Subduction initiation in mid-ocean induced by mantle suction flow. Issue 3 (13th August 2018)

• Record Type: Journal Article
• Authors: Baes, Marzieh; Sobolev, Stephan V; Quinteros, Javier
• Is Part Of: Geophysical journal international. Volume 215:Issue 3(2018:Dec.)
• Page Start: 1515
• Page End: 1522
• Publication Date: 2018-08-13
• Subjects: Numerical modelling -- Subduction zone processes -- oceanic transform and fracture zone processes; Geophysics -- Periodicals; 550
• DOI: 10.1093/gji/ggy335
• Languages: English
• ISSNs: 0956-540X

Abstract

SUMMARY: Pre-existing weakness zones in the lithosphere such as transform faults/fracture zones and extinct mid-oceanic ridges have been suggested to facilitate subduction initiation in an intra-oceanic environment. Here, we propose that the additional forcing coming from the mantle suction flow is required to trigger the conversion of a fracture zone/transform fault into a converging plate boundary. This suction flow can be induced either from the slab remnants of former converging plate boundaries or/and from slabs of neighbouring active subduction zones. Using 2-D coupled thermo-mechanical models, we show that a sufficiently strong mantle flow is able to convert a fracture zone/transform fault into a subduction zone. However, this process is feasible only if the fracture zone/transform fault is very close to the mid-oceanic ridge. Our numerical model results indicate that time of subduction initiation depends on the velocity, domain size and location of mantle suction flow and age of the oceanic plate.