利用接收函数方法研究瑞丽—龙陵断裂两侧S波速度结构  

S-wave Velocity Structures in Both Sides of Ruili-Longling Fault Inversed by Receiver Function

作　　者：傅竹武[1] 王苏[1] 刘建华[2] 胥颐[2] 

机构地区：[1]云南大学地球物理系,昆明650091 [2]中国科学院地质与地球物理研究所,北京100029

出　　处：《地震研究》2007年第3期223-228,共6页Journal of Seismological Research

基　　金：国家自然科学基金项目(40664001);国家自然科学基金重点项目(40034010)共同资助.

摘　　要：利用研究区(23.9°～25.1°N,97.8°～99.0°E)内瑞丽—龙陵断裂两侧4个流动数字地震台记录到的宽频带远震P波波形数据进行接收函数反演,得到了台站下方0～100km深度范围内地壳、上地幔的S波速度细结构。结果如下:(1)在研究区内,以瑞丽—龙陵断裂为界,其西北侧Moho面深度为38～40km,东南侧Moho面深度约为38km。(2)断裂两侧地壳、上地幔S波速度结构存在显著差异,西北侧台站下方地壳和上地幔均存在大范围低速区;东南侧台站下方上地幔中无明显低速层,地壳内存在低速层,但范围和速度差都较小。(3)断裂两侧台站下方地壳和上地幔S波速度结构的较大差异,证明它们分属不同的构造单元。(4)研究区内的S波速度结构存在明显的横向非均匀性。The studied area is 23.9° -25. 1°N, 97.8° -99°E. The studied four digital seismic stations distributed in the both sides of the Ruili-Longling fault in the studied area. The S-wave velocity structures within the depth of 0-100 km beneath four stations are inversed from the broadband teleseismic P waveforms by receiver function. The results show ： （ 1 ） In the northwest side of the Ruili-Longling fault, the depth of Moho is 3840 km, and in the southeast side, the depth of Moho is about 38 km. （2） The S-wave velocity structures of the crust and upper mantle differ obviously in the both sides of the fault. In the northwest side, there are lower velocity zones in both crust and upper mantle beneath the stations; but in the southeast side, there are lower velocity zones only in the crust beneath the stations, and their range and velocity difference are small. （3） It is proved by the obvious difference of S-wave velocity structures between the both sides that the both sides of the Ruili-Longling fault belong to different structural units. （4） In the study area, the S wave velocity structure shows strong horizontal heterogeneity.

关 键 词：瑞丽-龙陵断裂 接收函数 S波速度结构 地壳 上地幔 云南 

分 类 号：P315.31[天文地球—地震学]