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选用2012年6月24日宁蒗-盐源MS5.7地震震源区的泸沽湖台站2008年9月—2013年9月连续5年的地震数据进行剪切波分裂计算,从剪切波分裂参数随时间的变化初步获得了宁蒗-盐源地区的区域应力特征,以及该地震发生前后地壳应力的特征性变化.泸沽湖台站快波偏振方向结果显示,该台站具有NE向和SE向两个优势取向,与研究区域内断裂的走向相同.该台站的慢波延迟时间表现出明显的变化,特别是在宁蒗-盐源MS5.7地震发生前后.在宁蒗-盐源地震发生前一年,泸沽湖台站的慢波延迟时间缓慢地增加,表明该地区地壳应力逐渐积累;直到该地震发生前一个月,泸沽湖台站的慢波延迟时间才开始急剧下降,表明地壳应力随着地震的发生而迅速释放.
Based on the seismic data of Luguhu Station in the source area of Ninglang-Yanyuan MS5.7 earthquake on June 24, 2012, the seismic data from September 2008 to September 2013 for five consecutive years are used to calculate the shear wave splitting. From the shear wave splitting The regional stress characteristics of Ninglang-Yanyuan area and the characteristic changes of crustal stress before and after the earthquake are preliminarily obtained with the time variation of the parameters.The results of fast polarization of the Luguhu station show that the station has NE and SE The orientation of the two dominant directions is the same as that of the fault in the study area.The slow wave delay time of this station shows obvious changes, especially before and after the Ninglang-Yanyuan MS5.7 earthquake, The year before the earthquake, the slow wave delay of Lugu Lake Station slowly increased, indicating that the crustal stress gradually accumulated in this area. Until one month before the earthquake, the slow wave delay of Lugu Lake Station began to drop sharply, indicating that Crustal stress is released rapidly with the earthquake.