2010年河津MS 4.8地震前后单台波速比变化特征分析

摘要

Based on the seismic phase report of Shanxi Province from January 2001 to October 2014, the variation of wave velocity ratio before and after Hejin MS 4.8 earthquake in the year 2010 is analyzed by using Wadati method of single station and multi-earthquake in this paper. And four stations,those with relatively continuous seismic phase data,were selected. The results showed that the middle wave velocity ratio displayed anomaly for two or three years at Linfen Seismic Station and Anze Seismic Station,which are situated in the northern side of Hejin MS 4.8 earthquake’s epicenter. At the same time,the different azimuthal partition result indicated that, the wave velocity ratio curve,which represented southwest of Linfen Seismic Station and south of Xixian Seismic Station,showed short period anomaly before Hejin MS 4.8 earthquake. The abnormity had obvious relationship with scope of earthquake pregnancy,the better ray the station accepted,the more obvious anomaly was showed.%在收集和整理2001年1月—2014年10月山西地区震相观测报告基础上，以2010年1月24日河津MS 4.8地震前后，山西南部4个记录震相数据连续性较好的地震台站（夏县、临汾、隰县、安泽）数据为研究对象，采用单台多震和达法，对波速比变化特征进行分析。结果显示，震中以北的临汾和安泽地震台，在震前具有持续2—3年的中期波速比低值异常；地震台站不同方位细化分析表明，震前临汾地震台西南方位和隰县地震台正南方位的波速比时间曲线出现短期异常变化。综合分析认为，单台波速比异常与地震台站方位和孕震区范围明显相关，且接收穿透孕震区较好射线的地震台短期异常较明显。