An explanation for earth's long-term rotational stability

Science

Volumn 275, Issue 5298, 1997, Pages 372-375

  Richards, Mark A ^a   Ricard, Yannick ^b   Lithgow Bertelloni, Carolina ^c   Spada, Giorgio ^d   Sabadini, Roberta ^e  

^a UNIVERSITY OF CALIFORNIA   (United States)

^b UNIVERSITÉ DE LYON   (France)

^c GEOPHYSICAL LABORATORY   (United States)

^d UNIVERSITY OF BOLOGNA   (Italy)

^e UNIVERSITY OF MILAN   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

ARTICLE; ASTRONOMY; MAGNETIC FIELD; MATHEMATICAL MODEL; MOTION; PHYSICS; PRIORITY JOURNAL; ROTATION; VISCOSITY;

PLANETARY ROTATION; PLATE MOTION; TRUE POLAR WANDER;

EID: 0030621137     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.275.5298.372     Document Type: Article

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32. 21 harmonic coefficients are nonzero). This mismatch results from model error of an undetermined nature (15). The compensation is achieved by subtracting the mismatched off-diagonal terms in the present-day inertia tensor from the calculations at all times, so that the present-day model rotation pole position corresponds exactly to Earth's North Pole; otherwise, the model and observed curves would not be comparable in any meaningful way because the model curves would begin at some latitude different from the North Pole. This solution is not entirely satisfactory, but it provides a way to compare the overall amplitudes of the TPW curves. Comparison between the detailed shapes of the observed and model TPW paths are probably not very meaningful because of the uncertainties in observations and the necessary compensation of the model curves.
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34. MAR. was supported by NSF grants EAR-9117538 and EAR-9629376 and is grateful to C. Froidevaux of the Ecole Normale Superieure, Paris, for support as a visiting scholar. R. Gordon and D. Jurdy provided helpful reviews of the original manuscript.