A combination of long-range sidescan sonar, airgun seismic reflection, and high-resolution echo-sounder data has allowed an overview of the different sedimentary processes along the southeast Canadian continental slope and rise. A large sediment drift identified along almost the entire length of the margin, mainly between the 3000 and 4000 m isobaths, testifies to the importance of geostrophic processes in this region. The presence of historic gravity-flow deposits downslope from those parts of the margin that were covered by glacial ice during the Wisconsinan, coupled with a lack of similar deposits along the probable ice-free parts of the margin, suggests an association between palaeoenvironmental conditions on the continental shelf and slope stability. Differences in canyon style along the Grand Banks slope are attributed to differences in slope angle and the speed and regularity of turbidity flow.
Single-channel seismic-reflection profiles and sidescan-sonar records collected by the R/V Neecho, cruise NE 79-06, on the inner shelf east of Cape Cod, Massachusetts