Abstract：Based on the motion field data of four GPS periods from 2013 to 2021, we calculate the strain field of each period, and discuss the spatiotemporal evolution characteristics of strain field in the four periods before the 2022 Menyuan MS6.9 earthquake in Qinghai province. The results show that: 1)The principal strain can reflect the strain characteristics of main pressure and main tension of single point. 2)The maximum shear strain rate field should pay more attention to the high value concentration area. The spatial distribution of the high value area in the first and fourth cycles before the Menyuan earthquake in 2016 and 2022 has implications for the study and judgment of earthquake risk area. 3)The positive-negative conversion high-density gradient zone and the center of four quadrants of strain field isoline are the key areas of the surface expansion rate field, which can be used as the deformation precursor information of medium and strong earthquakes.
CAI Xiaochao,TANG Hongtao. Characteristics of Crustal Deformation before the 2022 Menyuan MS6.9 Earthquake in Qinghai Province[J]. jgg, 2023, 43(7): 669-673.
