Morphometry and morphology of fan-shaped landforms in the high-Arctic settings of central Spitsbergen, Svalbard

Abstract

In this study, the distribution, morphometry and morphology of alluvial fans and colluvial cones were investigated in a high-Arctic, periglacial environment. The main aims were to present their surface morphology types, analyse the relationship between the morphometric properties of fans and their catchments, and to investigate potential factors controlling the morphometry of fans. Data from a set of 297 fan-shaped landforms in central Spitsbergen, Svalbard, were presented and analysed to ascertain factors likely to influence their distribution and character. First, based on the dominant morphological processes, the studied landforms were divided into three groups: fluvial-flow-dominated fans, debris-flow-dominated fans, and colluvial fans. Then, to analyse the relationship between fans and their catchments, 20 variables were investigated. Those analyses indicate that small catchments, characterised by a low relief and high Melton's R number, tend to produce small and steep fans. This tendency was most visible for colluvial fans and debris-flow-dominated fans but less so for fluvial-flow-dominated fans. The latter tend to adjust stronger to the local topography. However, in all cases, these associations were weaker than in morphometry studies based on data from other climatic settings. The most important controls on the distribution of the studied fan-shaped landforms seem to be the availability of accommodation space (related to deglaciation time) and local erosion base level.