Sea ice characteristics and the role of sediment inclusions in deep- sea deposition: Arctic-Antarctic comparisons

Much of Arctic sea ice forms over the shallow continental shelves along the perimeter of the basin. Ice which escapes the shelf is transported several years within the Beaufort Gyre and Transpolar Drift stream, before exiting the Arctic Basin through Fram Strait. This ice, and especially that in the Siberian branch of the Transpolar Drift stream in the Eurasian Basin, may incorporate large quantities of particulate matter during formation on the shelf. Subsequent seasonal surface melting and winter freezing on the ice underside results in surface accumulation of particulate matter. Rafting of floes over and under each other results in a complex ice stratigraphy and redistribution of sediment accumulations. In contrast, Antarctic sea ice has only limited sources for sediment incorporation, and most of the ice-cover melts each year. These variations in Arctic and Antarctic ice characteristics are illustrated by analyses of ice crystal texture, c-axis orientations, salinity, δ¹⁸O in ice cores and discussion of potential sediment input. -Authors