The Thickness of Talus Deposits in the Periglacial Area of SW Spitsbergen (Fugleberget Mountainside) in the Light of Slope Development Theories

Abstract

Periglacial slopes are susceptible to recent climate change. The rate of morphogenetic processes depends on numerous factors. The most important of these is the warming of the air and ground, increased precipitation (extreme rainfall in particular), and the rate of snow cover decay. The dynamics of these processes may effectively modify contemporary slope development models. The paper shows the structure of selected talus slopes on a Fugleberget mountainside, based on field observations and radar (GPR) soundings. The results are then compared to classical slope models. The radar survey in April and May 2014 used a RAMAC CU II Malå GeoScience system equipped with a 30 MHz RTA antenna (Rough Terrain Antenna). Five GPR profiles of different lengths were obtained along the talus axes, transversally on Fugleberget and partly on the Hansbreen lateral moraine. According to the radar soundings, the maximum thickness of the debris deposits is 25–30 m. The thickness of the weathered material increases towards the talus cone’s terminal part, and debris deposits overlap marine sediments. The talus slopes’ morphometry shows that their current forms differ from standard slope models, which may be due to the significant acceleration of geomorphic processes resulting from climate change, including rapid warming in the last four decades.

Polish Polar Research

“…As a result of isostatic uplift, abrasion platforms with variably aged marine sediments were formed. These elevated structures have been largely transformed by erosion, as well as by colluvial accumulation and solifluction on the slopes (Pękala 1989;Dolnicki and Grabiec 2022). Isostatic uplift of terraces on Spitsbergen was irregular and also affected by local tectonic activity (Lindner et al 1986).…”

Conceptual model for talus slope development in Brattegg Valley (SW Spitsbergen) based on sedimentology of debris deposits in periglacial zone

“…Most of the modern observed forms began to develop during the last deglaciation (Ballantyne 2002). Thus, the oldest internal structures of these forms are post-Last Glacial Maximum or may date back to the beginning of the Holocene (Farnsworth et al 2020;Senderak et al 2021;Dolnicki and Grabiec 2022).…”