Core-mantle boundary deformations and J2 variations resulting from the 2004 Sumatra earthquake
Abstract
The deformation at the core-mantle boundary produced by the 2004 Sumatra earthquake is investigated by means of a semi-analytic theoretical model of global coseismic and postseismic deformation, predicting a millimetric coseismic perturbation over a large portion of the core-mantle boundary. Spectral features of such deformations are analysed and discussed. The time-dependent postseismic evolution of the elliptical part of the gravity field (J2) is also computed for different asthenosphere viscosity models. Our results show that, for asthenospheric viscosities smaller than 10^18 Pa s, the postseismic J2 variation in the next years is expected to leave a detectable signal in geodetic observations.
Cite
@article{arxiv.0707.0638,
title = {Core-mantle boundary deformations and J2 variations resulting from the 2004 Sumatra earthquake},
author = {V. Cannelli and D. Melini and P. De Michelis and A. Piersanti and F. Florindo},
journal= {arXiv preprint arXiv:0707.0638},
year = {2007}
}
Comments
14 pages, 8 figures, 1 table. It will appear in Geophysical Journal International