反投影全球子台网P波记录研究2010年4月14日玉树地震破裂过程  

Imaging the rupture of 14 April, 2010 Yushu earthquake using back-projection of global subarray P-waves

作　　者：徐彦[1] 张俊伟[1] 苏有锦[1] 

机构地区：[1]云南省地震局,昆明650224

出　　处：《地球物理学报》2011年第5期1243-1250,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41004022);云南省科技计划面上项目(2010CD129);云南省政府十项措施(数字地震学参数在地震预测预报中的应用研究)资助

摘　　要：我们运用反投影远震P波研究了2010年4月14日玉树地震的破裂过程.通过台站响应函数对从IRIS下载的经过波形筛选的206个震中距在30°～95°间的台站进行选取.29个能够得到最好台站响应函数且波形相似度高的台站的记录被用于最终的反投影研究.在研究中我们运用4阶方根叠加法和2 s窗长、1 s滑动的滑动窗对总时长为100 s,始于P波前20 s的波形记录进行反投影.反投影结果显示玉树地震震源破裂时间为20 s,破裂尺度为60 km.在玉树地震的整个破裂过程中能量主要在两个时间和空间上释放.一个能量释放点是震后6 s,位于震中附近;另一个是震后12 s,位于震中位置东南,靠近结古镇的区域,且这次能量释放是玉树地震破裂过程中能量最大的.最大能量释放地点和实际震害最重的区域相吻合.反投影远震P波得到的震源破裂模型是软件自动生成的震动图的有效补充,能为震后应急救援服务.We present the rupture details of Yushu earthquake from the back projection of teleseismic P waves. By applying ARF we get 29 out of 206 stations with distance range of 30 to 95 degree, which have a good array response function and high waveform cross-correlation coefficient, in the final back projecting process. We apply 4th root stack method and moving window with 2 sec length and 1 sec step to 100 sec long waveform starting 20 sec before P arrival. The back projection result shows that the total rupture time of the Yushu earthquake is 20 sec, and the rupture length is 60 kin. The energy release of the Yushu earthquake is mainly concentrated at two time-space points. One is about 6 sec after the origin time and close to the epicenter. The second energy burst is 12 sec after the origin time and located southeast of the epicenter closing to the Jiegu county. This energy burst is the biggest energy burst in the whole source rupture process. The biggest energy burst is close to the heavily damaged area. The source rupture model from the back projection can aid the earthquake rapid response and rescue and can be a complement to ShakeMap.

关 键 词：玉树地震 反投影 破裂过程 

分 类 号：P315[天文地球—地震学]