Publications
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A new amphibious earthquake catalog for the Alaska Peninsula: Training, testing, and applying machine learning earthquake picking in offshore and amphibious environments A new amphibious earthquake catalog for the Alaska Peninsula: Training, testing, and applying machine learning earthquake picking in offshore and amphibious environments
The dual seismological developments of large-scale offshore observational networks and high-quality machine-learning earthquake detection and picking allow unprecedented seismicity detection in high hazard subduction zones. We develop a high resolution machine learning enhanced seismicity catalog for the Alaska Peninsula stretch of the Alaska-Aleutian Subduction Zone, which was...
Authors
Grace Barcheck, Natalia A. Ruppert
Investigating high‐resolution spatial variability of site response in the Los Angeles Basin using a dense sensor network Investigating high‐resolution spatial variability of site response in the Los Angeles Basin using a dense sensor network
We characterize seismic site response across a densely instrumented region of the Los Angeles Basin by combining data from the Community Seismic Network (CSN) and regional networks in the Advanced National Seismic System (ANSS). Mixed-effects regression is used to partition ground-motion model residuals and compute pseudo-spectral acceleration site residuals (ηs) from the NGA-West2...
Authors
Rashid Shams, Chukwuebuka C. Nweke, Grace Alexandra Parker
Phase evolution and elemental partitioning in impact melts from Meteor Crater, Arizona Phase evolution and elemental partitioning in impact melts from Meteor Crater, Arizona
The impact of the Canyon Diablo iron meteorite in Arizona ∼61,000 years ago resulted in partial vaporization of the meteorite and target rocks, producing a vapor plume and melt particles with taenite, olivine and clinopyroxene in glassy matrix. The resulting Meteor Crater is ∼1.2 km in diameter and ∼200 m deep. Although the crater has been the natural laboratory for impact cratering, the
Authors
Lung S. Chan, Hans-Rudolf Wenk, Amber L. Gullikson, A. Kattenmalavadi, W. Alvarez, E. L. Grant
3D broadband ground motion simulations of Cascadia megathrust earthquakes: Full-margin scenarios incorporating variable magnitudes and frontal thrust splay faulting 3D broadband ground motion simulations of Cascadia megathrust earthquakes: Full-margin scenarios incorporating variable magnitudes and frontal thrust splay faulting
Great megathrust earthquakes (∼Mw 8–9) that rupture along the Cascadia Subduction Zone pose significant shaking and tsunami hazards to the U.S. Pacific Northwest. Although these large earthquakes are documented in the geologic record, none have been recorded with modern instrumentation, complicating regional seismic hazard assessments. To improve constraints on seismic hazard estimates...
Authors
Audrey M. Dunham, Erin A. Wirth, Alex R. Grant, Arthur D. Frankel, Madeleine C. Lucas, Anna Ledeczi, Harold Tobin, Janet Watt, David A. Schmidt, Jeonghyeop Kim, James Biemiller
ETAS-positive: Extracting unbiased epidemic-type aftershock models from incomplete earthquake catalogs ETAS-positive: Extracting unbiased epidemic-type aftershock models from incomplete earthquake catalogs
Earthquake catalogs are inherently incomplete, and short-term fluctuations in catalog completeness can strongly bias estimates of seismicity parameters. Here, we extend the positive statistics framework recently introduced for estimating Gutenberg–Richter a and b values to the Epidemic-Type Aftershock Sequence (ETAS) model. The approach focuses on complete magnitude–time intervals...
Authors
Nicholas J. van der Elst, Sebastian Hainzl
Estimating aftershock risk for entry into earthquake-damaged buildings Estimating aftershock risk for entry into earthquake-damaged buildings
We present a simple method to estimate the risk of experiencing strong shaking from aftershocks during entry into earthquake-damaged buildings. We compute wait times until the probability of strong ground shaking from aftershocks reaches a predefined risk threshold; for example, a 0.4 percent probability of experiencing Modified Mercalli Intensity 7 or greater shaking during the planned...
Authors
Jeanne L. Hardebeck, Alan J. Poulos
Fully contained laboratory earthquakes: The effect of asperity aspect ratio and free surfaces Fully contained laboratory earthquakes: The effect of asperity aspect ratio and free surfaces
Corner frequency (fc) and seismic moment (M0) are key parameters derived from seismic signals that are used to characterize earthquake stress drop, rupture area, and slip. These parameters are also affected by fault geometry and boundary conditions. However, the systematic study of these effects in laboratory settings has been challenging. This study presents laboratory earthquake...
Authors
Sara Beth Cebry, Jun Young Song, Gregory C. McLaskey
Competing effects of elastic heterogeneity and viscous flow on interseismic coupling at Cascadia Competing effects of elastic heterogeneity and viscous flow on interseismic coupling at Cascadia
Interseismic coupling maps are important tools for estimating future earthquake hazard at subduction zones. Often interseismic coupling is estimated from surface velocities using a homogeneous elastic Earth model. However, inversions that incorporate viscoelastic mantle flow or elastic heterogeneity show that each can change the spatial distribution and magnitude of estimated coupling...
Authors
Elizabeth M. Sherrill, Kaj M. Johnson, Frederick Pollitz
CRESCENT earthquake dynamic rupture, earthquake cycle, and tsunami code verification platform CRESCENT earthquake dynamic rupture, earthquake cycle, and tsunami code verification platform
Physics-based simulations are critical for understanding natural hazards. The increasing complexity of numerical codes requires benchmark exercises to verify that different computational methods yield consistent results when solving the same governing equations. Here, we present an open-access web platform designed for the verification of earthquake dynamic rupture, seismic cycle, and...
Authors
Loic Bachelot, Fabian Kutschera, Michael Barall, Brittany Erickson, Eric Dunham, Alice-Agnes Gabriel, Ruth A. Harris, Shuo Ma, Amanda M. Thomas, Wenqiang Zhang
Corundum discovered by SuperCam and the Perseverance rover at Jezero crater, Mars Corundum discovered by SuperCam and the Perseverance rover at Jezero crater, Mars
Mars is primarily composed of mafic mineral assemblages and their alteration products, but small, scattered rocks strewn across the landscape offer clues to greater petrological diversity. While traversing the Jezero crater rim, the Perseverance rover encountered several plagioclase-rich light-toned float rocks. SuperCam identified the distinctive signature of corundum (α-Al2O3) in these...
Authors
A.M. Ollila, O. Beyssac, A. Fau, O. Forni, E. Clave, P.S.A. Beck, C. C. Bedford, V. Payre, E. Dehouck, S.A. Connell, J.A. Manrique, P. Pilleri, O. Gasnault, G.M. Martinez, A. Udry, S. Bernard, P. Gasda, T. Acosta-Maeda, R.B. Anderson, Travis S.J. Gabriel, F. Calef, J.F. Bell, J. N. Maki, S. Schroder, C. Quantin-Nataf, J.R. Johnson, B. Chide, K. Rammelkamp, F. Poulet, C. Royer, M. Rock, N.L. Lanza, S.K. Sharma, G. Lopez-Ryeys, T. Fouchet, J. Comellas, A. Zastrow, E. Coutis, R.C. Wiens, A. Cousin, S. Maurice, S. M. Clegg, P. Bernardi, T. Nelson
Simulation-based scenario ShakeMaps for large magnitude (MW6.5+) crustal earthquakes on the Seattle, Tacoma, and southern Whidbey Island faults, Washington, USA Simulation-based scenario ShakeMaps for large magnitude (MW6.5+) crustal earthquakes on the Seattle, Tacoma, and southern Whidbey Island faults, Washington, USA
Scenario ground‐motion maps based on empirical ground‐motion models (GMMs) provide a rapid and generally reliable means of estimating the amplitude and distribution of earthquake shaking. However, because GMMs are designed for broad applicability, they often rely on simplified representations of Earth structure, which can limit their accuracy in regions with complex source, path, and...
Authors
Ian P. Stone, Erin A. Wirth, Alex R. Grant, Julia Grossman, Arthur D. Frankel
Testing characteristic magnitude distributions in modern PSHA models Testing characteristic magnitude distributions in modern PSHA models
The characteristic magnitude distribution hypothesis predicts a higher rate of large earthquakes than a Gutenberg–Richter extrapolation of the small‐earthquake rate would imply. Characteristic magnitude distributions have been commonly applied to faults in probabilistic seismic hazard analysis (PSHA), and in modern models they can emerge from the way short‐term seismicity constraints are...
Authors
Morgan T. Page, Kevin Ross Milner, Edward H. Field