A Vent-Field-Scale Model of the East Pacific Rise 9 degrees 50 %26apos; N Magma-Hydrothermal System

作者：Lowell Robert P^*; Farough Aida; Germanovich Leonid N; Hebert Laura B; Horne Rebecca

来源：Oceanography, 2012, 25(1): 158-167.

DOI：10.5670/oceanog.2012.13

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 degrees 50%26apos;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 1991-1992 and 2005-2006. If the recharge surface area is 10(5) m(2), a one-dimensional model of hydrothermal recharge using EPR 9 degrees 50%26apos;N parameters gives rise to rapid sealing as a result of anhydrite precipitation; however, if the area of recharge widens at depth to similar to 10(6) m(2), sealing by anhydrite precipitation may not significantly affect hydrothermal circulation.

• 出版日期2012-3
• 单位Virginia Tech; 美国弗吉尼亚理工大学(Virginia Tech)