现今全球洋脊系统的定向性与等距性及其形成的动力学机制  

DIRECTIONAL AND EQUIDISTANT DISTRIBUTION OF MID-OCEANIC RIDGES AND THE MECHANISM OF THEIR FORMATION

作　　者：吴珍汉[1] 崔盛芹[1] 

机构地区：[1]中国地质科学院地质力学研究所

出　　处：《地质力学学报》1995年第1期15-24,共10页Journal of Geomechanics

摘　　要：现今全球大洋中脊系统的分布具有球面上的定向性与等距性，横向上的波动性，时代上的长期性与对称性及洋中脊位置相对于大洋岩石圈的稳定性等基本特征，洋脊系统的展布与地球自转存在密切相关性。大洋中脊系统分布的基本特点决定于固体地球内部的动力系统。已有资料表明，地球各圈层均受西向驱动力与重力两大全球性基本构造动力的驱动作用。在西向驱动力、重力与热力的长期作用下，固体地球各圈层均表现出不同程度的流变性。本文通过解流变体的Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ动力学方程，求得团体地球岩石圈—软流圈的水平速度分量Ｖθ与径向速度分量Ｖｒ。据此对全球洋脊系统分布的定向性、等距性、垂向波动性及与地球自转的密切相关性等基本特征及其产生的动力学机制进行初步的解释。he present directional and equidistant distribution of the mid-oceanic ridges on foe earth's surface,the sinusoidal oppositely compensating top and bottom surfaces of the asthenosphere across the ridges,the long development of synchronous tholeiitic rocks symmetrically arranged on either side of the ridge with respect to the crest,as well as the constancy of their positions relative to the oceanic lithosphere,all these have a close relation with earth's rotation and are determined by the dynamic system within the solid earth.It is considered that the earth is driven by two major force systems-the westward directed force due to earth's rotation and gravity. Under the action of these forces for a considerably long duration of time the different layers of the earth exhibit rheological behaviors to different extents. Using Navier-Stokes equation,we have a solution of the redial and lateral velocities,for the lithosphere and asthenosphere,which may give a satisfactory explanation to the above features.

关 键 词：大洋中脊 等距性 地球自转 动力学 洋脊 

分 类 号：P737.2[天文地球—海洋地质]