2022年门源6.9级地震前后b值时空特征研究  

Research on Spatio-Temporal Characteristics of b-Value before and after the 2022 Menyuan M S6.9 Earthquake

作　　者：郭瑛霞 朱益民 余腾[4] 李启雷[2] 张丽峰 余娜[1,2] GUO Yingxia;ZHU Yimin;YU Teng;LI Qilei;ZHANG Lifeng;YU Na(Geodynamics Field Observation and Research Station of Qinghai-Tibet Plateau,CEA,153 Qaidam Road,Xining 810000,China;Qinghai Earthquake Agency,153 Qaidam Road,Xining 810000,China;School of Land Science and Technology,China University of Geosciences,29 Xueyuan Road,Beijing 100083,China;School of Civil Engineering and Architecture,Suqian University,399 South-Huanghe Road,Suqian 223800,China)

机构地区：[1]中国地震局青海格尔木青藏高原内部地球动力学野外科学观测研究站,西宁市810000 [2]青海省地震局,西宁市810000 [3]中国地质大学(北京)土地科学技术学院,北京市100083 [4]宿迁学院建筑工程学院,江苏省宿迁市223800

出　　处：《大地测量与地球动力学》2023年第11期1155-1161,共7页Journal of Geodesy and Geodynamics

基　　金：中国地震局青海格尔木青藏高原内部地球动力学野外科学观测研究站专项;中国地震局震情跟踪定向工作任务(2023010114);青海省基础研究计划(2023-ZJ-770);宿迁学院地质环境与工程健康监测重点实验室项目。

摘　　要：为探讨青海门源M_S6.9地震前后b值变化特征,选取震前10 a进行时间扫描发现,震前震源区b值存在一定程度的下降,震后出现小幅回升,可能与震后应力释放有关。利用青海测震台网2000年以来的小震目录,在最小完备震级基础上进行b值空间扫描和Δb值计算发现,门源6.9级地震发生在低b值区域边缘,且震前1 a震源区Δb值变化不显著,表明门源地震的应力积累主要发生在2021年之前。对余震序列b值变化进行分析认为,早期b值变化可为后期余震的位置预测提供一定参考。In order to explore the variation characteristics of b-value before and after the Menyuan M S6.9 earthquake in Qinghai,we select a time scale of 10 years before the earthquake for time scanning.It’s found that the b-value in the focal area decreases to a certain extent before the earthquake,and then shows a small rebound after the earthquake,which may be related to the post-seismic stress release.Using the catalogs of small earthquakes from Qinghai seismic network since 2000,the spatial scanning of b-value and calculation ofΔb-value based on the minimum magnitude of completeness show that the Menyuan M S6.9 earthquake occurred at the edge of low b-value region,and theΔb-value in the focal area one year before the earthquake did not change significantly,indicating that the stress accumulation of the Menyuan earthquake mainly took place before 2021.The b-value change of aftershock sequence in early stage can provide some reference for the location prediction of later aftershocks.

关 键 词：门源6.9级地震 B值 时空特征 

分 类 号：P315[天文地球—地震学]