Utilizing Results from InSAR to Develop Seismic Location Benchmarks and Implications for Seismic Source Studies



Surface Rupture

Figure 1a - Western China study area. Stations with 2-D propagation path corrections (PPCs) are shown (red triangles) [Steck et al., 2000] as well as nuclear test sites (blue squares). Red box is major study region. Blue box is InSAR region of detailed study.
Figure 1b - InSAR view of rupture for the Mw=7.5 Tibet event on 1997 November 8 determined to have a strike/slip mechanism. Can also see slight rupture to the south, denoted as secondary rupture (Peltzer et al., 1999).
Figure 1c - United States Geological Survey (USGS) catalog locations for the area around the Manyi/Tibet earthquake (Mw=7.5) on 08NOV1997. Shown are events before and including the mainshock (green), events between the mainshock and the second satellite pass used to create the InSAR image for the center section of the main rupture (red), and events after the second satellite pass through March 1999 (blue). The epicenters between the mainshock and second satellite pass are possible candidates for an event that occurred during the secondary rupture (red line ~50 km south of main rupture), three of which were chosen as the most likely candidates (highlighted). Focal mechanisms are shown for the Manyi mainshock event (Velasco et al., 2000) and a 1973 Ms=6.9 event west of the Manyi mainshock (Molnar and Chen, 1983).

Introduction | Surface Rupture | Data and Velocity Models | Synthetic Tests and Relocation Procedure | Search for Secondary Rupture Event | Relocation Results | Waveforms for Candidate Events | Relocation of Candidate Events | Conclusions and Recommendations | References