摘要
Based on arrival time data of seismic phases of ML≥2. 0 earthquakes measured at Shanxi Digital Seismic Network for the period from January 2001 to October 2014,V_P/ V_S in the Shanxi region is calculated using the Wadati single station and multi-earthquake method,and an investigation is conducted into the variation behavior of V_P/ V_S in the Shanxi region before and after the three earthquakes of MS≥4. 5 in 2010. Our study finds that abnormal V_P/ V_S appeared earlier at distant stations before all of the three earthquakes,which is at the time range from 6 months to 1 year before the earthquakes,and later at near stations,at the time range 10 days to 2 months before earthquakes. Therefore,it s possible to narrow down the scope of the location in earthquake prediction from the distant and near station data. The calculations of Dongshan seismic station indicate that the size of the residual of the origin time has impact on the detail of V_P/ V_S variation,thus,appropriate thresholds should firstly be set for the residuals of origin time at each seismic station in practical application,to ensure scientific and steady V_P/ V_S calculations.
Based on arrival time data of seismic phases of ML≥2. 0 earthquakes measured at Shanxi Digital Seismic Network for the period from January 2001 to October 2014,V_P/ V_S in the Shanxi region is calculated using the Wadati single station and multi-earthquake method,and an investigation is conducted into the variation behavior of V_P/ V_S in the Shanxi region before and after the three earthquakes of MS≥4. 5 in 2010. Our study finds that abnormal V_P/ V_S appeared earlier at distant stations before all of the three earthquakes,which is at the time range from 6 months to 1 year before the earthquakes,and later at near stations,at the time range 10 days to 2 months before earthquakes. Therefore,it s possible to narrow down the scope of the location in earthquake prediction from the distant and near station data. The calculations of Dongshan seismic station indicate that the size of the residual of the origin time has impact on the detail of V_P/ V_S variation,thus,appropriate thresholds should firstly be set for the residuals of origin time at each seismic station in practical application,to ensure scientific and steady V_P/ V_S calculations.
基金
co-funded by the China Earthquake Science and Technology Spark Plan Project(XH12008Y
XH13004)
the Youth Backbone Project of China Earthquake Administration(20140305)
Shanxi Foundation for Basic Research,China(2013011029)
