Some observations on the formation of an active pronival rampart at Grunehogna Peaks, Western Dronning Maud Land, Antarctica

• Published in: Permafrost and Periglacial Processes
• Main Authors: Hedding, D.W. (David William), Meiklejohn, K.I. (Ian), Le Roux, J.J. (Jacobus Johannes), Loubser, M.J. (Michael John), Davis, Jacqueline K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-Blackwell 2010
• Subjects: Pronival rampart; Protalus rampart; Debris transport; Firn field; Fossil ramparts; Slopes (Physical geography) > Antarctica; Dronning Maud Land; Grunehogna; Grunehogna Peaks; Antarc*; Antarctica; Permafrost and Periglacial Processes
• Online Access: http://hdl.handle.net/2263/15951; https://doi.org/10.1002/ppp.698

Summer observations of the morphology and the debris accumulation processes at an actively forming pronival rampart at Grunehogna Peaks, Western Dronning Maud Land, Antarctica demonstrate that rockfall debris accumulation is causing downslope (outward) rampart extension even though the distal slope is not at the angle of repose. Field experiments show that the vast majority of rocks can traverse a stable firn surface to reach the proximal slope of the rampart and more than half end up on the distal slope or beyond. The formation processes indicate that the morphological characteristics and environmental conditions under which such features develop may be more varied than conceived in current models. Consequently, caution must be employed when fossil ramparts are used to infer palaeo-environmental conditions. The Department of Environmental Affairs and Tourism and the National Research Foundation are gratefully acknowledged for logistical and financial support.