Maximum Magnitude Estimation of the Aftershocks of the M6 Earthquake Sequence, Mainland China
Session: New Insights Into the Preparatory Phase of Earthquakes From Tectonic, Field and Lab Experiments [Poster]
Type: Poster
Date: 4/19/2021
Presentation Time: 03:45 PM Pacific
Description:
It's well-known that large earthquakes are followed by abundant aftershocks which can last a long time and affect wide spatial areas. Among those aftershocks, the largest aftershock can cause additional injuries and damages, putting people and buildings at serious risk. Therefore, estimation of the largest aftershock's magnitude is of considerable importance for seismic hazard assessment and rescue operations. In this work, we estimate the largest aftershock's magnitude of the 69 M6 earthquake sequences in the Chinese Mainland which occurred from 1966 to the present by using the equation for the magnitude of the inferred largest aftershock proposed by Shcherbakov and Turcotte (2004). Moreover, we also analyze the results with different methods calculating the b-value and the magnitude of completeness MC and estimate the maximum magnitude of aftershocks with different time intervals after the mainshocks. The results show that the estimation trends to be a certain value when time intervals become larger and this value is consistent with the magnitude of the real largest aftershock for about 50% earthquake sequences. And the percentage of successful estimation is more than 40% in one day after the mainshock. In addition, the percentage of successful estimation varies with the type of earthquake sequence with about 31% for swarm type, 52% for mainshock–aftershock type, and 71% for isolated type. For different estimation methods, we find that the estimations are more accurate and have a lower coefficient of variation when using GFT and modified MAXC to calculate the value of MC and using the maximum likelihood method to calculate b-value. In a word, although we can't predict precisely when and where the largest aftershock will occur, the method we proposed can provide a rational magnitude estimation for the largest aftershock in a short period after the mainshock.
This study was supported by the National Key R & D Program of China (2017YFC1500502, 2018YFC1503305) and the National Key Research and Development Project (2018YFE0109700).
Presenting Author: Mengyu Xie
Student Presenter: No
Authors
Mengyu Xie Presenting Author xiemengyu@seis.ac.cn China Earthquake Networks Center |
Lingyuan Meng Corresponding Author menglingyuan@seis.ac.cn China Earthquake Networks Center |
Yanyan Han hanyy@seis.ac.cn China Earthquake Networks Center |
Yang Zang zangyang@seis.ac.cn China Earthquake Networks Center |
Yawei Ma yawei_m@seis.ac.cn China Earthquake Networks Center |
Yue Wang wangyue@seis.ac.cn China Earthquake Networks Center |
Shiguang Deng dengsg@seis.ac.cn China Earthquake Networks Center |
Jin Song songjinbent@seis.ac.cn China Earthquake Networks Center |
Xiaotao Zhang zhangxiaotao@seis.ac.cn China Earthquake Networks Center |
Wen Yang yangwen@seis.ac.cn China Earthquake Networks Center, Beijing, , China (Mainland) |
Haixia Shi shihaixia08@seis.ac.cn China Earthquake Networks Center, Beijing, , China (Mainland) |
Maximum Magnitude Estimation of the Aftershocks of the M6 Earthquake Sequence, Mainland China
Category
New Insights Into the Preparatory Phase of Earthquakes From Tectonic, Field and Lab Experiments