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Poroelastic response of mid‐ocean ridge hydrothermal systems to ocean tidal loading: Implications for shallow permeability structure
Author(s) -
Barreyre Thibaut,
Sohn Robert A.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl066479
Subject(s) - hydrothermal vent , hydrothermal circulation , geology , poromechanics , permeability (electromagnetism) , ridge , mid ocean ridge , oceanography , seabed , petrology , amplitude , geophysics , seismology , paleontology , geotechnical engineering , porous medium , porosity , membrane , biology , genetics , physics , quantum mechanics
We use the time delay between tidal loading and exit‐fluid temperature response for hydrothermal vents to model the poroelastic behavior and shallow upflow zone (SUZ) effective permeability structure of three mid‐ocean ridge (MOR) sites with different spreading rates. Hydrothermal vents at Lucky Strike field exhibit relatively small phase lags corresponding to high SUZ effective permeabilities of ≥ ~10 −10 m 2 , with variations that we interpret as resulting from differences in the extrusive layer thickness. By contrast, vents at East Pacific Rise site exhibit relatively large phase lags corresponding to low SUZ effective permeabilities of ≤ ~10 −13 m 2 . Vents at Main Endeavour field exhibit both high and low phase lags, suggestive of a transitional behavior. Our results demonstrate that tidal forcing perturbs hydrothermal flow across the global MOR system, even in places where the tidal amplitude is very low, and that the flow response can be used to constrain variations in SUZ permeability structure beneath individual vent fields.