The Structure Changes in Longmenshan Fault Zone from Time-Lapse Tomography and GPS Observations

Session: Waveform Cross-Correlation-Based Methods in Observational Seismology [Poster]
Type: Poster
Date: 4/30/2020
Time: 08:00 AM
Room: Ballroom
Description: 

The stress interaction or triggering between large earthquakes was found usually by Column stress modeling. Direct measurement on changes of seismic velocity in the fault zone and GPS movement can provide more real details in stress evolution and coseismic and interseismic changes. Pei et al. (2019) presented four phases travel time data in Longmenshan fault zone that show large velocity decrease of coseismic changes and healing in broken zone of Wenchuan earthquake and accelerated healing phase at the southern asperity right after the nearby 2013 Mw 6.6 Lushan earthquake. Here we find that GPS observation shows faster shortening between hanging wall and footwall after Wenchuan earthquake and near stationary after Lushan earthquake, which is consistent with velocity changes. Both velocity changes and GPS movement rate variations suggest that Lushan Earthquake accelerated the healing of Wenchuan Earthquake fracture zone, and ductile deformation happened in the gap between Wenchuan and Lushan earthquake which could not result in large earthquake within the gap.

Presenting Author: Shunping Pei

Authors