[关键词]
[摘要]
利用2016年云南测震台网记录到的地脉动数据,运用H/V谱比法计算分析了47个测震台站在0.1~20.0Hz频段内的场地响应。选取2012~2016年期间云南测震台网记录到的ML≥2.5地震做单台震级偏差统计分析,挑出受场地放大作用而出现单台震级大于台网平均震级的台站做去场地放大校正,然后重新统计单台震级偏差情况。计算结果显示云南测震台网的台站受台基条件和所处位置等地质构造因素影响,均存在一定程度的场地放大作用,大部分台站场地响应的卓越频率为1~6Hz,放大倍数为2~4倍。受场地放大作用的影响,大姚、芒市等19个台站的单台ML震级大于台网平均震级。在去除场地放大作用后,台站单台震级与台网平均震级的偏差有所减小。
[Key word]
[Abstract]
Using micro tremors noise data recorded by the Yunnan Digital Seismic Network in 2016, we analyzed the site response of 47 seismic stations in 0.1~20Hz frequency band, based on the H/V spectral ratio method. We analyzed the single magnitude deviation recorded from earthquakes of ML ≥ 2.5 in the Yunnan Digital Seismic Network from 2012 to 2016. The stations with single magnitude greater than the average magnitude of network are selected, and their single magnitude deviation are recalculated. The results show that all stations of the Yunnan Digital Seismic Network have a degree of site amplification because of many factors, such as the situation of site platform and geological structure. For most seismic stations, the excellent site response frequency is 1~6Hz, and the amplification is 2~4 times. Due to the effect of the site amplification, the single ML magnitudes of 19 stations such as Dayao and Mangshi are greater than the average magnitude of the network. The deviations between the single magnitude and the average magnitude of the network are decreased, after the removal of the site amplification.
[中图分类号]
P315
[基金项目]
中国地震局测震台网青年骨干培养专项(20170621)、云南省地震局青年地震科学基金(2018k02)共同资助