Discussion on shear-wave spIitting of the June 24,2012 NingIang-Yanyuan MS5.7 earthquake
Liu Sha
Wu Peng
Yang Jiansi
Su Jinrong
Abstract：On June 24 2012,an earthquake with MS 5.7 happened in the junction of Ninglang in Yunnan Province and Yanyuan in Sichuan Province.This paper chose the seismic data recorded by the station LGH from September 2008 to September 2013 to analyze shear-wave splitting of the Ninglang-Yanyuan MS 5.7 earthquake.The regional stress characteristics and the stress changes before and after the earthquake are obtained preliminarily from the change of shear-wave splitting parameters with time.The polarization results of fast shear-wave at the station LGH show that there are two polarization directions,i.e .,NE and SE,which are consistent with the strike of the faults in the studied area.There is a visible change in the delay time of slow shear-wave during the observational five years,especially before and after the MS 5.7 earthquake.One year before the earthquake,the delay time of slow wave slowly increased,suggesting the stress accumulation.Till one month before the earthquake,the delay time of slow wave decreases rapidly,indicating the stress in the crust releases rapidly with the earthquake occurrence.
Keywords：shear-wave splittingpolarization direction of fast shear-wavedelay time of slow wavestress in the crust
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 787-795 )