Determination of ground displacement of 25 April 2015 Nepal earthquake by GNSS precise point positioning

Abstract

The April 2015 Nepal earthquake (known as the Gorkha earthquake) occurred at 06:11:25 (UTC) on the 25th of April, with a magnitude of 7.8Mw. It was the worst natural disaster to strike Nepal since the 1934 Nepal-Bihar earth-quake. Precise determinatron of ground displacement in this area will provide important information to better under-stand the structure and scope of the earthquake, contributing to faster and more accurate earthquake prediction. In this paper, we use precise point positioning to determine the displacements of 17 GNSS stations around the epicenter for the day of the earthquake. The processing results show that the common displacement direction is close to south-southwest with the largest value being approximately 2 m and the affected area being about 160 km in the southeast direction centered around the earthquake epicenter. However, a detectable GNSS signal was still observed at a station some 647 km away from the epicenter.