Ice-sheet related landforms at the continental shelf edge, Albatross Bank, Alaska

Abstract

Albatross Bank is a flat glaciated bedrock bank (Fig. 1a) located on the distal edge of the Alaskan continental shelf south of Kodiak Island (Fig. 1b). The bank illustrates the glacial geomorphology from an active ice edge during Marine Isotopic Stage (MIS) 2 ( c. 22–19 ka) sea-level regression (Briner & Kaufman 2008). The multibeam echo-sounder (MBES) images presented here provide the first detailed morphological evidence that the furthest extent of glacial advance in the late Pleistocene reached the shelf edge of the Gulf of Alaska. Other disparate areas of MBES imagery from the distal edge of the SE Alaska shelf to the western part of the Gulf of Alaska show evidence of glacial advance to the shelf break and support earlier depictions of Wisconsinan glaciation (Kaufman & Manley 2004; Briner & Kaufman 2008). Fig. 1. Multibeam swath bathymetry and bathymetric profiles of glacial features on Albatross Bank, Alaskan continental shelf. ( a ) Sun-illuminated multibeam-bathymetric image showing a band of seafloor iceberg ploughmarks (red inset, box f), bedrock outcrops and subglacial meltwater channels (red inset, box c). Acquisition system Reason SeaBat 8111. Frequency 100 kHz. Grid-cell size c. 10 m. ( b ) Location of study …