【作者】 孙克忠； 冯锐； 周海南； 姚政生；

【Author】 Sun Kezhong (Institute of Geophysics,Chinese Academy of Sciences) Feng Rui Zhou Hainan (Institute of Geophysics,State Seismological Bureau) Yao Zhengsheng (Seismologicai Institute of Lanzhou,State Seismological Bureau)

【机构】 中国科学院地球物理研究所； 国家地震局地球物理研究所； 国家地震局兰州地震研究所；

【摘要】 利用长周期数字地震仪的面波记录,研究了西藏-日本剖面的岩石圈构造,在资料处理中采取了纯路径效应提取和反演连续速度模型的计算技术,分别得到了大陆边缘、华北和青藏高原的岩石圈速度分布.前两个地区上地幔的速度结构相似,不仅岩石层较薄,而且存在高低速度层相间的分布,表现出活动构造的特点;青藏高原具有稳定地台的上地幔构造.但其地壳部分都属活动构造.这三个大地基本单元在构造上的差异可以从地壳追寻到上地幔200 km深处,反映出印度板块和太平洋板块的不同运动.据此推断华北、日本的地震活动在动力源上属于壳-幔性质,而青藏高原的地震属于壳内性质.更多还原

【Abstract】 Authors have utilized the data of surface wave recorded in long period digital seismometers to study the lithospheric structure in the Tibet-Japan profile.In the data processing certain computational approaches for pure-path effect of surface wave and continuous velocity model are adopted for obtaining velocity distributions in lithosphere of the Asian continental margin, North China and Tibetan plateau.The velocity structures of the upper mantle in the first two regions are somewhat similar in the characteristics of thin lithosphere and alternative distribution of high-low velocity,which show some features in active tectonics.The upper mantle structure in the Tibetan plateau is like that in a stable platform and the corresponding crustal structure shows active tectonic feature.The differences in the structures among above three tectonic units are likely to extent from the crust down to 200 km deep in the upper mantle,which indicates the different movements of Indian and Pacific ocean plates. It is inferred that the dynamic process of seismicity in North China and Japan is of crust-mantle in nature,but of crust in the Tibetan plateau.更多还原