Abstract The Canadian Beaufort Sea extends from offshore Banks Island to 141 °W longitude (Fig. 1). It is rimmed to the south by the Yukon Coastal Plain, the outer Mackenzie Delta, including Richards Island, and Tuktoyaktuk Peninsula. The narrow coastal plain of northern Yukon is bounded to the south by the British Mountains and the Porcupine Plateau (Fig. 1). The broad Amundsen Gulf separates the Anderson and Horton plains of the Northwest Territories mainland from Banks Island and Victoria Island. The continental margin beneath the Beaufort Sea can be divided into several physiographic regions. The shallow-water shelf is 50–100 km wide and is characterized by low, uniform slope gradients of 1–2 m/km. An abrupt increase in the sea-floor slope gradient marks the shelf edge. Water depths at the shelf break vary from 60 m near 141°W to almost 500 m west of Banks Island. Two channel-like features cut across the Beaufort shelf. Northeast of Herschel Island, the Mackenzie Trough (formerly Mackenzie Canyon) cuts obliquely across the shelf in a northwesterly direction (Fig. 1). Southwest of Banks Island, the broad Amundsen Gulf channel cuts across the shelf in a northwesterly direction. Both of these bathymetric troughs are 100–500 m deep and are geologically recent in origin. The continental slope seaward of the shelf edge is 20–50 km wide and is characterized by variable slope gradients of 5–30 m/km. The outer continental slope north of the Mackenzie Trough is marked by a steep, sea-floor escarpment with local slope gradients of up to 170 m/km (Fig. 1)