[关键词]
[摘要]
使用辽宁地区中小地震的数字波形资料,基于Brune圆盘模型计算了2012年2月~2016年12月盖州青石岭震群ML ≥ 2.5地震的震源动力学参数。结果表明,震群的视应力为0~12bar,视应力随时间整体表现为突升突降中逐渐衰减的变化形态;应力降随震级的增大而增加,这与Nuttli的板内地震增加应力降(ISD)模型较吻合;通过对比1999年岫岩5.4级地震序列中ML ≥ 3.5地震的震源参数定标率发现,同震级的青石岭地震其应力降要小10倍左右,综合震源区地质构造、震源机制等因素认为,流体可能在青石岭震群的孕育和发生过程中起了重要作用。
[Key word]
[Abstract]
In this paper,by using the waveform data of medium and small earthquakes in Liaoning Province,we calculated the dynamic source parameters of 68 ML ≥ 2.5 earthquakes from February 2012 to 2016,based on the Brune model. The results demonstrated that the range of apparent stresses of the Qingshiling earthquake swarm is 0-12bar. Apparent stress decreases gradually with the characteristics of rising and dropping rapidly. The stress drop increases with magnitude,which is consistent with the result gained by Nuttli that intraplate earthquake follows the ISD model. Compared with the scaling relationship between stress drop and magnitude of ML ≥ 2.5 earthquakes in the 1999 Xiuyan MS5.4 earthquake sequence,the stress drop of medium and small earthquakes in the Qingshiling earthquake swarm are smaller with the same magnitude apparently,about 10 times,that indicates fluid intrusion may play an important role in development and occurring of earthquakes.
[中图分类号]
P315
[基金项目]
中国地震局地震科技星火计划项目(XH18013Y)资助