Three-dimensional numerical models of the influence of a buoyant oceanic plateau on subduction zones

Wendy Mason, Louis-Noel Moresi, Peter Betts, M Miller

Research output: Contribution to journalArticleResearchpeer-review

65 Citations (Scopus)

Abstract

We have investigated potential effects on a subduction zone during oceanic plateau-trench collision, using three-dimensional numerical models. An oceanic plateau of varied density was embedded in the slab, which was pinned at one end. The plateaus strongly influenced the shape of the trench. For a plateau with a higher density, the trench retreat rate was reduced in the region surrounding the plateau, and the plateau subducted along with the slab. For lower density plateaus, the trench in the region of the plateau advanced, and the plateau compressed and resisted subduction, spreading laterally along the trench. With a weaker slab rheology, the arcuate shape of the trench towards the free end of the trench was enhanced. Beneath the most buoyant plateaus, a tear formed in the subducted portion of the slab, soon after the slab tip reached the top of the lower mantle. We compare the model results with a region in the northwest Pacific, where the Ogasawara Plateau meets the trench of the Izu-Bonin-Mariana subduction zone. (C) 2009 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)71 - 79
Number of pages9
JournalTectonophysics
Volume483
Issue number1-2
DOIs
Publication statusPublished - 2010

Cite this