GPS Co-seismic and Post-seismic Response to the 3·11 Massive Earthquake in Japan

A massive Ms 9.0 earthquake occurred on 11 March 2011,off the Pacific coast of the northeastern part of the Japanese main land.In this paper,using developed PPP software,the co-seismic and post-seismic surface movement information and precipitable water vapor were extracted from IGS stations data located in Japan and the surrounding countries and State Oceanic Administration operational GNSS stations data.First,the co-seismic horizontal motion trajectory,three-dimensional coordinate time series and the dynamic changes of precipitable water vapor in the zenith direction for GPS sites were achieved using kinematic PPP.Then,using static PPP,this paper obtained the pre-seismic and post-seismic three-dimensional coordinate in 24-hours solution of GPS sites.Based on the calculating results,this paper reveals the co-seismic surface movement process and post-seismic permanent deformation of GPS sites,and verifies the snowfall process in Japan disaster area.These measurements are therefore of high value for earthquake monitoring and disaster warning using GPS technology.