2021年玛多M_(S) 7.4地震前M_(S) 3、M_(S) 4地震空区嵌套异常分析

Analysis of M_(S) 3 and M_(S) 4 seismic gap nesting anomalies before Maduo M_(S) 7.4 earthquake in 2021

利用地震活动图像等传统测震学方法,对玛多M_(S)7.4地震前的M_(S)3、M_(S)4地震空区嵌套异常演化过程作进一步梳理分析,并进行了回顾总结,得出如下认识和结论:(1)该地震空区具有孕育强震的能力且出现视应力高值现象,预示着区内有发震危险性;(2)未来主震震中出现在空区嵌套的交界区附近,这一特征对于认识空区嵌套异常、缩小预测发震区域极其重要;(3)回顾玛多地震前空区演化过程,有2次显著地震事件,使跟踪从中长期转为中短期再转为短期,这可为空区跟踪过程中发震紧迫性的判定不断积累经验。

Using traditional seismological methods such as seismicity patterns,the evolution process of the MS 3 and M_(S) 4 seismic gap nesting anomalies before the Maduo M_(S) 4.4 earthquake was further analyzed and retrospectively summarized.The following cognitions and conclusions were drawn:①The seismic gap has the capacity to generate strong earthquakes and exhibits a phenomenon of high apparent stress,indicating the risk of earthquake occurrence.②The epicenter of the future mainshock occurs close to the junction zone of the nested seismic gap,which is extremely important for understanding the seismic gap nesting anomalies and narrowing down the predicted seismic area.③Looking back at the evolution process of the seismic gap before the Maduo earthquake,there were two significant seismic events that made the tracking from medium-long term to medium-short term and then to short term,which can continuously accumulate experience for determining the urgency of earthquake occurrence in the process of seismic gap tracking.