2017年青海称多震群活动特征及其对中强震的指示意义

Characteristics of 2017 Chengduo,Qinghai earthquake swarm and its implications for moderate earthquakes

2017年称多震群为青海省称多县第一次记录到的M_(L)3.0以下小震群活动,发生在唐古拉地震带M_(S)5.0地震平静被打破且M_(L)4.0以上地震活跃的背景下。为研究2017年称多震群对青海及邻区后续震情的影响,对该震群的活动特征、震群参数、震源机制、视应力等进行了计算和分析。结果主要表明:该震群为前兆震群,震群中地震以走滑为主。对比唐古拉地震带历史震群活动对应中强震情况,分析认为本次震群的发生表明唐古拉地震带未来中强震发震迹象增强,应注意加强对其震情跟踪研究。

Chengduo earthquake swarm of 2017,an M_(L)<3.0 earthquake swarm recorded for the first time in Chengduo Country,Qinghai Province,occurred under the background that the calm of M_(S)5.0 earthquakes in Tanggula seismic belt was broken and M_(L)>4.0 earthquakes were active.To study the influence of the Chengduo earthquake swarm on subsequent earthquakes in Qinghai and its adjacent areas,the activity characteristics,swarm parameters,focal mechanism,and apparent stress of the swarm were calculated and analyzed.The results showed that the earthquake swarm is a precursor swarm,in which the earthquakes are mainly strike-slip.By comparing with historical swarm activities in Tanggula seismic belt,it is considered that the occurrence of this swarm indicates that the occurrence signs of medium and strong earthquakes in Tanggula seismic belt in the future are enhanced,and attention should be paid to strengthening the earthquake tracking research.