Core - mantle boundary deformations and J 2 variations resulting from the 2004 Sumatra earthquake
نویسنده
چکیده
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 Pa s, the postseismic J2 variation in the next years is expected to leave a detectable signal in geodetic observations.
منابع مشابه
Slow postseismic recovery of geoid depression formed by the 2004 Sumatra-Andaman Earthquake by mantle water diffusion
[1] Earthquakes are accompanied with mass redistributions and cause changes in gravity field and shape of geoid, an equipotential surface coincident with the mean sea surface. Such coseismic changes were detected by satellite gravimetry after the 2004 Sumatra-Andaman Earthquake, but little has been known on what happens on geoid after the earthquake. Here we report slow postseismic recovery of ...
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