海拉尔CTBTO地震台阵下方小尺度非均匀体研究  

Study on the small-scale heterogeneities below the Hailaer CTBTO seismic array

作　　者：沈旭章[1,2] 张淑珍[1,3] 郑重[4] 郝春月[4] 

机构地区：[1]中国地震局兰州地震研究所,兰州730000 [2]中国地震局地震预测研究所兰州科技创新基地,兰州730000 [3]甘肃省地震局兰州观象台,兰州730000 [4]中国地震局地球物理研究所,北京100081

出　　处：《地球物理学报》2010年第5期1158-1166,共9页Chinese Journal of Geophysics

基　　金：国家自然基金项目(40904014);中国地震局地震预测研究所基本科研业务专项(2009A19)资助

摘　　要：利用国际禁核组织在海拉尔布设的小孔径地震台阵的16个深远地震波资料,分离出了P波波场中不相干的尾波.频率域中对波场扰动的研究表明,在0.5～3.0 Hz的频率范围内,观测到的波场扰动可以利用P波在随机介质中的散射进行解释.不同远震事件得到的稳定结果表明,在该台阵下方34 km厚的地壳和110 km厚的岩石层中可能存在相关长度为2.0～7.4 km的散射体.Incoherent seismic wavefield fluctuations recorded by Hailaer CTBTO seismic array are separated from 16 deep teleseismic events. The frequency-dependent intensities of the mean and fluctuation wavefields are analyzed. The observed wavefield fluctuations in the frequency range 0.5~3.0 Hz can be explained by scattering of the teleseismic P-wave front at random media-type structures. The stable and narrow range of the fluctuation parameters from these teleseismic events indicates evidence for scattered seismic phases which are generated inside the crust and lithosphere. The reasonable structural models contain heterogeneities with 2.0~7.4 km correlation lengths in the 34 km thick crust and the 110 km thick lithosphere.

关 键 词：散射 非均匀体 波场扰动 海拉尔CTBTO台阵 

分 类 号：P315[天文地球—地震学]