A polynya that forms from strong winds in a persistent direction that push the ice away from a barrier (the coast, fast ice, a grounded iceberg, or an ice shelf).
Lateral moraines are piles of loose unsorted rocks along the side margins of the glacier. The rocks may be pushed there by the moving ice or dumped from the glacier's rounded surface. As glaciers melt
, their remaining load of rocks is distributed in several ways. Rocks may be dropped in place by the melting ice; they may be rolled to the ice margins, or they may be deposited by meltwater streams. Collectively, these deposits are called 'glacial drift'. 'Till' refers to the debris deposited directly by the glacier. Rock debris rolls off the glacier edges and builds piles of loose unconsolidated rocks called 'glacier moraine'. 'Lateral moraines' form along the side of a glacier and curl into a 'terminal moraine' at the glacier's downvalley end. Drift and moraines are valuable to geologists because they outline the boundaries of past glaciations.
A sediment ridge, located on a glacier's surface adjacent to the valley walls, extending down glacier to the terminus. It forms by the accumulation of rock material falling onto the glacier from the v
alley wall, rather than by water deposition. Debris deposited along the side of a glacier, comprising both rockfall debris from above and debris ground up by ice-marginal processes.