Hydrothermal Plume Measurements: A Regional Perspective

An extensive deep-tow survey around an active submarine vent field was conducted to map the three-dimensional distribution of hydrothermal emissions and calculate the hydrothermal discharge of heat and manganese. Emissions from the 10-kilometer-long vent field formed a nearly isopycnal plume about 250 meters thick and elongated in the direction of the local net current. Net export of hydrothermal discharge from both point and diffuse sources was estimated from the advective transport of the plume; the heat flux was 5.8 $\pm $ 2.9 $\times $ 10$^{8}$ watts and the dissolved manganese flux was 0.2 $\pm $ 0.1 moles per second. Flux measurements of this type could be expanded to encompass entire ridge segments, allowing comparison with theoretical thermal and chemical process models on a common spatial scale.