Effects of rock avalanches on glacier behaviour and moraine formation

Reznichenko, Natalya V., Davies, Tim R. H. and Alexander, David J. (2011) Effects of rock avalanches on glacier behaviour and moraine formation. Geomorphology, 132 3-4: 327-338. doi:10.1016/j.geomorph.2011.05.019

Author Reznichenko, Natalya V.
Davies, Tim R. H.
Alexander, David J.
Title Effects of rock avalanches on glacier behaviour and moraine formation
Journal name Geomorphology   Check publisher's open access policy
ISSN 0169-555X
Publication date 2011-09-15
Sub-type Article (original research)
DOI 10.1016/j.geomorph.2011.05.019
Volume 132
Issue 3-4
Start page 327
End page 338
Total pages 12
Place of publication Amsterdam, Netherlands
Publisher Elsevier
Collection year 2012
Language eng
Formatted abstract
Abstract: Although large rock avalanches are infrequent, sediment production in active orogens is dominated by such events, which may strongly influence geomorphic processes. Where rock avalanches fall onto glaciers, they may affect glacier behaviour and moraine formation. We outline the processes of rock avalanche initiation and motion, and show that supraglacial deposits of rock avalanche debris have distinct sedimentological and thermal properties. Laboratory experiments on the effects of such debris on ice ablation are supplemented by field data from two rock avalanches in the Southern Alps, New Zealand. Their effects are compared with those of the thinner supraglacial debris that results from small rockfalls and melt-out of englacial debris. Implications of rock–avalanche debris cover for glacier behaviour are explored using a mass-balance model of the Franz Josef Glacier in New Zealand, demonstrating a likely supraglacial rock avalanche origin for the Waiho Loop moraine, and considering the potential hazard of a large rock avalanche onto the present-day glacier.

Highlights: ► We summarised the knowledge of rock avalanche initiation and runout onto glaciers. ► The rock avalanches effect on ice-surface ablation is compared with melt-out debris. ► These effects are studied on two modern rock avalanches on glaciers, Southern Alps. ► Resultant effects on glacier mass balance, its dynamic and deposition are determined. ► The Franz Josef Glacier used as an example of hazard and paleoclimatic implications.
Keyword Rock avalanches
Supraglacial debris
Ice-surface ablation
Glacier advances
Terminal moraines
Paleoclimatology and hazards
Central Southern Alps
Debris layer
Karakoram Himalaya
Catastrophic landslides
Balance model
Denali fault
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Geography, Planning and Environmental Management Publications
Official 2012 Collection
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Citation counts: TR Web of Science Citation Count  Cited 25 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 30 times in Scopus Article | Citations
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