Results 101 to 110 of about 3,029 (140)
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Growth of large sulfide structures on the endeavour segment of the Juan de Fuca ridge
Earth and Planetary Science Letters, 1986Abstract Mapping and sampling with DSRV “Alvin” has established that sulfide blocks 0.5 m across, dredged from the axial valley of the Endeavour Segment at 47°57′N, are samples of unusually large sulfide structures. The steep-sided structures, up to 30 m in length, 20 m in height, and 10–15 m across, are localized by venting along normal faults at ...
Margaret K. Tivey, John R. Delaney
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Heat flux from black smokers on the Endeavour and Cleft segments, Juan de Fuca Ridge
Journal of Geophysical Research: Solid Earth, 1994We have estimated the heat flux from black smoker vents on the Juan de Fuca Ridge to evaluate their importance for heat transfer from young oceanic crust. The velocity and temperature of smoker effluent were measured from the manned submersible Alvin within a few centimeters of vent orifices, using a turbine flowmeter with an attached temperature probe.
Ursula Ginster +2 more
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Deep Sea Research Part I: Oceanographic Research Papers, 2001
Abstract Bio-acoustic surveys and associated zooplankton net tows have documented anomalously high concentrations of zooplankton within a 100 m layer above the hydrothermal plumes at Endeavour Segment, Juan de Fuca Ridge. These and other data suggest that congregating epi-plume zooplankton are exploiting a food substrate associated with the ...
James P. Cowen +6 more
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Abstract Bio-acoustic surveys and associated zooplankton net tows have documented anomalously high concentrations of zooplankton within a 100 m layer above the hydrothermal plumes at Endeavour Segment, Juan de Fuca Ridge. These and other data suggest that congregating epi-plume zooplankton are exploiting a food substrate associated with the ...
James P. Cowen +6 more
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Applied Geochemistry, 2009
Abstract Hydrothermal chimney sulfides, vent cap chimney samples, Fe-oxide and basalts from sediment-starving Juan de Fuca Ridge, in the Endeavour segment, exhibit a range of Pb isotope ratios ( 206 Pb/ 204 Pb = 18.658–18.769; 207 Pb/ 204 Pb = 15.457–15.566; 208 Pb/ 204 Pb = 37.810–38.276).
Hui-Qiang Yao +9 more
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Abstract Hydrothermal chimney sulfides, vent cap chimney samples, Fe-oxide and basalts from sediment-starving Juan de Fuca Ridge, in the Endeavour segment, exhibit a range of Pb isotope ratios ( 206 Pb/ 204 Pb = 18.658–18.769; 207 Pb/ 204 Pb = 15.457–15.566; 208 Pb/ 204 Pb = 37.810–38.276).
Hui-Qiang Yao +9 more
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Along‐axis variations within the plate boundary zone of the southern segment of the Endeavour Ridge
Journal of Geophysical Research: Solid Earth, 1988The width of and along‐axis variations within the plate boundary zone of the southern segment of the Endeavour Ridge of the Juan de Fuca Ridge System have been quantified using Sea MARC I side‐looking sonar imagery. The sonar imagery was calibrated with video and photographic surveying to provide visual corroboration of the activity, spacing, and ...
Angela M. Barone, William B. F. Ryan
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Geology, 2001
The 500-m-long Mothra hydrothermal field is the largest venting site in areal extent on the Endeavour segment of the Juan de Fuca Ridge. Within this field, there are at least five actively venting sulfide complexes, spaced 40 to 200 m apart along a trend of 020.
Deborah S. Kelley +2 more
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The 500-m-long Mothra hydrothermal field is the largest venting site in areal extent on the Endeavour segment of the Juan de Fuca Ridge. Within this field, there are at least five actively venting sulfide complexes, spaced 40 to 200 m apart along a trend of 020.
Deborah S. Kelley +2 more
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Journal of Geophysical Research: Solid Earth, 1993
A detailed seismic refraction survey was carried out over the Endeavour Segment of the Juan de Fuca Ridge, a medium‐rate spreading center which lies off western North America, to investigate the creation and evolution of oceanic crust. A bathymetric high and the presence of hydrothermal vents suggested that the study area was the most recent locus of ...
Connie F. Cudrak, Ron M. Clowes
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A detailed seismic refraction survey was carried out over the Endeavour Segment of the Juan de Fuca Ridge, a medium‐rate spreading center which lies off western North America, to investigate the creation and evolution of oceanic crust. A bathymetric high and the presence of hydrothermal vents suggested that the study area was the most recent locus of ...
Connie F. Cudrak, Ron M. Clowes
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Estimates of crustal permeability on the endeavour segment of the Juan de Fuca mid-ocean ridge
Earth and Planetary Science Letters, 1996Observational studies of hydrothermal venting on the Endeavour segment of the Juan de Fuca Ridge place strong constraints on the spacing and area of vent fields, the depth of circulation, and the hydrothermal heat flux. A method is described to estimate a uniform crustal permeability from these parameters under the assumptions that upflow is confined ...
William S.D. Wilcock, Alex McNabb
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Geochimica et Cosmochimica Acta, 2007
Abstract We present first data on the geochemistry, mineralogy and morphology of near-vent sediments (35 and 200 m from active vent) and ridge flank sediments (approximately 3 km from the vent field) as well as oxyhydroxide deposits from the Endeavour segment, Juan de Fuca Ridge.
Elitsa Hrischeva, Steven D. Scott
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Abstract We present first data on the geochemistry, mineralogy and morphology of near-vent sediments (35 and 200 m from active vent) and ridge flank sediments (approximately 3 km from the vent field) as well as oxyhydroxide deposits from the Endeavour segment, Juan de Fuca Ridge.
Elitsa Hrischeva, Steven D. Scott
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Methane oxidation in deep-sea hydrothermal plumes of the endeavour segment of the Juan de Fuca Ridge
Deep Sea Research Part I: Oceanographic Research Papers, 1993Methane oxidation rates were measured in samples from a deep-sea lateral hydrothermal plume generated from a vent field on the Endeavour Segment of the Juan de Fuca Ridge. Specific CH4 oxidation rates of up to 0.15 day−1, corresponding to turnover times on the order of 1 week, are the highest such rates so far reported for the water column of any ...
M.A. de Angelis +2 more
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