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Sea‐level fluctuations due to subduction: The role of mantle rheology
Author(s) -
Piromallo C.,
Spada G.,
Sabadini R.,
Ricard Y.
Publication year - 1997
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/97gl01561
Subject(s) - geology , subduction , geoid , mantle (geology) , geodynamics , geophysics , sea level , discontinuity (linguistics) , tectonics , hydrostatic equilibrium , crustal recycling , seismology , oceanography , mathematical analysis , physics , mathematics , quantum mechanics , measured depth
By means of a stratified viscoelastic Earth model we study the effect of sinking slabs on the dynamic topography, the non‐hydrostatic geoid and the long‐term sea level variations. Sea level fluctuations due to subduction are found to be sensitive to the nature of the 670 km seismic discontinuity and to the rheological layering of the mantle. The response of our model to both a single subduction and a realistic distribution of slabs is studied by a numerical simulation based on a simplified approach. Consistent with previous results, we find that an upper bound to relative sea level time variations associated with the initiation of a new subduction in the upper mantle is ∼ 0.1 mm/yr. Relative sea level changes driven by the dynamic readjustment of internal mass heterogeneities may thus be comparable with those attributed to other changes in the tectonic regime on a large scale. This confirms the relevance of subduction as an important contributor to long‐term sea level fluctuations.