A high-resolution seismic catalog for the 2021 M_(S)6.4/M_(W)6.1 Yangbi earthquake sequence, Yunnan, China: Application of AI picker and matched filter  

作　　者：Yijian Zhou Abhijit Ghosh Lihua Fang Han Yue Shiyong Zhou Youjin Su 

机构地区：[1]Institute of Geophysics,China Earthquake Administration,Beijing 100081,China [2]Department of Earth Sciences,University of California,Riverside,California 92521,USA [3]Institute of Theoretical and Applied Geophysics,Peking University,Beijing 100871,China [4]Yunnan Earthquake Agency,Yunnan 650224,China

出　　处：《Earthquake Science》2021年第5期390-398,共9页地震学报（英文版）

基　　金：supported jointly by National Key R&D Program of China(No.2018YFC1503400);National Natural Science Foundation of China projects(Nos.41774067,U2039204,and 42074046);Science for Earthquake Resilience(No.XH20082Y);US National Science Foundation(No.1941719);University of California at Riverside.

摘　　要：We present a high-resolution seismic catalog for the 2021 M_(S)6.4/M_(W)6.1 Yangbi sequence.The catalog has a time range of 2021-05-01 to 2021-05-28,and contains~8,000 well located events.It captures the features of the whole foreshock sequence and the early aftershocks.We designed a detection strategy incorporating both an artificial intelligent(AI)picker and a matched filter algorithm.Here,we adopt a hybrid AI method incorporating convolutional and recurrent neural network(CNN&RNN)for event detection and phase picking respectively(i.e.CERP),a light-weight AI picker that can be trained with small volume of data.CERP is first trained with detections from a STA/LTA and Kurtosis-based method called PAL,and then construct a rather complete template set of~4,000 events.Finally,the matched filter algorithm MESS augments the initial detections and measures differential travel times with cross-correlation,which finally results in precise relocation.This process gives 9,026 detections,among which 7,943 events can be well relocated.The catalog shows as expected power-law distribution of frequency magnitude and reveals detailed pattern of seismicity evolution.The main features are:(1)the foreshock sequence images simple fault geometry with consistent strike,but also show a variable event depth along strike;(2)the mainshock ruptures the same fault of the foreshock sequence and activate conjugate faults further to the southeast;(3)complex seismicity are developed in the post-seismic period,indicating complex triggering mechanisms.Thus,our catalog provides a reliable basis for further investigations,such as b-value studies,rupture process,and triggering relations.

关 键 词：Yangbi earthquake seismic catalog earthquake detection AI picker matched filter. 

分 类 号：P315.7[天文地球—地震学]