Study and Detection on the Geodynamic Effects of the Earth's Fluid Outer Core

doi:10.7523/j.issn.2095-6134.2003.2.021

Abstract

Abstract:

The long-term, continuous gravity data, recorded with superconducting gravimeters (SCG) at the Global Geodynamics Project (GGP) observatories including one at Wuhan, and the corresponding station atmospheric pressure records have been comprehensively processed and analyzed in order to study and detect the geodynamical effects of the Earth's fluid outer core (FOC). The elasto-gravitational deformation responses of the Earth to thesolar-luni tidal forces, surface tractions and the perturbations of the pressure and gravity on the core-mantle boundary (CMB) and the solid inner core boundary (ICB) due to the dynamical behaviors of the FOC, are systematically discussed. Based on the resonance enhancement in diurnal tidal gravity observations, the Earth's free core nutation (FCN) is studied by stacking the tidal gravity data obtained with the international SCG. As a result, the FCN parameters are determined accurately. The free oscillations of the FOC are theoretically investigated by using a variational approach of the displacement field. And the corresponding eigenvalue-eigenvector problem for the finite element computation is deduced. By simultaneouslyusing the long-term, continuous and high-quality gravity data observed with the SCG at the GGP observatories, the translational oscillations of the solid inner core is studied.

Key words: superconducting gravimeters, global geodynamics project, deformation responses of the earth, free core nutation, free oscillations of the fluid outer core

CLC Number:

P312.4

XU Jian-Qiao SUN He-Ping. Study and Detection on the Geodynamic Effects of the Earth's Fluid Outer Core[J]. , 2003, 20(2): 247-253.

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