114 17 Allen, C. E. Tyler, P. A. Van Dover, C. L. Allen, CE Harbor Branch Oceanog Inst Inc, Div Marine Sci, 5600 USI N, Ft Pierce, FL 34946 USA Harbor Branch Oceanog Inst Inc, Div Marine Sci, Ft Pierce, FL 34946 USA Southampton Oceanog Ctr, Sch Ocean & Earth Sci, Southampton SO14 3ZH, Hants, England Coll William & Mary, Dept Biol, Williamsburg, VA 23187 USA Journal of the Marine Biological Association of the United Kingdom 817-821 81 5 carbon-isotope composition stable-carbon western pacific fatty-acids mussels 2001 OCT 0025-3154 ISI:000172659800013 Specimens of the chemoautotrophic symbiont-bearing hydrothermal vent clam Calyptogena pacfica were collected from hydrothermal,,cuts at the Endeavour segment of the Juan de Fuca Ridge. Total lipid was extracted from gill, foot and mantle tissues, and lipid class and fatty acid composition determined by thin laver chromatography with flame ionization detection (TLC FID), gas chromatography (GC) and gas chromatography with mass spectrometry (GC-MS). An abundance of n-7 monounsaturated fatty acids (MUFA), especially in the gill, reflected the large contribution of chemoautotrophic symbiotic bacteria to he nutrition of this clam. The absence of n-8 MUFA suggests that C. pacifica does not contain methanotrophic symbiotic bacteria. Low levels of highly unsaturated fatty acids (HUFA) such as 20:5 n-3 and 22:6 n-3 were detected in C. pacfica and their presence is attributed to a source other than chemoautotrophic symbiotic bacteria. Significant levels of non-methylene interrupted dienoic fatty acids and eicosatrienoic acid (20:3) were also detected in C pacfica and it is suggested that these fatty acids are synthesized from n-7 MUFA as alternatives to HUFA. In contrast to shallow water bivalves. elevated levels of triglyceride were detected in the gills compared to the mantle. 501AA Times Cited:3 Cited References Count:18 <Go to ISI>://000172659800013 English 122 17 Almendros, J. Barclay, A. H. Wilcock, W. S. D. Purdy, G. M. Almendros, J US Geol Survey, 345 Middlefield Rd,MS 910, Menlo Park, CA 94025 USA Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Univ Granada, Inst Andaluz Geofis, E-18071 Granada, Spain Geophysical Research Letters 3109-3112 27 19 cracks attenuation rocks waves 2000 OCT 1 0094-8276 ISI:000089711900021 Microearthquake data recorded on four ocean bottom seismometers are used to study shear-wave splitting on the Endeavour Segment of the Juan de Fuca Ridge. The covariance matrix decomposition method is used to determine the sensor orientation from explosive shot data and to estimate the anisotropy parameters for 238 earthquake records. At three of the four sites, the results show a remarkably consistent fast direction parallel to the ridge axis. The time delays between the fast and the slow waves range from 40 to 200 ms, with an average of 90 ms. They are not clearly related to earthquake range, focal depth or source-receiver azimuth. The splitting of the shear waves is interpreted as an effect of structural anisotropy due to the presence of ridge-parallel cracks in the shallow crust. If we assume that anisotropy is concentrated in the upper 1-2 km, the splitting times require a high crack density of similar to 0.1. 361FG Times Cited:3 Cited References Count:19 <Go to ISI>://000089711900021 English 1 17 Archer, S. D. W. S. D. Wilcock G. M. Purdy EoS Trans. AGU 727 77 1996 2 17 Baker, E. T. G. J. Massoth Earth Planet. Sci. Letters 59-73 85 1987 96 17 Barclay, A. H. Wilcock, W. S. D. Barclay, Ah Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Geochemistry Geophysics Geosystems GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS - 5 mid-ocean ridge layer 2a structure seismic anisotropy microearthquakes marine geology and geophysics : midocean ridge processes seismology : oceanic crust east pacific rise mid-atlantic ridge upper oceanic-crust hydrothermal field poissons ratio refraction experiment structure beneath sulfide deposits median valley layer 2a 2004 JAN 17 1525-2027 ISI:000188306200001 We present the results of a study to invert microearthquake and explosive shot data from the Endeavour segment of the intermediate-spreading Juan de Fuca Ridge. The average isotropic P wave velocity structure, derived from the shot data, in the uppermost 1.5 km of the oceanic crust is characterized by an increase with age of similar to8% from the axis to at least 0.5 Ma, that is attributed to the sealing of layer 2A porosity by hydrothermal processes. Superimposed on this variation are axis-parallel, 2-km-wide, alternating bands of high and low velocity with a peak-to-peak variation of 5-12%. High and low velocities away from the axis correspond to bathymetric trenches and ridges, respectively and are likely due to variations in layer 2A thickness. P wave azimuthal anisotropy is present in the data that is best fit with a model of 9% anisotropy at 750 m depth, decreasing to 1% at 3 km depth and is likely due to the preferential alignment of vertical cracks and fissures in the along-axis direction. Anisotropy and velocity heterogeneity are coupled; anisotropy alone may explain the form but not the magnitude of the axis-parallel bands. There are strong trade-offs between the hypocentral depths of microearthquakes and the P and S wave velocity structures. Changing the mean hypocentral depth by up to 0.5 km leads to only modest increases in the travel time RMS but the resulting velocity models appear more feasible when the earthquakes are forced deeper than when they are forced shallower. 765VZ Times Cited:1 Cited References Count:59 <Go to ISI>://000188306200001 English 3 5 Baross, J. A. J. W. Deming D. M. Karl The Microbiology of Deep-Sea Hydrothermal Vents 169-217 1995 Boca Raton, FL CRC Press 153 17 J A Baross W S D Wilcock D S Kelley E F DeLong S C Cary Geophys. Monograph Series Geophys. Monograph Series 1-13 144 r2k-synthesis 2004 doi: 10.1029/144GM01 157 17 Battaglia, T. M. Dunn, E. E. Lilley, M. D. Holloway, J. Dable, B. K. Marquardt, B. J. Booksh, K. S. Analyst Analyst 602-606 129 7 2004 doi: 10.1039/b404505j 4 17 Bemis, K. G. R. P. Von Herzen M. J. Mottl J.Geophys. Res. 6351-6365 98 1993 82 17 Berdeal, I. G. Hautala, S. L. Thomas, L. N. Johnson, H. P. Berdeal, Ig Univ Washington, Sch Oceanog, Box 355351, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Deep-Sea Research Part I-Oceanographic Research Papers 367-386 53 2 o flow-topography interaction current observations mid-ocean ridges tidal currents larval dispersal hydrothermal fields ne pacific juan de fuca ridge endeavour segment de-fuca-ridge northeast pacific-ocean bottom-boundary-layer hydrothermal vents endeavor segment tidal currents southern juan plumes circulation topography 2006 FEB 0967-0637 ISI:000235876200011 Velocity measurements with high vertical resolution, and a two-dimensional linear quasianalytic model for subinertial oscillatory flows, are used to analyze the vertical structure of flow in the axial valley at Endeavour Segment, Juan de Fuca Ridge. At a site away from hydrothermal vents, observed semidiurnal flows are independent of depth, rectilinear and parallel to the valley axis, while subinertial flows are intensified and re-aligned along-valley toward the bottom. This behavior is consistent with solutions from the model, which show attenuation of subinertial across-valley flow with depth. This cross-flow attenuation is most pronounced for valleys with widths less than the internal Rossby radius of deformation. Reduction of across-valley flow with depth results in a weakened Coriolis force that cannot fully balance the along-valley pressure-gradient force. The resulting force imbalance yields a directly accelerated bottom-intensified along-valley flow. The importance of this physical process in other submarine valleys depends on their geometry, stratification and latitude. If active, this mechanism provides a dynamic background environment for the axial valley to which hydrothermal venting would add complexity. The strong vertical shears and spiraling flows observed within the axial valley for diurnal tidal and lower-frequency flows have important implications in the transport of hydrothermal vent fluid and the dispersal of larvae of vent organisms by bottom currents. (c) 2005 Elsevier Ltd. All rights reserved. 019ZB Times Cited:1 Cited References Count:41 <Go to ISI>://000235876200011 English 168 17 Bergquist, D. C. Eckner, J. T. Urcuyo, I. A. Cordes, E. E. Hourdez, S. Macko, S. A. Fisher, C. R. Mar Ecol Prog Ser Mar Ecol Prog Ser 49-65 330 2007 106 17 Bertram, M. A. Cowen, J. P. Thomson, R. E. Feely, R. A. Bertram, Ma Univ Washington, Sch Oceanog, Box 355351, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Univ Hawaii, Sch Ocean & Earth Sci, Honolulu, HI 96822 USA Inst Ocean Sci, Sidney, BC V8L 4B2, Canada NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA Journal of Geophysical Research-Oceans 3191 107 C11 r2k-hp hydrothermal particles iron biogenic productivity flux de-fuca ridge east pacific rise endeavor segment midocean ridge dissolved phosphate metal adsorption organic material particle fluxes north pacific sea-floor 2002 NOV 0148-0227 ISI:000180570400012 [1] Sequentially sampling sediment traps set with 33 day sampling intervals were deployed with current meters on three moorings in the northeast Pacific Ocean between July 1994 and May 1995. One mooring was deployed near the Main Vent field on Endeavour Ridge (On-Axis site, 47degrees57.0'N, 129degrees05.7'W), a second, 3 km west of the Main vent site (West site), and the third, 43 km northeast of the Main vent site (East or background site). Ascending and descending particles were collected near 1600 and 2000 m depth, well above and within the top of laterally spreading hydrothermal plumes. The elemental composition of particles was used to evaluate their origins: biogenic fluxes were indicated by elevated Ca or Si, hydrothermal fluxes by elevated Fe, Mn, and Cu, and lithogenic fluxes by elevated Ti. We link temporal variability in both the ascending and descending particle composition and flux to variations in lateral transport of hydrothermal constituents and to seasonal drawdown of hydrothermal plume particles by biogenic material from the upper ocean. The relatively low hydrothermal Fe content of ascending material late in the experiment is thought to be due to uptake by descending biogenic material. These results suggest that seasonal productivity and particle export from the ocean surface can modulate the hydrothermal flux of elements to the waters above and to the sediments below. 638KP Times Cited:1 Cited References Count:46 <Go to ISI>://000180570400012 English 5 17 Blank, J. G. J. R. Delaney D. J. Des Marais Geochim. Cosmochim. Acta Geochim. Cosmochim. Acta 875887 57 1993 91 17 Bohnenstiehl, D. R. Dziak, R. P. Tolstoy, M. Fox, C. G. Fowler, M. Bohnenstiehl, DR Columbia Univ, Lamont Doherty Earth Observ, 61 Route 9W, Palisades, NY 10964 USA Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA Oregon State Univ, Hatfield Marine Sci Ctr, NOAA, Pacific Marine Environm Lab, Newport, OR 97365 USA Geochemistry Geophysics Geosystems GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS Q09003 5 9 r2k-tcs dike earthquake hydrothermal system mid-ocean ridge seismic triggering marine geology and geophysics : midocean ridge processes seismology : volcano seismology tectonophysics : dynamics, seismotectonics wave detection thresholds denali fault earthquake mid-atlantic ridge volcanic activity midocean ridge propagating rift p-wave swarm magnitude hydrophones 2004 SEP 1 1525-2027 ISI:000223887800004 Two large clusters of earthquake activity in June of 1999 and January of 2000 have dominated recent seismicity along the Endeavour Segment of the Juan de Fuca Ridge. The impacts of the June 1999 sequence on the hydrologic system, which include changes in vent temperature and chemistry within the Main Endeavour Vent Field, have been well documented previously. Analysis of seismic and hydroacoustic data indicates that both sequences exhibit a swarm-like behavior, characterized by the absence of a dominant main shock event. The epicentral locations of events within the two swarms overlap spatially, with centroid positions near 47degrees49' and 47degrees46'N latitude. During the June 1999 swarm, the initial activity spans the along-axis region where a shallow axial magma chamber reflector was later imaged. The epicenters then migrate similar to12 km to the south at a rate of 0.3 m/s, consistent with lateral dike propagation. A distinct subcluster of events also occurred in the vicinity of Surveyor Volcano on the overlapping portion of the Cobb Segment. Given its distance from the main swarm, this activity may represent a triggered response to dynamic shaking. The January 2000 swarm has a more limited along-axis extent, relative to the June 1999 swarm, with no indication of lateral migration. Much of this activity is concentrated in a region predicted to have undergone extension due to dike propagation in 1999. Although it contains fewer total events and is of shorter duration, relative to the June 1999 swarm, the January 2000 activity exhibits a higher peak rate of seismicity and greater mean event magnitude. As in situ temperature monitoring was not in place during January 2000 and vent fluids were not sampled until June 2000, the impacts of this swarm on the hydrothermal system are unknown. The southernmost tip of the Endeavour Segment also is found to be a region of repeating swarm activity. Although morphologic evidence indicates the Cobb Segment has been propagating northward recently, this seismic activity suggests that the western limb of the Endeavour-Cobb overlap zone remains active. 854FU Times Cited:2 Cited References Count:54 <Go to ISI>://000223887800004 English 111 17 Bohnenstiehl, D. R. Tolstoy, M. Dziak, R. P. Fox, C. G. Smith, D. K. Bohnenstiehl, DR Columbia Univ, Lamont Doherty Earth Observ, 61 Route 9W,Box 1000, Palisades, NY 10964 USA Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA Oregon State Univ, NOAA, Cooperat Inst Marine Resources Studies, Newport, OR 97365 USA NOAA, Pacific Marine Environm Lab, Newport, OR 97365 USA Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA Tectonophysics 49-70 354 1-2 r2k-cp earthquake sequence omori law endeavour segment easter microplate oceanic transform normal fault transform-fault zone de-fuca ridge earthquake source parameters link cluster-analysis easter microplate volcanic activity fracture-zones omori formula t-waves seismicity 2002 AUG 30 0040-1951 ISI:000178093400003 Hydroacoustic data from autonomous arrays and the U.S. Navy's Sound Surveillance System (SOSUS) provide an opportunity to examine the temporal and spatial properties of seismicity along portions of the slow-spreading Mid-Atlantic Ridge (MAR), intermediate-spreading Juan de Fuca Ridge (JdFR) and fast-spreading East Pacific Rise (EPR). Aftershock and foreshock events are selected from the hydroacoustic earthquake catalog using single-link cluster (SLC) analysis, with a combined space-time metric. In the regions examined, hydroacoustic data improve the completeness level of the earthquake catalog by similar to1.5-2.0 orders of magnitude, allowing the decay constant,p, of the modified Omori law (MOL) to be determined for individual sequences. A non-parametric goodness-of-fit test indicates six of the seven sequences examined are described well by a MOL model. The p-values obtained for individual ridge and transform sequences using hydroacoustic data are larger than that previously estimated from the analysis of a stacked sequence generated from teleseismic data. For three sequences along the Siqueiros, Discovery and western Blanco Transforms, p-values are estimated to be similar to0.94-1.29. The spatial distribution of aftershocks suggests that the mainshock rupture is constrained by intra-transform spreading centers at these locations. An aftershock sequence following a 7.1M(s) thrust event near the northern edge of the Easter Microplate exhibits p=1.02 +/- 0.11. Within the sequence, aftershocks are located to the north of a large topographic ridge, which may represent the surface expression of the shallow-dipping fault that ruptured during the mainshock. Two aftershock sequences near 24degrees25'N and 16degrees35'N on the MAR exhibit higher p-values, 1.74 +/- 0.23 and 2.37 +/- 1.65, although the latter estimate is not well constrained because of the small number of aftershocks. Larger p-values along the ridge crest might reflect a hotter thermal regime in this setting. Additional monitoring, however, will be needed to determine if p-value differences between the ridge and transform sequences are robust. A 1999 sequence on the Endeavour segment of the JdFR, which has been correlated with changes in the hydrothermal system, is described poorly by the MOL model. The failure of the MOL model, the anomalously large number of earthquakes within the sequence and absence of a clearly dominant mainshock are inconsistent with aftershock activity and the simple tectonic origin that has been proposed previously for this sequence. (C) 2002 Elsevier Science B.V. All rights reserved. 595EG Times Cited:23 Cited References Count:59 <Go to ISI>://000178093400003 English 6 17 Butterfield, D. A. R. E. McDuff M. Mottl, M. D. Lilley G. J. Massoth J. E. Lupton J.Geophys. Res. 95619583 99 1994 139 17 Butterfield, D. A. Nelson, B. K. Wheat, C. G. Mottl, M. J. Roe, K. K. Geochimica et Cosmochimica Acta Geochimica et Cosmochimica Acta 4141-4153 65 22 2001 7 17 Butterfield, D. A. K. K. Roe G. J. Massoth R. W. Embley R. E. McDuff J. R. Delaney EoS Trans. AGU 420 76 1995 124 17 Canales, J. P. Detrick, R. S. Carbotte, S. M. Kent, G. M. Diebold, J. B. Harding, A. Babcock, J. Nedimovic, M. R. Van Ark, E. Journal of Geophysical Research Journal of Geophysical Research B12104 110 r2k-cs 2005 148 17 J. Pablo Canales Satish C. Singh Robert S. Detrick Suzanne M. Carbotte Alistair Harding Graham M. Kent John B. Diebold Jeffrey Babcock Mladen R. Nedimović Earth Planet. Sci. Lett. Earth Planet. Sci. Lett. 353-366 246 r2k-cs juan de fuca MCS 2006 doi:10.1016/j.epsl.2006.04.032 141 17 Carbotte, S. M. Detrick, R. S. Harding, A. Canales, J. P. Babcock, J. Kent, G. Van Ark, E. Nedimovic, M. Diebold, J. Geology Geology 209 34 3 r2k-cp 2006 175 17 Carney, S. L. Flores, J. F. Orobona, K. M. Butterfield, D. A. Fisher, C. R. Schaeffer, S. W. Comp Biochem Physiol B Biochem Mol Biol Comp Biochem Physiol B Biochem Mol Biol 2006 174 17 Carney, S. L. Peoples, J. R. Fisher, C. R. Schaeffer, S. W. 2002 140 17 Chadwell, C. D. Spiess, F. N. Hildebrand, J. A. Dragert, H. American Geophysical Union, Fall Meeting 2002, abstract# T22A-1130 2002 130 17 Chadwick, W. W. Scheirer, D. S. Embley, R. W. Johnson, H. P. Journal of Geophysical Research Journal of Geophysical Research 16075-16100 106 B8 r2k-cs/h 2001 185 17 Cooper, K. M. Goldsstein, S. J. Sims, K. W. W. Murrell, M. T. Earth and Planetary Science Letters Earth and Planetary Science Letters 459-475 206 r2k-tcs 2003 102 17 Copley, J. T. P. Tyler, P. A. Van Dover, C. L. Philp, S. J. Copley, Jtp Univ Southampton, Southampton Oceanog Ctr, Sch Ocean & Earth Sci, European Way, Southampton SO14 3ZH, Hants, England Univ Southampton, Southampton Oceanog Ctr, Sch Ocean & Earth Sci, Southampton SO14 3ZH, Hants, England Coll William & Mary, Dept Biol, Williamsburg, VA 23187 USA Marine Ecology-Progress Series 171-181 255 hydrothermal vents reproductive development spatio-temporal variation successional model mid-atlantic ridge pacific hydrothermal vents population-structure northeast pacific northumberland population sexual dimorphism endeavor segment communities ecology area 2003 0171-8630 ISI:000184268600014 The microdistribution and dynamics of deep-sea hydrothermal vent communities often reflect the extreme heterogeneity of their environment. Here we present an assessment of spatial variation in the reproductive development of the alvinellid polychaete Paralvinella palmiformis at the High Rise vent field (Endeavour Segment, Juan de Fuca Ridge, NE Pacific). Samples collected from different locations across the vent field suggest patchy reproductive development for this species. Males and females from several locations contained few or no developing gametes, while gametes were abundant in samples collected at the same time from other locations. Samples lacking gametes were distinguished by body size-frequency distributions with peaks at smaller sizes and the presence or absence of other fauna consistent with early stage assemblages in a successional mosaic model previously proposed for Endeavour Segment communities. Where gametes were present, synchrony of reproductive development between females within samples and between samples was evident. Reproductive synchrony between pairs of samples initially declined over a 7 d interval between samples, suggesting a rapid rate of reproductive development for R palmiformis. Samples collected 1 mo apart, however, displayed similar frequency distributions of developing gametes. A peak of mature male and female gametes appeared to develop and disappear within the limited temporal resolution of the samples, consistent with possible simultaneous maturation of gametes despite pseudocopulation and sperm storage in this species. 703FD Times Cited:3 Cited References Count:41 <Go to ISI>://000184268600014 English 152 17 J P Cowen E T Baker R W Embley Geophys. Monograph Series Geophys. Monograph Series 227-244 144 r2k-tcs r2k-bi/ch/h 2004 doi: 10.1029/144GM15 121 17 Cowen, J. P. Bertram, M. A. Wakeham, S. G. Thomson, R. E. Lavelle, J. W. Baker, E. T. Feely, R. A. Cowen, JP Univ Hawaii, Dept Oceanog, 1000 Pope Rd, Honolulu, HI 96822 USA Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA Skidaway Inst Oceanog, Savannah, GA 31411 USA Fisheries & Oceans Canada, Inst Ocean Sci, Sidney, BC V8L 4B2, Canada NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA Deep-Sea Research Part I-Oceanographic Research Papers 1093-1120 48 4 r2k-hp hydrothermal plumes organic carbon production ascending/descending flux endeavour segment juan de fuca ridge particulate organic material scattering layer north pacific methane oxidation abyssal waters vent field matter ocean manganese system 2001 APR 0967-0637 ISI:000167058500006 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 hydrothermal plume. Ascending, organic-rich particles could provide a connection, Consequently, two paired sequentially sampling ascending and descending particle flux traps and a current meter were deployed on each of three moorings from July 1994 to May 1995. Mooring sites included an on-axis site (OAS; 47 degrees 57.0'N, 129 degrees 05.7'W) near the main Endeavour vent field, a "down-current" site 3 km west of the main vent field (WS), and a third background station 43 km northeast of the vent field (ES). Significant ascending and descending particle fluxes were measured at all sites and depths. Lipid analyses indicated that ascending POC was derived from mid-depth and deep zooplankton whereas descending POC also contained a component of photosynthetically derived products from the sea surface. Highest ascending POC fluxes were found at the hydrothermal plume-swept sites (OAS and WS). The limited data available, however, precludes an unequivocal conclusion that hydrothermal processes contribute to the ascending flux of organic carbon at each site. Highest ascending to descending POC flux ratios were also found at WS. Observed trends in POC, PMn/PTi, and PFe/PTi clearly support a hydrothermal component to the descending flux at the plume-swept WS site (no descending data was recovered at OAS) but not at the background ES site. Alternative explanations for ascending particle data are discussed. First-order calculations for the organic carbon input (5-22 mg C m(-2) d(-1)) required to sustain observed epi-plume zooplankton anomalies at Endeavour are comparable both to measured total POC flux to epi-plume depths (2-5 mg C m(-2) d(-1): combined hydrothermal and surface derived organic carbon) and to estimates of the total potential in situ organic carbon production (2-9 mg C m(-2) d(-1)) from microbial oxidation of hydrothermal plume H-2. CH4 and NH4+. (C) 2001 Published by Elsevier Science Ltd. All rights reserved. 403TL Times Cited:7 Cited References Count:75 <Go to ISI>://000167058500006 English 110 17 Cowen, J. P. Wen, X. Y. Popp, B. N. Cowen, JP Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA Earthtech Inc Tyco Int, Honolulu, HI 96822 USA Univ Hawaii, Dept Geol & Geophys, Honolulu, HI 96822 USA Geochimica Et Cosmochimica Acta Geochimica et Cosmochimica Acta 3563-3571 66 20 r2k-hp de-fuca ridge southern california bight endeavor segment isotopic-ratios guaymas basin ocean oxidation carbon fractionation system 2002 OCT 0016-7037 ISI:000178730000004 Methane concentration and the stable carbon isotopic composition (delta(13)C-CH4) were measured in aging hydrothermal plume waters originating at the Endeavour Segment, Juan de Fuca Ridge. CH4 concentrations decreased systematically from 600 nM at on-axis stations to <11 nM at a distal station 15 kin off axis background CH4 concentrations are <2 nM. CH4 behaves nonconservatively in plume waters and does not cor,relate with conservative parameters such as temperature anomaly (Deltatheta), but is highly correlated with NH4+ and total dissolvable Mn, delta C-13-CH4 values for plume depth samples varies inversely, and significantly (R-2 = 0.89) with methane concentrations normalized to Deltatheta, Some delta C-13-CH4 values (+ 1.8 and + 10.9 parts per thousand) measured at the 15 kin off-axis station are among the heaviest yet reported from a natural marine environment. Less than 5% of original hydrothermal methane remains in the plume at this station. The data are consistent with extensive microbial methane oxidation. A narrow range of fractionation factors (r(c) approximate to 1.0072 to 1.0077) was calculated for the Endeavour samples. These fractionation factors a-re less than those reported by Coleman et al. (1981). but fall near the trend line of their r(c) versus temperature data when extrapolated to plume water temperature (similar to2 degreesC). Copyright (C) 2002 Elsevier Science Ltd. 606JC Times Cited:7 Cited References Count:40 <Go to ISI>://000178730000004 English 155 17 Crone, T. J. Wilcock, W. S. Barclay, A. H. Parsons, J. D. PLoS ONE PLoS ONE e133 1 1 r2k 2006 doi: 10.1371/journal.pone.0000133 189 17 Crone, T. J. Wilcock, W. S. D. Geochemistry Geophysics Geosystems GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS Q07001 6 7 r2k 2005 8 17 Curewitz, D. J. A. Karson J.Volcan. Geo. Res. 149-168 79 1997 162 17 Dable, B. K. Marquardt, B. J. 2006 2006 773-780 60 7 2006 doi: 10.1366/000370206777887125 134 17 Davis, E. Becker, K. Dziak, R. Cassidy, J. Wang, K. Lilley, M. Nature Nature 335-8 430 6997 2004 9 17 Davis, E. E. J. L. Karsten Earth Planet. Sci. Lett. Earth Planet. Sci. Lett. 385-396 79 1986 116 17 Davis, E. E. Wang, K. Thomson, R. E. Becker, K. Cassidy, J. F. Davis, EE Geol Survey Canada, Pacific Geosci Ctr, 9860 W Saanich Rd, Sidney, BC V8L 4B2, Canada Geol Survey Canada, Pacific Geosci Ctr, Sidney, BC V8L 4B2, Canada Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA Inst Ocean Sci, Dept Fisheries & Oceans, Sidney, BC V8L 4B2, Canada Journal of Geophysical Research-Solid Earth 21953-21963 106 B10 de-fuca ridge oceanic-crust axial-volcano half-space earthquake permeability strain 2001 OCT 10 0148-0227 ISI:000171420800016 Three-year records of crustal fluid pressures and temperatures at four Ocean Drilling Program (ODP) sites on the northern Juan de Fuca Ridge and eastern ridge flank reveal a broad range. of variations that include hydrologic transients that are contemporaneous with earthquakes along the ridge axis, the Nootka transform fault, and within the Juan de Fuca plate. One example of such a transient is the response to what is inferred to be a seafloor spreading event that triggered a swarm of earthquakes near the Endeavour ridge segment, beginning with a M-W = 4.6 event on June 8, 1999. The largest transients were observed at ODP Sites 1024 and 1025 located 25.6 and 33.5 km east of the Endeavour axis. Pressures rose coseismically with the first earthquake of the swarm by roughly 1.6 and 1 kPa, continued to rise to maxima of 3.2 and 2.0 kPa within hours, then decayed to half the peak levels in 1 and 2 days at the two respective sites. A small (similar to0.2 kPa) response of the same sign followed by a decay over 100 days was observed at Site 1027 situated 101 km east of the axis, and a similarly small response but of opposite sign was observed at Site 857 in Middle Valley, located along strike of the Endeavour segment roughly 50 km to the north of the earthquake swarm. The pressure transients are inferred to reflect a combination of the instantaneous internal plate deformation associated with extension at the ridge axis and lateral water flow in the crust following strain-induced fluid pressure gradients. The rate at which the transients dissipate constrains the regional-scale permeability of the upper igneous crust to be of the order of 10(-10)-10(-9) m(2). Instantaneous strain calculated from the initial amplitude of the transients ranges from 8 X 10(-9) at the most distal site to 1.7 X 10(-7) at the most proximal. The magnitude of regional strain is much larger than that which would result from the simultaneous earthquake, and we conclude that the first and all subsequent earthquakes of the swarm, and the crustal strain responsible for the hydrologic transients, are the consequence of a dominantly aseismic spreading "event" involving similar to 12 cm of dilatation at the ridge axis. There were no clear indications of associated magmatic activity; hence episodic spreading may take place outside the influence of either dike injection or seismic rupture. Given the excellent sensitivity of pore pressure to strain, we anticipate that this simple observational technique can be applied to the investigation of seismic and aseismic deformation in a variety of tectonically active settings. 479TZ Times Cited:22 Cited References Count:35 <Go to ISI>://000171420800016 English 10 17 de Angelis, M. A. M. D. Lilley E. J. Olson and J. A. Baross Deep-Sea Res. 1169-1186 (20) 1993 13 17 Delaney, J. R. Crest 91-Flange Research, Teams EoS. Trans. AGU 231 72 1991 11 17 Delaney, J. R. H. P. Johnson J. L. Karsten 11,747-11,750 86 1981 16 17 Delaney, J. R. D. S. Kelley E. A. Mathez D. R. Yoerger J. Baross M. Schrenk M. K. Tivey J. Kaye V. Robigou EOS, Trans. Amer. Geophys. Union 67-73 82 2001 15 17 Delaney, J. R. M. D. Lilley R. E. McDuff D. S. Kelley W. S. Wilcock V. Robigou EoS. Trans. AGU 756 77 1996 12 17 Delaney, J. R. R. E. McDuff J. E. Lupton EoS Trans. AGU 973 65 1984 14 17 Delaney, J. R. V. Robigou R. E. McDuff M. K. Tivey J.Geophys. Res. 19,663-19,682 97 1992 17 17 Deming, J. W. J. A. Baross Geochim. Cosmochim. Acta Geochim. Cosmochim. Acta 3219-3230 57 1993 177 17 C. Devey C. R. Fisher S. Scott Oceanography Oceanography 162-171 20 1 2007 84 17 Di Iorio, D. Lemon, D. Chave, R. Di Iorio, D Univ Georgia, Dept Marine Sci, 230 Marine Sci Bldg, Athens, GA 30602 USA Univ Georgia, Dept Marine Sci, Athens, GA 30602 USA ASL Environm Sci, Sidney, BC, Canada Journal of Atmospheric and Oceanic Technology 1602-1617 22 10 hp juan de fuca ridge sound speed heat-flux black-sea endeavor ocean plumes 2005 OCT 0739-0572 ISI:000232908500013 A self-contained acoustical scintillation instrument is described that has been used to measure flow and turbulence characteristics in two diverse oceanographic settings. This instrument is a battery-operated and internally logging acoustic propagation system that is ideally suited to monitor long-term flow and small-scale effective refractive index fluctuations. When the temperature variability dominates the acoustic scattering, as is the case of a hydrothermal vent plume, then a measure of the vertical buoyancy-driven flow, together with the root-mean-square temperature fluctuations, can be obtained. Results for vent structure Hulk of the Main Endeavour vent field of the Juan de Fuca Ridge show that the long-term (71 days) temperature fluctuations, together with the vertical flow, can be used to estimate heat flux density. Measurements also show oscillations in the log-amplitude variance that result from plume advection by the ambient tidal currents and demonstrate the need for a long time series measurement. When the turbulent velocity dominates the acoustic scattering, as is the case in some energetic bottom boundary layer flows, then the turbulent kinetic energy dissipation rate is derived, assuming isotropic and homogeneous models. The methodology and results are summarized from an application to the Bosporus Canyon of the Black Sea, to monitor the flow and turbulence associated with Mediterranean seawater inflow. 978YH Times Cited:0 Cited References Count:24 <Go to ISI>://000232908500013 English 118 17 Ding, K. Seyfried, W. E. Tivey, M. K. Bradley, A. M. Ding, K Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA Earth and Planetary Science Letters Earth and Planetary Science Letters 417-425 186 3-4 r2k-h/ch hydrothermal vents fluid phase geochemical indicators mid-ocean ridges geochemistry system chemistry sensor water 2001 APR 15 0012-821X ISI:000168318500007 The first in situ measurements of dissolved H-2 and H2S in high-temperature vent fluids were made at the Main Endeavour Field (Juan de Fuca Ridge) using the submersible Alvin and a newly developed electrochemical sensor. The measurements were successfully conducted ill chimneys at sites of venting fluid and in pools of more quiescent hydrothermal fluid that underlie flanges on chimney structures at a depth of 2200 m below the sea surface. Fluid temperatures measured simultaneously with dissolved gas concentrations were up to 370 degreesC. At the highest temperatures, dissolved H-2 and H2S concentrations were 0.72 and 17.3 mmol/kg, respectively, which are consistent with data obtained at the same sites through conventional sampling methods. The relatively high concentration of dissolved gases measured by both techniques, however, may be linked to recent tectonic and Volcanic activity. The ability to measure in situ dissolved gas concentrations simultaneously with fluid temperature in real time represents a major advance in the approaches available to study the origin and temporal evolution of seafloor hydrothermal systems at mid-ocean ridges. Although the present investigation is primarily based on sensor deployment for relatively shortterm measurement of vent fluids, long-term monitoring of vent fluid holds great promise for further applications. (C) 2001 Elsevier Science B.V. All rights reserved. 425YD Times Cited:9 Cited References Count:24 <Go to ISI>://000168318500007 English 85 17 Ding, K. Seyfried, W. E. Zhang, Z. Tivey, M. K. Von Damm, K. L. Bradley, A. M. Ding, K Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA Univ New Hampshire, Complex Syst Res Ctr, Durham, NH 03824 USA Earth and Planetary Science Letters Earth and Planetary Science Letters 167-174 237 1-2 r2k-h/ch hydrothermal fluid in situ ph mid-ocean ridges partial molal properties main endeavor field flow-through cell de-fuca ridge high-pressures conductivity measurements thermodynamic properties high-temperatures vent fluids transport-properties 2005 AUG 30 0012-821X ISI:000232047400012 Here we report the first in situ pH of hydrothermal vent fluids at mid-ocean ridges. Measurements were made during dives with DSV Alvin to the Main Endeavour Field (Juan de Fuca Ridge) and the East Pacific Rise at 21 degrees N, and 9 degrees-10 degrees N using solid-state electrochemical sensors. Vent fluid temperature and pressure ranged from 180 to 384 degrees C and 220 to 250 bar, respectively. pH((in situ)) of the highest temperature vent fluid is only slightly acidic (5.1-5.4), although sharply lower values occur at the seawater/vent-fluid interface. Knowledge of pH((in situ)) is essential for unravelling the complex geochemical and biogeochemical processes controlling the evolution of seafloor hydrothermal systems. (c) 2005 Elsevier B.V. All rights reserved. 966UK Times Cited:0 Cited References Count:32 <Go to ISI>://000232047400012 English 19 17 Dixon, J. E. E. Stolper J. R. Delaney Earth Planet. Sci. Lett. Earth Planet. Sci. Lett. 87-104 90 1988 20 17 Dymond, J. S. Roth Geochim et Cosmochim Acta. 2525-2536 52 1988 186 17 Dziak, R. P. Bohnenstiehl, D. R. Cowen, J. P. Baker, E. T. Rubin, K. H. Haxel, J. H. Fowler, M. J. Geology Geology 579-582 35 7 r2k-cp/h 2007 129 17 Dziak, R. P. Chadwick Jr, W. W. Fox, C. G. Embley, R. W. Geology Geology 119-122 31 2 r2k-cp/h r2k-tcs 2003 159 17 Dziak, R. P. Cowen, J P Baker, E T Bohnenstiehl, D. Chadwick, B. Resing, J. Embley, R W Eos Trans AGU Eos Trans AGU 87 4 r2k-tcs 2006 156 17 Dziak, R. P. Fox, C. G. Schreiner, A. E. Geophys. Res. Lett Geophys. Res. Lett 135–138 22 2 1995 101 17 Edwards, K. J. McCollom, T. M. Konishi, H. Buseck, P. R. Edwards, Kj Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Geomicrobiol Grp, McLean Lab, MS 8, Woods Hole, MA 02536 USA Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Geomicrobiol Grp, McLean Lab, Woods Hole, MA 02536 USA Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA Arizona State Univ, Tempe, AZ 85287 USA Geochimica Et Cosmochimica Acta Geochimica et Cosmochimica Acta 2843-2856 67 15 r2k-bi/ch mid-atlantic ridge iron-oxidizing bacteria hydrothermal vent site gallionella-ferruginea isotope fractionation elemental sulfur geochemical constraints endeavor segment microorganisms oxidation 2003 AUG 0016-7037 ISI:000184418200011 We present results of incubation studies conducted at low temperatures (similar to4degreesC) in the vicinity of a seafloor hydrothermal vent system. We reacted Fe-, S-, Cu-, and Zn-bearing minerals including pyrite, marcasite, chalcopyrite, sphalerite, elemental sulfur, and a portion of a natural chimney sulfide structure for 2 months at the Main Endeavour Segment of the Juan de Fuca Ridge in the Pacific Ocean. Our study utilizes Fluorescent In Situ Hybridizations (FISH), Scanning and Transmission Electron Microscopy (SEM, TEM), and light microscopic analysis. The surfaces of these minerals are solely colonized by Bacteria and not by Archaea. Colonization densities vary over an order of magnitude with the following sequence: elemental sulfur > chimney sulfide > marcasite > pyrite > sphalerite > chalcopyrite, and correspond well with the abiotic oxidation kinetics of these materials, excepting elemental sulfur, which is both the least reactive to oxidizing species and the most heavily colonized. Colonization densities also correspond with apparent degree of reaction (dissolution pitting + accumulation of secondary alteration products). Heavy accumulations of secondary Fe oxides on Fe-bearing minerals, most notably on the chimney sulfide, form in situ as the result of mineral dissolution and the activity of neutrophilic Fe-oxidizing bacteria. Results suggest that mineral-oxidizing bacteria play a prominent role in weathering of seafloor sulfide deposits, and that microbial utilization of mineral substrates contributes to biomass production in seafloor hydrothermal environments. Copyright (C) 2003 Elsevier Science Ltd. 705WD Times Cited:12 Cited References Count:53 <Go to ISI>://000184418200011 English 81 17 Fontaine, F. J. Wilcock, W. S. D. Fontaine, FJ Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Journal of Geophysical Research-Solid Earth B06102 111 B6 r2k-h east pacific rise mid-atlantic ridge de-fuca-ridge double-diffusive convection sodium-chloride solutions ashes vent field oceanic-crust phase-separation porous-media thermodynamic properties 2006 JUN 16 0148-0227 ISI:000238572700002 [ 1] Mid-ocean ridge hydrothermal systems are known to vent fluids with salinities substantially different from seawater as a result of phase separation and segregation of the resulting vapor and brine phases. Time series of vent temperature and salinity ( chlorinity) show that some black-smoker vent fields such as the Main Endeavour Field on the Juan de Fuca Ridge have vented fluids with salinities well below seawater for over a decade, which raises important questions concerning the fate of brines in these systems. One widely accepted model is that high-density brines formed by supercritical phase separation sink to the base of hydrothermal systems, leading to the development of a two-layer system in which a recirculating brine layer underlies a single-pass seawater cell. We first present theoretical arguments to constrain the dynamics of such a deep brine layer in a system still undergoing phase separation, and we conclude that if brines are stored in a basal layer, they are unlikely to convect because they will be stably stratified. One consequence of this result is that the brine layer beneath black smoker systems has to be thin (< 10 m) to match the high heat fluxes. However, estimates of the rate at which brines are accumulating in the crust below the main field on the Endeavour segment of the Juan de Fuca Ridge suggest that the brine layer is likely at least 100 m thick. To resolve this apparent paradox, we propose an alternative model. We argue that interfacial tensions between fluid and solid phases will likely favor the segregation of vapor into the main fractures and brine into the smaller fissures and backwaters. This allows the vapor to flow efficiently through the system and transport large heat fluxes while most of the porosity in the lower part of the system fills with brines. It is generally believed that the pressure gradients in mid-ocean ridge hydrothermal systems are close to cold hydrostatic. At the high temperatures and pressures characteristic of the deeper parts of these systems, brines with salinities as high as 20 wt % NaCl have densities around 800 - 900 kg m(-3) and will be buoyant in a cold-hydrostatic system. Rather than sinking to the base of the system, it is possible that brines produced by supercritical phase separation rise slowly until they reach a level of neutral buoyancy as they cool or enter high-permeability regions in which the pressure gradients decrease. 057CM Times Cited:0 Cited References Count:100 <Go to ISI>://000238572700002 English 181 17 Fontaine, F. J. Wilcock, W. S. D. Butterfield, D. A. Earth and Planetary Science Letters Earth and Planetary Science Letters 132-145 257 1-2 2007 88 17 Foustoukos, D. I. James, R. H. Berndt, M. E. Seyfried, W. E. Foustoukos, DI Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA Open Univ, Dept Earth Sci, Milton Keynes MK7 6AA, Bucks, England Minnesota Dept Nat Resources, Div Lands & Minerals, St Paul, MN 55155 USA Chemical Geology Chemical Geology 17-26 212 1-2 r2k-h/ch lithium isotopes juan de fuca ridge submarine hydrothermal systems phase separation hydrothermal alteration east pacific rise phase-separation oceanic-crust midocean ridge chemistry boron seawater exchange basalt 350-degrees-c 2004 NOV 26 0009-2541 ISI:000225542200003 Vent fluids issuing from the Main Endeavour Field (MEF), Juan de Fuca Ridge, were analyzed for delta(7)Li to help constrain subseafloor hydrothermal alteration and phase separation processes. Magmatic activity prior to sampling of the fluids in 1999 enhanced heat and mass transfer, as indicated by the large scale, but temporary, changes in vent fluid chemistry. In particular, dissolved chloride concentrations indicate formation of supercritical Cl-poor vapors, which affected alteration throughout the MEF system. delta(7)Li of fluids, however, ranges from +7.2 to +8.9%o and reveals no significant correlation with dissolved chloride, being consistent with results of hydrothermal experiments that show no lithium isotope fractionation during supercritical phase separation. On a chloride-normalized basis, Li concentration data indicate relatively short residence times or high fluid/rock mass ratios of vent fluids most impacted by phase separation effects. Reaction path models involving Li isotope data also show elevated fluid/rock mass ratios. Boron data, in contrast, suggest direct input from degassing magma. Enhanced heat flow associated with magmatic injection at depth inhibits penetration of seawater-derived hydrothermal fluid into fresh basalt, particularly in those systems where magmatic volatile input is most active. The inverse correlation between Li/Cl and B/Cl in vapor-rich vent fluids may be a useful indicator of recent subseafloor magmatic activity. (C) 2004 Elsevier B.V. All rights reserved. 877BG Times Cited:3 Cited References Count:43 <Go to ISI>://000225542200003 English 98 17 Foustoukos, D. I. James, R. H. Seyfried, W. E. Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN USA Open Univ, Dept Earth Sci, Milton Keynes, Bucks, England Geochimica Et Cosmochimica Acta Geochimica et Cosmochimica Acta A101-A101 67 18 r2k-h/ch 2003 SEP 0016-7037 ISI:000185517600195 Suppl. 1 724ZF Times Cited:1 Cited References Count:1 <Go to ISI>://000185517600195 English 183 17 Foustoukos, D. I. Seyfried Jr, W. E. Geochimica et Cosmochimica Acta Geochimica et Cosmochimica Acta 2056-2071 71 8 2007 142 17 Fox, C. G. J. Geophys. Res 923–12 95 12 1990 21 17 Ginster, U. M. J. Mottl R. P. Von Herzen J.Geophys. Res. 4937-4950 99 1994 149 17 Peter R. Girguis Raymond W. Lee Science Science 231 312 April 14 2006 r2k-ba 2006 182 17 Glickson, D. A. Kelley, D. S. Delaney, J. R. Geochemistry Geophysics Geosystems GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS 8 6 2007 131 17 Golden, C. E. Webb, S. C. Sohn, R. A. Journal of Geophysical Research (Solid Earth 108 B1 2003 143 17 Goldfarb, M. S. Delaney, J. R. Journal of Geophysical Research Journal of Geophysical Research 4585-4594 93 B5 1988 133 17 Govenar, B. W. Bergquist, D. C. Urcuyo, I. A. Eckner, J. T. Fisher, C. R. Cahiers de biologie marine 247-252 43 2002 112 17 Harasewych, M. G. Kantor, Y. I. Harasewych, MG Smithsonian Inst, Natl Museum Nat Hist, Dept Systemat Biol, Washington, DC 20560 USA Smithsonian Inst, Natl Museum Nat Hist, Dept Systemat Biol, Washington, DC 20560 USA Russian Acad Sci, AN Severtzov Inst Problems Evolut, Moscow 117071, Russia Journal of Molluscan Studies 39-44 68 hydrothermal vents family 2002 FEB 0260-1230 ISI:000174645700006 Buccinum thermophilum new species, is described from abyssal depths of the Endeavour Vent Field, a portion of the Juan de Fuca Ridge in the northeastern Pacific. The new species is provisionally assigned to the subgenus Viridibuccinum Golikov and Sirenko, 1988, primarily on the basis of its conchological similarities with some of the species included in this subgenus, especially its type species B. (V) viridum Dail, 1890. The anatomy of this new species is similar in most respects to that of the few species of Buccininae for which the anatomy is known. Buccinum thermophilum most closely resembles B. viridum, B. rondinum Dail, 1919, and, to a much lesser extent, Buccinum diplodetum Dail, 1907, which has a similar geographic and bathymetric range. Part 1 535LJ Times Cited:2 Cited References Count:14 <Go to ISI>://000174645700006 English 22 17 Hedrick, D. B. R. D. Pledger D. C. White J. A. Baross FEMS Microbiol. Ecol. 1-10 101 1992 187 17 Houghton, J. L. Shanks, W. C. Seyfried, W. E. Geochimica et cosmochimica acta Geochimica et Cosmochimica Acta 2863-2873 68 13 r2k-h/ch 2004 171 17 Hourdez, S. Lamontagne, J. Peterson, P. Weber, R. E. Fisher, C. R. Biological Bulletin Biological Bulletin 95-99 199 2 2000 132 17 Huber, J. A. Butterfield, D. A. Baross, J. A. Applied and Environmental Microbiology 1585-1594 68 4 2002 99 17 Jackson, D. R. Jones, C. D. Rona, P. A. Bemis, K. G. Jackson, Dr Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08903 USA Rutgers State Univ, Dept Geol Sci, New Brunswick, NJ 08903 USA Geochemistry Geophysics Geosystems GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS - 4 hydrothermal marine geology and geophysics : heat flow (benthic) and hydrothermal processes oceanography : general : ocean acoustics marine geology and geophysics : instruments and techniques current profiler observations ridge hydrothermal plume de-fuca ridge scattering particles 2003 NOV 14 1525-2027 ISI:000186651000001 A method is developed for using multibeam sonar to map the flow velocity field of black smoker plumes. The method is used to obtain two-dimensional cross-sectional maps of vertical velocity, but is capable of mapping velocity in three dimensions. This is in contrast to conventional current meters, which measure only at several points and acoustic Doppler current profilers, whose diverging beams cannot readily map the interior of a plume. Geometric corrections are used to estimate the vertical component of velocity, compensating for ambient current. The method is demonstrated using data from the main plume at the Grotto vent complex in the Main Endeavour Field, Juan de Fuca Ridge, and the errors due to noise, signal fluctuations, and fluctuations in plume structure are estimated. 744UJ Times Cited:0 Cited References Count:23 <Go to ISI>://000186651000001 English 173 17 Johnson, H. P. Dziak, R. P. Fisher, C. R. Fox, C. G. Pruis, M. J. Eos (Transactions, American Geophysical Union) Eos (Transactions, American Geophysical Union) 233–236 82 2001 172 17 Johnson, H. P. Hutnak, M. Dziak, R. P. Fox, C. G. Urcuyo, I. Fisher, C. Cowen, J. P. Nabelek, J. Nature Nature 174–177 407 2000 23 17 Johnson, H. P. J. L. Karsten J. R. Delaney E. E. Davis R. G. Currie R. L. Chase J.Geophys. Res. 22972315 88 1983 24 17 Juniper, K. Fisher, C. et al., InterRidge News 23-25 3 1994 25 5 Juniper, S. K. J. Sarrazin S. Humphris R. Zierenberg L. Mullineau R. Thomson Physical, Chemical, Biological, and Geological Interactions within Seafloor Hydrothermal Systems 178-193 1995 Amer. Geophys. Union 26 17 Kadko, D. W. Moore Geochim. Cosmochim. Acta Geochim. Cosmochim. Acta 659-668 52 1988 27 17 Kadko, D. C. N. D. Rosenberg J. E. Lupton R.W. Collier, and M. D. Lilley Earth Planet. Sci. Lett. Earth Planet. Sci. Lett. 315-335 99 1990 30 17 Kappel, E. S. W. B. F. Ryan J.Geophys. Res. 13925-13940 91 1986 136 17 Karson, J. A. Tivey, M. A. Delaney, J. R. J. Geophys. Res 2181 107 2002 28 32 Karsten, J. L. 1988 University of Washington, 329 pp 29 17 Karsten, J. L. J. R. Delaney J. M. Rhodes R. A. Liias J.Geophys. Res. 19235-19256 95 1990 31 17 Kaye, J. J. A. Baross FEMS Microb. Ecol. 249-260. 32 2000 32 17 Kelley, D. S. J. A. Baross J. R. Delaney Annual Review Earth and Planetary Science. 30:15.1-15.108 r2k-synthesis 2002 117 17 Kelley, D. S. Delaney, J. R. Yoerger, D. R. Kelley, Ds Univ Washington, Sch Oceanog, POB 357940, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Woods Hole Oceanog Inst, Deep Submergence Lab, Woods Hole, MA 02543 USA Geology Geology 959-962 29 10 r2k-cs/h endeavour segment juan de fuca ridge hydrothermal vents black smokers sulfides east pacific rise systems growth fluids model 2001 OCT 0091-7613 ISI:000171421500022 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. The clusters are composed of multiple steep-sided pinnacles that rise up to 20 m above the seafloor. Most of the sulfide structures are awash in diffusely venting fluids (30-200 degreesC) that support rich and diverse macrofaunal and microbial communities. Isolated black smoker chimneys vent 302 degreesC fluids. The linear arrays of sulfide complexes delineate a zone of active faulting near the western wall of the axial valley. This fault network serves as the conduit for the rising fluids. 479UG Times Cited:9 Cited References Count:14 <Go to ISI>://000171421500022 English 145 17 Kelley, D. S. Früh-Green, G. L. Ophiolites and Oceanic Crust; New Insights from Field Studies and the Ocean Drilling Program 237-260 2000 180 17 Kelly, N. E. Metaxas, A. Marine Biology Marine Biology 649-662 151 2 2007 150 17 Brian Kristall Deborah S. Kelley Mark D. Hannington John R. Delaney Geolochemisty, Geophysics, Geosystems Geolochemisty, Geophysics, Geosystems Q07001 7 7 r2k-h/ch Endeavour Mothra chimney sulfide diffuse venting 2006 doi:10.1029/2005GC001166 95 17 Lam, P. Cowen, J. P. Jones, R. D. Lam, P Univ Hawaii, Sch Ocean & Earth Sci & Technol, Dept Oceanog, 1000 Pope Rd, Honolulu, HI 96822 USA Univ Hawaii, Sch Ocean & Earth Sci & Technol, Dept Oceanog, Honolulu, HI 96822 USA Portland State Univ, Dept Biol, Portland, OR 97207 USA Fems Microbiology Ecology 191-206 47 2 r2k-hp/ch/bi ammonia oxidation chemolithoautotrophy in situ organic carbon production hydrothermal plume fluorescence in situ hybridization endeavour mid-ocean ridge nitrification marine nitrogen cycling 16s ribosomal-rna northwestern mediterranean-sea marine nitrifying bacteria oxidizing bacteria organic-carbon nitrosomonas-europaea methane oxidation endeavor segment nitrous-oxide substrate concentration 2004 FEB 15 0168-6496 ISI:000189095500006 Direct evidence for autotrophic ammonia oxidation is documented for the first time in a deep-sea hydrothermal plume. Elevated NH4+ concentrations of up to 341 +/- 136 nM were recorded in the plume core at Main Endeavour Field, Juan de Fuca Ridge. This fueled autotrophic ammonia oxidation rates as high as 91 nM day(-1), or 92% of the total net NH4+ removal. High abundance of ammonia- oxidizing bacteria was detected using fluorescence in situ hybridization. Ammonia-oxidizing bacteria within the plume core (1.0-1.4 x 10(4) cells ml(-1)) accounted for 7.0-7.5% of the total microbial community, and were at least as abundant as methanotrophs. Ammonia-oxidizing bacteria were a substantial component of the particle-associated communities (up to 51%), with a predominance of the r-strategist Nitrosomonas-like cells. In situ chemolithoamotrophic organic carbon production via ammonia oxidation may yield 3.9-18 mg C m(-2) day(-1) within the plume directly over Main Endeavour Field. This rate was comparable to that determined for methane oxidation in a previous study, or at least four-fold greater than the flux of photosynthetic carbon reaching plume depths measured in another study. Hence, autotrophic ammonia oxidation in the neutrally buoyant hydrothermal plume is significant to both carbon and nitrogen cycling in the deep-sea water column at Endeavour, and represents another important link between seafloor hydrothermal systems and deep-sea biogeochemistry. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved. 776BQ Times Cited:2 Cited References Count:89 <Go to ISI>://000189095500006 English 79 17 Lang, S. Q. Butterfield, D. A. Lilley, M. D. Johnson, H. P. Hedges, J. I. Lang, SQ Univ Washington, Sch Oceanog, Box 355351, Seattle, WA 98105 USA Univ Washington, Sch Oceanog, Seattle, WA 98105 USA Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA Geochimica Et Cosmochimica Acta Geochimica et Cosmochimica Acta 3830-3842 70 15 bi/ch/h juan de-fuca ridge young oceanic-crust rich sediment alteration sea volcanic-eruption east pacific rise amino-acids elevated-temperatures subseafloor habitat endeavor segment phase-separation 2006 AUG 1 0016-7037 ISI:000239765800005 The circulation of hydrothermal fluid through the upper oceanic crustal reservoir has a large impact on the chemistry of seawater, yet the impact on dissolved organic carbon (DOC) in the ocean has received almost no attention. To determine whether hydrothermal circulation is a source or a sink for DOC in the oceans, we measured DOC concentrations in hydrothermal fluids from several environments. Hydrothermal fluids were collected from high-temperature vents and diffuse, low-temperature vents on the basalt-hosted Juan de Fuca Ridge axis and also from low-temperature vents on the sedimented eastern flanks. High-temperature fluids from Main Endeavour Field (MEF) and Axial Volcano (AV) contain very low DOC concentrations (average = 15 and 17 mu M, respectively) compared to background seawater (36 mu M). At MEF and AV, average DOC concentrations in diffuse fluids (47 and 48 mu M, respectively) were elevated over background seawater, and high DOC is correlated with high microbial cell counts in diffuse fluids. Fluids from off-axis hydrothermal systems located on 3.5-Ma-old crust at Baby Bare Seamount and Ocean Drilling Program (ODP) Hole 1026B had average DOC concentrations of 11 and 13 mu M, respectively, and lowered DOC was correlated with low cell counts. The relative importance of heterotrophic uptake, abiotic sorption to mineral surfaces, thermal decomposition, and microbial production in fixing the DOC concentration in vent fluids remains uncertain. We calculated the potential effect of hydrothermal circulation on the deep-sea DOC cycle using our concentration data and published water flux estimates. Maximum calculated fluxes of DOC are minor compared to most oceanic DOC source and sink terms. (c) 2006 Elsevier Inc. All rights reserved. 073TP Times Cited:0 Cited References Count:87 <Go to ISI>://000239765800005 English 161 17 Larson, B. I. Olson, E. J. Lilley, M. D. Geochim. Cosmochim. Acta Geochim. Cosmochim. Acta 2510-2523 71 10 2007 doi: 10.1016/j.gca.2007.02.013 104 17 Lilley, M. D. Butterfield, D. A. Lupton, J. E. Olson, E. J. Lilley, Md Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Univ Washington, NOAA, Pacific Marine Environm Lab, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98195 USA NOAA, Pacific Marine Environm Lab, Newport, OR 97365 USA Nature Nature 878-881 422 6934 de-fuca ridge east pacific rise midocean ridge spreading centers crustal structure fluids juan field evolution seamount 2003 APR 24 0028-0836 ISI:000182432600051 The Endeavour segment of the Juan de Fuca ridge is host to one of the most vigorous hydrothermal areas found on the global mid-ocean-ridge system, with five separate vent fields located within 15 km along the top of the ridge segment(1). Over the past decade, the largest of these vent fields(2), the 'Main Endeavour Field', has exhibited a constant spatial gradient in temperature and chloride concentration in its vent fluids, apparently driven by differences in the nature and extent of subsurface phase separation(3). This stable situation was disturbed on 8 June 1999 by an earthquake swarm(4). Owing to the nature of the seismic signals and the lack of new lava flows observed in the area during subsequent dives of the Alvin and Jason submersibles (August-September 1999), the event was interpreted to be tectonic in nature(4). Here we show that chemical data from hydrothermal fluid samples collected in September 1999 and June 2000 strongly suggest that the event was instead volcanic in origin. Volatile data from this event and an earlier one at 9degreesN on the East Pacific Rise show that such magmatic events can have profound and rapid effects on fluid-mineral equilibria, phase separation, He-3/heat ratios and fluxes of volatiles from submarine hydrothermal systems. 670WR Times Cited:20 Cited References Count:30 <Go to ISI>://000182432600051 English 35 17 Lilley, M. D. D. A. Butterfield E. J. Olson J. E. Lupton S. E. Macko and R. E. McDuff Nature Nature 4547 364 1993 36 5 Lilley, M. D. R. A. Feely J. H. Trefry Humphris, S. E. Zierenberg, R. A. Mullineaux, L. S. Thomson, R. E. Geophysical Monograph Series, 91, Seafloor hydrothermal systems: physical, chemical, biological, and geochemical interactions 369-391 1995 Washington, D.C. America Geophysical Union 34 17 Lilley, M. D. R. E. McDuff C. N. Dahm EoS Trans. AGU 1721 68 1987 37 5 Lister, C. R. B. P. A. Rona K. Bostrom L. Laubier K.L. Smith,, Jr. Hydrothermal Processes at Seafloor Spreading Centers 141-176 1983 New York Plenum 146 17 Little, S. A. Stolzenbach, K. D. Purdy, G. M. JOURNAL OF GEOPHYSICAL RESEARCH Journal of Geophysical Research 12,927-12,945 95 B8 1990 38 17 Lupton, J. E. J.R, Delaney H. P. Johnson M. K. Tivey Nature 316 621-623 1985 108 17 Macdonald, I. R. Tunnicliffe, V. Southward, E. C. Macdonald, IR Texas A&M Univ, 6300 Ocean Dr, Corpus Christi, TX 78412 USA Texas A&M Univ, Corpus Christi, TX 78412 USA Univ Victoria, Victoria, BC V8W 3N5, Canada Marine Biol Assoc UK, Plymouth PL1 2PB, Devon, England Cahiers De Biologie Marine 395-398 43 3-4 pogonophora obturata jones 2002 0007-9723 ISI:000179938200040 627NB Times Cited:3 Cited References Count:6 <Go to ISI>://000179938200040 English 113 17 Martell, K. A. Tunnicliffe, V. Macdonald, I. R. Tunnicliffe, V Univ Victoria, Dept Biol, POB 3020, Victoria, BC V8W 3N5, Canada Univ Victoria, Dept Biol, Victoria, BC V8W 3N5, Canada Texas A&M Univ, Geochem & Environm Res Grp, College Stn, TX 77843 USA Journal of Molluscan Studies 45-53 68 hydrothermal system undatum predation field environments reproduction behavior segment animals fluids 2002 FEB 0260-1230 ISI:000174645700007 The newly described buccinid gastropod Buccinum thermophilum Harasewych & Kantor, 2001 is currently known only at hydrothermal vents of the Endeavour Segment of Juan de Fuca Ridge. Collected specimens from three vents show differences in shell features (colour, erosion, scarring) and size distributions. Such distinctions suggest that this buccinid forms resident, localiscd populations with limited inter-vent migration. Snail abundance in images taken every 31 hours varied markedly over time but showed no correlation With emerging fluid temperatures. Stomach contents indicate that this buccinid is an active predator and opportunistic scavenger with a broad diet. Substratum use did not differ significantly from availability but short-term, small aggregations occur, perhaps for mating and to exploit patchy prey. Majid crabs are active predators of these snails. Egg masses are similar to those described for other buccinids with over 200 egg-filled sacs in a mass; it was not possible to differentiate food eggs from embryos as all eggs underwent multiple divisions. Size-frequency distribution from the adults and the lack of advanced embryos in summer-collected egg masses provide some evidence of seasonality in reproduction. Part 1 535LJ Times Cited:3 Cited References Count:38 <Go to ISI>://000174645700007 English 40 17 McDuff, R. E. J. R. Delaney EOS, Trans. AGU F710 76 1995 39 17 McDuff, R. E. J. R. Delaney M. D. Lilley D. A. Butterfield EoS Trans. AGU. 618 75 1994 176 17 McKiness, Z. P. McMullin, E. R. Fisher, C. R. Cavanaugh, C. M. Marine Biology Marine Biology 109-116 148 1 2005 41 32 McLaughlin, E. A. 1998 University of Washington, Seattle 107 17 Mehta, M. P. Butterfield, D. A. Baross, J. A. Mehta, MP Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA Applied and Environmental Microbiology 960-970 69 2 mid-atlantic ridge methanococcus-thermolithotrophicus fixing microorganisms spartina-alterniflora nucleotide-sequence evolutionary implications methanogenic bacteria structural genes fixation genes seawater 2003 FEB 0099-2240 ISI:000180927100031 The subseafloor microbial habitat associated with typical unsedimented mid-ocean-ridge hydrothermal vent ecosystems may be limited by the availability of fixed nitrogen, inferred by the low ammonium and nitrate concentrations measured in diffuse hydrothermal fluid. Dissolved N2 gas, the largest reservoir of nitrogen in the ocean, is abundant in deep-sea and hydrothermal vent fluid. In order to test the hypothesis that biological nitrogen fixation plays an important role in nitrogen cycling in the subseafloor associated with unsedimented hydrothermal vents, degenerate PCR primers were designed to amplify the nitrogenase iron protein gene nifH from hydrothermal vent fluid. A total of 120 nifH sequences were obtained from four samples: a nitrogen-poor diffuse vent named marker 33 on Axial Volcano, sampled twice over a period of I year as its temperature decreased; a nitrogen-rich diffuse vent near Puffer on Endeavour Segment; and deep seawater with no detectable hydrothermal plume signal. Subseafloor nifH genes from marker 33 and Puffer are related to anaerobic clostridia and sulfate reducers. Other nifH genes unique to the vent samples include proteobacteria and divergent Archaea. All of the nifH genes from the deep-seawater sample are most closely related to the thermophilic, anaerobic archaeon Methanococcus thermolithotrophicus (77 to 83% amino acid similarity). These results provide the first genetic evidence of potential nitrogen fixers in hydrothermal vent environments and indicate that at least two sources contribute to the diverse assemblage of nifH genes detected in hydrothermal vent fluid: nifH genes from an anaerobic, hot subseafloor and nifH genes from cold, oxygenated deep seawater. 644PK Times Cited:17 Cited References Count:81 <Go to ISI>://000180927100031 English 86 17 Mehta, M. P. Huber, J. A. Baross, J. A. Mehta, MP Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Environmental Microbiology 1525-1534 7 10 bi midocean ridge subseafloor 16s ribosomal-rna phylogenetic analysis marine crenarchaeota methanogenic archaea h-2-using methanogen fuca ridge nifh genes diversity sea 2005 OCT 1462-2912 ISI:000231737100004 Archaea have been detected throughout the oceanic water column and are quantitatively important members of picoplankton in the deep ocean. Two common groups, group I Crenarchaeota and group II Euryarchaeota, are consistently detected in warm hydrothermal fluid and are assumed to have been drawn into the subseafloor, mixed with hydrothermal fluid and then expelled. However, because they remain resistant to cultivation, very little is known about their physiology. Here we show that cold deep-seawater from the axial valley of Endeavour Segment on the Juan de Fuca Ridge contains not only groups I and II archaea as expected, but also unique potentially archaeal nitrogenase (nifH) genes, which are required for nitrogen fixation. These nifH genes are phylogenetically distinct and have dissimilar G+C content compared with those of hydrothermal vent archaea, suggesting that they belong to non-thermophilic deep-sea archaea. Furthermore, this sample did not contain mcrA genes, which are present in methanogens, the only known archaeal nitrogen fixers. These nifH genes were not detected in upper water column samples, or in a deep-seawater sample 100 km away from the spreading axis of the Juan de Fuca Ridge. We propose that these unique nifH genes may be localized to archaea that circulate through the nitrogen-poor subseafloor at the mid-ocean ridge as part of their life cycle. 962MO Times Cited:1 Cited References Count:47 <Go to ISI>://000231737100004 English 89 17 Metaxas, A. Metaxas, A Dalhousie Univ, Dept Oceanog, Halifax, NS B3H 4J1, Canada Dalhousie Univ, Dept Oceanog, Halifax, NS B3H 4J1, Canada Limnology and Oceanography 1949-1956 49 6 de-fuca-ridge hydrodynamical processes benthic invertebrates axial volcano dispersal settlement transport circulation barnacles currents 2004 NOV 0024-3590 ISI:000225137100005 Larval supply in marine benthic invertebrates influences patterns of settlement and recruitment to adult populations. To successfully colonize newly formed or distant hydrothermal vents, which are discontinuous and ephemeral habitats, larvae of vent invertebrates must possess long-range dispersal abilities. However, a significant proportion of locally produced larvae must remain within the adult habitat to maintain the observed dense assemblages of invertebrates. I compared spatial and temporal patterns in larval availability (flux and abundance) at hydrothermal vents within and between ridge segments in the northeast Pacific ocean at Axial Seamount and Endeavour Segment on the Juan de Fuca Ridge and at Magic Mountain on Explorer Ridge. Near-bottom (within 50 cm) larval supply (individuals m(-2) d(-1)) at five vents on Axial Seamount, measured with passively collecting traps in 2000 and 2001, varied temporally by an order of magnitude, but not spatially at scales of tens of meters to kilometers. The most abundant larval taxa were gastropods (particularly the limpet Lepetodrilus fucensis) and polychaetes. Larval abundance in the water column within the axial valley was measured with net tows by the remotely operated vehicle ROPOS at the three ridge segments: Axial Seamount (2000, 2001); Endeavour Segment (2001, 2002); Magic Mountain (2002). Abundance was greater by an order of magnitude at the Endeavour Segment than at Axial Seamount and Magic Mountain, and it did not differ between on-vent (within tens of meters) and off-vent (up to 5 km from the venting source) locations within the axial valley. The uniformly high abundance of larvae within axial valleys suggests that larval supply within a ridge segment is most likely localized, implying significant larval retention on the scale of vent fields and possibly ridge segments. 871MF Times Cited:3 Cited References Count:33 <Go to ISI>://000225137100005 English 123 17 Nedimovic, M. R. Carbotte, S. M. Harding, A. J. Detrick, R. S. Canales, J. P. Diebold, J. B. Kent, G. M. Tischer, M. Babcock, J. M. Nature Nature 1149-1151 436 r2k-cs 2005 43 17 Pledger, R. J. B. Crump J. A. Baross FEMS Microbial. Ecol. 233 14 1994 42 17 Pledger, R. J. J.A.Baross, J.Gen. Microbiol. 203 137 1991 92 17 Proskurowski, G. Lilley, M. D. Brown, T. A. Proskurowski, G Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA Earth and Planetary Science Letters Earth and Planetary Science Letters 53-61 225 1-2 carbon dioxide hydrothermal vents radiocarbon bicarbonate endeavour de-fuca-ridge mid-atlantic ridge midocean ridge carbon-dioxide spreading centers phase-separation vent field juan fluids segment 2004 AUG 30 0012-821X ISI:000223824100005 Stable and radiocarbon isotope measurements made on CO2 from high temperature hydrothermal vents on the Endeavour Segment of the Juan de Fuca Ridge indicate a magmatic source of carbon to the hydrothermal system after a 1999 earthquake. The radiocarbon measurements require that a large fraction of seawater bicarbonate originally present in the downwelled. fluid be removed during hydrothermal circulation. The Endeavour Segment is devoid of overlying sediments and has shown no observable signs of surficial magmatic activity during the previous 20 years of ongoing studies. The appearance of isotopically heavy, radiocarbon dead CO2 after a 1999 earthquake swarm indicate that this earthquake event was magmatic in origin. Evidence for the removal of seawater bicarbonate is a significant find because many studies to date have corrected CO2 data based on the presumption of the presence of seawater bicarbonate. Utilizing both stable and radiocarbon measurements there is some evidence of a sedimentary source of carbon at Endeavour. These findings, which represent the first temporally coherent set of radiocarbon measurements from hydrothermal vent fluids, demonstrate the utility of radiocarbon analysis in hydrothermal studies. (C) 2004 Elsevier B.V. All rights reserved. 853JR Times Cited:3 Cited References Count:40 <Go to ISI>://000223824100005 English 184 17 Proskurowski, G. Lilley, M. D. Kelley, D. S. Olson, E. J. Chemical Geology Chemical Geology 331-343 229 4 2006 44 17 Reyes, A. O. W. S. Moore D.S. Stakes Earth Planet.Sci. Lett. 99-113 131 1995 45 17 Robigou, V. J. R. Delaney D. Stakes Robigou, V. J. R. Delaney C. B. Parker Geophys. Res. Lett. Geophys. Res. Lett. 1887-1890 20 1993 151 17 Peter A. Rona Karen G. Bemis Christopher D. Jones Darrell R. Jackson Kyohiko Mitsuzawa Deborah Silver Geophys. Res. Lett. Geophys. Res. Lett. L19313 33 r2k-hp 2006 doi:10.1029/2006GL027211 46 17 Rosenberg, N. D. J. E. Lupton D. Kadko R. Collier M. D. Lilley H. Pak Nature Nature 604607 334 1988 128 17 Rudnicki, M. D. Elderfield, H. Mottl, M. J. Earth and Planetary Science Letters Earth and Planetary Science Letters 173-189 187 1-2 2001 48 17 Sarrazin, J. S. K. Juniper Marine Ecology Progress Series 1-19 185 1999 47 17 Sarrazin, J. V. Robigou K. Juniper J. R. Delaney Marine Ecology Progress Series 5-24 153 1997 50 17 Schrenk, M. O. J. Z. Kaye J. A. Baross D. S. Kelley J. R. Delaney Eos, Trans. AGU 59 79 1998 49 17 Schrenk, M. O. D. S. Kelley J.A. Baross Proceedings of the Geol. Soc. Amer. 7 31 1999 51 17 Schultz, A. J. R. Delaney R. E. McDuff 12,299-12,314 97 1992 165 17 Scott, K. M. Bright, M. Fisher, C. R. 1998 170 17 Scott, K. M. Bright, M. Macko, S. A. Fisher, C. R. Marine Biology Marine Biology 25-34 135 1 1999 97 17 Seewald, J. Cruse, A. Saccocia, P. Seewald, J Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA Bridgewater State Coll, Dept Geog & Earth Sci, Bridgewater, MA 02325 USA Earth and Planetary Science Letters Earth and Planetary Science Letters 575-590 216 4 hydrothermal systems main endeavour field aqueous volatiles fluid-rock reaction phase separation east pacific rise seafloor geothermal systems vent fluids phase-separation crustal structure sulfide deposits midocean ridge segment chemistry constraints 2003 DEC 10 0012-821X ISI:000187461800011 The Main Endeavour Field, northern Juan de Fuca Ridge, experienced intense seismic activity in June 1999. Hydrothermal vent fluids were collected from sulfide structures in September 1999 and July 2000 and analyzed for the abundance of H-2, H2S, CH4, CO2, NH3, Mg and Cl to document temporal and spatial changes following the earthquakes. Dissolved concentrations Of CO2, H-2, and H2S increased dramatically in the September 1999 samples relative to pre-earthquake abundances, and subsequently decreased during the following year. In contrast, dissolved NH3 and CH4 concentrations in 1999 and 2000 were similar to or less than pre-earthquake values. Aqueous Cl abundances showed large decreases immediately following the earthquakes followed by increases to near preearthquake values. The abundances of volatile species at the Main Endeavour Field were characterized by strong inverse correlations with chlorinity. Phase separation can account for 20-50% enrichments Of CO2, CH4, and NH3 in low-chlorinity fluids, while temperature- and pressure-dependent fluid-mineral equilibria at near-critical conditions are responsible for order of magnitude greater enrichments in dissolved H2S and H. The systematic variation of dissolved gas concentrations with chlorinity likely reflects mixing of a low-chlorinity volatile-enriched vapor generated by supercritical phase separation with a cooler gas-poor hydrothermal fluid of seawater chlorinity. Decreased abundances of sediment-derived NH3 and CH4 in 1999 indicate an earthquake-induced change in subsurface hydrology. Elevated CO2 abundances in vent fluids collected in September 1999 provide evidence that supports a magmatic origin for the earthquakes. Temperature-salinity relationships are consistent with intrusion of a shallow dike and suggest that the earthquakes were associated with movement of magma beneath the ridge crest. These data demonstrate the large and rapid response of chemical fluxes at mid-ocean ridges to magmatic activity and associated changes in subsurface temperature and pressure. (C) 2003 Elsevier B.V. All rights reserved. 756JK Times Cited:7 Cited References Count:46 <Go to ISI>://000187461800011 English 188 5 Seyfried Jr, W. E. Ding, K. Rao, B. Roland Hellmann and Scott A. Wood Water-Rock Interactions, Ore Deposits, and Environmental Geochemistry r2k-h/ch 2002 The Geochemical Society 100 17 Seyfried, W. E. Seewald, J. S. Berndt, M. E. Ding, K. Foustoukos, D. I. Seyfried, WE Univ Minnesota, Dept Geol & Geophys, Pillsbury Hall,310 Pillsbury Dr SE, Minneapolis, MN 55455 USA Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA Journal of Geophysical Research-Solid Earth 5 108 B9 r2k-h/ch hydrothermal vent fluid geochemistry hydrothermal alteration magmatic heating phase separation phase segregation east pacific rise molal thermodynamic properties seafloor geothermal systems phase-separation midocean ridge cleft segment quartz solubilities halide systematics geologic fluids cracking event 2003 SEP 16 0148-0227 ISI:000185479000003 [1] In June 1999, an intense swarm of earthquakes occurred on the Endeavour segment of the Juan de Fuca Ridge influencing hydrothermal activity in and around the Main Endeavour Field (MEF). Here we report the dissolved concentrations of 31 species from five high-temperature vents sampled 3 months after the seismic event. The spatial variability of vent fluid chemistry is extreme. Vapor-dominated vent fluids at Cantilever and Sully sites have high measured temperatures (375degrees - 379 degreesC), high dissolved gas and boron concentrations, but low SiO2. Modeling results indicate that these fluids can be accounted for by supercritical phase separation and brine condensation. Other vent fluids have moderate temperatures (340degrees - 366 degreesC) and chloride concentrations ( 208 - 426 mmol/ kg), and may result from mixing of supercritical, vapor- rich fluids with evolved seawater. Phase equilibria calculations indicate that in addition to chloride, redox, temperature, and especially pressure play key roles in accounting for compositional variability of vent fluids at MEF. In comparison with earlier ( 1988) data, the 1999 data set reveals significantly lower chloride concentrations and higher boron, whereas alkali and alkaline earth cations are lower by 10 - 20% in keeping with chloride decrease. That dissolved chloride, boron, and other elements returned to preevent levels when again sampled in 2000 provide additional data documenting the inherently dynamic nature of hydrothermal systems at mid-ocean ridges. 724GC Times Cited:13 Cited References Count:73 <Go to ISI>://000185479000003 English 77 17 Seyfried, W. E. Seewald, J. S. Berndt, M. E. Ding, K. Foustoukos, D. I. Journal of Geophysical Research Journal of Geophysical Research B07105 109 r2k-h/ch 2004 80 17 Skebo, K. Tunnicliffe, V. Berdeal, I. G. Johnson, H. P. Tunnicliffe, V Univ Victoria, Dept Biol, POB 3080, Victoria, BC V8W 3N5, Canada Univ Victoria, Dept Biol, Victoria, BC V8W 3N5, Canada Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Deep-Sea Research Part I-Oceanographic Research Papers 1044-1060 53 6 ch plankton patterns horizontal profile hydrothermal vents axial valley endeavour segment juan de fuca ridge mid-atlantic ridge endeavor ridge vent field vertical-distribution midocean ridge north pacific water column georges bank sea plankton 2006 JUN 0967-0637 ISI:000239533000007 Zooplankton and nekton at 2000 in depth in the axial valley of Endeavour Segment, Juan de Fuca Ridge, show marked variability in abundances in a plane at 20 in above bottom. A remotely operated vehicle flew a gridded rectangle 3.2x0.5km that included two large high-temperature and two small low-temperature vent fields. Numbers of zooplankton, jellyfish, shrimp and fish were recorded with a video camera, and the abundance patterns were examined with the program SADIE (c). Each organism group displayed a distinctive distribution pattern. Abundance gaps over the high-temperature fields were significant and, for the more abundant copepods, were related to the locations of individual smokers. Pelagic shrimp and macrourid fish abundances were correlated and concentrated around the northern high temperature field. Distinct aggregations of zooplankton and nekton were correlated with the fluid indicators from both the low temperature diffuse effluent and the focused high temperature vents. Patterns were likely established by organism choice that forms aggregations and gaps, and by physical processes that entrain passive particles near vigorous smoker plumes. While enhanced plankton and nekton numbers were not observed over the vent fields, overall abundances in the axial valley may be sustained by production transported from the vent fields on the seafloor. (c) 2006 Elsevier Ltd. All rights reserved. 070OS Times Cited:0 Cited References Count:54 <Go to ISI>://000239533000007 English 126 17 Spinelli, G. A. Fisher, A. T. Geochemistry Geophysics Geosystems GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS 5 2 2004 147 17 Stakes, D. McClain, J. VanZandt, T. McGill, P. Begnaud, M. Geophysical Research Letters 2745-2748 25 14 1998 52 17 Stakes, D. S. W. S. Moore G. L. Holloway M. K. Tivey M. Hannington T. T. Tengdin EOS, Trans. Amer. Geophys. Union 273-274 73 1991 127 17 Stein, J. S. Fisher, A. T. Journal of Geophysical Research Journal of Geophysical Research 8563-8580 106 B5 2001 53 17 Straube, W. L. J. W. Deming C. C. Somerville R. R. Colwell J. A. Baross Appl. Environ. Micro. 1440-1447 56 1990 54 32 Summit, M. 2000 University of Washington, Seattle, WA. 120 17 Summit, M. Baross, J. A. Summit, M Washington Univ, Dept Earth & Planetary Sci, Campus Box 1169, St Louis, MO 63130 USA Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA Univ Washington, Dept Oceanog, Seattle, WA 98195 USA Proceedings of the National Academy of Sciences of the United States of America 2158-2163 98 5 east pacific rise hydrothermal systems volcanic-eruption endeavor segment sulfide deposits midocean ridge crust deep evolution chemistry 2001 FEB 27 0027-8424 ISI:000167258900013 The subseafloor at the mid-ocean ridge is predicted to be an excellent microbial habitat, because there is abundant space, fluid flow, and geochemical energy in the porous, hydrothermally influenced oceanic crust. These characteristics also make it a good analog for potential subsurface extraterrestrial habitats. Subseafloor environments created by the mixing of hot hydrothermal fluids and seawater are predicted to be particularly energy-rich, and hyperthermophilic microorganisms that broadly reflect such predictions are ejected from these systems in low-temperature (approximate to 15 degreesC), basalt-hosted diffuse effluents. Seven hyperthermophilic heterotrophs isolated from low-temperature diffuse fluids exiting the basaltic crust in and near two hydrothermal vent fields on the Endeavour Segment, Juan de Fuca Ridge, were compared phylogenetically and physiologically to six similarly enriched hyperthermophiles from samples associated with seafloor metal sulfide structures. The 13 organisms fell into four distinct groups: one group of two organisms corresponding to the genus Pyrococcus and three groups corresponding to the genus Thermococcus. Of these three groups, one was composed solely of sulfide-derived organisms, and the other two related groups were composed of subseafloor organisms. There was no evidence of restricted exchange of organisms between sulfide and subseafloor habitats, and therefore this phylogenetic distinction indicates a selective force operating between the two habitats. Hypotheses regarding the habitat differences were generated through comparison of the physiology of the two groups of hyperthermophiles; some potential differences between these habitats include fluid flow stability, metal ion concentrations, and sources of complex organic matter. 407EH Times Cited:36 Cited References Count:46 <Go to ISI>://000167258900013 English 94 17 Teagle, D. A. H. Alt, J. C. Teagle, Dah Univ Southampton, Sch Ocean & Earth Sci, Southampton Oceanog Ctr, Southampton SO14 3ZH, Hants, England Univ Southampton, Sch Ocean & Earth Sci, Southampton Oceanog Ctr, Southampton SO14 3ZH, Hants, England Univ Michigan, Dept Geol Sci, Ann Arbor, MI 48109 USA Economic Geology and the Bulletin of the Society of Economic Geologists 561-584 99 3 drilling project hole-504b oceanic-crust troodos ophiolite endeavor segment escanaba trough atlantic ridge metal mobility guaymas basin systems constraints 2004 MAY 0361-0128 ISI:000221995800007 Burial of midocean ridges by elastic sediments, particularly at continental margins, profoundly affects the geometry and chemistry of hydrothermal circulation and mineralization in the upper crust. Middle Valley, the sediment-covered northern extension of the bare-rock Endeavour segment of the Juan de Fuca Ridge, is host to the base metal-rich (Cu-Zn) Bent Hill massive sulfide deposit. At a water depth of 2,400 in, the similar to9 Mt Bent Hill deposit is a steep-sided body similar to200 m across and similar to100-m-thick. Ocean Drilling Program (ODP) hole 856H penetrates through the massive sulfide and underlying feeder zone extending to a total depth of 500 m below sea floor through the base of the strongly recrystallized (quartz + chlorite) sediment pile and into the uppermost volcanic basement. The basaltic rocks beneath the Bent Hill deposit include narrow sills intruded into indurated sediments, a volcanic flow erupted on top of sediments, and pillow lavas below the lowermost sediments recovered. Similar styles of alteration are present in both the sills and flows, and alteration is dominated by the effects of large-scale hydrothermal upflow rather than hydrothermal activity associated with individual eruptions or intrusions. The basalts are slightly to completely altered to greenschist facies secondary minerals, principally quartz, chlorite, and titanite, with subsidiary epidote, Cu-Fe sulfides, and rare actinolite. There are steep mineralogical, chemical, and isotopic alteration gradients from the highly altered basalt-sediment interfaces down to the less altered flow interiors, suggesting the channeling of hydrothermal fluids along the basalt-sediment boundaries. Alteration is reflected in intense metasomatic changes in the basalts. Assuming immobile TiO2, the most intensely altered basalts have undergone about 20 percent mass loss during recrystallization to chlorite-quartz rocks, with depletions in silica, alumina, and alkali, alkali earth, and base metals. Chloritized pillow margins with strongly light rare earth element-enriched chondrite-normalized patterns ([La/Sm](N) = 1.5; cf. fresh basalts, similar to0.7), that mimic profiles for midocean ridge hydrothermal fluids, require fluid-rock exchange with large quantities of hydrothermal fluid (W/R similar to27,000). Oxygen isotope compositions of chlorite-quartz rocks (delta(18)O = 1.8-2.4parts per thousand) suggest that alteration occurred between similar to320degrees and 370 degreesC. Strontium isotope compositions of the altered basalts and the chlorite-quartz rocks are not homogeneous and range from Sr-87/Sr-86 ratio = 0.7037 to 0.7046. There is a strong mode in Sr-87/Sr-86 ratio at similar to0.7038, suggesting that much of the alteration occurred by isotopic exchange with a hydrothermal fluid of that composition. This ratio is significantly lower than that measured for 265 C fluids venting from the nearby ODP mound (Sr-87/Sr-86 = 0.7044). The occurrence of epidote and isocubanite in the chloritized glassy pillow margins suggests that these rocks may retain a record of the high-temperature (>350 degreesC) hydrothermal fluid responsible for the formation of the overlying Bent Hill massive sulfide deposit. The strontium isotope composition of the chloritized glassy pillow margins, and hence the mineralizing fluid, is slightly more radiogenic (87Sr/86Sr = 0.7046). This composition could result from the addition of similar to15 percent of a pelagic or sedimentary component to the Sr-87/Sr-86 ratio = 0.7038 fluid responsible for most of the Sr isotope exchange with the upper basement. The sediments beneath the Bent Hill deposit are also strongly recrystallized to quartz and chlorite. Although their strontium isotope compositions are much lower than those in pelagic or terrigenous sediments in the region (Sr-87/Sr-86 = 0.709-0.720), the range of compositions (Sr-87/Sr-86 = 0.7046-0.7060) has little overlap with that of the altered basalts and chlorite-quartz rocks from the sills and uppermost basement. This lack of overlap suggests that the sediments either retain some of their original sedimentary strontium or that there is a range of fluid compositions in the sediment pile beneath the Bent Hill deposit. Sediments from the margins of Middle Valley, far from zones of active black smoker venting (ODP site 855), have Sr-87/Sr-86 ratios with a significant hydrothermal component (0.7059-0.7086). These ratios indicate that the subsurface hydrology of Middle Valley is dominated by evolved fluids rather than seawater, and that recharge into this system is not through boundary faults or through the sedimentary blanket as suggested by previous models. Rather, exposed basement rocks that form the flanks of Middle Valley are the most likely zones of regional seawater recharge to the deep high-temperature hydrothermal systems. 828TI Times Cited:1 Cited References Count:91 <Go to ISI>://000221995800007 English 55 17 Thomson, R. E. J. R. Delaney R. E. McDuff D. R. Janecky J. S. McClain Earth Planet. Sci. Lett. Earth Planet. Sci. Lett. 141-154 111 1992 103 17 Thomson, R. E. Mihaly, S. F. Rabinovich, A. B. McDuff, R. E. Veirs, S. R. Stahr, F. R. Thomson, Re Inst Ocean Sci, 9860 W Saanich Rd, Sidney, BC V8L 4B2, Canada Inst Ocean Sci, Sidney, BC V8L 4B2, Canada PP Shirshov Oceanol Inst, Moscow 117851, Russia Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Nature Nature 545-549 424 6948 r2k-hp/o/ba de-fuca ridge mid-atlantic ridge hydrothermal plumes northeast pacific heat-flux biology evolution ocean 2003 JUL 31 0028-0836 ISI:000184454700041 Understanding how larvae from extant hydrothermal vent fields colonize neighbouring regions of the mid-ocean ridge system remains a major challenge in oceanic research(1,2). Among the factors considered important in the recruitment of deep-sea larvae are metabolic lifespan, the connectivity of the seafloor topography, and the characteristics of the currents(3). Here we use current velocity measurements from Endeavour ridge to examine the role of topographically constrained circulation on larval transport along-ridge. We show that the dominant tidal and wind-generated currents in the region are strongly attenuated within the rift valley that splits the ridge crest, and that hydrothermal plumes rising from vent fields in the valley drive a steady near-bottom inflow within the valley. Extrapolation of these findings suggests that the suppression of oscillatory currents within rift valleys of mid-ocean ridges shields larvae from cross-axis dispersal into the inhospitable deep ocean. This effect, augmented by plume-driven circulation within rift valleys having active hydrothermal venting, helps retain larvae near their source. Larvae are then exported preferentially down-ridge during regional flow events that intermittently over-ride the currents within the valley. 706LG Times Cited:11 Cited References Count:19 <Go to ISI>://000184454700041 English 87 17 Thomson, R. E. Subbotina, M. M. Anisimov, M. V. Thomson, Re Inst Ocean Sci, Dept Fisheries & Oceans, 9860 W Saanich Rd, Sidney, BC V8L 4B2, Canada Inst Ocean Sci, Dept Fisheries & Oceans, Sidney, BC V8L 4B2, Canada Russian Acad Sci, PP Shirshov Oceanol Inst, Moscow 117997, Russia Journal of Geophysical Research-Oceans - 110 C1 hp/o de-fuca ridge northeast pacific plumes segment motions fluid ocean model 2005 JAN 22 0148-0227 ISI:000226580100001 [1] Hydrothermal venting at Endeavour Ridge is focused at five major vent fields spaced at similar to2 - km intervals along a narrow ( similar to1 km wide) north- south trending rift- valley. A Princeton Ocean Model with an axially symmetric rift- valley centered within a rotating, full- depth ( 2400 m) stratified ocean is used to simulate the circulation and associated temperature and salinity fields generated by vertical heat fluxes from the five vent fields. Steady seafloor heat fluxes are introduced instantaneously to a quiescent ocean using the model provision for boundary fluxes. The model achieves a quasi- steady state in about 80 days. Results are consistent with observation. In particular, buoyant plumes emanating from the larger vent fields rise to " trapping'' depths as shallow as 1850 m ( similar to350 m above bottom) and spread laterally with the vent- induced circulation. Plume anomalies remain confined to within several kilometers of the ridge, except to the west where anomalies extend more than 10 km off- axis. As with observations, modeled currents within the valley consist of a strong ( similar to10 cm s(-1)) poleward inflow within roughly 75 m of the bottom and an equally strong equatorward counterflow above that depth. Weak ( similar to1 cm s(-1)) equatorward flow develops over the flank of the west ridge and weak poleward flow over the flank of the east ridge. Cyclonic relative vorticity dominates the model circulation within the valley while anticyclonic vorticity prevails above the depth of neutral plume buoyancy. Findings support the notion that turbulent entrainment by buoyant plumes forces a mean poleward flow within the confines of the Endeavour Ridge axial valley. 891KP Times Cited:1 Cited References Count:29 <Go to ISI>://000226580100001 English 61 17 Tivey, M. A. H. P. Johnson J.Geophys. Res. 12,685-12,694 92 1987 56 17 Tivey, M. A. H. P. Johnson CRC Critical Reviews in Aquatic Science 473-496 1, 3 1989 109 17 Tivey, M. A. Johnson, H. P. Tivey, MA Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Geology Geology 979-982 30 11 magnetic field hydrothermal vents marine geology ocean crust endeavor segment sulfide deposits system growth 2002 NOV 0091-7613 ISI:000178902000006 A near-bottom geophysical survey on the Endeavour segment of the northern Juan de Fuca Ridge shows that regions of well-defined low crustal magnetization are strongly correlated with both active and extinct submarine hydrothermal vent sites. In particular, at the Main Endeavour Field, we find discrete magnetization lows associated with each cluster of vents. Magnetization lows are directly centered beneath the vent clusters and have diameters of similar to100 m, which implies a near-vertical, narrow, pipe-like source region located directly beneath the surface expression of the vent edifices. Lows are also separated from each other by only 200 m, which further implies highly focused zones. Magnetization lows are also associated with inactive and extinct vent areas, which indicates that alteration of the magnetic minerals in the crust rather than (necessarily temporary) thermal demagnetization is the primary process responsible for the low magnetization. These narrow pipe-like bodies are highly characteristic of alteration pipes found in ophiolites and are indicative of hydrothermal fluid up-flow zones. Thus, each magnetization low may define an individual upwelling zone, with distinct subsurface plumbing and thermal structure. The crustal-magnetization patterns provide important constraints on the geometry of the subsurface plumbing beneath these hydrothermal vent systems. At the Main Endeavour Field, magnetization lows are distributed along the trend of the rift valley in a semiregular pattern with a spacing of similar to200 m, arguing that upward flow may be partitioned into regularly spaced intervals along the axis of the rift valley. 609KH Times Cited:6 Cited References Count:24 <Go to ISI>://000178902000006 English 60 17 Tivey, M. K. Geochim. Cosmochim. Acta Geochim. Cosmochim. Acta 1993-1949 59 1995 154 17 M K Tivey Geophys. Monograph Series Geophys. Monograph Series 137-152 144 r2k-h/ch 2004 doi: 10.1029/144GM09 57 17 Tivey, M. K. J. R. Delaney Earth Planet. Sci. Lett. Earth Planet. Sci. Lett. 303-317 77 1986 59 17 Tivey, M. K. R. E. McDuff J.Geophys. Res. 12617-12637 95 1990 58 17 Tivey, M. K. L. O. Olson V. W. Miller R. D. Light Nature Nature 51-54 346 1990 62 17 Tivey, M. K. D. S. Stakes T. L. Cook M. D. Hannington S. Petersen J.Geophys. Res. 22859-22883 104 1999 138 17 Tolstoy, M. Vernon, F. L. Orcutt, J. A. Wyatt, F. K. Geology Geology 503-506 30 6 2002 169 17 Tsurumi, M. Tunnicliffe, V. Deep-Sea Research Deep-Sea Research 611-629 1 50 2003 166 17 Urcuyo, I. A. Massoth, G. J. Julian, D. Fisher, C. R. Deep Sea Research Part I: Oceanographic Research Papers Deep Sea Research Part I: Oceanographic Research Papers 763-780 50 6 2003 167 17 Urcuyo, I. A. Massoth, G. J. Macdonald, I. R. Fisher, C. R. 1998 164 17 Van Ark, E. M. Detrick, R. S. Canales, J. P. Carbotte, S. M. Harding, A. J. Kent, G. M. Nedimovic, M. R. Wilcock, W. S. D. Diebold, J. B. Babcock, J. M. Journal of Geophysical Research Journal of Geophysical Research B02401 112 B2 r2k-cs/cp r2k-cp/h 2007 137 17 Van Dover, C. L. German, C. R. Speer, K. G. Parson, L. M. Vrijenhoek, R. C. Science Science 1253-1257 295 5558 2002 63 17 Veirs, S. R. R. E. McDuff M. D. Lilley J. R. Delaney J Geophys. Res. 29,239-29,247 104, B12 1999 83 17 Veirs, S. R. McDuff, R. E. Stahr, F. R. Veirs, SR Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Geochemistry Geophysics Geosystems GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS Q02004 7 2 r2k-hp/o currents heat heat flux hydrography hydrothermal vents de-fuca ridge mid-atlantic ridge hot smoker plumes northeast pacific juan currents temperature variability segment diffuse 2006 FEB 2 1525-2027 ISI:000235156000001 [1] We characterize hydrothermal plumes and hydrography within the axial valley of the Endeavour segment ( Juan de Fuca ridge, northeast Pacific) using data from an autonomous underwater vehicle, a lowered CTD, and two current meter moorings. Our survey of the Main Endeavour hydrothermal vent field (MEF) shows hydrographic variability on scales as short as similar to 20 m and similar to 10 min. Within the similar to 100 m deep axial valley, the mean flow is 1 - 5 cm/s to the north, and tidal oscillations have similar to 5 cm/s amplitude. Combining the mean flow with an estimate of the difference in average temperature observed north and south of MEF, we find that the net along-axis horizontal heat flux has a mean magnitude of similar to 8 - 42 MW. An advection/diffusion model forced by local current records explains the observed temporal hydrographic variability and shows that mean horizontal flux variance is correspondingly high ( standard deviation similar to 63 MW). A steady state MEF heat budget, constrained by the observed horizontal flux and measurements of vertical fluxes from other studies, has two implications: the MEF heat flux is partitioned about equally between diffuse and focused vents, and about 85% of the flux from diffuse plumes is entrained by focused plumes. 010AS Times Cited:0 Cited References Count:30 <Go to ISI>://000235156000001 English 178 17 Voight, J. R. Sigwart, J. D. Marine Biology Marine Biology 129-133 152 1 2007 64 17 Volpe, A. M. S. J. Goldstein Eos Trans. AGU. 1702 671 1990 119 17 Wakeham, S. G. Cowen, J. P. Burd, B. J. Thomson, R. E. Wakeham, Sg Skidaway Inst Oceanog, 10 Ocean Sci Circle, Savannah, GA 31411 USA Skidaway Inst Oceanog, Savannah, GA 31411 USA Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA Fisheries & Oceans Canada, Inst Ocean Sci, Sidney, BC V8L 4B2, Canada Geochimica Et Cosmochimica Acta Geochimica et Cosmochimica Acta 923-939 65 6 r2k-hp particulate organic material sediment trap experiment deep-sea pacific-ocean wax esters north pacific water column neocalanus-cristatus abyssal waters vent shrimps 2001 MAR 0016-7037 ISI:000167617000006 Samples of ascending and descending particulate matter from the hydrothermal plume at Endeavour Segment of the Juan de Fuca Ridge were analyzed for their lipid composition to investigate the biogeochemistry of particulate matter associated with oceanic hydrothermal processes. The ascending flux of lipid was up to approximate to six-fold greater than the descending flux, and ascending particles were significantly enriched up to approximate to 200-fold in lipid compared with descending particles. The dominant fatty acids in both ascending and descending particles were C-16:1, C-18:1 omega9, C-20:1 and C-22:1, and the major neutral lipids were C-20:1 and C-22:1 fatty alcohols and cholesterol, C-20:1 and C-22:1 alcohols constituted up to >70% of neutral lipids in ascending particles at sites directly influenced by the plume, compared to 54% at the background site and 35 to 54% in descending particles. Comparison with zooplankton collected above the plume suggested that a large fraction of this lipid was derived from zooplankton that mag; be opportunistically feeding on organic matter associated with the plume. The high Aux of lipid moving upward in the water column in the vicinity of the vent plume is roughly equivalent to downward fluxes at similar oceanic depths and suggests an important mechanism by which particulate lipids may be dispersed in the marine water column. Copyright (C) 2001 Elsevier Science Ltd. 413MY Times Cited:5 Cited References Count:59 <Go to ISI>://000167617000006 English 67 17 Wilcock, W. S. D. McNabb, A. Earth Plant. Sci. Lett. 83-91 138 1996 68 17 Wilcock, W. S. J. R. Delaney Earth Planet Sci. Lett. 49-64 145 1996 125 17 Wilcock, W. S. D. Geophys. Res. Lett Geophys. Res. Lett 3999–4002 28 20 2001 90 17 Wilcock, W. S. D. Wilcock, WSD Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98115 USA Univ Washington, Sch Oceanog, Seattle, WA 98115 USA Geochemistry Geophysics Geosystems GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS - 5 earthquake swarm hydrothermal system mid-ocean ridge venting temperature marine geology and geophysics : heat flow (benthic) and hydrothermal processes marine geology and geophysics : midocean ridge processes tectonophysics : hydrothermal systems (8424) de-fuca ridge east pacific rise floor eruption site event plumes axial volcano magmatic events cracking event oceanic-crust fluids permeability 2004 NOV 13 1525-2027 ISI:000225189700001 Observations from the East Pacific Rise (EPR) and the Endeavour segment of the Juan de Fuca Ridge show that local earthquake swarms can lead to increased hydrothermal venting temperatures after a delay of several days. I develop two models for this process. In the temperature perturbation model, a new pathway opens to a heat source, and the temperatures of fluids leaving the reaction zone increase. By considering the exchange of heat between the fluid flowing up a conduit and the wall rock, I solve for the resulting perturbation to venting temperatures. For flow in a crack the response is delayed, and the delay increases as the crack narrows or the reaction zone deepens, but for a pipe the venting temperature increases either quickly or barely at all. In the pressure perturbation model, there is a transient increase in pressures at depth due to a decrease in porosity, the release of overpressured fluids, or a readjustment of pressures in response to a change in the relative permeabilities of the upflow and downflow zones. One-dimensional solutions for pressure diffusion show that this model can lead to a delayed increase in outflow fluxes which may be accompanied by increased venting temperatures. The temperature perturbation model fits the data from the EPR event well. The Endeavour event is less well constrained, and both models can fit the observations adequately. Local seismic networks and time series of fluid flux, chemistry, and temperature will be required to fully exploit hydrothermal perturbation events to infer subseafloor hydrology. 872EE Times Cited:2 Cited References Count:63 <Go to ISI>://000225189700001 English 105 17 Wilcock, W. S. D. Archer, S. D. Purdy, G. M. Wilcock, WSD Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98195 USA Univ Washington, Sch Oceanog, Seattle, WA 98195 USA Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA Journal of Geophysical Research-Solid Earth - 107 B12 mid-ocean ridge microearthquake mid-atlantic ridge east pacific rise de-fuca crustal structure oceanic-crust cross-correlation structure beneath propagating rift plate boundary midocean ridge 2002 DEC 11 0148-0227 ISI:000181191200001 [1] We report the results of a 55-day microearthquake experiment on the Endeavour segment of Juan de Fuca Ridge. The network covered a 5-km section of the ridge axis centered on the Main vent field and extended 15-km off axis on the west flank. The ridge axis and flanks were seismically active, and 1750 earthquakes were located with a minimum of five travel time picks including at least one S wave. Over half the earthquakes occurred in swarms, and a waveform cross-correlation technique was used to obtain relative locations. On the western flank, the hypocenters for four swarms at midcrustal depths are compatible with steeply dipping fault planes that strike at 035-050degreesN and oblique to the abyssal hills. Focal mechanisms determined from P wave first motions and P/S amplitude ratios are predominantly strike-slip with north-south compression and appear to be affected by the reorganization of the Explorer plate. Earthquakes beneath the ridge axis are concentrated in a band of intense seismicity at 1.5-3.5 km depth. To the north of High Rise vent field, the seismicity defines a plane striking parallel to the ridge axis and dipping east at 70degrees and the earthquakes appear to extend beneath an axial reflector previously imaged at 2.3 km depth. Farther south, the hypocenters are not compatible with a single fault plane. Focal mechanisms are characterized by subhorizontal tension axes oriented in all directions except parallel to the ridge and suggest a stress field that is about equally influenced by ridge spreading and hydrothermal cooling. 649DG Times Cited:2 Cited References Count:69 <Go to ISI>://000181191200001 English 66 17 Woods, A. W. J. R. Delaney 117-129 112 1992 69 17 Yoerger, D. R. D. S. Kelley J. R. Delaney J.International Robotics 1000-1014 19 2000 70 17 You, C. F. D. A. Butterfield A. J. Spivack J. M. Gieskes T. Gamo, and A. J. Campbell Earth Planet. Sci. Lett. Earth Planet. Sci. Lett. 227-238 123 1994