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dc.contributor.authorTheunissen, Thomas Louis Roger Dominique
dc.contributor.authorHuismans, Ritske Sipke
dc.contributor.authorLu, Gang
dc.contributor.authorRiel, Nicolas
dc.date.accessioned2022-10-06T13:27:19Z
dc.date.available2022-10-06T13:27:19Z
dc.date.created2022-09-25T16:13:15Z
dc.date.issued2022
dc.identifier.issn0012-8252
dc.identifier.urihttps://hdl.handle.net/11250/3024344
dc.description.abstractThe choice of crustal and mantle densities in numerical geodynamic models is usually based on convention. The isostatic component of the topography is not calibrated to fit observations resulting in not very well constrained elevations. The density distribution on Earth is not easy to constrain because it involves multiple variables (temperature, pressure, composition, and deformation). We aim in this study to provide a reference case for geodynamic modelling where crustal and mantle densities are calibrated to fit the relative continent/mid-ocean ridge elevation in agreement with observations. We first review observed Earth topography of stable continents and of active mid-ocean ridges and define the characteristic average elevation of these domains. We use self-consistent thermodynamic calculations of dry mantle rocks that include partial melting to calibrate densities of the continental lithospheric mantle and beneath the mid-ocean ridge. The thermodynamic solutions are coupled with a 2-D incompressible plane strain finite element method for viscous-plastic creeping flows to solve for the dynamic evolution during extension from continental rifting to mid-ocean spreading. The combined results from 2-D thermo-mechanical models and 1-D isostatic calculations show that the relative elevation difference between mid-ocean ridges and continents depends on crustal density, mantle composition, and the degree of depletion of the lithospheric mantle. Based on these results we calibrate the reference density that only depends on temperature, which can be used in classic thermo-mechanical models based on the Boussinesq approximation. Finally the model calibration provides a solution that fits (1) the elevation of active mid-ocean ridges far from hotspots (-2750 ± 250 m), (2) the elevation of stable continents far from hotspots (+400 ± 400 m), (3) the average depletion buoyancy of the continental lithospheric mantle (between -20 and -50 ± 15 kg/m3 depending on lithospheric thickness) and (4) the average continental crust density (2835 ± 35 kg/m3 for a 35 km thick crust).en_US
dc.language.isoengen_US
dc.publisherElsevieren_US
dc.rightsNavngivelse 4.0 Internasjonal*
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/deed.no*
dc.titleRelative continent - mid-ocean ridge elevation: a reference case for isostasy in geodynamicsen_US
dc.typeJournal articleen_US
dc.typePeer revieweden_US
dc.description.versionpublishedVersionen_US
dc.rights.holderCopyright 2022 the authorsen_US
dc.source.articlenumber104153en_US
cristin.ispublishedtrue
cristin.fulltextoriginal
cristin.qualitycode2
dc.identifier.doi10.1016/j.earscirev.2022.104153
dc.identifier.cristin2055142
dc.source.journalEarth-Science Reviewsen_US
dc.identifier.citationEarth-Science Reviews. 2022, 233, 104153.en_US
dc.source.volume233en_US


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