Arctic Ice Gouging and Ice Keel Turbates

Abstract

Distinctive surficial morphology (Fig. 1) and stratification are generated when sea-ice keels are driven along the seabed in the Beaufort Sea (Fig. 2). The morphology consists of linear ice-gouge furrows that criss-cross extensive shallow shelves in overlapping patterns (Fig. 3). Intense ice gouging in the Arctic is associated with the stamukhi zone [Reimnitz and Barnes, 1974], where sea-ice ridges form and are grounded on the shelf between 15–50 m water depth. Ice gouges in the Beaufort Sea typically are incised 1 m into the sea floor with maximum incisions over 4 m deep, relief of over 7 m and densities greater than 200 km^-2 [Barnes et al., 1984]. The orientations and terminations of ice gouges indicate oblique uphill scouring as well as strong shore-parallel movement. Sea-floor morphology linked to studies of ice motion at Barrow, Alaska (Fig. 4) support the idea that gouging occurred during ice break-up [Shapiro and Barnes, 1991]. In contrast, investigations of ice-gouge terminations off Canada indicate ice-push events resulted from ice motion in response to storms during freeze-up [Héquette et al.,1995].