Support is provided for the acquisition of side-looking sonar imagery to study one of the world's most important subsea "drainage systems" situated directly in front of the outlet of the Pleistocene Laurentide icecap in the Hudson Strait and extending to the slopes and basins of the Labrador Sea. The proposed research is a multi-year collaborative effort between McGill University, Montreal, Canada, Bedford Institute of Oceanography (BIO)/ Atlantic Geoscience Centre (AGC), Dartmouth, Nova Scotia, the Geological Observatory (L-DGO) of Columbia University. The scientific objectives to be addressed are three fold. (1) To define depositional and morphological elements of the Northwest Atlantic Mid-Ocean Canyon (NAMOC), as a type example of non-classical fan turbidite system without shifting distributary channels and terminal lobes and to acquire a quantitative hydrodynamic understanding of the sediment-laden flows that have passed through the channels. (2) To identify the principle sedimentological processes active on an ice-marginal slope and to explain variation in continental slope dynamics in terms of ice sheet expansion and rapid melting. (3) To use data collected in the program to advance the techniques of remote acoustic characterization of the sedimentary substrate.