Earth's non-hydrostatic gravity gradients from GOCE
Abstract
Since 2009, the GOCE mission has been measuring the second-order derivatives of the Earth's gravity potential, providing a fundamentally new picture on our planet's gravity field. Because of their directionality, these data are particularly sensitive to the geometry of the sources and thus very appropriate to investigate Earth's interior processes. Considering this aim, we have built global maps of the non-hydrostatic part of the Earth's gravity gradients, by removing from the data the contribution of an idealized, elliptical rotating Earth's model at hydrostatic equilibrium, with an internal structure given by the PREM model. The gravity gradients data we use are those expressed in a terrestrial frame by the GOCE High-Level Processing Facility, combining the GOCE measurements with a GRACE-based model at large scales. We have also estimated synthetic gradient values from isostatic lithospheric models and a mantle convection model including slabs subducting down to the core-mantle boundary. By comparing the GOCE-based gradients with the modeled ones, we show they can be explained by a superposition of deep and shallow processes, opening indeed new perspectives to understand the Earth's interior, from the surface to its depths.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.G31B0932P
- Keywords:
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- 1200 GEODESY AND GRAVITY