%0 Journal Article
%T A Vent-Field-Scale Model of the East Pacific Rise 9¡ã50'N Magma-Hydrothermal System
%A Robert P. Lowell
%A Aida Farough
%A Leonid N. Germanovich
%A Laura B. Hebert
%J Oceanography
%D 2012
%I The Oceanography Society (TOS)
%X This paper describes a two-limb single-pass modeling approach constrained by vent temperature, heat flow, vent geochemistry, active-source seismology, and seismically inferred circulation geometry to provide first-order constraints on crustal permeability, conductive boundary layer thickness, fluid residence times, and magma replenishment rates for the magma-hydrothermal system at the East Pacific Rise (EPR) near 9¡ã50'N. Geochemical data from black smokers and nearby diffuse-flow patches, as well as an estimate of heat flow partitioning, suggest that nearly 90% of the heat output stems from heat supplied by the subaxial magma chamber, even though almost 90% of that output appears as diffuse flow at the seafloor. Estimates of magma replenishment rates are consistent with the evolution of lava chemistry over the eruption cycle between 1991¨C1992 and 2005¨C2006. If the recharge surface area is 105 m2, a one-dimensional model of hydrothermal recharge using EPR 9¡ã50'N parameters gives rise to rapid sealing as a result of anhydrite precipitation; however, if the area of recharge widens at depth to ~ 106 m2, sealing by anhydrite precipitation may not significantly affect hydrothermal circulation.
%K Ridge 2000
%K mid-ocean ridges
%K spreading centers
%K East Pacific Rise
%K modeling vent fields
%U http://tos.org/oceanography/archive/25-1_lowell.pdf