Boundary layer measurements and their implications for sediment transport on the eastern Norwegian Sea continental slope

Benthic currents, temperature, salinity, and suspended sediment concentration were measured in 1993–1994 on the Bear Island Fan, at water depths of approximately 1700 m, near the wreckage of the Russian nuclear submarine “Komsomolets”. A maximum current speed of 51 cm/s and a mean speed of approximately 10 cm/s was recorded. There was a marked seasonal pattern in flow strength, and the net transport was northward along the slope contours. The strongest flow event of the year, however, was directed to the southwest. The smooth (apart from burrows created by benthic fauna), unscoured appearance of the sediment surface in bottom photographs suggest that the deep currents on the continental slope are weak. Our measurements, however, show that the currents frequently exceeded the erosion threshold speed. Peak concentration values during the energetic winter period were within the range expected for an erosion event. The data indicate a high potential for sediment erosion and transport on the Bear Island Fan, with implications for the possible transport of contaminants from the submarine.