汶川8.0级地震动卓越周期分析*

(1.云南省地震局,昆明 650224; 2.四川省地震局,成都 610041)

汶川8.0级地震; P波; S波; 卓越周期; 震中距

Predominant Period of the Wenchuan MS8.0 Earthquake Motion
YE Jian-qing1,SU Jin-rong2,CHEN Hui1

(1.Earthquake Administration of Yunnan Province,Kunming 650224,Yunnan,China)(2.Earthquake Administration of Sichuan Province,Chengdu 610041,Sichuan,China)

Wenchuan MS8.0 earthquake; P wave; S wave; predominant period; epicenter distance

备注

利用四川省地震局测震台网记录的汶川8.0级地震波形资料,采用频谱分析方法,研究了汶川地震P、S波卓越周期与震中距的关系,同时给出了8级主震和6.1级余震的卓越周期与震中距的关系。讨论了震害与地震动卓越周期的相关性,分析显示龙门山断裂带两侧地块的卓越周期存在明显差异,东侧华南块体的卓越周期小于西侧地块的卓越周期,表明东侧华南块体的坚硬程度比西侧川西高原的巴颜喀拉和川滇块体的高。

Based on the frequency spectrum analysis of the seismic waves recorded by the Sichuan seismic network during the Wenchuan earthquake,we study the relation between the predominant periods of P and S waves and the epicentral distance,and give the predominant period-epicentral distance relations of the Wenchuan mainshock and the M6.1 aftershock respectively.The predominant periods are different on two sides of the Longmenshan fault.The predominant period on the South China block,the east side of Longmanshan fault,is less than that on the west side.This suggests that the South China block is harder than the Bayankala and Sichuan-Yunnan blocks.