2021年11月30日西藏双湖M_(S)5.8地震总结  

Summary of the Shuanghu M_(S)5.8 earthquake in Tibet on November 30,2021

作　　者：高锦瑞 索朗占堆 姜祥华 解孟雨 黎明晓[2] 赵静[2] GAO Jinrui;Suolangzhandui;JIANG Xianghua;XIE Mengyu;LI Mingxiao;ZHAO Jing(Earthquake Agency of Tibet Autonomous Region,Lhasa 850000,China;China Earthquake Networks Center,Beijing 100045,China)

机构地区：[1]西藏自治区地震局,中国西藏850000 [2]中国地震台网中心,中国北京100045

出　　处：《地震地磁观测与研究》2022年第5期169-178,共10页Seismological and Geomagnetic Observation and Research

基　　金：中国地震局地震科技星火计划(项目编号:XH21031);地震预测开放基金(项目编号:2021EFOF01);2021年度震情跟踪定向工作任务(项目编号:2021010129)。

摘　　要：2021年11月30日西藏双湖M_(S)5.8地震发生在多玛—尼玛断裂附近,震源机制解显示为拉张型破裂,与羌塘块体的主要变形特征一致。本文对此次地震的构造背景、震源参数、序列特征和震前异常特征及周边强震危险性进行分析总结。由余震活动特征和b值、h值等分析可知,此次地震为主震—余震型序列,且余震衰减速度较快。通过对震前异常的梳理总结,发现在地震发生前,震中附近区域存在地震发生率指数高值异常、调制比高值异常和W_(q)值高值异常。这些基于小震目录计算的多种地震学参数可为地震监测能力较低地区的中强地震预测提供一些依据。通过对双湖M_(S)5.8地震的总结,以期为西藏西部监测能力较低地区的强震中短期预报积累震例资料,并为今后西藏地区地震台网更好地服务于地震预测预报提供合理的规划和建议。On November 30,2021,the Shuanghu M_(S)5.8 earthquake in Tibet occurred near the Doma-Nima fault.The focal mechanism solution shows a tensile fracture,which is consistent with the main deformation characteristics of the Qiangtang block.In this paper,the tectonic background,focal parameters,sequence characteristics,anomaly characteristics before the earthquake,and the risk of strong earthquakes around the earthquake are analyzed and summarized.According to the characteristics of aftershock activity and the calculation results of theb value and h value,this earthquake is a mainshock aftershock type sequence,and the aftershock attenuation speed is fast.By combing and summarizing the anomalies before the earthquake,it is found that there are high-value anomalies of earthquake incidence index,high-value anomalies of modulation ratio,and W_(q) value anomalies near the epicenter before the earthquake.These seismological parameters calculated based on the catalogue of small earthquakes can provide some basis for the prediction of moderately strong earthquakes in areas with low seismic monitoring capability.Through the summary of the Shuanghu M_(S)5.8 earthquake,we accumulate earthquake case data for the medium and short-term prediction of strong earthquakes in areas with a low monitoring capability in western Tibet,and provide reasonable suggestions on how to better serve earthquake prediction in the future station network planning in Tibet.

关 键 词：双湖M_(S)5.8地震 地震序列 震前异常 地震学参数 

分 类 号：P315[天文地球—地震学]