Elizabeth S Cochran
Biography
Dr. Elizabeth S. Cochran is an observational seismologist at the United States Geological Survey in Pasadena, California. Elizabeth serves as Project Chief of the Induced Seismicity project in the Earthquake Science Center. Her research interests include investigating the link between increased earthquake rates in the Central and Eastern U.S. and energy production activities, specifically disposal of large volumes of wastewater. She also conducts research on earthquake early warning, earthquake triggering, rupture processes, and seismic wave propagation, and has led several large seismic deployments following significant earthquakes in the United States. Elizabeth previously served as Chief Scientist of the ShakeAlert Earthquake Early Warning project working to develop a system to warn of incoming ground shaking from moderate to large earthquakes. She was also the co-founder of the Quake Catcher Network, a crowd-sourced seismic network that uses low cost sensors connected to desktop or inside of laptops and phones located in homes, offices and schools to detect earthquakes. 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
Earthquake Early Warning – Fine-Tuning for Best Alerts
The goal of an earthquake early warning (EEW) system is to provide an alert to people and automatic systems after an earthquake begins but before the shaking reaches their location. As the USGS and its partners are developing an EEW system, called ShakeAlert®, for the West Coast, the benefits, costs, capabilities, and limitations are being investigated. Two recent studies explored the...
Apparent earthquake rupture predictability
To what extent can the future evolution of an ongoing earthquake rupture be predicted? This question of fundamental scientific and practical importance has recently been addressed by studies of teleseismic source time functions (STFs) but reaching contrasting conclusions. One study concludes that the initial portion of STFs is the same regardless...
Meier, M.-A.; Ampuero, P.; Cochran, Elizabeth S.; Page, Morgan T. Characteristics of frequent dynamic triggering of microearthquakes in Southern California
Dynamic triggering of earthquakes has been reported at various fault systems. The triggered earthquakes are thought to be caused either directly by dynamic stress changes due to the passing seismic waves, or indirectly by other nonlinear processes that are initiated by the passing waves. Distinguishing these physical mechanisms is difficult...
Fan, Wenyuan; Barbour, Andrew; Cochran, Elizabeth S.; Lin, Guoqing 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...
Kemna, K.B.; Pena Castro, A.F.; Harrington, R.M.; Cochran, Elizabeth S. VS30 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">MLML) 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...
Yong, Alan; Cochran, Elizabeth S.; Andrews, Jennifer; Hudson, Kenneth; Antony Martin; Yu, Ellen; Herrick, Julie A; Dozal, Jessica 3D 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...
Ross, Z.; Cochran, Elizabeth S.; Trugman, D.; Smith, Jonathan D. Minimal 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...
Cochran, Elizabeth S.; Wickham-Piotrowski, A.; Kemna, K.; Harrington, R.M; Dougherty, S.; Pena Castro, A. Activation 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...
Cochran, Elizabeth S.; Skoumal, Robert; McPhillips, Devin; Ross, Z.; Keranen, Katie M. The 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...
Cochran, Elizabeth S.; Wolin, Emily; McNamara, Daniel E.; Yong, Alan; Wilson, David C.; Alvarez, Mark; Van Der Elst, Nicholas; McClain, Adria Ruth; Steidl, Jamison Haase How 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...
Meier, M.-A.; Kodera, Y.; Bose, M.; Chung, A. I.; Hoshiba, M.; Cochran, Elizabeth S.; Minson, Sarah E.; Hauksson, E.; Heaton, T. How 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...
Cochran, Elizabeth S.; Husker, Allen L. The 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...
Dougherty, S.; Cochran, Elizabeth S.; Harrington, R. M. Depth 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...
Yu, C.; Hauksson, E.; Zhan, Z.; Cochran, Elizabeth S.; Helmberger, D.
President Obama Honors Quake-Catcher Network Inventor Elizabeth Cochran
Dr. Elizabeth Cochran, a geophysicist with the U.S. Geological Survey, was named one of President Obama’s recipients of the Presidential Early Career Awards for Scientists and Engineers, the highest honor bestowed by the United States government on science and engineering professionals in the early stages of their independent research careers.