Stamukhi shoals of the Arctic - some observations from the Beaufort Sea

Abstract

A number of linear shoals, representing pronounced topographic anomalies on the surface of the Arctic shelf, have been studied in the Prudhoe Bay area. These shoals have been referred to in several previous studies. Based on seismic reflection records, Reimnitz et al., (1972a), stated that the shoals are constructional features younger than the post-Wisconsin transgression. Large chunks of grounded ice have frequently been seen on the linear shoals of the inner shelf. These ice chunks form barriers parallel to the shore (Reimnitz, et al. 1972b). Reimnitz and Barnes (1974) considered the lack of gravel concentrations on the shoals to be evidence that the stream of pack ice drifting past northern Alaska carries very little gravel today. Lewellen (1977) referred to the linear shoals as submerged barrier islands, while Reimnitz, et al., (1977b) pointed out that, although similar in shape to barrier islands, the linear shoals are very different in composition and do not appear to represent drowned harrier islands. They show that the shoals localize the formation of major shear and pressure events in the ice, which in turn cause the formation of linear belts of deformed and grounded ice. Today the shoals appear to be migrating under the influence of ice-bottom interaction, and indeed may have formed in response to ice-bottom interaction within the "stamukhi zone". The shoals migrate rather slowly and retain their shapes over periods of 25 years, yet control the location and stabilize the outer edge of the floating fast ice zone, and provide shelter for the inner shelf and coast. Reimnitz et al. (1977b) surmised that similar artificial structures might be used to modify the ice environment on the arctic shelf.