Elizabeth S Cochran
Dr. Elizabeth S. Cochran is an observational seismologist at the United States Geological Survey in Pasadena, California. She conducts research on human-induced earthquakes, earthquake early warning, earthquake triggering, rupture processes, and seismic wave propagation.
Elizabeth has led several large seismic deployments following significant earthquakes in the United States. She served as Acting Director of the Earthquake Science Center in 2021. Elizabeth was the Project Chief of the Induced Seismicity project in the Earthquake Science Center from 2018-2021 and Chief Scientist of the ShakeAlert Earthquake Early Warning project from 2016-17. She was the co-founder of the Quake Catcher Network, a crowd-sourced seismic network that detected earthquakes using low-cost sensors connected to desktop or inside of laptops and phones. Elizabeth received a B.S. in geophysics from University of California, Santa Barbara and a M.Sc. and Ph.D. in geophysics and space physics from the University of California, Los Angeles. In 2010, she was recognized with a Presidential Early Career Award for Scientists and Engineers (PECASE), which is the highest honor bestowed by the United States government on outstanding scientists and engineers in the early stages of their independent research careers.
Experience
2011 – Present Research Geophysicist, US Geological Survey
2011 – Present Visiting Associate in Geophysics, California Institute of Technology
2007 – 2011 Assistant Professor, Department of Earth Sciences, University of California, Riverside
2005 – 2007 Postdoctoral Scholar, Institute of Geophysics and Planetary Physics, Scripps
2000 – 2005 Research Assist./Assoc., Department of Earth and Space Science, University of California, Los Angeles
Education
University of California, Santa Barbara Geophysics B.S., 2000
University of California, Los Angeles Geophysics and Space Physics M.S., 2003
University of California, Los Angeles Geophysics and Space Physics Ph.D., 2005
Honors and Activities
· Presidential Early Career Award for Scientists and Engineers (PECASE), 2010.
· NSF Faculty Early Career Development (CAREER) Award, 2010.
· Geological Society of America, Subaru Outstanding Woman in Science Award, 2006.
· Young Fellow of the Institute of Geophysics and Planetary Physics, 2004.
· Southern California Earthquake Center Seismology Discipline Co-Chair, 2009-2017.
· IRIS Standing Committee Member; Data Management (2008-2010), Education and Public Outreach (2012-2014).
Science and Products
Using a large-n seismic array to explore the robustness of spectral estimations
VS30 and Dominant Site Frequency (fd) as Provisional Station ML Corrections (dML) in California
EERI earthquake reconnaissance report: 2019 Ridgecrest earthquake sequence
3D fault architecture controls the dynamism of earthquake swarm
Real-time performance of the PLUM earthquake early warning method during the 2019 M6.4 and M7.1 Ridgecrest, California, Earthquakes
Minimal clustering of injection-induced earthquakes observed with a large-n seismic array
Activation of optimally and unfavourably oriented faults in a uniform local stress field during the 2011 Prague, Oklahoma, sequence
The U.S. Geological Survey’s Rapid Seismic Array Deployment for the 2019 Ridgecrest Earthquake Sequence
How often can Earthquake Early Warning systems alert sites with high intensity ground motion?
How low should we go when warning for earthquakes?
The LArge-n Seismic Survey in Oklahoma (LASSO) experiment
Depth determination of the 2010 El Mayor‐Cucapah earthquake sequence (M ≥ 4.0)
Science and Products
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Filter Total Items: 76
Using a large-n seismic array to explore the robustness of spectral estimations
Spectral analysis is widely used to estimate and refine earthquake source parameters such as source radius, seismic moment, and stress drop. This study aims to quantify the precision of the single spectra and empirical Green's function spectral ratio approach using the Large‐n Seismic Survey in Oklahoma (LASSO) array. The dense station coverage in an area of local saltwater disposal offers a uniquAuthorsK.B. Kemna, A.F. Pena Castro, R.M. Harrington, Elizabeth S. CochranVS30 and Dominant Site Frequency (fd) as Provisional Station ML Corrections (dML) in California
New seismic stations added to a regional seismic network cannot be used to calculate local magnitude (ML) until a revised regionwide amplitude decay function is developed. Each station must record a minimum number of local and regional earthquakes that meet specific amplitude requirements prior to recalibration of the amplitude decay function. Station component adjustments (dML; Uhrhammer et aAuthorsAlan Yong, Elizabeth S. Cochran, Jennifer Andrews, Kenneth Hudson, Antony Martin, Ellen Yu, Julie A Herrick, Jessica DozalEERI earthquake reconnaissance report: 2019 Ridgecrest earthquake sequence
The Ridgecrest Earthquake Sequence began the morning of 4 July 2019 with an M6.4 earthquake at 10:33 a.m., closely following several small foreshocks. The epicenter of this event was roughly 11 miles (18 km) east-northeast of Ridgecrest (Figure 1) within the Naval Air Weapons Station China Lake (NAWS-CL). Seismic and geologic data established that the M6.4 earthquake occurred primarily along a steAuthorsEERI Learning from Earthquakes Program, Katherine Scharer3D fault architecture controls the dynamism of earthquake swarm
The vibrant evolutionary patterns made by earthquake swarms are incompatible with standard, effectively two-dimensional (2D) models for general fault architecture. We leverage advances in earthquake monitoring with a deep-learning algorithm to image a fault zone hosting a 4-year-long swarm in southern California. We infer that fluids are naturally injected into the fault zone from below and diffusAuthorsZ. Ross, Elizabeth S. Cochran, D. Trugman, Jonathan D. SmithReal-time performance of the PLUM earthquake early warning method during the 2019 M6.4 and M7.1 Ridgecrest, California, Earthquakes
We evaluate the timeliness and accuracy of ground‐motion‐based earthquake early warning (EEW) during the July 2019 M6.4 and 7.1 Ridgecrest earthquakes. In 2018, we began retrospective and internal real‐time testing of the propagation of local undamped motion (PLUM) method for earthquake warning in California, Oregon, and Washington, with the potential that PLUM might one day be included in the ShaAuthorsSarah E. Minson, Jessie Kate Saunders, Julian Bunn, Elizabeth S. Cochran, Annemarie S. Baltay, Deborah L. Kilb, Mitsuyuki Hoshiba, Yuki KoderaMinimal clustering of injection-induced earthquakes observed with a large-n seismic array
The clustering behavior of injection‐induced earthquakes is examined using one month of data recorded by the LArge‐n Seismic Survey in Oklahoma (LASSO) array. The 1829‐node seismic array was deployed in a 25 km×32 km area of active saltwater disposal in northern Oklahoma between 14 April and 10 May 2016. Injection rates in the study area are nearly constant around the time of the deployment. WeAuthorsElizabeth S. Cochran, A. Wickham-Piotrowski, K. Kemna, R. M Harrington, S. Dougherty, A. Pena CastroActivation of optimally and unfavourably oriented faults in a uniform local stress field during the 2011 Prague, Oklahoma, sequence
The orientations of faults activated relative to the local principal stress directions can provide insights into the role of pore pressure changes in induced earthquake sequences. Here, we examine the 2011 M 5.7 Prague earthquake sequence that was induced by nearby wastewater disposal. We estimate the local principal compressive stress direction near the rupture as inferred from shear wave splittiAuthorsElizabeth S. Cochran, Robert Skoumal, Devin McPhillips, Z. Ross, Katie M. KeranenThe U.S. Geological Survey’s Rapid Seismic Array Deployment for the 2019 Ridgecrest Earthquake Sequence
Rapid seismic deployments following large earthquakes capture ephemeral near‐field recordings of aftershocks and ambient noise that can provide valuable data for seismological studies. The U.S. Geological Survey installed 19 temporary seismic stations following the 4 July 2019 Mw 6.4 and 6 July 2019 (UTC) Mw 7.1 earthquakes near the city of Ridgecrest, California. The stations record the aftershocAuthorsElizabeth S. Cochran, Emily Wolin, Daniel E. McNamara, Alan Yong, David C. Wilson, Mark Alvarez, Nicholas van der Elst, Adria Ruth McClain, Jamison Haase SteidlHow often can Earthquake Early Warning systems alert sites with high intensity ground motion?
Although numerous Earthquake Early Warning (EEW) algorithms have been developed we still lack a detailed understanding of how often and under what circumstances useful ground motion alerts can be provided to end-users. Here we analyze the alerting performance of the PLUM, EPIC and FinDer algorithms by running them retrospectively on the seismic strong motion data of the 219 earthquakes in Japan siAuthorsM.-A. Meier, Y. Kodera, M. Bose, A. I. Chung, M. Hoshiba, Elizabeth S. Cochran, Sarah E. Minson, E. Hauksson, T. HeatonHow low should we go when warning for earthquakes?
A key goal of earthquake early warning (EEW) systems is to alert populations who may be affected by a particular level of ground shaking so that they can take action to reduce impacts of that shaking, such as injuries, damages to physical infrastructure, or emotional distress. Most EEW systems work by rapidly determining the location and size of an earthquake, estimating shaking levels, and then dAuthorsElizabeth S. Cochran, Allen L. HuskerThe LArge-n Seismic Survey in Oklahoma (LASSO) experiment
In 2016, the U.S. Geological Survey deployed more than 1,800 vertical-component nodal seismometers in Grant County, Oklahoma to study induced seismic activity associated with production of the Mississippi Limestone Play. The LArge-n Seismic Survey in Oklahoma (LASSO) array operated for approximately one month, covering a 25-km-by-32-km region with a nominal station spacing of ~400 m. Primary goalAuthorsS. Dougherty, Elizabeth S. Cochran, R. M. HarringtonDepth determination of the 2010 El Mayor‐Cucapah earthquake sequence (M ≥ 4.0)
The 2010 MW 7.2 El Mayor‐Cucapah earthquake ruptured a zone of ~120 km in length in northern Baja California. The geographic distribution of this earthquake sequence was well constrained by waveform relocation. The depth distribution, however, was poorly determined as it is near the edge of, or outside, the Southern California Seismic Network. Here we use two complementary methods to constrain theAuthorsC. Yu, E. Hauksson, Z. Zhan, Elizabeth S. Cochran, D. Helmberger - News