On assessing the age of deep oceanic water by carbon-14

Abstract

The rate of circulation and age of the deep water of the oceans is of much interest. Worthington (1955) has suggested an age of 100–160 years for northern North Atlantic water which has reached the Carribean and Cayman Seas. I (in part. Cooper, 1955, 1956) have suspected that the rate of circulation of much of the North Atlantic deep water may be even faster than Worthington's results suggest. Provisional direct observations by G. Wüst & G. Dietrich (private communication) also suggest that the deep circulation is quite rapid.

The Antarctic convergence South of New Zealand

“…The significance of this interesting result is difficult to evaluate with the data available and further work on the distribution of 14C activity in Antarctic waters is planned. The physicochemical influences on the 14C/12C ratio in ocean waters as outlined by Cooper (1956) will need to be kept in mind, an attempt made to estimate the northwards flow of 14C-poor water derived from the melting of "old" ice, and the contribution of the upwards moving Deep Water calculated, This has been shown (Brodie and Burling, 1958) to be of great oceanographic "age" (around 2,500 years). The admixture of a very small volume of Deep Water with the Antarctic Upper Water through normal processes of vertical turbulence could conceivably produce an appreciable apparent "age" of surface water without the hydrological properties of the Upper Water being significantly altered from their "recent" characteristics, -…”