The relatively steep continental slope offshore north Norway (3–7°) is dissected by several valleys (e.g. Taylor et al. 2000; Rise et al. 2013), none of which is related to coastal rivers opening into the fjords dominating the coast (Corner 2005). Two end-member valley forms have been identified: (1) classical submarine canyons characterized by a V-shaped cross-section, which can be followed from the shelf edge to the base of the continental slope where they continue as deep-sea channels; and (2) steep-sided, flat-floored valleys, some of uniform width, others widening upslope, some of which can be followed upslope to the shelf break while others have their headwalls located further downslope; debris-flow lobes occur beyond their downslope terminations (Rise et al. 2013).