Publikationsdatum:
2013-05-26
Beschreibung:
We present a 26-day time series (October 2010) of physical properties (volume flux, flow velocity, expansion rate) of a vigorous deep-sea hydrothermal plume measured using our Cabled Observatory Vent Imaging Sonar (COVIS), which is connected to the NEPTUNE Canada Cabled Observatory at the Main Endeavour Field on the Juan de Fuca Ridge. COVIS quantitatively monitors the initial buoyant rise of the plume from ~ 5 m to ~ 15 m above the vents. The time series exhibits temporal variations of the plume vertical volume flux (1.93-5.09 m 3 /s), centerline vertical velocity component (0.11-0.24 m/s) and expansion rate (0.082-0.21 m/m); these variations have major spectral peaks at semi-diurnal (~ 2 cycle/day) and inertial oscillation (~ 1.5 cycle/day) frequencies. The plume expansion rates (average ~ 0.14 m/m) are inversely proportional to the plume centerline vertical velocity component (coefficient of determination R 2 ~ 0.5). This inverse proportionality, as well as the semi-diurnal frequency, indicates interaction between the plume and ambient ocean currents consistent with an entrainment of ambient seawater that increases with the magnitude of ambient currents. The inertial oscillations observed in the time series provide evidence for the influence of surface storms on the hydrodynamics of hydrothermal plumes.
Digitale ISSN:
1525-2027
Thema:
Chemie und Pharmazie
,
Geologie und Paläontologie
,
Physik
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