Title of Submission
Backarc Thermal Structure Controls Slab-Mantle Viscous Coupling Depth in Subduction Zones
Degree Program
Geosciences, PhD
Major Advisor Name
Matthew Kohn
Type of Submission
Scholarly Poster
Abstract
A primary feature of subduction zones is the point at which the slab and mantle viscously couple—defining the initiation of mantle wedge circulation. Here we consider the effects of the backarc thermal structure on coupling depth using two-dimensional thermomechanical models. Models show a strong correlation between coupling depth and backarc lithospheric thickness and coupling is always associated with the breakdown of antigorite. Backarc lithospheric thickness is a good predictor of coupling depth and can be indirectly estimated from surface heat flow. Consistently high backarc heat flow in circum-Pacific subduction zones may indicate a common depth of slab-mantle coupling globally.
Funding Information
NSF-PIRE/OIA Grant: PIRE: Exterra Field Institute and Research Endeavor (E-FIRE) to Matthew J. Kohn