A low viscosity wedge in subduction zones

Citation
Mi. Billen et M. Gurnis, A low viscosity wedge in subduction zones, EARTH PLAN, 193(1-2), 2001, pp. 227-236
Citations number
43
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
EARTH AND PLANETARY SCIENCE LETTERS
ISSN journal
0012-821X → ACNP
Volume
193
Issue
1-2
Year of publication
2001
Pages
227 - 236
Database
ISI
SICI code
0012-821X(20011130)193:1-2<227:ALVWIS>2.0.ZU;2-O
Abstract
Geochemical, petrologic and seismological observations indicate that there may be high concentrations of water in the region above a subducting slab ( the mantle wedge), which could decrease the viscosity of the mantle locally by several orders of magnitude. Using numerical models we demonstrate that a low viscosity wedge has a dramatic influence on the force balance in a s ubduction zone and leads to an observable signal in the topography, gravity and geoid. A regional dynamic model of the Tonga-Kermadec subduction zone shows that the viscosity of the wedge is at least a factor of 10 smaller th an surrounding mantle lithosphere and asthenosphere. consistent with estima tes from seismic dissipation and deformation experiments. (C) 2001 Elsevier Science B.V. All rights reserved.