TY - JOUR
T1 - Near‐axis heat flow measurements on the northern Juan De Fuca Ridge
T2 - Implications for fluid circulation in oceanic crust
AU - Johnson, H. Paul
AU - Becker, Keir
AU - Von Herzen, Richard
PY - 1993/9/3
Y1 - 1993/9/3
N2 - Present models of the cooling of oceanic crust suggest that convection of hydrothermal fluid is a major component of the process. In axial regions, abundant faults and open fissures are associated with the venting of high temperature hydrothermal fluid. In older crust, where the insulating sediment cover is thick, previous studies have shown that basement topography is the dominant forcing factor for within‐crust fluid circulation. In the intermediate region, where young crust is lightly sedimented, heat flow data are difficult to obtain with traditional techniques. To determine whether topography or permeability is the dominant process controlling fluid circulation in the near‐axis region, we conducted a profile of heat flow measurements using the submersible ALVIN, on the Endeavour Segment of the Juan de Fuca Ridge. Our data indicate that topographic forcing is responsible for the long wavelength variations, with high heat flow at the ridge summits, and low values in the inter‐ridge valleys. The locations of the extreme values of heat flow taken within the context of subsurface faulting are consistent with a model where a ridge‐valley topographic pair comprises a single circulation cell. This model predicts that the source area for the high temperature axial vents may be in the flanking inter‐ridge valleys.
AB - Present models of the cooling of oceanic crust suggest that convection of hydrothermal fluid is a major component of the process. In axial regions, abundant faults and open fissures are associated with the venting of high temperature hydrothermal fluid. In older crust, where the insulating sediment cover is thick, previous studies have shown that basement topography is the dominant forcing factor for within‐crust fluid circulation. In the intermediate region, where young crust is lightly sedimented, heat flow data are difficult to obtain with traditional techniques. To determine whether topography or permeability is the dominant process controlling fluid circulation in the near‐axis region, we conducted a profile of heat flow measurements using the submersible ALVIN, on the Endeavour Segment of the Juan de Fuca Ridge. Our data indicate that topographic forcing is responsible for the long wavelength variations, with high heat flow at the ridge summits, and low values in the inter‐ridge valleys. The locations of the extreme values of heat flow taken within the context of subsurface faulting are consistent with a model where a ridge‐valley topographic pair comprises a single circulation cell. This model predicts that the source area for the high temperature axial vents may be in the flanking inter‐ridge valleys.
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U2 - 10.1029/93GL00734
DO - 10.1029/93GL00734
M3 - Article
AN - SCOPUS:0027872585
VL - 20
SP - 1875
EP - 1878
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 17
ER -