Abstract:
Based on fixed deformation data within 200 km away from the epicenter of the Wenan earthquake, combined with the fault activity,this paper analyzes the temporal evolution of crustal deformation of the Capital Region and its relationship with seismic activity before and after the Wenan
M5.1 earthquake. The result indicates that: (1)part of the observation items show extensional or compressive changes before the earthquake. (2)The tide plane strain state in earth's surface has different characteristics before and after the moderate strong earthquakes. (3)Plane strain parameter curve shows significant synchronal transition around 2011,but,there is no moderate strong earthquakes occurred in the capital region and its joint area,so the synchronal transition may be related to the tectonic stress field changing caused by the Japan 9.0 great earthquake on Mar.2011.