Rapid Identification and Emergency Investigation of Surface Ruptures and Geohazards Induced by the Ms 7.1 Yushu Earthquake

The rapid identification based on InSAR technology was proved to be effective in our emergency investigation of surface ruptures and geohazards induced by the Yushu earthquake. The earthquake-generating fault of the Yushu earthquake is the Yushu section of the Garze-Yushu faults zone. It strikes NWW-NW, 23 km long near the Yushu County seat, dominated by left-lateral strike slip, and appearing as a surface rupture zone. The macroscopic epicenter is positioned at Guo-yang-yan-song-duo of Gyegu Town (33 degrees 03'11 ' N, 96 degrees 51'26 ' E), where the co-seismic horizontal offset measured is 1.75 m. Geohazards induced by the Yushu earthquake are mainly rockfalls, landslides, debris flows, and unstable slopes. They are controlled by the earthquake-generating fault and are mostly distributed along it. There are several geohazard chains having been established, such as earthquake, canal damage, soil liquefying, landslide-debris flow, earthquake, soil liquefying, roadbed deformation, etc. In order to prevent seismic hazards, generally, where there is a visible surface rupture induced by the Yushu earthquake, reconstruction should be at least beyond 20 m, on each side, from it. Sufficient attention should also be given to potential geohazards or geohazard chains induced by the earthquake.