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Earthquake early warning: Toward modeling optimal protective actions

Over the past few years early earthquake warning systems have been incorporated into earthquake preparation efforts in many locations around the globe. These systems provide an excellent opportunity for advanced warning of ground shaking and other hazards associated with earthquakes. This study aims to optimize this advanced warning for individuals inside a building when the alert is received. A c
Authors
M. Wood, X. Zhang, X. Zhao, Sara McBride, Nicolas Luco, D. Baldwin, T. Covas

2018 M7.1 Anchorage and 2021 M7.2 Nippes, Haiti earthquake case studies for Virtual Earthquake Reconnaissance Team (VERT) activation protocols, policies, and procedures to gather earthquake response footage

The collection of online videos and imagery to use in disaster reconnaissance is increasing in frequency, due to accessibility of platforms and the ubiquitous nature of smartphones and recording devices. In this short article, we explore the processes, goals, and utility of Virtual Emergency Reconnaissance Teams (VERTs) to collect footage and imagery of geohazards (earthquakes, volcanoes, tsunamis
Authors
Sara McBride, J. Bellizzi, S. Gin, G. Henry, D. F. Sumy, D. Baldwin, E. Fischer

Update on the Center for Engineering Strong-Motion Data (CESMD)

he Center for Engineering Strong-Motion Data (CESMD), an internationally utilized joint center of the U.S. Geological Survey (USGS) and the California Geological Survey (CGS), provides a unified access point for earthquake strong-motion records and station metadata from the CGS California Strong-Motion Instrumentation Program (CSMIP), the USGS National Strong-Motion Project (NSMP), the USGS Advanc
Authors
L. Hagos, H. Haddadi, Lisa Sue Schleicher, Jamison Haase Steidl, Lind Gee, M. Dhar

Western U.S. deformation models for the 2023 update to the U.S. National Seismic Hazard Model

This report describes geodetic and geologic information used to constrain deformation models of the 2023 update to the National Seismic Hazard Model (NSHM), a set of deformation models to interpret these data, and their implications for earthquake rates in the western United States. Recent updates provide a much larger data set of Global Positioning System crustal velocities than used in the 2014
Authors
Fred Pollitz, Eileen L. Evans, Edward H. Field, Alexandra Elise Hatem, Elizabeth H. Hearn, Kaj M Johnson, Jessica R. Murray, Peter M. Powers, Zheng-Kang Shen, Crystal Wespestad, Yuehua Zeng

GPS velocity field of the Western United States for the 2023 National Seismic Hazard Model update

Global Positioning System (GPS) velocity solutions of the western United States (WUS) are compiled from several sources of field networks and data processing centers for the 2023 U.S. Geological Survey National Seismic Hazard Model (NSHM). These solutions include both survey and continuous‐mode GPS velocity measurements. I follow the data processing procedure of Parsons et al. (2013) for the Unifo
Authors
Yuehua Zeng

Viscoelastic fault-based model of crustal deformation for the 2023 update to the U.S. National Seismic Hazard Model

The 2023 update to the National Seismic Hazard (NSHM) model is informed by several deformation models that furnish geodetically estimated fault slip rates. Here I describe a fault‐based model that permits estimation of long‐term slip rates on discrete faults and the distribution of off‐fault moment release. It is based on quantification of the earthquake cycle on a viscoelastic model of the seismo
Authors
Fred Pollitz

Earthquakes in the shadows: Why aftershocks occur at surprising locations

For decades there has been a debate about the relative effects of dynamic versus static stress triggering of aftershocks. According to the static Coulomb stress change hypothesis, aftershocks should not occur in stress shadows—regions where static Coulomb stress has been reduced. We show that static stress shadows substantially influence aftershock occurrence following three M ≥ 7 California mains
Authors
Jeanne L. Hardebeck, Ruth A. Harris

Using machine learning techniques with incomplete polarity datasets to improve earthquake focal mechanism determination

Earthquake focal mechanisms are traditionally produced using P‐wave first‐motion polarities and commonly require well‐recorded seismicity. A recent approach that is less dependent on high signal‐to‐noise exploits similar waveforms to produce relative polarity measurements between earthquake pairs. Utilizing these relative polarity measurements, it is possible to produce composite focal mechanisms
Authors
Robert Skoumal, David R. Shelly, Jeanne L. Hardebeck

Impact of sedimentary basins on Green’s functions for static slip inversion

Earthquakes often occur in regions with complex material structure, such as sedimentary basins or mantle wedges. However, the majority of co-seismic modelling studies assume a simplified, often homogeneous elastic structure in order to expedite the process of model construction and speed up calculations. These co-seismic forward models are used to produce Green’s functions for finite-fault inversi
Authors
Leah Langer, Stephen Beller, Evan Tyler Hirakawa, Jeroen Tromp

Revised earthquake recurrence intervals in California, USA: New paleoseismic sites and application of event likelihoods

Recurrence intervals for ground rupturing earthquakes are critical data for assessing seismic hazard. Recurrence intervals are presented here for 38 paleoseismic sites in California. Eleven of these include new or updated data; the remainder use data previously included in the Unified California Earthquake Rupture Forecast Version 3 (UCERF3). The methods and results are consistent with UCERF3. In
Authors
Devin McPhillips

Quantifying modeling uncertainty in simplified beam models for building response prediction

The use of simple models for response prediction of building structures is preferred in earthquake engineering for risk evaluations at regional scales, as they make computational studies more feasible. The primary impediment in their gainful use presently is the lack of viable methods for quantifying (and reducing upon) the modeling errors/uncertainties they bear. This study presents a Bayesian ca
Authors
S. Farid Ghahari, Khachik Sargsyan, Mehmet Çelebi, Ertugrul Taciroglu