Gravity changes before and after the 2010 Ms7.1 Yushu earthquake

Abstract

Absolute and relative gravity observations from 1998–2010 from the China Crustal Movement Observation Network, a major national scientific project, have been used to model the gravity field and its variations associated with the April 14, 2010 Ms7 . 1 Yushu earthquake. The evolution of the regional gravity field and its relationship with seismicity before and after the Yushu earthquake are studied. The observed gravity changes are closely related to the active Ganzi-Yushu Fault, and gravity measurements can be used to observe the migration of material accompanying active faults and crustal tectonics. The dynamic variation of the gravity field reflects its evolution prior to and during the Yushu earthquake. The gravity measurements near its epicenter are as large as 80 × 10 − 8 m/s 2 , and they show wave-like increases with time prior to the Yushu earthquake.