Geomorphic evidence for present-day snow-avalanche and debris-flow impact in the Icelandic Westfjords

The geomorphic impact of present-day processes on slopes, with emphasis on the impact of snow avalanches and debris flows, is investigated in North-western Iceland. Data are obtained from topographical maps, aerial photographs and field survey, as well as from measurements of talus characteristics and estimates of the volumes of recent deposits. The impact of various kinds of snow avalanches (dry and wet slab avalanches and slush flows) that have occurred recently in the area is shown. The effects of avalanches, including material transport and avalanche boulder tongue development, and the resulting landforms are identified and analysed. The geomorphic significance of debris flows is also examined, their deposits described and erosional and depositional landforms (channels, levees and lobes) measured. The geomorphological impact in the Icelandic Westfords area is discussed in relation to research in other environments. Observations indicate that snow avalanches are locally significant but their impact on talus slopes and talus cones where there are also debris-flow deposits is moderate. In contrary debris-flow deposits are a strong geomorphic agent on slopes. (c) 2006 Elsevier B.V. All rights reserved.