Moho面和上地幔间断面大尺度地形起伏的低阶球谐分析  

The Low Degree Spherical Harmonic Analysis on the Large Scale Topographies of the Moho and the Upper Mantle Discontinuities

作　　者：何小波[1] 周蕙兰[1] 

机构地区：[1]中国科学院研究生院计算地球动力学重点实验室,北京100049

出　　处：《中国科学院研究生院学报》2005年第3期315-321,共7页Journal of the Graduate School of the Chinese Academy of Sciences

基　　金：国家自然科学基金 (4 0 3 740 0 9;40 2 3 40 47)资助

摘　　要：对全球地形高程和Moho面深度 (CRUST2 0模型 )及上地幔各间断面深度数据进行了球谐分析 .在此基础上 ,通过叠加前 4阶模式得到了各类数据的空间大尺度分布信息 ,通过叠加振幅平方值最大的 4项得到了各类数据的空间主能量分布 .结果表明 ,Moho面和‘41 0’间断面的地形存在半球尺度的大尺度非对称性 ,而且南北半球非对称性比东西半球的更显著 ;而‘5 2 0’和‘660’间断面的地形起伏已没有半球尺度那么大的非对称性 ,而是尺度略小些的不对称性 .In this paper,the global topography,the depth of the Moho (the crustal model CRUST2 ^0),the depths of upper mantle discontinuities were analyzed using the spherical harmonics.Based on these data,the spatial large scale distribution information has been obtained by stacking the first 4 degree modes,and the main energy distributions have been understood by synthesizing the four items with the maximal squares of amplitudes.The results show that there exists a large scale asymmetry on the scale of semi-sphere in the topographies of the Moho and the ‘410’ discontinuities,and the asymmetry character of the north-south semi-spheres is more obvious than that of the west-east semi-spheres;However,there exists a scale asymmetry on the small side in the topographies of ‘520’ and ‘660’ discontinuities,instead of such a large semi-sphere scale asymmetry.

关 键 词：球谐分析 Moho面 上地幔间断面 非对称性 

分 类 号：P312.2[天文地球—固体地球物理学]