Publications
Filter Total Items: 2057
Nodal seismograph recordings of the 2019 Ridgecrest Earthquake Sequence Nodal seismograph recordings of the 2019 Ridgecrest Earthquake Sequence
The 2019 Ridgecrest, California earthquake sequence included Mw 6.4 and Mw 7.1 earthquakes that occurred on successive days beginning on 4 July 2019. These two largest earthquakes of the sequence occurred on orthogonal faults that ruptured the Earth’s surface. To better evaluate the 3D subsurface fault structure, (P- and S-wave) velocity, 3D and temporal variations in seismicity, and...
Authors
Rufus D. Catchings, Mark Goldman, Jamison Haase Steidl, Joanne Chan, Amir A. Allam, Coyn Criley, Zhenning Ma, Daniel S. Langermann, Garet Jax Huddleston, Andrian T. McEvilly, Daniel David Thomas Mongovin, Yehuda Ben-Zion
Strain-estimated ground motions associated with recent earthquakes in California Strain-estimated ground motions associated with recent earthquakes in California
Peak ground velocity (PGV) is a commonly used parameter in earthquake ground‐motion models (GMMs) and hazard analyses, because it is closely related to structural damage and felt ground shaking, and is typically measured on broadband seismometers. Here, we demonstrate that strainmeters, which directly measure in situ strain in the bulk rock, can easily be related to ground velocity by a...
Authors
Noha Sameh Ahmed Farghal, Annemarie S. Baltay Sundstrom, John Langbein
Rainfall triggers more deep-seated landslides than Cascadia earthquakes in the Oregon Coast Range, USA Rainfall triggers more deep-seated landslides than Cascadia earthquakes in the Oregon Coast Range, USA
The coastal Pacific Northwest USA hosts thousands of deep-seated landslides. Historic landslides have primarily been triggered by rainfall, but the region is also prone to large earthquakes on the 1100-km-long Cascadia Subduction Zone megathrust. Little is known about the number of landslides triggered by these earthquakes because the last magnitude 9 rupture occurred in 1700 CE. Here...
Authors
Sean R LaHusen, Alison R Duvall, Adam M. Booth, Alex R. Grant, Benjamin A Mishkin, David R. Montgomery, William Struble, Joshua J. Roering, Joseph Wartman
Forecasting for a fractured land: A case study of the communication and use of aftershock forecasts from the Mw 7.8 2016 Kaikōura earthquake in Aotearoa New Zealand Forecasting for a fractured land: A case study of the communication and use of aftershock forecasts from the Mw 7.8 2016 Kaikōura earthquake in Aotearoa New Zealand
Operational earthquake forecasts (OEFs) are represented as time‐dependent probabilities of future earthquake hazard and risk. These probabilities can be presented in a variety of formats, including tables, maps, and text‐based scenarios. In countries such as Aotearoa New Zealand, the U.S., and Japan, OEFs have been released by scientific organizations to agencies and the public, with the...
Authors
Julia S. Becker, Sally H. Potter, Sara K. McBride, Emma E. Hudson-Doyle, Matthew Gerstenberger, Anne-Marie Christopherson
Developing post-alert messaging for ShakeAlert, the earthquake early warning system for the West Coast of the United States of America Developing post-alert messaging for ShakeAlert, the earthquake early warning system for the West Coast of the United States of America
As ShakeAlert, the earthquake early warning system for the West Coast of the U.S., begins its transition to operational public alerting, we explore how post-alert messaging might represent system performance. Planned post-alert messaging can provide timely, crucial information to both emergency managers and ShakeAlert operators as well as calibrate expectations among various publics or...
Authors
Sara K. McBride, Ann Bostrom, Jeannette Sutton, Robert Michael deGroot, Annemarie S. Baltay Sundstrom, Brian Terbush, Paul Bodin, Maximilian Dixon, Emily Holland, Ryan Arba, Paul C. Laustsen, Sophia Liu, Margaret J. Vinci
A stress-similarity triggering model for aftershocks of the MW6.4 and MW7.1 Ridgecrest earthquakes A stress-similarity triggering model for aftershocks of the MW6.4 and MW7.1 Ridgecrest earthquakes
The July 2019 Mw 6.4 and 7.1 Ridgecrest earthquakes triggered numerous aftershocks, including clusters of off‐fault aftershocks in an extensional stepover of the Garlock fault, near the town of Olancha, and near Panamint Valley. The locations of the off‐fault aftershocks are consistent with the stress‐similarity model of triggering, which hypothesizes that aftershocks preferentially...
Authors
Jeanne L. Hardebeck
Are the stress drops of small earthquakes good predictors of the stress drops of moderate-to-large earthquakes? Are the stress drops of small earthquakes good predictors of the stress drops of moderate-to-large earthquakes?
The stress drops of small earthquakes often exhibit spatial patterns of variability. If moderate and large earthquakes follow the same spatial patterns, the stress drops of possible future damaging earthquakes could be better predicted by considering the stress drops of nearby small events. Better stress drop predictability could reduce ground-motion uncertainty in Probabilistic Seismic...
Authors
Jeanne L. Hardebeck
Seismicity induced by massive wastewater injection near Puerto Gaitán, Colombia Seismicity induced by massive wastewater injection near Puerto Gaitán, Colombia
Seven years after the beginning of a massive wastewater injection project in eastern Colombia, local earthquake activity increased significantly. The field operator and the Colombian Geological Survey immediately reinforced the monitoring of the area. Our analysis of the temporal evolution of the seismic and injection data together with our knowledge of the geological parameters of the...
Authors
I Molina, J.S. Velasquez, Justin Rubinstein, A Garcia-Aristizabal, V Dionicio
Laboratory electrical conductivity of marine gas hydrate Laboratory electrical conductivity of marine gas hydrate
Methane hydrate was synthesized from pure water ice and flash frozen seawater, with varying amounts of sand or silt added. Electrical conductivity was determined by impedance spectroscopy, using equivalent circuit modeling to separate the effects of electrodes and to gain insight into conduction mechanisms. Silt and sand increase the conductivity of pure hydrate, we infer by contaminant...
Authors
Steven Constable, Ryan Lu, Laura A. Stern, Wyatt L. Du Frane, Jeffery J. Roberts
Localized fluid discharge by tensile cracking during the post-seismic period in subduction zones Localized fluid discharge by tensile cracking during the post-seismic period in subduction zones
It is thought that extensional structures (extensional cracks and normal faults) generated during the post-seismic period create fluid pathways that enhance the drainage of the subducting plate interface, thus reducing the pore pressure and increasing fault strength. However, it remains to be elucidated how much pore fluid pressure decreases by the extension crack formation. Here we...
Authors
Makoto Otsubo, Jeanne L. Hardebeck, Ayumu Miyakawa, Asuka Yamaguchi, Gaku Kimura
Documentation of Surface Fault Rupture and Ground‐Deformation Features Produced by the 4 and 5 July 2019 Mw 6.4 and Mw 7.1 Ridgecrest Earthquake Sequence Documentation of Surface Fault Rupture and Ground‐Deformation Features Produced by the 4 and 5 July 2019 Mw 6.4 and Mw 7.1 Ridgecrest Earthquake Sequence
The MwMw 6.4 and MwMw 7.1 Ridgecrest earthquake sequence occurred on 4 and 5 July 2019 within the eastern California shear zone of southern California. Both events produced extensive surface faulting and ground deformation within Indian Wells Valley and Searles Valley. In the weeks following the earthquakes, more than six dozen scientists from government, academia, and the private sector...
Authors
Daniel J. Ponti, James Luke Blair, Rosa Carla M, Kate Thomas, Alexandra Pickering, Sinan Akciz, Stephen J. Angster, Jean-Philipe Avouac, Jeffrey Bachhuber, Steven Bacon, Nicolas C. Barth, S. Bennett, Kelly Blake, Stephan Bork, Benjamin A. Brooks, Thomas Bullard, Paul A. Burgess, Colin Chupik, Timothy E. Dawson, Michael DeFrisco, Jaime E. Delano, Stephen B. DeLong, James D. Dolan, Andrea Donnellan, Christopher DuRoss, Todd Ericksen, Erik Frost, Gareth J. Funning, Ryan D. Gold, Nicholas A Graehl, Carlos Gutierrez, Elizabeth Haddon, Alexandra Elise Hatem, John Helms, Janis Hernandez, Christopher S. Hitchcock, Peter Holland, Kenneth W. Hudnut, Katherine J. Kendrick, Richard D Koehler, Ozgur Kozaci, Tyler C. Ladinsky, Robert Leeper, Christopher Madugo, Maxime Mareschal, James McDonald, Devin McPhillips, Christopher Milliner, Daniel Mongovin, Alexander Morelan, Stephanie Nale, Johanna Nevitt, Matt O’Neal, Brian J. Olsen, Michael Oskin, Salena Padilla, Jason Patton, Belle E. Philibosian, Ian Pierce, Cynthia Pridmore, Nathaniel Roth, David Sandwell, Katherine M. Scharer, Gordon G. Seitz, Drake Singleton, Bridget Smith-Konter, Eleanor Spangler, Brian J. Swanson, Jessica Thompson Jobe, Jerome Treiman, Francesca Valencia, Joshua Vanderwal, Alana Williams, Xiaohua Xu, Judith Zachariasen, Jade Zimmerman, Robert Zinke
Pseudo-prospective evaluation of UCERF3-ETAS forecasts during the 2019 Ridgecrest sequence Pseudo-prospective evaluation of UCERF3-ETAS forecasts during the 2019 Ridgecrest sequence
The 2019 Ridgecrest sequence provides the first opportunity to evaluate Uniform California Earthquake Rupture Forecast v.3 with epidemic‐type aftershock sequences (UCERF3‐ETAS) in a pseudoprospective sense. For comparison, we include a version of the model without explicit faults more closely mimicking traditional ETAS models (UCERF3‐NoFaults). We evaluate the forecasts with new metrics...
Authors
William J. Savran, Maximillian J. Werner, W. Marzocchi, David A. Rhoades, David D. Jackson, Kevin R. Milner, Edward H. Field, Andrew J. Michael