Decadal variations in gravity caused by a tilt of the inner core

Geophysical Journal International

Volumn 172, Issue 3, 2008, Pages 921-933

  Dumberry, Mathieu ^a,b  

^a UNIVERSITY OF LEEDS   (United Kingdom)

^b UNIVERSITY OF ALBERTA   (Canada)

Author keywords

Earth rotation variations; Elasticity and anelasticity; Time variable gravity

Indexed keywords

ANELASTICITY; DECADAL VARIATION; DEFORMATION; ELASTICITY; GRAVITY FIELD; INERTIA; INNER CORE; MOMENT TENSOR; TEMPORAL VARIATION; TILT;

EID: 39049112825     PISSN: 0956540X     EISSN: 1365246X     Source Type: Journal    
DOI: 10.1111/j.1365-246X.2007.03624.x     Document Type: Article

References (36)

1. Alterman, Z., Jarosch, H. & Pekeris, C.L., 1959. Oscillations of the Earth, Proc. R. Soc. Lond., A, 252, 80-95.
2. Buffett, B.A., Mathews, P.M., Herring, T.A. & Shapiro, I.I., 1993. Forced nutations of the Earth: Contributions from the effects of ellipticity and rotation on the elastic deformations, J. geophys. Res., 98, 21659-21676.
3. Chao, B.F. & Gross, R.S., 1987. Changes in the earth's rotation and low-degree gravitational field induced by earthquakes, Geophys. J. R. astr. Soc., 91, 569-596.
4. Chen, J.L. & Wilson, C.R., 2003. Low degree gravitational changes from earth rotation and geophysical models, Geophys. Res. Lett., 30, 2257, doi: 10.1029/2003GL018688.
5. Chen, J.L., Wilson, C.R., Eanes, R.J. & Tapley, B.D., 2000. A new assessment of long-wavelength gravitational variations, J. geophys. Res., 105, 16271-16277.
6. Chen, J.L., Wilson, C.R. & Tapley, B.D., 2005. Interannual variability of low-degree gravitational change, 1980-2002, J. Geodesy, 78, 535-543.
7. Cox, C.M. & Chao, B.F., 2002. Detection of large-scale mass redistribution in the terrestrial system since 1998, Science, 297, 831-833.
8. Cox, C.M., Au, A., Boy, J.-P. & Chao, B.F., 2004. Time-variable gravity: Using satellite-laser-ranging as a tool for observing long term changes in the Earth system, in Proceedings from the 13th International Workshop on Laser Ranging, eds Noomen, R., Klosko, S., Noll, C. & Pearlman, M., NASA/CP-2003-212248.
9. Crossley, D.J., 1975. The free oscillation equations at the center of the Earth, Geophys. J. R. astr. Soc., 41, 153-163.
10. Dahlen, F.A., 1972. Elastic dislocation theory for a self-gravitating elastic configuration with an initial static stress field, Geophys. J. R. astr. Soc., 28, 357-383.
11. Dahlen, F.A., 1974. On the static deformation of an Earth model with a fluid core, Geophys. J. R. astr. Soc., 36, 461-485.
12. Dahlen, F.A. & Fels, S.B., 1978. A physical explanation for the static core paradox, Geophys. J. R. astr. Soc., 55, 317-332.
13. Dahlen, F.A. & Tromp, J., 1998. Theoretical Global Seismology, Princeton University Press, Princeton, New Jersey.
14. Denis, C., Almavict, M., Rogister, Y. & Tomecka-Suchon, S., 1998. Methods for computing internal flattening, with applications to the Earth's structure and geodynamics, Geophys. J. Int., 132, 603-642.
15. Dumberry, M., 2007. Gravitational torque on the inner core and decadal polar motion, Geophys. J. Int., doi: 10.1111/j.1365-246X.2007.03653.x.
16. Dumberry, M. & Bloxham, J., 2002. Inner core tilt and polar motion, Geophys. J. Int., 151, 377-392.
17. Dumberry, M. & Bloxham, J., 2004. Variations in the Earth's gravitational field caused by torsional oscillations in the core, Geophys. J. Int., 159, 417-434.
18. Dziewonski, A.M. & Anderson, D.L., 1981. Preliminary reference Earth model, Phys. Earth planet. Inter., 25, 297-356.
19. Edmonds, A.R., 1960. Angular Momentum in Quantum Mechanics, Princeton University Press, New Jersey.
20. Greff-Lefftz, M. & Legros, H., 1995. Core mantle coupling and polar motion, Phys. Earth planet. Inter., 91, 273-283.
21. Greiner-Mai, H. & Barthelmes, F., 2001. Relative wobble of the Earth's inner core derived from polar motion and associated gravity variations, Geophys. J. Int., 144, 27-36.
22. Gross, R.S., Fukumori, I. & Menemenlis, D., 2005. Atmosphere and oceanic excitation of decade-scale Earth orientation variations, J. geophys. Res., 111, B09405, doi: 10.1029/2004JB003565.
23. Hide, R., Boggs, D.H., Dickey, J.O., Dong, D., Gross, R.S. & Jackson, A., 1996. Topographic core-mantle coupling and polar motion on decadal time-scales, Geophys. J. Int., 125, 599-607.
24. Hulot, G., Le Huy, M. & Le Mouël, J.-L., 1996. Influence of core flows on the decade variations of the polar motion, Geophys. Atrophys. Fluid Dyn., 82, 35-67.
25. Jackson, A., Bloxham, J. & Gubbins, D., 1993. Time-dependent flow at the core surface and conservation of angular momentum in the coupled core-mantle system, in Dynamics of the Earth's Deep Interior and Earth Rotation, Vol. 72, pp. 97-107, eds Le Mouël, J.-L., Smylie, D.E. & Herring, T., AGU Geophysical Monograph, Washington, DC.
26. Jault, D., Gire, C. & Le Mouël, J.-L., 1988. Westward drift, core motions and exchanges of angular momentum between core and mantle, Nature, 333, 353-356.
27. Jeffreys, H., 1970. The Earth, 5th edn, Cambridge University Press, London, UK.
28. Lambeck, K., 1980. The Earth's Variable Rotation: Geophysical Causes and Consequences, Cambridge University Press, Cambridge.
29. Love, A.E.H., 1909. The yielding of the Earth to disturbing forces, Proc. R. Soc. Lond., A, 82, 73-88.
30. Mathews, P.M., Buffett, B.A., Herring, T.A. & Shapiro, I.I., 1991. Forced nutations of the Earth: Influence of inner core dynamics. 1. Theory, J. geophys. Res., 96, 8219-8242.
31. Mitrovica, J.X. & Forte, A.M., 2004. A new inference of mantle viscosity based upon joint inversion of convection and glacial isostatic adjustment data, Earth planet. Sci. Lett., 225, 177-189.
32. Phinney, R.A. & Burridge, R., 1973. Representation of the elastic-gravitational excitation of a spherical Earth model by generalized spherical harmonics, Geophys. J. R. astr. Soc., 34, 451-487.
33. Ramillien, G., Lombard, A., Cazenave, A., Ivins, E.R., Llubes, M., Remy, F. & Biancale, R., 2006. Interannual variations of the mass balance of the Antarctica and Greenland ice sheets from GRACE, Global planet. Change, 53, 198-208.
34. Stevenson, D.J., 1987. Limits on lateral density and velocity variations in the Earth's core, Geophys. J. R. astr. Soc., 88, 311-319.
35. Tamisiea, M.E., Mitrovica, J.X. & Davis, J.L., 2007. GRACE gravity data constrain ancient ice geometries and continental dynamics over Laurentia, Science, 316, 881-883.
36. Zatman, S. & Bloxham, J., 1997. Torsional oscillations and the magnetic field within the Earth's core, Nature, 388, 760-763.