Global model of the upper mantle lateral density structure based on combining seismic and isostatic models

Robert Tenzer, Mohammad Bagherbandi, Peter Vajda

Research output: Journal article publicationJournal articleAcademic researchpeer-review

9 Citations (Scopus)

Abstract

We compile the global model of the upper mantle lateral density structure with a 2×2 arc-deg spatial resolution using the values of the crust-mantle density contrast estimated relative to the adopted crust density model. The combined least-squares approach based on solving Moritz's generalization of the Vening-Meinesz inverse problem of isostasy is facilitated to estimate the crust-mantle density contrast. The global geopotential model (EGM08), the global topographic/bathymetric model (DTM2006. 0) including ice-thickness data, and the global crustal model (CRUST2. 0) are used to compute the isostatic gravity anomalies. The estimated upper mantle densities globally vary between 2751 and 3635 kg/m3. The minima correspond with locations of the divergent oceanic tectonic plate boundaries (along the mid-oceanic ridges). The maxima are found along the convergent tectonic plate boundaries in the Andes and Himalayas (extending under the Tibetan Plateau). A comparison of the estimated upper mantle densities with the CRUST2. 0 data shows a relatively good agreement between these two models within the continental lithosphere with the differences typically within ±100 kg/m3. Much larger discrepancies found within the oceanic lithosphere are explained by the overestimated values of the CRUST2. 0 upper mantle densities. Our result shows a prevailing pattern of increasing densities with the age of oceanic lithosphere which is associated with the global mantle convection process.
Original languageEnglish
Pages (from-to)65-73
Number of pages9
JournalGeosciences Journal
Volume17
Issue number1
DOIs
Publication statusPublished - 26 Feb 2013
Externally publishedYes

Keywords

  • crust
  • density interface
  • gravity
  • isostasy
  • mantle

ASJC Scopus subject areas

  • Environmental Science(all)
  • Earth and Planetary Sciences(all)

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