Publications
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A massive rock and ice avalanche caused the 2021 disaster at Chamoli, Indian Himalaya
On 7 Feb 2021, a catastrophic mass flow descended the Ronti Gad, Rishiganga, and Dhauliganga valleys in Chamoli, Uttarakhand, India, causing widespread devastation and severely damaging two hydropower projects. Over 200 people were killed or are missing. Our analysis of satellite imagery, seismic records, numerical model results, and eyewitness videos reveals that ~27x106 m3 of rock and glacier ic
Authors
D. H. Shugar, Mylène Jacquemart, D. Shean, S. Bhushan, K. Upadhyay, A. Sattar, W. Schwanghart, Sara K. McBride, M. Van Wyk de Vries, M. Mergili, A. Emmer, C. Deschamps-Berger, M. McDonnell, R. Bhambri, S. Allen, E. Berthier, J.L. Carrivick, J.J. Clague, M. Dokukin, S.A. Dunning, Herbert Frey, S. Gascoin, U. K. Haritashya, C. Huggel, A. Kaab, J.S. Kargel, J.L. Kavanaugh, P. Lacroix, D. N. Petley, S. Rupper, M.F. Azam, S.J. Cook, A.P. Dimri, M. Eriksson, D. Farinotti, J. Fiddes, K.R. Gnyawali, S. Harrison, M.K. Jha, M. Koppes, S. Kumar, S. Leiness, U. Majeed, S. Mai, A. Muhuri, J. Noetzli, F. Paul, I. Rashid, K. Sain, J. Steiner, F. Ugalde, C.S. Watson, M.J. Westoby
Evidence for latent crustal fluid injection transients in southern California from long-duration earthquake swarms
Earthquake swarms are manifestations of aseismic driving processes deep in the crust. We examine the spatiotemporal distribution of aseismic processes in Southern California using a 12-years catalog of swarms derived with deep learning algorithms. In a core portion of the plate boundary region, which is not associated with elevated heat flow, we identify 92 long-duration swarms ranging from 6 mont
Authors
Zachary E. Ross, Elizabeth S. Cochran
NGA-East ground-motion characterization model Part II: Implementation and hazard implications
As a companion article to Goulet et al., we describe implementation of the NGA-East ground motion characterization (GMC) model in probabilistic seismic hazard analysis (PSHA) for sites in the Central and Eastern United States (CEUS). We present extensions to the EPRI/DOE/NRC seismic source characterization (SSC) model for the CEUS needed for full implementation of NGA-East. Comparisons are present
Authors
Robert Youngs, Christine A. Goulet, Yousef Bozorgnia, Nicolas Kuehn, Linda Al Atik, Robert Graves, Gail M. Atkinson
A framework for evaluating earthquake early warning for an infrastructure network: An idealized case study of a northern California rail system
Earthquake early warning (EEW) systems provide a few to tens of seconds of warning before shaking hits a site. Despite the recent rapid developments of EEW systems around the world, the optimal alert response strategy and the practical benefit of using EEW are still open-ended questions, especially in areas where EEW systems are new or have not yet been deployed. Here, we use a case study of a rai
Authors
Sarah E. Minson, Elizabeth S. Cochran, Stephen Wu, Shunta Noda
Seismic wave propagation and basin amplification in the Wasatch Front, Utah
Ground‐motion analysis of more than 3000 records from 59 earthquakes, including records from the March 2020 Mw 5.7 Magna earthquake sequence, was carried out to investigate site response and basin amplification in the Wasatch Front, Utah. We compare ground motions with the Bayless and Abrahamson (2019; hereafter, BA18) ground‐motion model (GMM) for Fourier amplitude spectra, which was developed on
Authors
Morgan P. Moschetti, David Henry Churchwell, Eric M. Thompson, John Rekoske, Emily Wolin, Oliver S. Boyd
Stress controls rupture extent and maximum magnitude of induced earthquakes
Seismic hazard forecasts of induced seismicity often require estimates of the maximum possible magnitude (Mmax). Empirical models suggest that maximum magnitudes, or expected number of earthquakes, are related to the volume of injected fluid. We perform a suite of 3D physics-based earthquake simulations with rate- and state-dependent friction, systematically varying the area of the pressurized reg
Authors
K. A. Kroll, Elizabeth S. Cochran
The proliferation of induced seismicity in the Permian Basin, Texas
The Permian Basin has a long history of induced earthquakes, but the seismicity rates have increased dramatically over the past two decades and included a MW 5.0 likely induced by wastewater disposal (WD) in March 2020. A detailed characterization of the proliferation of seismicity in the Permian Basin throughout this time period is needed for improving the scientific understanding of the mechanis
Authors
Robert Skoumal, Daniel T. Trugman
Correlation of porosity variations and rheological transitions on the southern Cascadia megathrust
The unknown onshore extent of megathrust earthquake rupture in the Cascadia subduction zone represents a key uncertainty in earthquake hazard for the Pacific Northwest that is governed by the physical state and mechanical properties of the plate interface. The Cascadia plate interface is segmented into an interseismically locked zone located primarily offshore that is expected to rupture in large
Authors
Hao Guo, Jeffrey McGuire, Haijiang Zhang
Prehistoric earthquakes on the Banning strand of the San Andreas fault, North Palm Springs, California
We studied a paleoseismic trench excavated in 2017 across the Banning strand of the San Andreas fault and herein provide the first detailed record of ground-breaking earthquakes on this important fault in Southern California. The trench exposed an ~40-m-wide fault zone cutting through alluvial sand, gravel, silt, and clay deposits. We evaluated the paleoseismic record using a new metric that combi
Authors
Bryan A. Castillo, Sally F. McGill, Katherine Scharer, Doug Yule, Devin McPhillips, James McNeil, Sourav Saha, Nathan D. Brown, Seulgi Moon
Structure and Qp-Qs relations in the Seattle and Tualatin basins from converted seismic phases
We use converted body‐wave phases from local earthquakes to constrain depth to basement and average attenuation relations for the Seattle basin in Washington and the Tualatin basin in Oregon. P‐, P‐to‐S‐(Ps), S‐to‐P‐(Sp), and S‐wave arrivals are present in three‐component recordings of magnitude 2.5–4.0 earthquakes at seismic stations located in these basins. Based on their relative travel times,
Authors
Ian Stone, Erin Wirth, Arthur Frankel
Horizontal-to-vertical spectral ratios from California sites: Open-source database and data interpretation to establish site parameters
Frequency-dependent horizontal-to-vertical spectral ratios (HVSR) of Fourier amplitudes from three-component recordings can provide information on one or more site resonant frequencies and relative levels of amplification at those frequencies. Such information is potentially useful for predicting site amplification but is not present in site databases that have been developed over the last 15–20 y
Authors
Pengfei Wang, Paolo Zimmaro, Tatiana Gospe, Sean Kamran Ahdi, Alan Yong, Jonathan P. Stewart
Ground motions in urban Los Angeles from the 2019 Ridgecrest earthquake sequence
We study ground-motion response in urban Los Angeles during the two largest events (M7.1 and M6.4) of the 2019 Ridgecrest earthquake sequence using recordings from multiple regional seismic networks as well as a subset of 350 stations from the much denser Community Seismic Network. In the first part of our study, we examine the observed response spectral (pseudo) accelerations for a selection of p
Authors
Filippos Filippitzis, Monica Kohler, Tom Heaton, Robert Graves, Robert W. Clayton, Richard G. Guy, J. J. Bunn, K. M. Chandy