2014年新疆于田M_S7.3地震及余震序列定位研究  

Research on Location of Yutian M_S7. 3 Earthquake and Aftershocks Sequence in 2014

作　　者：冉慧敏[1] 魏斌[1] 张志斌[1] 赵庆[1] 

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：《地震研究》2014年第4期565-571,669,共7页Journal of Seismological Research

基　　金：地震科技星火计划青年项目(XH13028Y);测震台网青年骨干培养专项(20120105)联合资助

摘　　要：使用区域一维速度模型,利用单纯形法,结合和田台阵的方位角测定了2014年2月12日新疆于田MS7.3地震的主震位置。使用双差定位方法对于田主震和465次余震序列进行了重新定位。结果表明：NS、EW和UD3个方向的平均相对误差分别为0.13km、0.14 km、0.15km,平均走时残差为0.012s。余震整体分布呈北东向展布,并向主震的西南和北东两个方向延伸,主震的西南方向长近40km、宽约30km,北东方向长近20km、宽约20km,震源深度集中在5-15km。余震序列的空间形态沿破裂显示了分段和非均匀特征：主震的西南方向地震数量较多,展布较宽,且近南北向分布,震源深度优势分布在5-15 km之间;北东方向地震较少,震源深度优势分布在5-10km之间;靠近山脉的地震震源要比远处的深。余震序列的时间特征为在震后的3天内,震源深度集中在5-15 km,此后的震源深度集中在5-10km,震源深度总体呈现变浅的趋势。Based on regional 1-D velocity model and combined with the azimuth of Hetian arrays, we determined the epicenter location of Yutian Ms7.3 main shock on Feb. 12, 2014 by using the simplex algorithm, and relocated the epicenter location of Yutian Ms7.3 main shock and 465 aftershocks by use of the double-difference location method. The result show that the average relative errors of location accuracy are 0. 13 km, 0. 14 km, 0. 15 km in NS, EW and UD respectively, and the average travel time residual is 0. 012 s. The overall spatial distribution of aftershocks is in NE direction, and extends to southwest and northeast of main shock. The aftershock distribu- tion area in the southwest of main shock are about 40 km long and 30 km wide, those in the northeast are about 20 km long and 20 km wide, and the focal depths focus on 5 - 15 km. The spatial distribution characteristic of aftershock sequence shows segmental and inhomogeneous along the rupture. The earthquakes in the southwest of the main shock are more, and distribute wide in NS, the focal depths of them mainly distribute in 5 - 15 kin. However, the earthquakes in the northeast of the main shock are less and the focal depth of them mainly distribute in 5 - 10 km. The focal depth of the aftershock near the mountain is deeper than that of the far. The temporal characteristic of aftershocks sequence are that the focal depth focus on 5 - 15 km within 3 days after the main shock, thereafter they are 5 - 10 kin, and show the tendency of becoming shallower and shallower.

关 键 词：于田MS7.3地震 单纯形法 方位角 双差定位 重定位 

分 类 号：P315.7[天文地球—地震学]