Deep-ocean circulation

Y. Nozaki, in Deep Ocean Circulation, Physical and Chemical Aspects, ed. T. Teramoto, Elsevier, Amsterdam, 1993, pp. 83-89. 

Joly observed elevated "Ra activities in deep-sea sediments that he attributed to water column scavenging and removal processes. This hypothesis was later challenged with the hrst seawater °Th measurements (parent of "Ra), and these new results conhrmed that radium was instead actively migrating across the marine sediment-water interface. This seabed source stimulated much activity to use radium as a tracer for ocean circulation. Unfortunately, the utility of Ra as a deep ocean circulation tracer never came to full fruition as biological cycling has been repeatedly shown to have a strong and unpredictable effect on the vertical distribution of this isotope. 

Fairbanks, R. G. (1989). A 17,000-year glacio-eustatic sea level record influence of glacial melting rates on younger dryas event and deep-ocean circulation. Nature 342, 637-642. 

Nozaki Y, Yamada M, Nikaido H (1990) The marine geochemistry of actinium-227 evidence for its migration through sediment pore water. Geophys Res Lett 17 1933-1936 Nozaki Y (1993) Actinium-227 a steady state tracer for the deep-se basin wide circulation and mixing studes. In Deep Ocean Circulation, Physical and Chemical Aspects. Teramoto T (ed) Elsevier p 139-155... 

Albarede F, Goldstein SL, Dautel D (1997b) The Nd isotopic composition of Mn-nodules from the Southern and Indian Oceans, the global oceanic Nd budget, and their bearing on deep ocean circulation. Geochim Cosmochim Acta 61 1277-1291... 

Distributions of DOC in the deep ocean. The x-axis is viewed in the context of the deep-ocean circulation, with formation in the North Atlantic, circulation around the Southern Ocean, and flow northward into the Indian and Pacific oceans. Source-. From Mansell, D. A. (2002) Biogeochemistry of Marine Dissoived Organic Matter, Academic Press, pp. 685-715. 

The density of seawater varies from a maximum of c = 29, observed in deep antarctic waters, to a minimum of c = 25 in subtropical oceanic thermoclinal waters. The high density of polar waters causes them to sink beneath subtropical waters and constitutes the driving force of deep oceanic circulation. 

Boyle E.A. and Keigwin L.D. (1985) Comparison of Atlantic nd Pacific paleochemical records for the last 25,000 years Changes i deep ocean circulation and chemical inventories. Earth and Planet. Sci. at. 76, 135-150. 

Cronin T. M., Raymo M. E., and Kyle K. P. (1996) Pliocene (3.2-2.4 Ma) ostracode faunal cycles and deep ocean circulation. North Atlantic Ocean. Geology 24(8), 695-698. 

Albare(c)de F., Goldstein S. L., and Dautel D. (1997) The neodymium isotopic composition of manganese nodules from the southern and Indian oceans, the global oceanic neodymium budget, and their bearing on deep ocean circulation. Geochim. Cosmochim. Acta 61(6), 1277-1291. 

Sheldon R. P. (1980) Episodicity of phosphate deposition and deep ocean circulation—a hypothesis. In Marine Phosphorites. Spec. Publ. 29 (ed. Y. K. Bentor). SEPM, pp. 239-247. 

Figure 13. Deep-ocean circulation through the ridges and basins of the southeastern Pacific. The east Pacific rise at 120° W provides an effective harrier to deep water penetrating eastward from the central Pacific. The stations, A and B, are referred to in the text. The figure was drawn from Lonsdale s (111) description of the deep waters of the eastern south Pacific.

Railsback, L.B., 1990. Influence of changing deep ocean circulation on the Phanerozoic oxygen isotopic record. Geochimica et Cosmochimica Acta 54 1501-1509. 

Application of Isotopic Studies of Co-rich Mn Crusts to the Study of Present-day Deep-ocean Circulation... 

Deep-ocean circulations are, however, not that rapid and the turnover of deep water masses requires hundreds or thousands of years, ample time to reduce the oxygen to zero without any chance of in situ supplementation. Within forty years the 5 mg oxygen per litre of a 4000 m deep ocean might theoretically be consumed by a surface primary production of 200 g of carbon per square metre per year. 

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