Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 2571

Observation-constrained multicycle dynamic models of the southern San Andreas and the northern San Jacinto Faults: Addressing complexity in paleoearthquake extent and recurrence with realistic 2D fault geometry

Understanding mechanical conditions that lead to complexity in earthquakes is important to seismic hazard analysis. In this study, we simulate physics-based multicycle dynamic models of the San Andreas fault (Carrizo through San Bernardino sections) and the San Jacinto fault (Claremont and Clark strands). We focus on a complex fault geometry based on the Southern California Earthquake Center Commu
Authors
Dunyu Liu, Benchuan Duan, Katherine Scharer, Doug Yule

Impact of fluid-rock interaction on strength and hydraulic transmissivity rvolution in shear fractures under hydrothermal conditions

Reactivated shear fractures contribute to the creation of pervasive fracture networks in geothermal systems. The creation, reactivation, and sustainability of fracture networks depend on complex coupling among thermal, hydraulic, mechanical, and chemical (THMC) processes. However, most laboratory experiments focus either solely on how fluid transport properties evolve in stationary fractures at el
Authors
Tamara Nicole Jeppson, David A. Lockner

Prospective and retrospective evaluation of the U.S. Geological Survey public aftershock forecast for the 2019-2021 Southwest Puerto Rico Earthquake and aftershocks

The Mw 6.4 Southwest Puerto Rico Earthquake of 7 January 2020 was accompanied by a robust fore‐ and aftershock sequence. The U.S. Geological Survey (USGS) has issued regular aftershock forecasts for more than a year since the mainshock, available on a public webpage. Forecasts were accompanied by interpretive and informational material, published in English and Spanish. Informational products incl
Authors
Nicholas van der Elst, Jeanne L. Hardebeck, Andrew J. Michael, Sara McBride, Elizabeth Vanacore

Empirical map-based nonergodic models of site response in the greater Los Angeles area

We develop empirical estimates of site response at seismic stations in the Los Angeles area using recorded ground motions from 414 M 3–7.3 earthquakes in southern California. The data are from a combination of the Next Generation Attenuation‐West2 project, the 2019 Ridgecrest earthquakes, and about 10,000 newly processed records. We estimate site response using an iterative mixed‐effects residuals
Authors
Grace Alexandra Parker, Annemarie S. Baltay

Comment on ‘Evidence for a large strike-slip component during the 1960 Chilean earthquake’ by H. Kanamori, L. Rivera, and S. Lambotte

Based on numerous studies of the relevant geodetic data, a low-angle thrusting mechanism has been assigned to the 1960 Chile earthquake. Kanamori, Rivera and Lambotte recently suggested that a component of dextral slip comparable to the thrusting be included in the mechanism to satisfy long-period, teleseismic observations. The absence of geodetic evidence for that huge strike-slip component is th
Authors
James C. Savage

Cross-platform analysis of public responses to the 2019 Ridgecrest earthquake sequence on Twitter and Reddit

Online social networks (OSNs) have become a powerful tool to study collective human responses to extreme events such as earthquakes. Most previous research concentrated on a single platform and utilized users’ behaviors on a single platform to study people’s general responses. In this study, we explore the characteristics of people’s behaviors on different OSNs and conduct a cross-platform analysi
Authors
Tao Ruan, Qingkai Kong, Sara McBride, Amatullah Sethjiwala, Qin Lv

Typology development of earthquake displays in free-choice learning environments, to inform earthquake early warning education in the United States

Free-choice learning environments, such as museums, national parks, interpretive trails, and visitor centers, are trusted sources of information in their communities and support lifelong learning. Earthquake education in these spaces creates awareness of earthquake hazards and risk in areas where people live or visit and, in turn, may increase engagement in preparedness behavior. The ShakeAlert® E
Authors
Danielle F. Sumy, Mariah Ramona Jenkins, Sara McBride, Robert Michael deGroot

Earthquake early warning for estimating floor shaking levels of tall buildings

This article investigates methods to improve earthquake early warning (EEW) predictions of shaking levels for residents of tall buildings. In the current U.S. Geological Survey ShakeAlert EEW system, regions far from an epicenter will not receive alerts due to low predicted ground‐shaking intensities. However, residents of tall buildings in those areas may still experience significant shaking due
Authors
S. Farid Ghahari, Annemarie S. Baltay, Mehmet Çelebi, Grace Alexandra Parker, Jeffrey McGuire, Ertugrul Taciroglu

Kinematic slip model of the July 8, 2021 M6.0 Antelope Valley, California, earthquake

We present a kinematic slip model of the July 8, 2021 Antelope Valley earthquake from a finite-source inversion based on regional seismic waveforms and static offsets from GPS and InSAR. Seismic waveforms are employed at 6s dominant period out to 100 km from the epicenter, and the combined GPS and InSAR datasets cover the near field and far field out to ∼ 100 km and constrain the overall rupture s
Authors
Fred Pollitz, Charles Wicks, William M Hammond

Photomosaics and logs associated with study of West Napa Fault at Ehlers Lane, north of Saint Helena, California

The West Napa Fault has previously been mapped as extending ~45 kilometers (km) from northern Vallejo to southern Saint Helena, California, dominantly running along the western edge of Napa Valley. A zone of fault strands (some previously unmapped) along a ~15-km section of the fault ruptured during the 2014 magnitude 6.0 South Napa earthquake, illustrating the need for further investigation of th
Authors
Belle E. Philibosian, Robert R. Sickler, Carol S. Prentice, Alexandra J. Pickering, Patrick Gannon, Kiara N. Broudy, Shannon A. Mahan, Jazmine N. Titular, Eli A. Turner, Cameron Folmar, Sierra F. Patterson, Emilie E. Bowman

The occurrence and hazards of great subduction zone earthquakes

Subduction zone earthquakes result in some of the most devastating natural hazards on Earth. Knowledge of where great (moment magnitude M ≥ 8) subduction zone earthquakes can occur and how they rupture is critical to constraining future seismic and tsunami hazards. Since the occurrence of well-instrumented great earthquakes, such as the 2004 M9.1 Sumatra–Andaman and 2011 M9.1 Tohoku earthquakes, t
Authors
Erin Wirth, Valerie J. Sahakian, Laura M Wallace, Daniel Melnick

Alert optimization of the PLUM earthquake early warning algorithm for the western United States

We determine an optimal alerting configuration for the propagation of local undamped motion (PLUM) earthquake early warning (EEW) algorithm for use by the U.S. ShakeAlert system covering California, Oregon, and Washington. All EEW systems should balance the primary goal of providing timely alerts for impactful or potentially damaging shaking while limiting alerts for shaking that is too low to be
Authors
Elizabeth S. Cochran, Jessie Kate Saunders, Sarah E. Minson, Julian Bunn, Annemarie S. Baltay, Debi Kilb, Colin T O'Rourke, Mitsuyuki Hoshiba, Yuki Kodera