Circular to semi-circular crater-like depressions in the seafloor are commonly referred to as pockmarks. Pockmarks were discovered in the 1960s on echo-sounding profiles from the Scotian Shelf, eastern Canada (King & MacLean 1970). While there is no consensus regarding their formation process, pockmarks are in general linked to the removal of soft surface sediments during fluid escape at the seafloor (Judd & Hovland 2009). In the Arctic Ocean, pockmarks are found in sizes ranging from <1 to >100 m in diameter, both on the continental shelf and in deeper-water settings. Within a limited area of the Mendeleev Rise crest at about 78°20′ N, pockmarks dominate the seafloor morphology in water depths around 800 m.
Description
The Mendeleev Rise comprises one of the major undersea features in the Arctic Ocean; it extends approximately 900 km along the 180° meridian from the continental slope west of Chukchi Borderland to about 84° N (Fig. 1a). Portions of the rise shallower than approximately 1000 m were subjected to ice grounding, except in the vicinity of 78° 20′ N where the 800 m deep crest contains no direct evidence of ice scouring (Jakobsson et al. 2014). Multibeam swath bathymetry collected with USCGC Healy in …
