Slip rates and seismic moment deficits on major active faults in mainland China

Abstract

The Chinese mainland features widespread active faults and intensive seismic activity; both can be described in terms of slip rates on these faults. Previous studies of fault slip rates in mainland China have focused on individual faults or fault segments, and large discrepancies exist among results derived from different methods. Here we derive a self-consistent estimate of the slip rates on all major faults in mainland China using the recently updated GPS data and an elastic block model. The predicted slip rates are high in western and low in eastern China, ranging from 25.1 ± 2.0 mm/yr in the Himalayan Thrust System to less than 1.0 mm/yr in north China. Using these slip rates, we estimated the rates of moment accumulation on the major fault zones and compared them with the seismic moment released on each fault zone using the Chinese historical earthquake catalog that extends for more than 2000 years in many regions. The results show nine seismic zones with large moment deficits (unreleased moment). Future refinement of GPS measurements and earthquake history will allow better estimates of slip rates on individual faults and better assessment of earthquake hazard on these faults in mainland China. Copyright 2011 by the American Geophysical Union.