内蒙古地区场地响应区域特征分析
详细信息 本馆镜像全文    |  推荐本文 | | 获取馆网全文
摘要
本文以内蒙古地区台站分布、地质构造和地震活动性为基础,将内蒙古的大部地区划分为三个研究区域分别进行了场地响应研究。对近几年积累的大量ML≥3.0级以上地震,共计39个台站记录到的124次地震事件的785条波形,根据S波的观测振幅谱,采用遗传算法分别反演了三个区域的介质非弹性衰减系数和台站场地响应,并对其进行了讨论。本文得到的介质衰减模型和台站场地响应,将对台网测定ML震级需要考虑的量规函数、台站校正值等提供重要参考。研究结果表明:除个别台站存在场地放大或缩小的响应外,绝大多数台站的场地响应表现出一定的区域性特征;西部区域(除极个别台站外)对高频存在明显衰减;中东部区域对整个频段的反映都比较稳定;东部区域对整个频段存在明显放大,这与该区域覆盖层厚度大相吻合。
Inner Mongolia region is divided into three areas on the basis of seismic activity, station layout and geological tectonics, in which 785 waveform recordings of 124 earthquakes with ML equal or greater than 3.0 from39 stations are processed in this study. We applied a lag-window spectral technique to obtain a stable Fourier spectrum of signals and noises. By adopting Genetic algorithm, reflected respectively transmission medium inelastic attenuation coefficient and station site response of three different tectonic regions are analyzed in order to obtain medium attenuation model and spectrum of station site response, which will be significant in providing important reference to earthquake magnitude corrected value of station. The results show that site response of most stations is of regional characteristics. In specific, high frequency shows strong attenuation for stations in western region;whereas no strong attenuation from stations in middle east region; remarkable enhancement of whole frequency arrangement from stations in eastern region. The above observation is in good agreement with the thickness variation of covering layer in the area.
引文
华卫,陈章立,郑斯华,2010.利用不同方法估算流动台站的场地响应.地震,30(3):30—43.
    刘杰,郑斯华,黄玉龙,2003.利用遗传算法反演非弹性衰减系数、震源参数和场地响应.地震学报,25(3):211—218.
    赵翠萍,张智强,夏爱国,刘杰,2004.利用数字地震波资料研究新疆天山中东段地区的介质衰减特征.防灾减灾工程学报,24(3):300—305.
    朱新运,2012.衰减、场地响应等地震波传播信息综合研究.国际地震动态,(12):0235—4975.
    章文波,谢礼立,郭明珠,2001.利用强震记录分析场地的地震反应.地震学报,23(6):604—614.
    Atkinson G.M.,Mereu R.F.,1992.The shape of ground motion attenuation curves in Southeastern Canada.Bul1.Seism.Soc.Am.,82(5):2014—2031.
    Atkinson G.M.,Boore D.,1995.New ground motion relations for eastern North America.Bull.Seism.Soc.Amer.,85:17—30.
    Brune J.N.,1970.Tectonic stress and the spectra of seismic waves from earthquakes.J.Geophys.Res.,75:4997—5009.
    Chael E.,1987.Spectral scaling of earthquakes in the Miramichi region of New Brunswick.Bull.Seism.Soc.Am.,77:347—365.
    Moya A.,Aguirre J.,Irikura K.,2000.Inversion of source parameters and site effects from strong ground motion records using genetic algorithms.Bull.Seis.Soc.Amer.,90(4):977—992.

版权所有:© 2023 中国地质图书馆 中国地质调查局地学文献中心