Results 141 to 150 of about 688 (177)

Magnetic structure of the Juan de Fuca-Gorda Ridge Area

Journal of Geophysical Research, 1969
By using the fracture pattern deduced by N. Pavoni (1966) with a different interpretation of the magnetic anomaly lineations, a reconstruction can be made in which the Juan de Fuca and Gorda ridges form a single, continuous, north-south trending feature. From this reconstruction, the present magnetic structural pattern can be derived by (1) development
George Peter, Robert Lattimore
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A microseismicity survey of Axial Seamount, Juan de Fuca Ridge

Bulletin of the Seismological Society of America, 1987
Abstract An array of ocean bottom seismometers and hydrophones were deployed within the caldera of Axial Seamount, located at the intersection of the Cobb-Eickelberg Seamount Chain and the Juan de Fuca Ridge. Recent manned submersible dives have discovered the presence of two distinct hydrothermal vent fields.
R. S. Jacobson, L. D. Bibee, R. W. Embley, S. R. Hammond   +3 more
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The magnetic structure of Axial Seamount, Juan de Fuca Ridge

Journal of Geophysical Research: Solid Earth, 1990
Axial Seamount is a large, volcanically active seamount located in the eastern Pacific on the central Juan de Fuca (JDF) ridge at 46°N, 130′W. Sea surface magnetic anomaly data show that Axial lies completely within crust formed during the Brunhes normal polarity epoch.
Maurice A. Tivey, H. Paul Johnson
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Seafloor Positioning Across Juan De Fuca Ridge

1994
Abstract : The results of an analysis of a complex data set acquired during the United States Geological Survey's Marine Crustal Deformation Study are presented. The experiment, which commenced in the spring of 1992 in a region of the Pacific known as the Juan de Fuca ridge, represents a first attempt to locally monitor plate dynamics in the marine ...
Fell, Patrick, Seay, C. Harris
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Mercury Thermoforms and Their Distribution in the Sedimentary Sequence of the Juan De Fuca Ridge

Geochemistry International, 2020
This paper addresses the vertical distribution of total mercury and its thermoforms in the Holocene–Upper Pleistocene sedimentary rocks from the Dead Dog active hydrothermal field in the Middle Valley, Juan de Fuca Ridge, Pacific Ocean. Sediment samples were taken from the core of Hole 858B drilled during ODP leg on the top of a sulfide hill, in a zone
L. N. Luchsheva, V. B. Kurnosov, Yu. I. Konovalov   +2 more
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Heat flow west of the Juan de Fuca Ridge

Journal of Geophysical Research, 1970
Fifteen new heat-flow measurements have been made as part of a general geophysical study west of the Juan de Fuca ridge. All but one are within 16 km of latitude 47°N, and they form a profile from the crest of the ridge to a point out on the Tufts abyssal plain.
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Structure of the Northern Symmetrical Segment of the Juan de Fuca Ridge

Marine Geophysical Researches, 1993
A seismic refraction profile was shot along the axis of the Northern Symmetrical Segment of the Juan de Fuca Ridge system. Three models of the along-axis crustal structure fit the observed data equally well. One model includes a low-velocity zone, the top of which is at a depth below the seafloor of approximately 3 km, that is continuous along-axis for
G. L. Christeson, G. M. Purdy, K. M. M. Rohr   +2 more
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Water column hydrothermal plumes on the Juan de Fuca Ridge

Journal of Geophysical Research: Solid Earth, 1990
Hydrographic surveys on the Juan de Fuca Ridge (JdFR) carried out from 1980 to 1987 show a complex pattern of 3He and Mn‐rich water column plumes produced by venting from several submarine hot spring areas. In the vicinity of Axial Volcano at latitude 46°N, distinct plumes were detected in 1980, 1982, and 1983 with3He signatures up to δ(3He) = 64% at ...
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Hydrothermal venting and the apparent magmatic budget of the Juan de Fuca Ridge

Journal of Geophysical Research: Solid Earth, 1992
The fact that vigorous hydrothermal discharge occurs on ridge segments with a variety of spreading rates and morphological characteristics makes it difficult to discern the large‐scale geological controls on the distribution of hydrothermal venting along the mid‐ocean ridge.
Edward T. Baker, Stephen R. Hammond
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Chemistry of hydrothermal solutions from the southern Juan de Fuca Ridge

Journal of Geophysical Research: Solid Earth, 1987
Fluids from three vent fields on the southern Juan de Fuca Ridge were sampled in September 1984 using the DSRV Alvin. The fluids are uniquely high in both chloride, which ranges up to twice the seawater value, and in metal content. Simple vapor‐liquid phase separation could not have produced both the high chlorinity and gas concentrations observed in ...
Karen L. Von Damm, James L. Bischoff
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