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Higher harmonic effects of the Earth's gravitational field from post‐glacial rebound as observed by Lageos
Author(s) -
Alexander J. C.
Publication year - 1983
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl010i011p01085
Subject(s) - harmonics , post glacial rebound , mantle (geology) , spherical harmonics , gravitational field , glacial period , physics , satellite , geodesy , geophysics , geology , classical mechanics , astronomy , quantum mechanics , geomorphology , voltage
Recently, long‐term orbital data from the artificial satellite Lageos have been analyzed to determine the rate of post‐glacial rebound. Rubincam has compared the observed values against values derived from two realistic earth models (Wu‐Peltier L1,L2), working with the second harmonic mode of excitation. The data support model L1, with a uniform mantle viscosity of 10 22 poise, over L2, with a lower mantle viscosity of 10 23 poise. We find the higher degree harmonic contributions are significant, and considerably strengthen the support for model L1. We perform such calculations using the same parameter values for glaciation as Rubincam, and also values due to Peltier and coworkers. We also show that a similar analysis of data from the satellite Starlette is less likely to be as definitive as analysis of Lageos data, since there are significant contributions from very high harmonics, indicating that the behavior of the earth must be known in much greater detail.