四川九寨沟7.0级地震强震动记录及特征分析

Strong Ground Motion Records and Its Characteristics in Jiuzhaigou M_S7.0 Earthquake on August 8,2017

对"国家强震动台网中心"在2017年8月8日四川九寨沟7.0级地震中获取的66组强震记录进行整理、基线校正和滤波等常规处理,分析记录的幅值以及频谱特征。此次地震记录到的强震记录PGA范围0.98~185gal,最大PGA为距震中最近的51JZB(九寨百河台)NS向获取;此次地震仪器烈度范围为0.93~6.8,与四川九寨沟7.0级地震烈度图对比结果显示仪器烈度与宏观调查烈度误差在1度以内;通过观测数据与霍俊荣和第五代《中国地震动参数区划图》地震动衰减关系对比,发现霍俊荣衰减关系更适用于此次地震的加速度衰减;用克里格插值方法绘制了水平向PGA等值线分布图,发现震中附近等值线呈NW向分布;分析了不同震中距和不同场地条件下典型台站的反应谱特性。

In this study,66 groups of three、|component acceleration records of the M S7.0 earthquake that occurred in Jiuzhaigou County,Sichuan Province,China,on August 8,2017 recorded by China Strong Motion Net Center(CSMNC)are analyzed and processed,including the base lines correction and filtering,used for comparing the characteristics of the amplitude and response spectra of the strong motion records.The results show that the peak ground acceleration(PGA)value ranges from 0.98~185 gal,and the largest PGA was recorded by the closest station,51JZB station.The instrumental intensity of the earthquake ranges from 0.93~6.8,and the comparison between the instrumental intensity and the seismic intensity map of Jiuzhaigou M S7.0 earthquake indicates that the instrumental intensity and macroseismic survey intensity differs in 1 degree.According to the comparison among the observation data,the ground motion attenuation relationship proposed by Huo Junrong,and the ground motion parameter zoning map of China(fifth generation),it is found that the attenuation relationship of Huo Junrong is more suitable for the acceleration attenuation of the Jiuzhaigou earthquake.The horizontal PGA contour map was drawn using the Kreager interpolation method,and the contours near the epicenter show NW distribution.