摘要
2023年8月6日山东省平原县发生M_(S)5.5地震,由于地震发生在少震区且有感范围较大,此次地震引起了广泛关注.为了分析此次地震序列的余震活动特征和发震构造,本文基于深度学习方法,利用2023年8月6日至31日的连续波形数据,对8月6日山东平原M_(S)5.5地震序列进行余震检测,并结合地震精定位、震源机制解和区域应力场的反演结果,分析了此次地震序列的发震构造及孕震动力学机制.精定位结果表明,余震序列大致沿NE向展布,且表现出由主震震源位置向NE和地表方向迁移的特征;同时,在17~22 km深度还存在“双破裂”现象.震源机制解的NE走向节面与陵县—冠县断裂走向基本一致,结合精定位结果,认为陵县—冠县断裂为此次地震的发震断裂.区域构造应力场显示,震源区受控于NEE向水平挤压和NNW向水平拉张的构造应力作用,在该构造应力场作用下,发震断裂发生以右旋走滑为主的单侧破裂.
On August 6,2023,an M_(S)5.5 earthquake struck Pingyuan County,Shandong Province,China.This event has attracted considerable attention due to its occurrence in a region with lower seismic activity and its extensive perceptible range.To study the characteristics of aftershock activity and the seismogenic tectonics within this earthquake sequence,we utilize continuous waveform data from August 6th to 31st,2023,based on deep learning,to detect aftershocks of the M_(S)5.5 earthquake in Pingyuan County on August 6th.Subsequently,earthquake accurate relocation,focal mechanism solutions,and regional stress field inversion were analyzed to determine the seismogenic structure and preseismic dynamic mechanism of the earthquake sequence.The results indicate that the aftershock sequence is predominantly distributed along the NE direction,showing a migrating trend from the main shock hypocenter towards the NE and the ground surface.A special phenomenon of‘double rupture’is observed at depths ranging from 17 to 22 km.The NE-trending nodal plane of the focal mechanism solution is fundamentally aligned with the strike of the Lingxian-Guanxian fault.Considering the accurate relocation results,it is concluded that the Lingxian-Guanxian fault is the seismogenic fault of the earthquake.According to the obtained regional tectonic stress field,the focal area is controlled by the tectonic stress characterizing with NEE horizontal compression and NNW horizontal tension.Under the influence of this tectonic stress field,the Lingxian-Guanxian fault exhibits a unilateral rupture dominated by right-handed strike-slip.
作者
戴宗辉
郑建常
周连庆
曲均浩
王鹏
尹迪
DAI ZongHui;ZHENG JianChang;ZHOU LianQing;QU JunHao;WANG Peng;YIN Di(Shandong Earthquake Agency,Jinan 250014,China;Institute of Earthquake Forecasting,China Earthquake Administration,Beijing 100036,China;Shandong Institute of Petroleum and Chemical Technology,Dongying Shandong 257061,China)
出处
《地球物理学报》
北大核心
2025年第3期925-937,共13页
Chinese Journal of Geophysics
基金
国家重点研发计划项目(2018YFE0109700-2)
山东省地震局科技创新团队培育专项(TD202302)共同资助。
关键词
深度学习
双差定位
震源机制解
构造应力场
发震构造
Deep learning
Double-Difference relocation
Focal mechanism solution
Tectonic stress field
Seismogenic structure
