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dc.contributor.authorJohnson, H. Paul  Concept link
dc.contributor.authorTivey, Maurice A.  Concept link
dc.contributor.authorBjorklund, Tor A.  Concept link
dc.contributor.authorSalmi, Marie S.  Concept link
dc.date.accessioned2010-08-26T18:07:24Z
dc.date.available2010-11-06T08:21:58Z
dc.date.issued2010-05-06
dc.identifier.citationGeochemistry Geophysics Geosystems 11 (2010): Q05002en_US
dc.identifier.urihttps://hdl.handle.net/1912/3875
dc.descriptionAuthor Posting. © American Geophysical Union, 2010. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 11 (2010): Q05002, doi:10.1029/2009GC002957.en_US
dc.description.abstractAreas of the seafloor at mid-ocean ridges where hydrothermal vents discharge are easily recognized by the dramatic biological, physical, and chemical processes that characterize such sites. Locations where seawater flows into the seafloor to recharge hydrothermal cells within the crustal reservoir are by contrast almost invisible but can be indirectly identified by a systematic grid of conductive heat flow measurements. An array of conductive heat flow stations in the Endeavour axial valley of the Juan de Fuca Ridge has identified recharge zones that appear to represent a nested system of fluid circulation paths. At the scale of an axial rift valley, conductive heat flow data indicate a general cross-valley fluid flow, where seawater enters the shallow subsurface crustal reservoir at the eastern wall of the Endeavour axial valley and undergoes a kilometer of horizontal transit beneath the valley floor, finally exiting as warm hydrothermal fluid discharge on the western valley bounding wall. Recharge zones also have been identified as located within an annular ring of very cold seafloor around the large Main Endeavour Hydrothermal Field, with seawater inflow occurring within faults that surround the fluid discharge sites. These conductive heat flow data are consistent with previous models where high-temperature fluid circulation cells beneath large hydrothermal vent fields may be composed of narrow vertical cylinders. Subsurface fluid circulation on the Endeavour Segment occurs at various crustal depths in three distinct modes: (1) general east to west flow across the entire valley floor, (2) in narrow cylinders that penetrate deeply to high-temperature heat sources, and (3) supplying low-temperature diffuse vents where seawater is entrained into the shallow uppermost crust by the adjacent high-temperature cylindrical systems. The systematic array of conductive heat flow measurements over the axial valley floor averaged ∼150 mW/m2, suggesting that only about 3% of the total energy flux of ocean crustal formation is removed by conductive heat transfer, with the remainder being dissipated to overlying seawater by fluid advection.en_US
dc.description.sponsorshipFunding was provided by NSF grants OCE0318566 and OCE0241294 and NSF/SGER grant OCE0902626.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2009GC002957
dc.subjectHydrothermalen_US
dc.subjectJuan de Fucaen_US
dc.subjectVentsen_US
dc.titleHydrothermal circulation within the Endeavour Segment, Juan de Fuca Ridgeen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2009GC002957


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