Study on shear wave splitting in the aftershock region of the Yao’an earthquake in 2000

摘要: After MS=6.5 Yao’an earthquake on January 15, 2000, a large amount of aftershock waveforms were recorded by the Near Source Digital Seismic Network (NSSN) installed Earthquake Administration Yunnan Province in region. It provides profuse data to systematically analyze features earthquake. The crustal anisotropy is realized shear wave splitting propagating upper crust. Based accurate relocations, parameters are determined with cross-correlation method, and results different stations regions discussed this paper. These conclusions obtained as follows: firstly, average fast directions region controlled regional stress field parallel maximum horizontal compressive direction; secondly, disparate vary structural settings fields; finally, delay time value affected all sorts factors, which affinitive medium, especially.