2020年2月3日四川青白江5.1级地震总结

Summary of Qingbaijiang MS 5.1 earthquake in Sichuan on February 3,2020

针对2020年2月3日四川青白江5.1级地震发生前的地震活动和地球物理观测异常、构造背景、震源物理参数,以及地震序列特征等进行系统总结。结果表明,青白江5.1级地震发生前存在小震调制比高值、地磁低点位移、重力固体潮高噪声等中短期异常;地震序列活动特征显示,此次地震为一次孤立型地震序列,序列参数计算结果与当前余震活动水平基本相符。另外,青白江地震发生在龙泉山断裂带上,震源机制计算结果显示为一次逆冲型破裂事件,与龙泉山断裂构造性质一致。同时,此次地震发生在四川盆地的少震弱震区,对于川滇及川滇藏交界地区后续7级以上地震的发生具有一定预测意义。

An MS 5.1 earthquake occurred in Qingbaijiang District,Chengdu City on February 3,2020.The tectonic background,source physical parameters,and sequence characteristics,as well as seismicity and geophysical observations before the event,are systematically summarized in this paper.The results show that there are some medium-term and short-term anomalies such as high solid tide modulation ratio,geomagnetic low point displacement,earth tidal gravity.The activity characteristics of the sequence show that the Qingbaijiang earthquake is an isolated earthquake type,and the sequence parameters are basically consistent with the current seismicity level of aftershock activity.In addition,the Qingbaijiang earthquake occurred on the Longquanshan fault zone,and the focal mechanism of the mainshock shows that it is a thrust type fracture event,which is consistent with the structural nature of the Longquanshan fault.Meanwhile,the earthquake occurred in the weak earthquake area in the Sichuan Basin,which has a certain significance for the prediction of the subsequent strong earthquakes in the Sichuan Yunnan and the area bordering Sichuan Yunnan Tibet.