Vermicular Ridge Features on Dundas Harbour, Devon Island, Nunavut

Abstract

Conspicuous ridges with a circular, sinuous and anastomosing morphology, termed Vermicular Ridge Features (VRFs), have been observed along the coast of Dundas Harbour, Devon Island, Nunavut, Canada. Periglacial and glacial processes can produce morphologically similar ridge landforms, such as stone circles or ice disintegration features. However, VRFs are both morphologically and morphometrically distinct. We utilize aerial drone imagery, digital elevation models, grain size analysis, and field observations of VRFs to compare morphology, morphometry, environmental conditions and substrate characteristics to documented periglacial and glacial features with a circular to anastomosing ridge pattern. We interpret VRFs to be formed by paraglacial processes produced from the passive ablation of stagnant “dead” ice and subsequent deposition of supra- and englacial debris as a hummocky “ring-ridge” moraine. If these features are, in fact, ring-ridge moraines, then this is the first documentation of a ring-ridge moraine in Nunavut, Canada.