ceyhun Erman, Ali Hasan Doğan, Cemali Altuntaş

Laboratory simulation of earthquake-induced damage in lava dome rocks

Earthquakes can impart varying degrees of damage and permanent, inelastic strain on materials, potentially resulting in ruptures that may promote hazards such as landslides and other collapse events. However, the accumulation of damage in rocks under the frequency and amplitude of shaking experienced during earthquake events is rarely systematically measured due to technical limitations. Here, we
Lauren N. Schaefer, Jackie E. Kendrick, Yan Lavallée, Jenny Schauroth, Oliver D. Lamb, Anthony Lamur, Takahiro Miwa, Ben M. Kennedy

Comparison of nonergodic ground-motion components from CyberShake and NGA-West2 datasets in California

In this study, we compare the Southern California Earthquake Center CyberShake platform against the Next Generation Attenuation‐West2 empirical datasets. Because the CyberShake and empirical datasets cover very different magnitude ranges and site conditions, we develop ground‐motion models (GMMs) for CyberShake datasets to compare trends with empirical GMMs and decompose the residuals for further
Xiaofeng Meng, Christine Goulet, Kevin R. Milner, Robert Graves, Scott Callaghan