Empirical model of the gravitational field generated by the oceanic lithosphere

Robert Tenzer, Wenjin Chen, Zhourun Ye

Research output: Journal article publicationJournal articleAcademic researchpeer-review

9 Citations (Scopus)

Abstract

We present an empirical model of the gravitational field generated by the oceanic lithosphere computed over the world's oceans with a spectral resolution complete to a spherical harmonic degree of 180. This gravity model is compiled based on applying methods for a spherical harmonic analysis and synthesis of the global gravity and crustal structure models. The in situ seawater densities and the density samples from ocean-floor drilling sites are utilized in the gravimetric forward modeling of bathymetry and marine sediments. The gravitational signal attributed to the oceanic lithosphere density structure is described empirically in terms of the ocean-floor age and depth. The former is explained by the increasing density with age due to conductive cooling of the oceanic lithosphere. The latter describes the gravitational signature of thermal lithospheric contraction, which is isostatically compensated by ocean deepening. The long-wavelength gravity spectrum reflects mainly the compositional and thermal structures within the sub-lithospheric mantle. We demonstrate that this empirical gravity model reproduces realistically most of the long-to-medium wavelength features of the actual gravity field, except for some systematic discrepancies, especially along continental slopes and large sedimentary accumulations, which cannot be described accurately by applied empirical models.
Original languageEnglish
Pages (from-to)72-82
Number of pages11
JournalAdvances in Space Research
Volume55
Issue number1
DOIs
Publication statusPublished - 1 Jan 2015
Externally publishedYes

Keywords

  • Density
  • Gravity
  • Ocean-floor spreading
  • Oceanic lithosphere

ASJC Scopus subject areas

  • Aerospace Engineering
  • Space and Planetary Science

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