2017年8月9日精河6.6级地震前LURR异常时空演化特征

Study on spatial-temporal evolution of LURR abnormality before the Jinghe M_S6.6 earthquake

基于加卸载响应比理论,对2017年8月9日新疆精河6.6级地震前加卸载响应比时空演化特征和异常区的孕震积分时程曲线进行分析。结果表明,在精河6.6级地震前,研究区出现了明显的加卸载响应比高值异常区域,异常区呈现环状特征;而且,异常区域随时间逐渐向震源附近迁移,异常演化过程中异常区域内部和周围发生了6次5级以上地震,其中,2次6级地震发生在异常高值减弱过程中,异常峰值到发震的时间分别为11、22个月,大于以往研究的理论发震时间,这可能是受构造应力区域性特征影响的缘故。

The load/unload response ratio（ LURR） theory is a promising method for predicting earthquakes by characterizing the extent of damage in the focal area. Based on the load/unload response ratio theory,the spatial-temporal evolution characteristics of LURR abnormality before the Jinghe M_S6.6 earthquake occurred on August 9,2016 were analyzed,and the seismogenic integral of the abnormal area was analyzed. The results show that there are a few LURR abnormal areas in the studied area before the Jinghe M_S6.6 earthquake,and the anomaly area is annular or flaky.With the abnormal development,abnormal areas migrate near the source. During the process of abnormal evolution,6 earthquakes with M≥5.0 occurred within and around the anomalous area,of which 2 earthquakes with M≥6.0 occurred in the process of abnormal high value weakening,and the characteristic time T_2 from abnormal peak value to the main shock are 11 months and 22 months,which are greater than the theoretical occurrence time of the earthquake. This shows that the tectonic activity in the study area is intense,and the seismicity of the area is very active.