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Generation of ascending flows in the Big Mantle Wedge (BMW) beneath northeast Asia induced by retreat and stagnation of subducted slab
Author(s) -
Kameyama Masanori,
Nishioka Ryoko
Publication year - 2012
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 - 10.1029/2012gl051678
Subject(s) - slab , geology , slab window , subduction , intraplate earthquake , mantle wedge , seismology , mantle (geology) , wedge (geometry) , convection , geophysics , tectonics , mechanics , oceanic crust , geometry , physics , mathematics
We conducted two‐dimensional numerical experiments of mantle convection with imposed kinematic motions of cold slabs, in order to study the mechanism for the generation of ascending flows in the “Big Mantle Wedge” (BMW), which has been recently proposed in order to relate the stagnant Pacific slab with the intraplate volcanism in northeast Asia. Our calculations demonstrated that the BMW is expanded oceanward in response to the retreating motion of trench and slab, which strongly affects the flows in the region. In particular, the subducting and retreating motion of slab induces a local but strong circulation near the oceanward end (or a hinge) of the stagnant slab in the BMW. Our findings suggest that ascending flows in the BMW can be triggered most easily near the hinge of the stagnant slab, which is in good agreement with the occurrence of several active intraplate volcanoes above the stagnant Pacific slab.