2021年云南双柏MS5.1地震序列的快速检测与精定位研究

(1.福建省地震局,福建 福州 350003; 2.中国地震局地球物理研究所,北京 100081; 3.中国地震局厦门海洋地震研究所,福建 厦门 381000; 4.云南省地震局,云南 昆明 650224; 5.中国地震局震源物理重点实验室,北京 100081; 6.防灾科技学院,河北 三河 065201)

双柏地震; 深度学习; 地震检测; 双差定位; 发震断层

Fast Detection and Relocation of the 2021 Shuangbai MS5.1 Earthquake Sequences in Yunnan
LIAO Shirong1,YANG Ting2,ZHANG Hongcai1,3,FAN Liping2,QIN Min4,FANG Lihua2,5,6

(1.Fujian Earthquake Agency,Fuzhou 350003,Fujian,China;2.Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;3.Xiamen Institute of Marine Seismology,China Earthquake Administration,Xiamen 381000,Fujian,China;4.Yunnan Earthquake Agency,Kunming 650224,Yunnan,China;5.Key Laboratory of Earthquake Source Physics,China Earthquake Administration,Beijing 100081,China;6.Institute of Disaster Prevention,Sanhe 065201,Hebei,China)

the Shuangbai earthquake; deep learning earthquake detection; double difference location; seismogenic fault

备注

2021年6月10日云南双柏发生MS5.1地震,6月28日又发生ML4.6地震。采用基于深度学习的地震检测算法,对主震及其后20 d的连续波形进行检测,并开展了震相关联、地震绝对定位、震级测定和精定位研究,获得了此次地震的完整序列目录。共检测到1 713个地震,比人工多检测出623个地震,震级分布范围为ML-0.8~5.1。研究表明:双柏MS5.1地震和ML4.6地震的余震整体呈NNE向分布,两个地震的发震断层较陡,近直立分布。发震断层北东侧浅、西南侧深,且断层面较窄。ML4.6地震的余震整体位于MS5.1地震余震序列的底部,显示2个地震可能是独立的事件。分析认为这两次地震的发震断层为楚雄—建水断裂西南侧的一条隐伏走滑断层。
At 19:46 on June 10,2021,an MS5.1 earthquake occurred in Shuangbai County,Yunnan Province,and another ML4.6 earthquake succeeded on June 28.In this paper,the earthquake detection algorithm based on deep learning is used to detect the continuous seismic waveforms 20 days after the mainshock.Then,phase association,magnitude measurement,earthquake location and relocation are carried out,and a complete catalog of earthquake sequence is obtained.The sequence contains a total of 1 713 earthquakes,among which 623 more earthquakes are detected than by the manual method.The magnitudes(ML)ranges from-0.8 to 5.1.The study shows that the aftershocks of the Shuangbai MS5.1 earthquake and the ML4.6 earthquake are generally distributed in NNE direction,and the seismogenic faults of the two earthquakes are steep and nearly vertical.The seismogenic fault is shallow in the northeast and deep in the southwest,and the fault plane is narrow.The aftershocks of the ML4.6 earthquake are located below the aftershocks of the MS5.1 earthquake; this indicates that the two main earthquakes may be independent events.The seismogenic fault of the two earthquake is a concealed,strike-slip fault located to the southwest of the Chuxiong-Jianshui fault.