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Publications

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Basin effects from 3D simulated ground motions in the Greater Los Angeles region for use in seismic-hazard analyses

We develop basin-depth-scaling models (i.e. “basin terms”) from the long-period (⁠T≥2s⁠) simulated ground motions of the Southern California Earthquake Center (SCEC) CyberShake project for use in seismic hazard analyses at sites within the sedimentary basins of southern California. Basin terms use the Next Generation Attenuation (NGA)-West-2 ground-motion models (GMMs) as reference models and use
Authors
Morgan P. Moschetti, Eric M. Thompson, Kyle Withers

Regional seismic velocity model for the U.S. Atlantic and Gulf Coastal Plains based on measured shear wave velocity, sediment thickness, and surface geology

The Atlantic and Gulf Coastal Plains (CPs) are characterized by widespread accumulations of low-velocity sediments and sedimentary rock that overlay high-velocity bedrock. Geology and sediment thickness greatly influence seismic wave propagation, but current regional ground motion amplification and seismic hazard models include limited characterization of these site conditions. In this study, a ne
Authors
Cassie Gann-Phillips, Ashly Cabas, Chunyang Ji, Chris H. Cramer, James Kaklamanos, Oliver S. Boyd

Evaluation of debris-flow building damage forecasts

Reliable forecasts of building damage due to debris flows may provide situational awareness and guide land and emergency management decisions. Application of debris-flow runout models to generate such forecasts requires combining hazard intensity predictions with fragility functions that link hazard intensity with building damage. In this study, we evaluated the performance of building damage fore
Authors
Katherine R. Barnhart, Christopher R. Miller, Francis K. Rengers, Jason W. Kean

Characteristics of debris-flow-prone watersheds and debris-flow-triggering rainstorms following the Tadpole Fire, New Mexico, USA

Moderate- or high-severity fires promote increases in runoff and erosion, leading to a greater likelihood of extreme geomorphic responses, including debris flows. In the first several years following fire, the majority of debris flows initiate when runoff rapidly entrains sediment on steep slopes. From a hazard perspective, it is important to be able to anticipate when and where watershed response
Authors
Luke A. McGuire, Francis K. Rengers, Ann Youberg, Alexander Gorr, Olivia J. Hoch, Rebecca Beers, Ryan Porter

Forecasting the long-term spatial distribution of earthquakes for the 2023 US National Seismic Hazard Model using gridded seismicity

Probabilistic seismic hazard analyses such as the U.S. National Seismic Hazard Model (NSHM) typically rely on declustering and spatially smoothing an earthquake catalog to estimate a long‐term time‐independent (background) seismicity rate to forecast future seismicity. In support of the U.S. Geological Survey’s (USGS) 2023 update to the NSHM, we update the methods used to develop this background o
Authors
Andrea L. Llenos, Andrew J. Michael, Allison Shumway, Justin Rubinstein, Kirstie Lafon Haynie, Morgan P. Moschetti, Jason M. Altekruse, Kevin R. Milner

Empirical ground-motion basin response in the California Great Valley, Reno, Nevada, and Portland, Oregon

We assess how well the Next-Generation Attenuation-West 2 (NGA-West2) ground-motion models (GMMs), which are used in the US Geological Survey’s (USGS) National Seismic Hazard Model (NSHM) for crustal faults in the western United States, predict the observed basin response in the Great Valley of California, the Reno basin in Nevada, and Portland and Tualatin basins in Oregon. These GMMs rely on sit
Authors
Sean Kamran Ahdi, Brad T. Aagaard, Morgan P. Moschetti, Grace Alexandra Parker, Oliver S. Boyd, William J. Stephenson

Apparent non-double-couple components as artifacts of moment tensor inversion

Compilations of earthquake moment tensors from global and regional catalogs find pervasive non-double-couple (NDC) components with a mean deviation from a double-couple (DC) source of around 20%. Their distributions vary only slightly with magnitude, faulting mechanism, or geologic environments. This consistency suggests that for most earthquakes, especially smaller ones whose rupture processes ar
Authors
Boris Rösler, Seth Stein, Adam T. Ringler, Jiří Vackár

Post-wildfire debris flows

Post-wildfire debris flows pose severe hazards to communities and infrastructure near and within recently burned mountainous terrain. Intense heat of wildfires changes the runoff characteristics of a watershed by combusting the vegetative canopy, litter, and duff, introducing ash into the soil and creating water repellant soils. Following wildfire, rainfall on bare ground is less able to infiltrat
Authors
Joseph Gartner, Jason W. Kean, Francis K. Rengers, Scott W. McCoy, Nina S. Oakley, Gary J. Sheridan

Preface to focus section on new frontiers and advances in global seismology

Over the last century, many of the fundamental advances in our understanding of the solid Earth have been underpinned by seismic observations recorded on long‐running networks of globally distributed seismic instruments (e.g., Agnew et al., 1976; Romanowicz et al., 1984; Hanka and Kind, 1994; Peterson and Hutt, 2014; Ringler et al., 2022a). During this time, seismic data quality and the speed of d
Authors
Robert E. Anthony, Nicolas Leroy, Robert Mellors, Adam T. Ringler, Joachim Saul, Martin Vallée, David C. Wilson

Noise constraints on global body‐wave measurement thresholds

Intermediate sized earthquakes (≈M4–6.5) are often measured using the teleseismic body‐wave magnitude (⁠𝑚b⁠). 𝑚b measurements are especially critical at the lower end of this range when teleseismic waveform modeling techniques (i.e., moment tensor analysis) are difficult. The U.S. Geological Survey National Earthquake Information Center (NEIC) determines the location and magnitude of all M 5 and g
Authors
Adam T. Ringler, David C. Wilson, Paul S. Earle, William L. Yeck, David B. Mason, Justin T. Wilgus

Distinct yet adjacent earthquake sequences near the Mendocino Triple Junction: 20 December 2021 Mw 6.1 and 6.0 Petrolia, and 20 December 2022 Mw 6.4 Ferndale

Two earthquake sequences occurred a year apart at the Mendocino Triple Junction in northern California: first the 20 December 2021 �w 6.1 and 6.0 Petrolia sequence, then the 20 December 2022 �w 6.4 Ferndale sequence. To delineate active faults and understand the relationship between these sequences, we applied an automated deep‐learning workflow to create enhanced and relocated earthquake catalogs
Authors
Clara Yoon, David R. Shelly

Data-driven adjustments for combined use of NGA-East hard-rock ground motion and site amplification models

Model development in the Next Generation Attenuation-East (NGA-East) project included two components developed concurrently and independently: (1) earthquake ground-motion models (GMMs) that predict the median and aleatory variability of various intensity measures conditioned on magnitude and distance, derived for a reference hard-rock site condition with an average shear-wave velocity in the uppe
Authors
Maria E. Ramos-Sepulveda, Jonathan P. Stewart, Grace Alexandra Parker, Morgan P. Moschetti, Eric M. Thompson, Scott J. Brandenberg, Youssef M A Hashash, Ellen Rathje
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