一种反演地幔横向密度差异的方法

重力位球谐系数及板块运动速度是两种独立的地球物理观测资料,但二者同时又是地幔内横向密度差异及与之相联系的地幔流动的结果,从而,中长波重力异常与板块运动的观测提供了探索地幔横向非均匀的一条途径。本文根据适合于低雷诺流动的最小粘滞损耗原理,利用张量场及矢量场的标量分解与传播子解的数学方法,将观测的重力位球谐系数和板块运动速度作为约束条件,发展了一种反演地幔横向密度差异的方法。

A METHOD TO INVERT LATERAL DENSITY CONTRAST IN THE EARTH''''S MANTLE

The geopotential harmornics and the moving velocities of plates are two kinds of independent geophysical obseration data, but both of them are resulted from the lateral density contrast and mantle flow which is also connected with the density contrast inside the Earth. Consequently, the long and medium wavelength geopotential anomaly and plate movement data provided us with a possibility to investigate the lateral heterogenity in mantle. By means of converting vector and tensor field to scalar field the partial differential equations governing mantle flow are transformed into a set of ordinary differential equations. Based on the principle of minimum dissipation for low Reynolds number flow, we developed a method to invert the lateral density contrast in the Earth's mantle, in which the observed geopotential harmornics and moving velocities of plates will be used as constrain conditions.