1989年以来华北地区中强震前地震矩加速释放空间扫描特征的研究

Research on Spatial Scanning Characteristic of Accelerating Moment Release before Moderate-strong Earthquakes in North China Region since 1989

利用地震矩释放程度m值对1989年以来华北地区12次MS≥5.0中强地震前的矩加速释放现象进行了研究。基于删除余震后的地震目录,提取了与矩加速释放相关的特征时—空尺度作为AMR现象在华北地区的扫描模型参数。采用震前1年逐3个月的扫描方式,得到了12次震例在震中附近与时间相依的m值的空间演变图像,并考察了震前震源区附近的Benioff应变释放情况。结果表明,华北地区MS5.0~5.5地震前AMR现象与实际震中和发震时刻的关联性不明显;而MS5.6~6.4地震前67%的震例在震中附近出现稳定和集中分布的矩释放加速区域,说明华北地区MS≥5.5中强震前AMR现象具有一定程度的普遍性,利用AMR现象对未来中强震发震地点的预测有一定的潜能和可挖掘性,但仍需其他方法相互佐证。

Firstly,we study the accelerating moment release（ AM R） before the 12 MS≥5. 0 moderate-strong earthquakes in North China region since 1989 by using the accelerating moment release m-value. Secondly,based on the catalogue of deleted aftershock,we extracted a temporal-spatial window related with AM R as the scanning model parameter in North China. Using the three monthly spatial scanning modes in one year before the earthquake,we obtained the temporal evolution variation of m-value with time,and investigated the Benioff train release around the epicenter area of 12 earthquakes. The result indicates that there was no obvious correlation betw een the AM R appeared before MS5. 6 ~ 6. 4 earthquakes and origin time. There appeared stable and concentrated AM R area before the 67% earthquakes out of the MS5. 6 ~ 6. 4 studied events around the epicenter area,which showed that the AM R phenomenon appeared before MS≥5. 0 moderate-strong earthquakes had a certain universality in North China. Using AM R to forecast the site of future moderate-strong earthquakes has some potential and develop ability,but it still needed other ways to evident.