Spatio-Temporal Changes of Microseismicity Around Recent Large Earthquakes in Continental China

Session: Seismicity and Tectonics of Stable Continental Interiors [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

During the pasting 10 years, there are 29 large earthquakes (M ≥ 6.0) occurred in Continental China, which cause significant casualties and losses in property. To better understand nucleation process of these events and improve seismic hazard assessment, we conduct a systematic examination of spatio-temporal changes of seismic activities associated with these large earthquakes. To build a more complete earthquake catalog, we apply a GPU version of the matched filter technique (MFT) to detect possible missing earthquakes around each large mainshock. We select the continuous waveforms recorded on the permanent stations from the China Seismic Network (CSN) within 300 km away from each mainshock. Our analysis procedure is nearly automatic, which includes selecting template events, data pre-processing, event scanning with the MFT and building the catalog. Taking the M6.1 Heilongjiang earthquake (occurred on January 2^nd, 2016 in North China) as an example, we detect about 3.3 times more earthquakes than the template catalog, and the GPU version runs about 18.2 times faster than the CPU version. Using the GPU version of MFT, we complete the detection with one month before and after all 29 large earthquakes. The detected results show 1.7 ~ 31.2 times more earthquakes than the corresponding template catalogs. Our next step is to systematically examine the foreshock and aftershock behaviors and compare the statistical behaviors of microseismicity with mainshock properties. Updated results will be presented at the meeting.

Presenting Author: Lu Li

Authors