Sediment Transport During the Winter on the Yukon Prodelta Norton Sound, Alaska

Abstract

ABSTRACT Winter in the northern Bering Sea brings a drastic reduction in terrestrial runoff and a substantial decrease in air-sea momentum transfer (wind and waves) owing to the formation of shorefast and pack ice. Despite these changes, quantities of suspended silt and clay over the Yukon prodelta in the winter of 1978 were essentially the same as those observed during fair weather summer periods, when the sediment discharge of the Yukon River is at its maximum and there is no ice layer to inhibit surface waves. Furthermore, the regional transport pattern involving northward mean flow across the prodelta in Norton Sound remains unchanged in the winter. Bottom current and light scattering measurements obtained during the summer of 1977 showed that spring tides are capable of resuspending fine sediment at depths of about 18 m on the prodelta in the absence of significant surface wave action. We conclude that during the winter the suspended matter transport system is driven by tidal current reworking of sediments which were introduced by the Yukon River during the previous summer.