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On the ratio of full‐resonance to square‐root‐impedance amplifications for shear‐wave velocity profiles that are a continuous function of depth On the ratio of full‐resonance to square‐root‐impedance amplifications for shear‐wave velocity profiles that are a continuous function of depth

Amplifications of seismic waves traveling upward through a continuous, interface‐free velocity profile are consistently smaller when computed using the square‐root‐impedance (SRI) method than when computed using full‐resonance (FR) calculations. This was found for a wide range of velocity profiles. For realistic profiles, for which the gradient of velocity decreases with depth, the...
Authors
David Boore, Norm A Abrahamson

Comparison of nonergodic ground-motion components from CyberShake and NGA-West2 datasets in California 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...
Authors
Xiaofeng Meng, Christine Goulet, Kevin R. Milner, Robert Graves, Scott Callaghan

Rupture directivity of the 25 October 2022 Mw 5.1 Alum Rock earthquake Rupture directivity of the 25 October 2022 Mw 5.1 Alum Rock earthquake

The 25 October 2022 Mw 5.1 Alum Rock earthquake shows strong evidence for southeast rupture directivity along the central Calaveras fault (CCF), as indicated by observed ground motions and simulated kinematic ruptures. Peak ground accelerations (PGAs) and peak ground velocities (PGVs) are notably higher to the southeast, with an order of magnitude difference for stations at the same...
Authors
Evan Tyler Hirakawa, Grace Alexandra Parker, Annemarie S. Baltay Sundstrom, Thomas C. Hanks

Quantification of geodetic strain rate uncertainties and implications for seismic hazard estimates Quantification of geodetic strain rate uncertainties and implications for seismic hazard estimates

Geodetic velocity data provide first-order constraints on crustal surface strain rates, which in turn are linked to seismic hazard. Estimating the 2-D surface strain tensor everywhere requires knowledge of the surface velocity field everywhere, while geodetic data such as Global Navigation Satellite System (GNSS) only have spatially scattered measurements on the surface of the Earth. To...
Authors
Jeremy Maurer, Kathryn Zerbe Materna

Chemical characterization of San Andreas Fault Observatory at Depth (SAFOD) Phase 3 core Chemical characterization of San Andreas Fault Observatory at Depth (SAFOD) Phase 3 core

We present new X-ray fluorescence compositions of 27 core samples from Phase 3, Hole G of the San Andreas Fault Observatory at Depth, nearly doubling the published dataset for the core. The new analyses consist of major and trace element compositions and the first published data for rare earth elements from Hole G. Whole-rock compositions were obtained to further the analysis of active...
Authors
Diane E. Moore, Kelly K. Bradbury

Rapid shallow megathrust afterslip from the 2021 M8.2 Chignik, Alaska earthquake revealed by seafloor geodesy Rapid shallow megathrust afterslip from the 2021 M8.2 Chignik, Alaska earthquake revealed by seafloor geodesy

The shallower portions of subduction zone megathrust faults host Earth’s most hazardous tsunamigenic earthquakes, yet understanding how and when they slip remains elusive because of challenges making seafloor observations. We performed Global Navigation Satellite System Acoustic seafloor geodetic surveys before and ~2.5 months after the 29 July 2021 Mw (moment magnitude) 8.2 Chignik...
Authors
Benjamin A. Brooks, Dara Elyse Goldberg, John DeSanto, Todd Ericksen, Spahr Webb, Scott Nooner, C. David Chadwell, James H. Foster, Sarah E. Minson, Robert C. Witter, Peter J. Haeussler, Jeffery T. Freymueller, William D. Barnhart, Johanna Nevitt

Strength recovery in quartzite is controlled by changes in friction in experiments at hydrothermal conditions up to 200°C Strength recovery in quartzite is controlled by changes in friction in experiments at hydrothermal conditions up to 200°C

The rate of fault zone restrengthening between earthquakes can be influenced by both frictional and cohesive healing processes. Friction is dependent on effective normal stress while cohesion is independent of normal stress, potentially explaining—in part—the lack of depth dependence of earthquake stress drops. Although amenable to laboratory testing, few studies have systematically...
Authors
Tamara Nicole Jeppson, David A. Lockner, Nicholas M. Beeler, Stephen H. Hickman

Earthquake detection with tinyML Earthquake detection with tinyML

Earthquake detection is the critical first step in earthquake early warning (EEW) systems. For robust EEW systems, detection accuracy, detection latency, and sensor density are critical to providing real‐time earthquake alerts. Traditional EEW systems use fixed sensor networks or, more recently, networks of mobile phones equipped with microelectromechanical systems (MEMS) accelerometers...
Authors
Timothy Hugh Clements

Nonlinear radiation damping: A new method for dissipating energy in dynamic earthquake rupture simulations Nonlinear radiation damping: A new method for dissipating energy in dynamic earthquake rupture simulations

Dynamic earthquake rupture simulations are used to understand earthquake mechanics and the ground shaking that earthquakes produce. These simulations can help diagnose past earthquake behavior and are also used to generate scenarios of possible future earthquakes. Traditional dynamic rupture models generally assume elastic rock response, but this can lead to peak on‐fault slip rates and...
Authors
Michael Barall, Ruth A. Harris

Investigating spatio-temporal variability of initial 230Th/232Th in intertidal corals Investigating spatio-temporal variability of initial 230Th/232Th in intertidal corals

One of the key factors in obtaining precise and accurate 230Th ages of corals, especially for corals with ages less than a few thousand years, is the correction for non-radiogenic 230Th based on an initial 230Th/232Th value (230Th/232Th0). Studies that consider coral 230Th/232Th0 values in intertidal environments are limited, and it is in these environments that corals have Th...
Authors
Hong-Wei Chiang, Belle E. Philibosian, Aron J. Meltzner, Chung-Che Wu, Chuan-Chou Shen, R. Lawrence Edwards, Chih-Kai Chuang, Bambang W. Suwargadi, Danny H. Natawidjaja

The new Self Anchored Suspension (SAS) Bridge of the San Francisco Bay Bridge System: A preliminary study of its response and behavior during a small earthquake The new Self Anchored Suspension (SAS) Bridge of the San Francisco Bay Bridge System: A preliminary study of its response and behavior during a small earthquake

Seismic behavior and performance of the new Self- Anchored Suspension (SAS) Bridge of the San Francisco Bay Bridge System is studied using response data recorded during the October 14, 2019, 𝑀𝑤⁢4.6 Pleasant Hill earthquake. The new bridge went into service within the last decade as a replacement for the older truss bridge that spanned between Yerba Buena Island and East Bay. During the...
Authors
Mehmet Celebi

60 years and beyond of Reviews of Geophysics 60 years and beyond of Reviews of Geophysics

Reviews of Geophysics is an AGU journal, first established in February 1963. It is a hybrid open access invitation-only journal that publishes comprehensive review articles across various disciplines within the Earth and Space Sciences. The selection criteria are rigorous and many submissions are declined without review. The journal is the highest ranked in the fields of Geochemistry and
Authors
Fabio Florindo, Valerio Acocella, Ann Marie Carlton, Paolo D’Odorico, Qingyun Duan, Andrew Gettelman, Jasper Halekas, Ruth A. Harris, Gesine Mollenhauer, Alan Robock, Claudine Stirling, Yusuke Yokoyama
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