Analysis of Anomalous Characteristics of Regional Crustal Deformation before the September 16^th,2019 Zhangye MS5.0 Earthquake,Gansu,China

作者：MA Haiping,WANG Qian,ZHANG Bo,WU Shanyi,WANG Pengtao,DOU Xiying,LI Minjuan

摘要：To study the crustal movement in the vicinity of the epicenter before the Zhangye MS5.0 earthquake in 2019, the characteristics of crustal deformation before the earthquake are discussed through the GPS velocity field analysis based on the CMONOC data observed from GPS. The baseline time series between two continuous GPS stations and the strain time series of an area among several stations are analyzed in the epicenter area. The resulting time series of baseline azimuth around the epicenter reflects that the energy of the fault in the northern margin of Qilian Mountain is accumulated continuously before 2017. Besides,the movement trend of azimuth slows down after 2017,indicating the stress accumulation on both sides of the seismogenic fault zone has reached a certain degree. The first shear strain and EWdirection linear strain in the epicentral area of the Zhangye MS5.0 earthquake remain steady after 2017,and the surface strain rate decreases gradually after 2016. It is illustrated that there is an obvious deformation loss at the epicentral region three years before the earthquake,indicating that a certain degree of strain energy is accumulated in this area before the earthquake.

发文机构：Gansu Earthquake Agency Lanzhou Geophysical Field Science State Observation Station

关键词：ZhangyeMS5.0earthquakeGPSreferencestationVelocityfieldBaselineazimuthtime-seriesStraintimeseries

分类号： P228.4[天文地球—大地测量学与测量工程]P315[天文地球—测绘科学与技术]