FY 1995
Chemical and biochemical transformations in hydrothermal plumes
Lilley, M.D., R.A. Feely, and J.H. Trefry
In Seafloor Hydrothermal Systems: Physical, Chemical, Biological, and Geological Interactions, S.E. Humphris, R. Zierenberg, L. Mullineaux, and R. Thomson (eds.), AGU, Washington, D.C., Geophysical Monograph 91, doi: 10.1029/GM091p0369, 369–391 (1995) |
| Hydrothermal plumes integrate the heat and mass flux originating at seafloor hydrothermal vents thereby providing both a means of detecting hydrothermal activity and estimating hydrothermal fluxes. Many chemical species are introduced into the deep sea via hydrothermal plumes in concentrations many orders of magnitude higher than that existing in background seawater (e.g. H2, CH43He, Mn, Fe) while others are scavenged from seawater by hydrothermal particles (e.g. PO4−3, V, As, rare earth elements, Th). Dilution by entrainment of background seawater in the buoyant portion of the plume is very rapid (see chapters by Lupton and McDuff, this volume) such that the hydrothermal component in the near-field portion of the neutrally buoyant plume represents only about 0.01% of the mixture. Nevertheless, chemical tracers such as 3He, CH4, and Mn are widely utilized in addition to temperature, salinity, and light transmission anomalies to detect hydrothermal venting and to draw inferences about the nature of the underlying geochemistry of the hydrothermal system. Many other chemical tracers can be utilized during plume studies to provide additional information about the nature of the venting. These include particles, H2, Al, and radioisotopes, among others. |
