Gravitational Gradients at Satellite Altitudes in Global Geophysical Studies

Pavel Novák, Robert Tenzer

Research output: Journal article publicationReview articleAcademic researchpeer-review

13 Citations (Scopus)

Abstract

Due to the ESA's satellite mission GOCE launched in March 2009, gravitational gradients sampled along the orbital trajectory approximately 250 km above the Earth's surface have become available. Since 2010, gravitational gradients have routinely been applied in geodesy for the derivation of global Earth's gravitational models provided in terms of fully normalized coefficients in a spherical harmonic series representation of the Earth's gravitational potential. However, in geophysics, gravitational gradients observed by spaceborne instruments have still been applied relatively seldom. This contribution describes their possible geophysical applications in structural studies where gravitational gradients observed at satellite altitudes are compared with those derived by a spectral forward modeling technique using available global models of selected Earth's mass components as input data. In particular, GOCE gravitational gradients are interpreted in terms of a superposition principle of gravitation as combined gravitational effects generated by a homogeneous reference ellipsoid of revolution, mean topographic and ice mass density distributions, depth-dependent mass density contrasts within bathymetry and lateral mass density anomalies with sediments and crustal layers. Respective gravitational effects are one by one removed from gravitational gradients observed at approximately 250 km elevation above ground. Removing respective gravitational gradients from observed gravitational gradients gradually reveals problematic geographic areas with model deficiencies. For the full interpretation of observed gravitational gradients, deficiencies of CRUST2.0 must be corrected and effects of deeper laying mass anomalies not included in the study considered. These findings are confirmed by parameters describing spectral properties of the gravitational gradients. The methodology can be applied for validating Earth's gravitational models and for constraining crustal models in the development phase.
Original languageEnglish
Pages (from-to)653-673
Number of pages21
JournalSurveys in Geophysics
Volume34
Issue number5
DOIs
Publication statusPublished - 1 Sep 2013
Externally publishedYes

Keywords

  • Bathymetry
  • Crust
  • Earth interior
  • Forward modeling
  • Gravitational gradients
  • Sediments
  • Spherical harmonics
  • Topography

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology

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