Abstract:From the seismic observation report from 2008 to 2021, we extract the travel time data of direct P and S waves of small earthquakes near Badong area. We calculate the wave velocity ratio by the Wadati method of single earthquake and multi-station and single station and multi-earthquake, respectively. We analyze the temporal and spatial evolution characteristics of wave velocity ratio before and after the Badong MS5.1 earthquake in 2013. We conclude: 1) the wave velocity ratio of 8 stations on the east and west sides of the epicenter before the Badong earthquake changed abnormally in varying degrees with decline-rising process. 2) The wave velocity ratio of multiple stations in the surrounding area of Badong earthquake experienced the change process of two years decline-two years rise before the earthquake, which is similar to the result of single station wave velocity ratio. 3) The spatial evolution images of the Wadati method of single earthquake and multi-station show that the low value of wave velocity ratio in the first two years of Badong earthquake are concentrated around the epicenter, and the wave velocity ratio rises to the high value after the earthquake.
CHEN Lijuan,WU Shaoyu,DONG Lei et al. The Abnormal Variations of Wave Velocity Ratio before and after December 16, 2013, Badong MS5.1 Earthquake[J]. jgg, 2022, 42(10): 1080-1084.