2019年12月26日湖北应城M4.9地震震源参数及余震活动性研究

Study on Source Parameters and Aftershock Activity of the M4.9 Yingcheng Earthquake on December 26,2019 in Hubei Province

摘要:

2019年12月26日湖北应城发生M4.9有感地震，其震感波及武汉大部分地区。为了分析该地震的发震构造及余震活动性，本文利用波形拟合方法测定了不同速度模型下该地震的震源机制解和矩心深度，并用Bootstrapping抽样反演技术评价反演结果；此外，利用模板匹配技术匹配主震和目录余震波形，获取了更为完整的余震目录。结果显示，应城地震以走滑为主，矩心深度7.5km左右，矩震级M_W4.67；应城地震有1个前震和17个余震，余震序列缺少M2~4事件，表明应城地震为孤立型地震，M2以下地震的b值为0.8。

Abstract:

The M4.9 Yingcheng earthquake on December 26,2019 in Hubei Province were felt by residents in most areas of Wuhan. In order to analyze the seismogenic structure and aftershock activity of this earthquake,the focal mechanisms and centroid depth of the earthquake are determined by waveform modelling with different velocity models. The inversion results are evaluated by bootstrapping sampling inversion technique. We use waveforms of the main shock and aftershocks to obtain a more complete aftershock catalog by template matching technique. The results show that the Yingcheng earthquake is dominant with strike slip movement,and the centroid depth is about 7.5km with the moment magnitude of M_W4.67. There are one foreshock and 17 aftershocks detected,but the aftershock sequence is in lack of M 2~4 events,which indicates that the Yingcheng earthquake is an isolated earthquake. The b-value of the earthquake sequence below M 2 is 0.8.