Formation, Meltout Processes and Landscape Alteration of High-Arctic Ice-Cored Moraines-Examples From Nordenskiold Land, Central Spitsbergen

• Published in: Polar geography (1995) Vol. 29; no. 3; pp. 157 - 187
• Main Authors: Lukas, Sven, Nicholson, Lindsey I., Ross, Fionna H., Humlum, Ole
• Format: Journal Article
• Language: English
• Published: Palm Beach, FL Taylor & Francis Group 01.07.2005; Winston
• Subjects: Arctic; Bgi / Prodig; Polar regions; Scandinavian arctic; Spitsbergen; Svalbard; Arctic Region; Degradation; Sedimentology; Moraine; Debris flow; Geomorphology; Glacier; Landform evolution
• ISSN: 1088-937X; 1939-0513
• DOI: 10.1080/789610198

The debris-covered ice-margins of three largely cold-based glaciers in central Spitsbergen were investigated to reconstruct their formation and degradation. Clast shapes indicate dominant englacial and supraglacial transport with a smaller subglacial component. Emplacement of material is inferred to have been through meltout along flowlines due to the relatively uniform and continuous debris cover along the glacier margins; no evidence of thrusting has been found. Degradation of all three belts is rapid and involves debris flows at unstable places-e.g., the margins of meltwater channels. Resultant exposure of underlying ice initiates or accelerates melting, thereby leading to further debris flows. Hence, once degradation starts, a self-reinforcing cycle that removes material from the glacier commences. Landform preservation potential on millennial time scales in a high-arctic, continuous permafrost environment is thus limited. This work has implications for the interpretation of Pleistocene landform associations that use modern analogues from Svalbard.