SCEC Award Number 11081 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Testing static vs dynamic triggering in southern California after the 2010 M7.2 El Mayor-Cucapah Earthquake
Name Organization
Zhigang Peng Georgia Institute of Technology
Other Participants Brendan Sullivan
Xiaofeng Meng
SCEC Priorities A4, A10, A11 SCEC Groups Seismology, FARM, EFP
Report Due Date 02/29/2012 Date Report Submitted N/A
Project Abstract
Understanding how earthquakes are triggered by static or dynamic stress changes remains to be one of the most debated topics in earthquake science. We took advantage of the dense seismic observations in SC following the 2010 Mw7.2 El Mayor-Cucapah earthquake, and apply a waveform-based template detection technique to identify missing earthquakes in the Salton Sea geothermal region after the mainshock. Using GPU parallel computing, we have successfully detected ~70 times more earthquakes than listed in the SCSN catalog around the mainshock [Meng et al., 2012]. These newly detected events suggest that dynamic triggering is mostly dominant immediately after the mainshock. However, static triggering became more important in the next few months after the mainshock. We are in the process of applying the same procedure to a larger space-time region in Southern California.
Intellectual Merit Our proposal is directly relevant to the Priorities for the Seismology Disciplinary Activities in 2011 on the “The 2010 M7.2 El Mayor-Cucapah Earthquake Sequence.” and “real-time processing of network data”. In addition, it address the following Science Priorities outlined in the SCEC3 RFP: (1) A4 “Statistical analysis and mapping of seismicity and source parameters with an emphasis on their relation to known faults”; and “A11. Constrain absolute stress and understand the nature of interaction between the faulted upper crust, the ductile crust and mantle, and how geologic history helps to resolve the current physical properties of the system.”. If successful, our proposed work could help to contribute to the aforementioned debate on static vs. dynamic triggering.
Broader Impacts The PI Peng has given multiple seminars and talks on the findings of non-volcanic tremor in Central and southern California at various institutions during SCEC3. These include the USGS Menlo Park (Summer, 2010), China Earthquake Administration in 2008 and 2011, and Caltech Seismolab in Spring 2009.
In addition, PI Peng has hosted a total of 5 SCEC summer interns during SCEC 3 (Summer Ohlendorf, Summer 2007; Amanda Fabian and Lujendra Ojha, Summer 2009; Adrian Doran and Meghan Fisher, summer, 2010). They have been working on various projects that are directly or partially funded by SCEC3. Their work has been presented at previous SCEC, AGU and SSA annual meetings, and some have resulted in peer-review publications [e.g., Chao et al., 2012; Kilb et al., 2012].
This project provided full support for the GT graduate student Xiaofeng Meng, who has become an export in detecting earthquakes in Central and Southern California. This work will become a major component of his thesis. Former graduate student P. Zhao (now postdoc at NORSAR) is also partially involved in this project.
Exemplary Figure Figure 2. An example of newly detected event near Salton Sea after the El Mayor-Cucapah mainshock. (a) Mean correlation coefficient trace versus time for the template event 10379125. The red dot corresponds to the detected event at ~12 min after the mainshock; (b) The histogram of the mean CC function; (c) A comparison of the template waveforms (red) and the continuous waveforms (grey) around the origin time of detected event (vertical dashed line). The channel names and the corresponding CC values are labeled on the left and right sides, respectively.