A Snow-bank Push Mechanism for the Formation of Some “Annual” Moraine Ridges

Abstract

Ice-marginal features in South Georgia include minor moraine ridges running approximately parallel to the ice margin and developed as superficial forms in various depths of till. It is suggested that these developed as ice-contact landforms, some being created by the interaction of the ice edge and abutting marginal snow bank, whilst the glacier is advancing. This advance is essentially short-term, being part of a seasonal variation in the position of the ice margin. “Snow-bank push” is the term proposed to describe this mechanism of ridge formation.

Depositional history of the North Taymyr ice‐marginal zone, Siberia—a landsystem approach

“…The northern side of the cuesta is today occupied by perennial snowfields and it is likely that these expanded during colder periods. Thus, the position of the moraine may in this case reflect where the ice sheet and the snowfield interacted, and the moraine formation can be similar to the 'snow-bank push' mechanism suggested by Birnie (1977) for annual moraines, although on a slightly larger scale.…”

Annual Moraine Ridges at Skàlafellsjökull, South-East Iceland

“…3); 2. At the distal edge of a marginal snowbank, a situation similar to that described by Birnie (1977) (Fi g.4); 3. Along the shore of a pro-glacial lake, where the ridge appeared to have formed in relationship to a winte r lake-i ce cover which may have been pushed forward by the glacier; and 4.…”

Observations on terminal moraine-ridge formation during recent advances of southern Norwegian glaciers

“…At the glacier margins, the glacier sole was free of basal debris at all times. During the early 1990s, a snow-foot push mechanism (sensu Birnie, 1977) was observed in some years, but not during the culmination of the advance around 2000.…”

“…In some years, a snow-foot push mechanism, as described by Birnie (1977) with marginal snow banks acting as an obstacle, took place at the Jostedalsbreen outlets. The fact that this mechanism occurred only during the early 1990s can be explained by meteorological data combined with the low altitude of the glaciers (Chinn et al, 2005;Winkler et al, 2009).…”