地球南北半球的非对称性  

ASYMMETRY BETWEEN THE SOUTHERN AND NORTHERN HEMISPHERES OF THE EARTH

作　　者：马宗晋[1] 宋晓东 杜品仁[1] 傅容珊[3] 孙付平[4] 汪洋[5] 

机构地区：[1]中国地震局地质研究所 [2]P.O.Box1000,Palisudes,NY10964,USA [3]中国科学技术大学地球和空间科学系 [4]郑州测绘学院大地测量系 [5]中国科学院地质与地球物理研究所

出　　处：《地球物理学报》2002年第1期26-33,共8页Chinese Journal of Geophysics

基　　金：国家攀登项目 ( 970 2 31 0 0 3)

摘　　要：依据新的计算分析和空间观测数据 ,进一步论述了地球南北半球的非对称性 .全球热散失量的计算得出 ,南半球高出北半球 3 3 %;南半球地幔热散失量是北半球的 2倍 .比较南北半球S波速度分布 ,得出南半球的上地幔为低速、高温 ,北半球的上地幔为高速、低温 .计算地幔各层的质心位置发现 ,地球的质心偏于北半球 .计算地球经、纬圈长度的年变化率表明 ,南半球在扩张 ,北半球在收缩 .用空间大地测量数据的检测结果证实 ,南半球处于扩张状态 ,北半球处于压缩状态 .对地球的非对称性作了初步的动力学解释 .Asymmetry between the southern and northern hemispheres of the Earth is further stated on the basis of new calculations, analyses and observations of space geodesy. The calculation of global thermal loss shows that the thermal loss of the southern hemisphere is more than that of the northern hemisphere by 33%, while the thermal loss of the southern hemisphere mantle is the twice of that of the northern hemisphere. Comparing the S wave velocity distribution of the southern and northern hemispheres, we concluded that the upper mantle of the southern hemisphere is characterized by low velocity and high temperature, while the upper mantle of the northern hemisphere features high velocity and low temperatre. The calculated 'mass center' of the mantle's layers implies that the mass center of the Earth is to the northern hemisphere. The annual variations of the longitudinal and latitudinal circle lengths demonstrate that the southern hemisphere appears to be expanding, while the northern hemisphere looks like contracting. These two contract states can be confirmed by the data of space geodetic measurement. A trial explanation for the asymmetry of the Earth is delivered.

关 键 词：地球形状 非对称性 地震构造系统 热流 地震波速 空间大地测量 

分 类 号：P22[天文地球—大地测量学与测量工程]