No abstract

The location of Svalbard at the interface between the warm Atlantic and cold Arctic oceans causes the terrestrial environment to be highly sensitive to contemporary climate warming. Talus slopes provide a component of glaciated areas that has been registering these changes on a scale of several thousand years. However, knowledge about their development during glacial recession is still limited. This paper fills this gap by providing unique data obtained by geophysical methods: electrical resistivity tomography (ERT) and ground-penetrating radar (GPR), regarding the talus slopes in Revdalen (SW Spitsbergen), which was last glaciated in the Neoglacial period. The results indicate that the thickness of talus slopes depends first of all on the size of the sediment supply area and only secondarily on the stage of development. The initial content of buried glacial ice in the talus deposits is differential and depends on both the rate of deglaciation and the local intensity of rock wall denudation. Over time, as a result of creep, the presence of massive ice is limited to ever lower parts of the slope. Above, there is aggradation of pore ice in delivered debris material. At the end of this stage, the buried glacial ice can form, or co-create together with pore ice, the core of subslope rock glaciers. The relatively long period since the beginning of the Revdalen deglaciation allowed a general model of the development of talus slopes in the polar environment to be prepared.

Talus slopes are a common sedimentary formation both in polar and high-mountain areas, but their development is still not sufficiently understood. This article discusses the environmental factors that have been influencing development of talus slopes since the deglaciation and their impact on the internal structure of slopes. Case studies of the slopes from SW Spitsbergen and the Tatra Mountains in Poland were compared in order to explore different evolution stages. Slopes’ structure was analysed using geophysical surveys based on two-dimensional electrical resistivity tomography (ERT) with a Wenner-Schlumberger array and an electrode spacing of 5 m, combined with geomorphological observations. The investigated talus slopes represent the paraglacial, periglacial and talus-alluvial environments. New data on the internal structure of talus slopes developing in the present or past glaciated areas adds to understanding talus slope evolution. There are many different views concerning the development of slopes during the paraglacial period, whose analysis seems to be crucial in the background of climate change and their record in slope structures. In addition, the study provided valuable information on the development and degradation of permafrost in slope materials.