祁连山主动源观测台站场地响应分析  

Site response of active-source observation stations in the Qilian Mountains

作　　者：姜秀璇 郭晓[1,2] 范兵 邹锐[1,2] JIANG Xiuxuan;GUO Xiao;FAN Bing;ZOU Rui(Lanzhou Institute of Seismology, CEA, Lanzhou 730000, Gansu, China;Gansu Lanzhou Geophysics National Observation and Research Station, Lanzhou 730000, Gansu, China)

机构地区：[1]中国地震局兰州地震研究所,甘肃兰州730000 [2]甘肃兰州地球物理国家野外科学观测研究站,甘肃兰州730000

出　　处：《地震工程学报》2021年第6期1343-1351,共9页China Earthquake Engineering Journal

基　　金：中国地震局地震科技星火计划(XH20060);国家重点研发计划课题(2018YFC1503206)。

摘　　要：场地响应是精确测定震源参数和稳健估计出高精度地壳介质衰减变化的关键影响因素之一,采用H/V尾波谱比法,对祁连山主动源观测台网中40个短周期观测台站的场地响应进行了分析。结果表明,祁连山主动源观测台网中40个短周期观测台站均存在不同程度的放大(衰减)作用,根据40个台站观测波形的尾波场地响应曲线特征,可将其分为平坦类、放大类、高频衰减类,在1~20 Hz频段内部分台站场地响应曲线呈现平坦,场地响应值为1~2倍;而大部分台站在不同频段有明显放大(衰减)作用,场地响应值为0.3~9倍。台站台基岩性可能是决定场地响应曲线特征和大小的主要因素,且与台基介质密度具有反相关性。Site response is one of the key factors affecting the accurate determination of source parameters and robust estimation of high-precision crustal medium attenuation.In this paper,the site responses of 40 short-period observation stations in the active-source observation network of Qilian Mountains were analyzed by using the H/V spectra ratio method.The results showed that the 40 short-period observation stations in the Qilian Mountains active-source observation network have amplification(attenuation)effect in varying degrees.According to the characteristics of coda site response curves of 40 stations,they can be divided into three types:flat,amplification,and high-frequency attenuation.The site response curves of some stations are flat in the frequency band of 1-20 Hz,and the site response value is 1-2 times;Most stations have obvious amplification(attenuation)effect in different frequency bands,and the site response value is 0.3-9 times.The lithology of station foundation may be the main factor determining the characteristics and size of site response curve,which has an inverse correlation with the medium density of station foundation.

关 键 词：甘肃地区 主动源观测台网 H/V谱比法 场地响应 

分 类 号：P319[天文地球—固体地球物理学]