Development of a Synthetic Earth Gravity Model by 3D mass optimisation based on forward modelling
MetadataShow full item record
Several previous Synthetic Earth Gravity Model (SEGM) simulations are based on existing information about the Earth’s internal mass distribution. However, currently available information is insufficient to model the Earth’s anomalous gravity field on a global scale. The low-frequency information is missing when modelling only topography, bathymetry and crust (including the Mohorovičić discontinuity), but the inclusion of information on the mantle and core does not seem to significantly improve this situation. This paper presents a method to determine a more realistic SEGM by considering simulated 3D mass distributions within the upper mantle as a proxy for all unmodelled masses within the Earth.The aim is to improve an initial SEGM based on forward gravity modelling of the topography, bathymetry and crust such that the missing low-frequency information is now included. The simulated 3D mass distribution has been derived through an interactive and iterative mass model optimisation algorithm, which minimises geoid height differences with respect to a degree-360 spherical harmonic expansion of the EGM2008 global external gravity field model. We present the developed optimisation algorithm by applying it to the development of a global SEGM that gives a reasonably close fit to EGM2008, and certainly closer than a SEGM based only on the topography, bathymetry and crust.
Published with permission
Showing items related by title, author, creator and subject.
A new degree-2190 (10 km resolution) gravity field model for Antarctica developed from GRACE, GOCE and Bedmap2 dataHirt, Christian; Rexer, M.; Scheinert, M.; Pail, R.; Claessens, Sten; Holmes, S. (2015)The current high-degree global geopotential models EGM2008 and EIGEN-6C4 resolve gravity field structures to ~10 km spatial scales over most parts of the of Earth’s surface. However, a notable exception is continental ...
The relation between degree-2160 spectral models of Earth’s gravitational and topographic potential: a guide on global correlation measures and their dependency on approximation effectsHirt, C.; Rexer, M.; Dewan, Ashraf; Rummel, R. (2017)© 2017 Springer-Verlag Berlin HeidelbergComparisons between high-degree models of the Earth’s topographic and gravitational potential may give insight into the quality and resolution of the source data sets, provide ...
Hirt, Christian; Kuhn, Michael; Featherstone, Will; Göttl, F. (2012)We use gravity implied by the Earth’s rock-equivalent topography (RET) and modelled isostatic compensation masses to evaluate the new global gravity field models (GGMs) from European Space Agency (ESA)’s Gravity Field and ...