Ice-Wallow Relief in the Beaufort Sea

The irregular morphology of the Beaufort Sea shoreface consists of broad, gentle depressions and rounded knolls, as revealed in contour charts prepared from U.S. Coast and Geodetic Survey data (Fig. 1), and a detailed diving-observations diagram (Fig. 2) [Reimnitz et al., 1972; Reimnitzand Barnes, 1974]. In most summers, this shoreface is marked by grounded ice floes, a relationship that has been noted in our earliest investigations of the area [Reimnitz et al., 1972]. Closely spaced, tightly navigated, and repeated bathymetric surveys were used to explain the morphology as dynamic ice-wallow relief [Reimnitz and Kempema, 1982]. The action of grounded ice wobbling on the bottom in a seaway, and of intensified currents scouring around grounded ice keels that present obstacles to flow, produces the characteristic relief (Figs. 3 and 4). Relief formation combines erosion and deposition, which result in complex ripple patterns and internal sedimentary structures, as shown in Figs. 3 and 4.