Sg、Sn震相对新疆及相邻地区速报地震定位的影响分析  

Sg,Sn SEISMIC PHASE INFLUENCE ON QUICK EARTHQUAKE LOCATION IN XINJIANG AND ITS ADJACENT AREAS

作　　者：赵石柱[1] 张勇[1] 闫新义 ZHAO Shi-zhu;ZHANG Yong;YAN Xin-yi(Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China)

机构地区：[1]新疆维吾尔自治区地震局,新疆乌鲁木齐830011

出　　处：《内陆地震》2021年第3期237-244,共8页Inland Earthquake

基　　金：新疆地震科学基金项目(201905、201903)。

摘　　要：选取2014年1月~2019年3月M_(s)≥4.0的新疆地震台网速报地震,通过标注初至震相Pg、Pn震相,对震中位置达到最大包围后,再标注续至震相Sg、Sn震相,分析增加Sg、Sn震相对新疆及相邻地区速报地震定位的影响。结果表明:网内地震,除了西昆仑和阿尔金山地区,新疆其他地区均可只标注Pg、Pn震相定位震中位置,且与中国地震台网中心统一目录的震中偏差不超过10 km;西昆仑及阿尔金山地区,标注3~5个Sg、Sn震相时,最接近中国地震台网统一目录的结果。网缘或网外地震,在最大空隙角超过180°时,就可能会出现震中反向。当出现震中反向结果时,标注Sg、Sn震相≥3个时,就能避免震中反向。当Sg、Sn震相标注3~7个时,与中国地震台网中心统一目录结果最接近。Selecting earthquake magnitude above 4 from January 2014 to March 2019,the epicenter is surrounded enough by recognition of first arrival phase Pg,Pn,recognize continue phase Sg,Sn,and then analyse the influence of Sg,Sn seismic phases on quick earthquake location in Xinjiang and its surrounding areas.The results show that for earthquakes in the network,except for the West Kunlun and Altun mountain areas,the epicenter position can be located only by marking Pg,Pn seismic phases,and the epicenter deviation from the unified catalogue of the center of China seismic network is no more than 10 km;In West Kunlun and Altun Mountains,when 3~5 seismic phases of Sg and Sn are marked,it is close to the results of the unified catalogue of China seismic network.When the maximum gap angle exceeds 180°,the epicenter reversal may occur.When the result of epicentral inversion occurs,the epicentral inversion can be avoided when the seismic phases of SG and Sn are marked≥3.When 3~7 seismic phases of Sg and Sn are marked,the results are close to the unified catalogue of China Seismic Network Center.

关 键 词：Sg、Sn震相 地震定位 震中反向 震中偏差 

分 类 号：P315.7[天文地球—地震学]