GPS observation in Sichuan-Yunnan and its vicinity before and after the Wenchuan earthquake in a decade

Abstract

Based on the horizontal velocity data observed by GPS during 2004–2007, 2007–2009, and 2011–2017 before, during, and after the Wenchuan earthquake in Sichuan-Yunnan and its vicinity, we analyze evolution features of the tectonic deformation caused by crustal movement in main active fault belts, and its possible influence. We conclude: the Wenchuan earthquake area showed obvious co-seismic thrust and dextral deformation from 2007 to 2009. The earthquake, to a certain extent, promoted tectonic movements on the Gansu-Sichuan boundary, Western Qinling fault zone, Anninghe-Zemuhe fault zone, and southern Xianshuihe fault zone. The vectors and strain filed acquired by GPS during Lushan and Jiuzhaigou earthquakes period may indicate that the southwest segment in the Longmenshan fault zone still has the possibility of larger earthquakes.