P. Schlosser et al., THE FIRST TRANS-ARCTIC C-14 SECTION - COMPARISON OF THE MEAN AGES OF THE DEEP WATERS IN THE EURASIAN AND CANADIAN BASINS OF THE ARCTIC-OCEAN, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 123(1-4), 1997, pp. 431-437
We present Delta(14)C data collected during three cruises to the Arcti
c Ocean that took place in the summers of 1987 (POLARSTERN cruise ARK
IV/3), 1991 (ARCTIC 91 Expedition), and 1994 (Arctic Ocean Section 94)
. The cruise tracks of these three expeditions cover all major basins
of the Arctic Ocean (Nansen, Amundsen, Makarov and Canada basins), and
can be combined to a trans-Arctic section reaching from the Barents S
ea slope to the southern Canada Basin just north of Bering Strait. The
section is based on 17 stations covering the entire water column (abo
ut 250 data points). The combined Delta(14)C data set was produced fro
m a mixture of large volume samples measured by low-level counting and
small volume samples measured by Accelerator Mass Spectrometry (AMS).
We use the Delta(14)C section, together with previously published Del
ta(14)C data from single stations located in several basins of the Arc
tic Ocean, to derive mean ''ages'': (isolation times) of the deep wate
rs in the Arctic Ocean. We estimate these mean ''ages'' to be approxim
ate to 250 years in the bottom waters of the Eurasian Basin and approx
imate to 450 years in the Canadian Basin Deep Water. A remarkable feat
ure of the Delta(14)C section is the homogeneity in the C-14 distribut
ion observed in the deep Canadian Basin. Within the measurement precis
ion of about +/- 2 parts per thousand (LV) to about +/- 5 parts per th
ousand (AMS), we cannot detect significant horizontal or vertical Delt
a(14)C gradients below 2000 m depth between the northern boundary of t
he Makarov Basin and the southern margin of the Canada Basin. There is
no statistically significant difference between samples measured by A
MS and by low-level counting.