Sharp thermal transition in the forearc mantle wedge as a consequence of nonlinear mantle wedge flow
MetadataShow full item record
In the forearc mantle wedge, the thermal field depends strongly on slab-driven mantle wedge flow. The flow is in turn affected by the thermal field via the temperature dependence of mantle rheology. Using thermal modeling, we show that the nonlinear feedback between the thermal and flow fields always leads to complete stagnation of the mantle wedge over a shallow, weakened part of the slab-mantle interface and an abrupt onset of mantle flow further down-dip. The abrupt increase in flow velocity leads to a sharp thermal transition from a cold stagnant to a hot flowing part of the wedge. This sharp thermal transition is inherent to all subduction zones, explaining a commonly observed sharp arc-ward increase in seismic attenuation.
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 38 (2011): L13308, doi:10.1029/2011GL047705.
Suggested CitationGeophysical Research Letters 38 (2011): L13308
Showing items related by title, author, creator and subject.
Van Ark, Emily M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-06)This thesis presents three studies which apply geophysical tools to the task of better understanding mantle melting phenomena at the upper and lower boundaries of the mantle. The first study uses seafloor bathymetry and ...
Simultaneous determination of thermal conductivity, thermal diffusivity and specific heat in sI methane hydrate Waite, William F.; Stern, Laura A.; Kirby, S. H.; Winters, William J.; Mason, D. H. (Blackwell Publishing, 2007-03-11)Thermal conductivity, thermal diffusivity and specific heat of sI methane hydrate were measured as functions of temperature and pressure using a needle probe technique. The temperature dependence was measured between −20°C ...
Mantle dynamics beneath the East Pacific Rise at 17°S : insights from the Mantle Electromagnetic and Tomography (MELT) experiment Baba, Kiyoshi; Chave, Alan D.; Evans, Rob L.; Hirth, Greg; Mackie, Randall L. (American Geophysical Union, 2006-02-17)The electromagnetic data from the Mantle Electromagnetic and Tomography (MELT) experiment are inverted for a two-dimensional transversely anisotropic conductivity structure that incorporates a correction for three-dimensional ...