Interseismic Coupling Along the Xianshuihe-Xiaojiang Fault System

Abstract

We use Global Positioning System (GPS) data to quantify the interseismic coupling along the Xianshuihe-Xiaojiang fault system (XXFS). Our results confirm 7–11 mm/yr left-lateral strike-slip motion along the XXFS. South of ~ 29.5° N, high interseismic coupling is found down to 20 km-depth along the Anninghe-Zemuhe fault. A second 130 km-long section, highly coupled down to 10–15 km-depth, is identified along the northern Xiaojiang fault. North of 30.2° N, the Xianshuihe fault appears to be predominantly creeping at depth. We quantitatively compared our results from GPS with the seismic moment release and accumulation on XXFS. Results highlight that along the Anninghe, Zemuhe and Xiaojiang faults, moment deficits for Mw > 7 earthquakes have now accumulated.KeywordsEastern TibetXianshuihe-Xiaojiang fault systemInterseismic fault couplingGeodesyEarthquake potential