HR: 0800h
AN: T31A-0489    [Abstracts]
TI: Heat Flux From the Endeavour Segment of the Juan de Fuca Ridge
AU: * Thompson, W J
EM: wjt2@u.washington.edu
AF: University of Washington, School of Oceanography Box 357940, Seattle, WA 98195-7940 United States
AU: McDuff, R E
EM: mcduff@u.washington.edu
AF: University of Washington, School of Oceanography Box 357940, Seattle, WA 98195-7940 United States
AU: Stahr, F R
EM: stahr@ocean.washington.edu
AF: University of Washington, School of Oceanography Box 357940, Seattle, WA 98195-7940 United States
AU: Yoerger, D R
EM: dyoerger@whoi.edu
AF: Woods Hole Oceanographic Institution, DSL MS7 Blake Bldg., Woods Hole, MA 02543 United States
AU: Jakuba, M
EM: jakuba@mit.edu
AF: Woods Hole Oceanographic Institution, DSL MS7 Blake Bldg., Woods Hole, MA 02543 United States
AB: The very essence of a hydrothermal system is transfer of heat by a convecting fluid, yet the flux of heat remains a poorly known quantity. Past studies of heat flux consisted primarily of point measurements of temperature and fluid flow at individual vent sites and inventories of the neutrally buoyant plume above the field. In 2000 the Flow Mow project used the Autonomous Benthic Explorer (ABE) to determine heat flux from Main Endeavour Field (MEF) on the Juan de Fuca Ridge by intersecting the stems of rising buoyant plumes. ABE carries instruments to measure conductivity, temperature and depth, and a MAVS current meter to determine the vertical velocity of the fluid, after correcting for vehicle motion. Complementary work on horizontal fluxes suggests that the vertical flux measured by ABE includes both the primary high buoyancy focused "smoker" sources and also entrained diffuse flow. In 2004, ABE was again used to determine heat flux not only from MEF, but also from the other four fields in the Endeavour Segment RIDGE 2000 Integrated Study Site. In this four year interval the flux of heat from MEF has declined by approximately a factor of two. The High Rise vent field has the greatest heat flux, followed by MEF, then Mothra, Salty Dawg and Sasquatch (of order 500, 300, 100, 50 MW respectively; heat flux at Sasquatch was below detection).
DE: 3015 Heat flow (benthic)
DE: 3080 Submergence instruments: ROV, AUV, submersibles
DE: 8130 Heat generation and transport
DE: 8135 Hydrothermal systems (0450, 1034, 3017, 3616, 4832, 8424)
SC: Tectonophysics [T]
MN: Fall Meeting 2005