Fault geometry and distribution of asperities of the 1997 Manyi, China (Mw = 7.5), earthquake: Integrated analysis from seismological and InSAR data

Abstract

The integration of seismic and InSAR interferogram data allows us to have a comprehensive understanding of the earthquake fault geometry and distribution of asperities for a remote event, namely the 1997 Manyi, China earthquake. We first obtained the slip distribution from teleseismic stations for several fault models, and then made synthetic interferograms in order to determine the optimum fault geometry. Our results show that the 1997 Manyi earthquake ruptured bilaterally with two segments dipping north and south for the western and eastern segments, respectively. The south dip of the eastern segment is essential for a better interpretation of the stations near the nodal plane, and a reversal of dip between the west and east segment is necessary to explain the pattern of observed InSAR interferograms due to the broader distribution of asperities. The fault rupture extended 170 km with maximum displacement of 6.1 m, and a total seismic moment of 2.24*1020 Nm (Mw = 7.5).