VISCOUS DRAG AND THE DIFFERENTIAL ROTATION OF THE EARTHS CORE

It is proposed that the differential rotation of the Earth's inner cor e deduced by Song and Richards is due to a combination of the decelera tion of the Earth's rotation and the viscous drag between the Earth's inner and outer cores. If this model is correct then the dynamic visco sity in the outer core of the Earth can be estimated to be mu approxim ate to 10(4) poise. Besides providing a novel way of determining the v iscosity of the core, this simple model suggests some new tests and sh ows how astronomical effects can influence geological phenomena.