Early investigations of artic shelf regions led to the hypothesis that certain micro-relief forms are related to the action of grounded ice (for example, Rex, 1955). Since the introduction of side-scan sonar as a tool for ocean-floor surveys, a number of workers have described the occurrence of linear bottom features produced by grounded ice. Such features have been found on modern polar shelves (Skinner, 1971; Pelletier and Shearer, 1972; Kovacs, 1972; Reimnitz and Barnes, 1972; Brooks, 1973), and as relict features (Berkson and Clay, 1973; Belderson and Wilson, 1973; Belderson and others, 1973). Studies of core samples, high resolution seismic profiles, and diving observations indicate that the sediments of the Beaufort Sea Shelf are highly distorted by the action of grounding ice, and that the recurrence rate of gouging is very high. It has also become evident that grounding ice is contributing considerably to the sediment transport processes of modern Arctic shelves.
Sediments from similar environments exposed on the continents today should also contain the record of ice gouging and related processes. Thus it has become apparent that drifting ice is an important agent influencing the sedimentary structures and the sediment transport regime of Arctic shelves today and has been in the past. The diagrams presented here, with supporting evidence in the form of side-scan sonar records, and ice and bottom photos, demonstrate the most prevalent processes and types of bottom features observed on the continental shelf off northern Alaska. As the map shows, most of the shelf is affected by these processes today.
