Snowfall and Oxygen-Isotope Variations off the North Coast of Ellesmere Island, N.W.T., Canada

• Published in: Journal of Glaciology
• Main Authors: Jeffries, Martin O., Roy Krouse, H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1987
• Subjects: Earth-Surface Processes; Arctic; Arctic Ocean; Ellesmere Island; Canada; Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000008698; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000008698

Abstract Snow-pack along the land-fast ice fringe off the north coast of Ellesmere Island was generally characterized by depth-hoar overlain by dense snow and wind slab. Mean snow depth in the study area was 0.54 m (1982-85) and the mean δ 18 O value of the snow-pack was -31.3˚/00. Isotope data were not obtained previously for this geographic region and, therefore, complement a previous study of δ 18 O variations in High Arctic snow (Koerner, 1979). The data are consistent with an Arctic Ocean moisture source. The δ 18 O profiles show seasonal variations, with winter snow being more depleted in 18 O than fall and spring snow. However, the δ 18 O profiles are dominated by a trend to higher δ 18 O values with increasing depth. This is attributed to a decrease in δ 18 O values as condensation temperatures fall during the autumn-winter accumulation period. During this time, there is also a change from relatively open to almost complete ice cover in the Arctic Ocean. The change in evaporation conditions and consequent effect on δ values gives rise to a sharp discontinuity in the δ 18 O profiles and a bi-modal δ 18 O frequency distribution. The bi-modal distribution is reinforced by a secondary isotope fractionation that occurs during depth-hoar formation. This isotope effect leads to a wider δ 18 O range but does not significantly alter the mean δ 18 O value.