Landslide-glacier interaction in a neoparaglacial setting at tverrbytnede, jotunheimen, Southern Norway

Owen, Geraint; Hiemstra, John F.; Matthews, John A.; Mcewen, Lindsey J.

Abstract

A tongue-like, boulder-dominated deposit in Tverrbytnede, upper Visdalen, Jotunheimen, southern Norway, is interpreted as the product of a rock avalanche (landslide) due to its angular to subangular boulders, surface morphology with longitudinal ridges, down-feature coarsening, and cross-cutting relationship to 'Little Ice Age' moraines. The rock avalanche fell onto glacier ice, probably channelled along a furrow between two glaciers, and stopped on the glacier foreland, resulting in its elongated shape and long runout distance. Its distal margin may have become remobilized as a rock glacier, but a rock glacier origin for the entire landform is discounted due to lack of source debris, presence of matrix, lack of transverse ridges, and sparcity of melt-out collapse pits. Lichenometric dating of the deposit indicates an approximate emplacement age of ad 1900. Analysis highlights the interaction of rock-slope failures and glaciers during deglacierization in a neoparaglacial setting, with reduced slope stability due to debuttressing and permafrost degradation, and enhanced landslide mobility due to flow over a glacier and topographic channelling. Implications for the differentiation of relict landslides, moraines and rock glaciers are discussed and interrelationships between these landforms are considered in terms of an ice-debris process continuum. © The authors 2010 Geografiska Annaler: Series A © 2010 Swedish Society for Anthropology and Geography.

• Journal Article Type: Article
• Publication Date: Dec 1, 2010
• Journal: Geografiska Annaler, Series A: Physical Geography
• Print ISSN: 1468-0459
• Publisher: Taylor & Francis
• Peer Reviewed: Peer Reviewed
• Volume: 92
• Issue: 4
• Pages: 421-436
• DOI: https://doi.org/10.1111/j.1468-0459.2010.00405.x
• Keywords: holocene, landslides, landslide-glacier interaction,; neoparaglacial, Norway
• Public URL: https://uwe-repository.worktribe.com/output/972911