地震序列中重复地震的累积滑动量对后续中强地震的前兆意义——以辽宁海城-岫岩地区4个显著地震序列为例

The precursory significance of cumulative slip of repea-ting earthquake sequences prior to moderately strong earthquakes——A case study of 4 remarkable earthquake sequences of Haicheng-Xiuyan

海城-岫岩地区是辽宁地震多发区,地震序列频发,具有区域地震窗口效应。在该地区一些显著的地震序列中,发现同一台站记录中有多个具有高度相似波形的地震,即重复地震序列。这些地震发震位置非常接近,破裂区域基本重合,因此可能反映孕震断层的一些活动特征。本文利用波形互相关方法对辽宁海城-岫岩地区4个显著地震序列进行重复地震识别,研究发现地震序列中重复地震的累积滑动量数值大小似乎与后续中强震在距离上有一定相关性,其中岫岩MS5.4地震前的前震序列产生的累积滑动量最大,并在主震前出现明显的滑动加速现象。

The Haicheng-Xiuyan region is an earthquake-prone area in Liaoning Province where earthquake sequences occurred frequently and is regarded to the regional seismic window. In this area we found many earthquake events with the highest waveform similarity in the records of the same station from some remarkable seismic sequences,namely repeating earthquake sequences.In principle rupture areas of the repeating events overlap with each other and are the most closely located. Therefore,these events may reflect the seismic process near the earthquake fault. In this paper,we identified 4 remarkable earthquake sequences of Haicheng-Xiuyan by waveform crosscorrelation. The result shows that the cumulative slip of repeating earthquakes is related with moderately strong earthquakes,among which Xiuyan Ms5. 4 foreshock sequences has the most strong and apparent pre-shock accelerating-like slip behavior.