Excess bottom radon 222 distribution in deep ocean passages

Journal Article · Fri Oct 20 04:00:00 EDT 1978 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JC083iC10p05068· OSTI ID:6799470

Sarmiento, J L; Broecker, W S; Biscaye, P E

Radon 222 and STD profiles were obtained as part of the Geosecs program in the Vema Channel in the southwest Atlantic Ocean and in the Samoan, Clarion, and Wake Island passages in the Pacific Ocean. The standing crop of excess radon 222 is higher in the passages than at other nearby locations. The most likely explanation for this is that there is a high flux of radon 222 from the floor of the passages. Since much of the floor is covered with manganese nodules and encrustations, the high flux of radon 222 may be attributable to the high concentrations of radium 226 in the outer few millimeters of such deposits. Laboratory measurements of radon 222 emissivity from maganese encrustations obtained in Vema Channel support this hypothesis. The excess radon 222 in the Vema Channel and Wake Island Passage is found in substantial quantities at heights above bottom greatly exceeding the heights at which excess radon 222 is found in nonpassage areas. The horizontal diffusion of radon emanating from the walls of the passages is unlikely to be the cause of the observed concentrations because the ratio of wall surface area to water volume is very low. The profiles must therefore be a result of exceptionally high apparent vertical mixing in the passages. Further work is needed to determine the nature of this apparent vertical mixing. The excess radon 222 and STD data in all four passages have been fit with an empirical model in which it is assumed that the bouyancy flux is constant with distance above bottom. The fits are very good and yield apparent buoyancy fluxes that are between 1 and 3 orders of magnitude greater than those obtained at nearby stations outside the passages for three of the four passages.

• Research Organization: Lamont-Doherty Geological Observatory and the Department of Geological Sciences, Columbia University, Palisades, New York 10964
• OSTI ID: 6799470
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 83:C10; ISSN JGREA
• Country of Publication: United States
• Language: English

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ALKALINE EARTH ISOTOPES
ALPHA DECAY RADIOISOTOPES
ATLANTIC OCEAN
DAYS LIVING RADIOISOTOPES
DIFFUSION
EVEN-EVEN NUCLEI
HEAVY NUCLEI
ISOTOPES
NUCLEI
OCEANOGRAPHY
PACIFIC OCEAN
RADIOISOTOPES
RADIUM 226
RADIUM ISOTOPES
RADON 222
RADON ISOTOPES
SEAS
SURFACE WATERS
YEARS LIVING RADIOISOTOPES