摘要
采用分布于鄂尔多斯地块及其周缘的32个地震台站记录到的19次地震事件共487条数字化波形记录,利用遗传算法反演得到了整个鄂尔多斯地块地壳内S波的三段几何扩散参数、S波非弹性衰减Q值随频率变化的关系式、32个台站的场地响应以及19次地震的震源参数.计算结果表明,鄂尔多斯地块地壳内S波非弹性衰减在1Hz处的Q值比地质构造活跃地区的结果要大得多.32个地震台站的场地响应在高频部分除个别台站外基本没有表现出明显的放大效应,但在低频区间部分台站之间有一定的差异.19次地震事件的地震矩对数值与震级ML有很好的线性关系.
We present attenuation characteristics of S waves in the crust of Ordos Massif. Using 487 pieces of digital oscillograms of 19 seismic events recorded at 32 seismologic stations located on Ordos massif and its surroundings, we calculate the parameters of three segments attenuation and the relation of inelastic attenuation Q value with frequency in the crust of Ordos Massif, the site responses of 32 stations and the source parameters of 19 events by the genetic algorithm. The result shows that： Q value at 1Hz of S waves in the crust of Ordos Massif is much larger than the result in the geologically active tectonic region. The site responses of 32 stations in the high-frequency section do not show clear amplifying effect except one or two stations, while in the low-frequency section, there is difference among the stations. The logarithmic value of seismic moment and the magnitude ML of 19 seismic events has a very good linear relationship.
出处
《地震学报》
CSCD
北大核心
2005年第5期488-497,共10页
Acta Seismologica Sinica
基金
国家"十五"重点科技攻关项目(2004BA601B01-04-03)
地震科学联合基金(104047)
中国地震局分析预报中心地震图象与数字化地震观测资料应用实验室资助.
关键词
鄂尔多斯地块
几何扩散
非弹性衰减
遗传算法
Ordos Massif
geometrical attenuation
inelastic attenuation
genetic algorithm
