Open AccessDeformation of the Viscoelastic Earth Due to the Secular Change In the Earth's Axis of Rotation
Author(s) -
Hanada H.
Publication year - 1988
Publication title -
geophysical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0952-4592
DOI - 10.1111/j.1365-246x.1988.tb00470.x
Subject(s) - earth's rotation , mantle (geology) , geophysics , geology , figure of the earth , geodesy , polar motion , post glacial rebound , viscoelasticity , geoid , earth's magnetic field , mechanics , tidal acceleration , mantle convection , physics , classical mechanics , lithosphere , planet , magnetic field , ice sheet , tectonics , thermodynamics , quantum mechanics , geomorphology , astrophysics , measured depth , paleontology
Summary The cause of the secular change in the Earth's rotation axis relative to the surface geography is regarded as the viscoelastic response of the earth to the mass displacement generated by late Pleistocene deglaciation and the sea level changes related to it. On the other hand, the secular drift of the pole will also bring about viscoelastic change in the Earth's shape because the Earth is not a sphere but a spheroid with an equatorial bulge. In the case of polar drift, we estimated the deformation of the Earth's surface and the Earth's core, as well as the change in the Earth's gravity field. We used a compressible, radially stratified, Maxwell viscoelastic earth model for the inverse calculations and also investigated if the viscous flow in the mantle can compensate for the mass redistribution caused by polar drift. As a result of these calculations, the viscous flow in the mantle seems not to be able to compensate for the mass redistribution caused by polar drift if the mantle viscosity is higher than 10 22 poise. the agreement or disagreement between the rotation axis of the Earth and the principal axis of inertia determined by satellites can add a new constraint to the viscosity of the Earth's mantle.