Diffuse venting at the ASHES hydrothermal field : heat flux and tidally modulated flow variability derived from in situ time-series measurements
Fornari, Daniel J.
Crone, Timothy J.
Kinsey, James C.
Kelley, Deborah S.
MetadataShow full item record
Time-series measurements of diffuse exit-fluid temperature and velocity collected with a new, deep-sea camera, and temperature measurement system, the Diffuse Effluent Measurement System (DEMS), were examined from a fracture network within the ASHES hydrothermal field located in the caldera of Axial Seamount, Juan de Fuca Ridge. The DEMS was installed using the HOV Alvin above a fracture near the Phoenix vent. The system collected 20 s of 20 Hz video imagery and 24 s of 1 Hz temperature measurements each hour between 22 July and 2 August 2014. Fluid velocities were calculated using the Diffuse Fluid Velocimetry (DFV) technique. Over the ∼12 day deployment, median upwelling rates and mean fluid temperature anomalies ranged from 0.5 to 6 cm/s and 0°C to ∼6.5°C above ambient, yielding a heat flux of 0.29 ± 0.22 MW m−2 and heat output of 3.1± 2.5 kW. Using a photo mosaic to measure fracture dimensions, the total diffuse heat output from cracks across ASHES field is estimated to be 2.05 ± 1.95 MW. Variability in temperatures and velocities are strongest at semidiurnal periods and show significant coherence with tidal height variations. These data indicate that periodic variability near Phoenix vent is modulated both by tidally controlled bottom currents and seafloor pressure, with seafloor pressures being the dominant influence. These results emphasize the importance of local permeability on diffuse hydrothermal venting at mid-ocean ridges and the need to better quantify heat flux associated with young oceanic crust.
Author Posting. © American Geophysical Union, 2016. 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 17 (2016): 1435–1453, doi:10.1002/2015GC006144.
Suggested CitationArticle: Mittelstaedt, Eric, Fornari, Daniel J., Crone, Timothy J., Kinsey, James C., Kelley, Deborah S., Elend, Mitch, "Diffuse venting at the ASHES hydrothermal field : heat flux and tidally modulated flow variability derived from in situ time-series measurements", Geochemistry, Geophysics, Geosystems 17 (2016): 1435–1453, DOI:10.1002/2015GC006144, https://hdl.handle.net/1912/8236
Showing items related by title, author, creator and subject.
Quantifying diffuse and discrete venting at the Tour Eiffel vent site, Lucky Strike hydrothermal field Mittelstaedt, Eric; Escartin, Javier E.; Gracias, Nuno; Olive, Jean-Arthur L.; Barreyre, Thibaut; Davaille, Anne; Cannat, Mathilde; Garcia, Rafael (American Geophysical Union, 2012-04-19)The relative heat carried by diffuse versus discrete venting of hydrothermal fluids at mid-ocean ridges is poorly constrained and likely varies among vent sites. Estimates of the proportion of heat carried by diffuse flow ...
Tarrell, Alvin E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1997-09)Saltwater marshes and wetlands are important buffers at the land-sea interface. Among the most biologically active ecosystems on Earth, natural and man-made wetlands are important interceptors of pollutants and nutrients ...
The Trans-Atlantic Geotraverse hydrothermal field : a hydrothermal system on an active detachment fault Humphris, Susan E.; Tivey, Margaret K.; Tivey, Maurice A. (2015-02)Over the last ten years, geophysical studies have revealed that the Trans-Atlantic Geotraverse (TAG) hydrothermal field (26°08’N on the Mid-Atlantic Ridge) is located on the hanging wall of an active detachment fault. ...