Abstract To study the distribution characteristics of the strain field before the earthquake, we conduct deep processing of the station displacement time series of 43 continuous GNSS stations in Yunnan from January 2012 to December 2018, and take 7 earthquakes with M≥5.7 as samples to obtain the surface strain and maximum shear strain distribution before earthquakes. The results show that: 1) Before the 7 earthquakes with M≥5.7, there is a significant surface strain change trend in Yunnan. In most cases, there is a pattern of strong compression and strong tension coexisting, and the cumulative surface strain generally exceeds ±4.0×10-8. The earthquakes mostly occur in high-gradient belts where surface strain (especially the surface squeeze) changes. 2) Before the 7 earthquakes with M≥5.7, there is a significant trend in the maximum shear strain change in Yunnan, and the cumulative maximum shear strain generally exceeds 5.0×10-8. The earthquakes mostly occur in the high gradient zone with the maximum shear strain change. 3) The surface strain (especially the surface squeeze) and the high gradient zone of the maximum shear strain change can be used as important areas for the research and judgment of the earthquake location of M≥5.7 earthquakes in the future.
YANG Jianwen,YE Beng,CHEN Jia et al. Using GNSS Data to Analyze the Distribution Characteristics of Strain Field before M≥5.7 Earthquake in Yunnan Area[J]. jgg, 2022, 42(3): 225-230.
YANG Jianwen,YE Beng,CHEN Jia et al. Using GNSS Data to Analyze the Distribution Characteristics of Strain Field before M≥5.7 Earthquake in Yunnan Area[J]. jgg, 2022, 42(3): 225-230.
