新疆及周边5次M_S7.0以上地震对天山地区小震活动的影响  

Influence of Five M_S7.0 earthquakes on Small Earthquake Activities in Xinjiang and its Surrounding Areas

作　　者：张琳琳[1] 唐兰兰[1] ZHANG Lin-lin;TANG Lan-lan(Earthquake Administration of Xinjiang Uygur Autonomous Region,Urumqi 830011,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：《地震》2018年第4期159-171,共13页Earthquake

基　　金：2016年度地震科技星火计划攻关项目(XH16041);中国地震局震情跟踪定向工作任务(2015010122)联合资助

摘　　要：2000年以来新疆及周边发生了5次M_S7.0以上地震,强震活动结束后,新疆境内局部应力将重新调整分布,从而导致一些地区小震活动速率增加,如2008年3月21日于田7.3级地震后,乌鲁木齐附近区域M_S1.6以上地震出现增强活动,同时对这些受强震活动影响的区域进行z值和b值扫描分析,结果表明:(1)强震前后负z值变化和b值的负变化一致;(2)初步认为,局部区域小震活动速率增加和小震增强区内对应中强震与强震震级大小、时间间隔以及震中距可能有关,强震震级越大,时间间隔愈短,距离越近,则小震活动速率增加明显,相对应的地震强度较大。There have been 5 earthquakes with magnitude above Ms7.0 since 2000 in Xinjiang and its surrounding areas. After these strong earthquakes, local stress in Xinjiang will be redistributed, which lead to the increase of the rate of small earthquakes activities in some areas, Such as Urumqi in Xinjiang Tianshan seismic zone, in which small earth-quakes with magnitude above MS 1.6 raised after the 21 March 2008 Ms7.3 Yutian, Xinjiang earthquake. Through the analysis of space-time scanned images for z-value and b-value in these regions affected by strong earthquake activities. The research results show that：① The change of negative z-value and b value area is consistent before and after strong earthquakes. ② A preliminary study suggests that the increase Of small earthquake activity rate for local area and its forthcoming moderate earthquake, which are related to the magnitude of strong earthquake and epicenter distance, the greater the magnitude of strong earthquake, the shorter the time interval, the closer the distance, then the rate of small earthquake activities increases more obviously, and the intensity of its corresponding medium-earthquake is likely to be greater.

关 键 词：强震活动 小震活动速率 z值 B值 新疆天山地区 

分 类 号：P315.7[天文地球—地震学]