New Microearthquake Catalog for the Parkfield Section of the San Andreas Fault, California
Session: Waveform Cross-Correlation-Based Methods in Observational Seismology [Poster]
Type: Poster
Date: 4/21/2021
Presentation Time: 03:45 PM Pacific
Description:
We present an updated earthquake catalog for the Parkfield section of the San Andreas Fault, California, spanning from December 2003 to March 2005. Although Parkfield is one of the best seismically instrumented regions, recent studies have shown that catalogs for the area are incomplete due to missing lower magnitude events, especially after the 2004 M6 Parkfield earthquake. The new catalog was compiled using a matched filter detection technique. We use the waveforms of more than 10000 earthquakes from high-quality relocated catalogs recorded at the High-Resolution Seismic Network (HRSN). Detection was performed filtering data between 2-8 Hz and using a detection threshold of 12 times the Median Average Deviation to the daily cross-correlation functions. For a more robust detection we also included earthquakes from adjacent regions in the 10000 templates, for example aftershocks from the 2003 M6.5 San Simeon earthquake, and removed these detections from the final catalog. To relocate the detected catalog, we used waveform cross-correlation location package XCORLOC adding waveforms from other seismic networks in the region for better constraint.
The time span of the new relocated catalog includes local earthquakes such as the 2004 M6 Parkfield and the 2003 M6.5 San Simeon earthquake and the 2004 M9.2 Sumatra earthquake at teleseismic distances. We will use the catalog to investigate and understand spatio-temporal evolutions of aftershocks following the 2004 M6 earthquake and how stress changes imposed from regional and remote earthquakes affect local seismicity. In addition, we plan to use the new catalog to better understand different microearthquake behaviors and seismogenic structures in the locked and creeping sections. Updated results will be presented at the meeting.
Presenting Author: Miguel Neves
Student Presenter: Yes
Authors
Miguel Neves Presenting Author Corresponding Author mjneves@gatech.edu Georgia Institute of Technology |
Zhigang Peng zpeng@gatech.edu Georgia Institute of Technology |
Guoqing Lin glin@rsmas.miami.edu University of Miami |
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New Microearthquake Catalog for the Parkfield Section of the San Andreas Fault, California
Category
Waveform Cross-correlation-based Methods in Observational Seismology