All fiords and trough‐shaped submarine valleys occur within glaciated coastal mountains or adjacent glaciated shelves and are completely absent from other coasts or shelf areas. This distribution strongly suggests that these landforms are of glacial origin and hence their dimensions can be used for assessing the rate of glacial scour. The total volume of these forms in the eastern North Atlantic measures about 750,000 km3, equivalent to a mass of 280 • 1013tonnes; this would be equivalent to the removal of a layer of rock 240 m thick. As for the distribution of the resultant drift, 30% of its mass can be explained in terms of lateglacial in‐filling of the troughs, 63% to 65% was dumped on the continental slopes and rises, about 1% was deposited on the polar abyssal plain, and 4 to 5% was rafted by icebergs to subpolar areas of the abyssal plain. Rates of scour in fiords and glacial submarine valleys ranged from 2.7 to 6.0 mm/year, which is an order of magnitude higher than the rate of erosion by land‐based glaciers. Data on glaciomarine sedimentation in the western North Atlantic and in deepsea trenches off southwest Alaska and southern Chile tally with these figures.