Scoresby Sund is the world's largest fjord system, and the wise lower part of the fjord is relatively shallow compared with the narrow and deep tributaries. Airgun and water gun seismic data suggests Quaternary sediments less than 12m thick on top of well unconsolidated, probably Mesozoic, sedimentary rocks. Well developed submarine moraines extending 2-3km into Scorseby Sund were found at Vikingebugt. In general the main areas of both Hall Bredening and Scoresby Sund were subject to erosion or non-deposition during a glaciation dated to the Younger Dryas. -K.Clayton