Abstract:
With waveform data of 110 earthquakes occurred during April 2009 to September 2016 recorded by stations of Beijing and its adjacent regional seismic networks, we studied the
Q value and site response of Beijing and its adjacent areas by the methods of Atkinson and Moya respectively. Combined with the tectonic settings, the research area is divided into three zones:Plain area (1), Yanhuai basin (2) and Yanshan mountain area (3).We got
Q value of each zone respectively, discussed the differences and causes of
Q value in each zone, and compared them with previous results.
Q value of each zone is:
Q1(
f)=182.00
f0.7073,
Q2(
f)=191.81
f0.6215,
Q3(
f)=486.12
f0.3506.We obtained 126 stations' site responses (including 51non-bedrock stations and 75 bedrock stations). The results show that, in the frequency range of 1~20 Hz, the non-bedrock station site responses (all in Plain area) have common features of amplification at low frequency and attenuation at high frequency. The maximum of the site response value reaches 8, the critical frequency between amplification and attenuation is about 6~13 Hz, and the lowest site response value is below to 0.1. Most of bedrock stations' site amplification effects at low frequency are not obvious, and the site responses of bedrock stations in Yanshan mountain area are relative more stable.