HR: 0800h
AN: T51B-0549    [Abstracts]
TI: Effects of fluid circulation in ocean crust on subduction zone temperature
AU: * Kummer, T D
EM: tkummer@nmt.edu
AF: Earth and Environmental Science Department, New Mexico Tech, 801 Leroy Place, Socorro, NM 87801, United States
AU: Spinelli, G A
EM: spinelli@nmt.edu
AF: Earth and Environmental Science Department, New Mexico Tech, 801 Leroy Place, Socorro, NM 87801, United States
AB: Hydrothermal circulation plays an important role in redistributing heat within and extracting heat from high- permeability ocean crust. We examine the effect of hydrothermal circulation on subduction zone temperature by modeling fluid and heat transport within a vertical cross-section through a subduction zone. The effect of hydrothermal circulation is quantified by comparing results from simulations with coupled fluid and heat transport to those from simulations with only heat conduction (no fluid flow). We examine how convergence rate and subduction geometry influence the evolution of hydrothermal circulation within the subducting crust. Two end- member geometries are modeled, one mimics the Middle America subduction zone off Nicoya Peninsula, Costa Rica, the other simulates the Barbados margin. We simulate fluid and heat flow for systems with upper basaltic basement permeability ranging from 10^-13 to 10^-10 m². Additionally, we examine the effect of permeability reduction within the basaltic basement as it is subducted. Models with fluid transport show suppressed temperatures along the subducting slab relative to models with no fluid transport. Faster convergence rates reduce the thermal effect of fluid circulation in subducting crust and temperatures are less suppressed. This reduced effect of hydrothermal circulation is also observed for smaller wedge tapers.
DE: 1829 Groundwater hydrology
DE: 1847 Modeling
DE: 3015 Heat flow (benthic)
DE: 3021 Marine hydrogeology
DE: 3060 Subduction zone processes (1031, 3613, 8170, 8413)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting