漾濞6.4级地震前后云南地区GNSS应变场变化分析北大核心CSCD

利用GAMIT/GLOBK软件对2018~2021年以来云南地区43个GNSS连续观测站数据进行处理,获得时间序列,采用克里金插值方法计算获取应变率场,分析漾濞M_(S)6.4地震前后区域应变场变化。结果表明,地震危险区应重点关注面应变压缩区域和最大剪应变高低值转换区域;漾濞M_(S)6.4地震发生在前期面应变压缩区域,震后又迅速转变为拉张状态;漾濞一带长期处于最大剪应变率高值区,剪切活动较强,震中附近的最大剪应变率在震前出现短期区域应变积累速率快速降低的现象。

Variation Analysis of GNSS Strain Field in Yunnan before and after the Yangbi MS6.4 Earthquake

GAMIT/GLOBK has been used to process the data of 43 GNSS continuous stations in Yunnan since 2018-2021 to obtain the time series. We use Kriging interpolation method to calculate and obtain the strain rate field and analyze the variation of regional strain field before and after the Yangbi M_S6.4 earthquake. The results show that the seismic risk area should be focused on the compression area of surface strain and the conversion area of high and low values of maximum shear strain. The Yangbi M_S6.4 earthquake occurred in the compression area of surface strain in the early stage, and quickly changed to extension state after the earthquake. Yangbi area has been in the high value area of maximum shear strain rate for a long time, and the shear activity is strong. The regional strain accumulation rate of maximum shear strain near the epicenter decreases rapidly in the short-term before the earthquake.