SCEC Award Number 15077 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Comprehensive detection of injection-induced seismicity in the Salton Sea Geothermal Field
Name Organization
Zhigang Peng Georgia Institute of Technology
Other Participants Xiaofeng Meng
SCEC Priorities 2a, 2b, 2f SCEC Groups Seismology, CS, FARM
Report Due Date 03/15/2016 Date Report Submitted 03/14/2016
Project Abstract
We systematically detect microseismicity in the Salton Sea Geothermal Field (SSGF) using both the EN borehole network and other permanent/temporary seismic network. Our last year’s effort has been focusing on matched filter detection around the occurrence time of 5 distant earthquakes that may have triggered microseismicity in this region before. By using many relocated events as templates, we scan through 5 days before and after each distant mainshock to detect additional seismicity. Out of all events examined, the 2009/08/03 Mw6.9 Baja California earthquake has triggered microseismicity during its surface waves. While the 2008 Mw6.0 Nevada earthquake and the 2010 Mw8.8 Chile earthquake did not show clear evidence of instantenous triggering during the surface waves, we found clear increase of seismicity within the next day following the distant mainshock. Our results suggest that Salton Sea region is critically stressed and capable of being dynamically triggered by large distant earthquakes.
Intellectual Merit This project contributes to a better understanding of induced seismicity by geothermal power plant operation in the Salton Sea area, as well as improved detections of seismicity in southern California. It also helps to better understand physical mechanisms of remote triggering.
Broader Impacts This project supported a female SCEC intern Bridget Casey (from Virginia Tech) to conduct research at Georiga Tech in Summer 2015. The remaining funding will be used to support summer research of a female graduate student Chenyu Li in summer 2016.
Exemplary Figure Figure 3. (a) Raw, (b) 2-16 Hz envelope, and (c) spectrogram of vertical seismogram at station RED for the 2009 Mw6.9 Baja California earthquake. (d) Template (red) and newly detected (black) events in Salton Sea around the 2009 Baja California mainshock. The black line is the cumulative number, and the solid dashed line mark the trend right before the mainshock. After Casey et al. (SCEC, 2015).