Table of Contents
What is ridge in glacier?
A ridge or pile of unstratified glacial sediment that is formed in front of the ice margin by the terminus of an advancing glacier, bulldozing sediment in its path.
What are serrated ridges?
A horn results when glaciers erode three or more arêtes, usually forming a sharp-edged peak. The divides between Cirque side walls or headwalls get narrow because of progressive erosion and turn into serrated or saw-toothed ridges sometimes referred to as aretes with very sharp crest and a zig-zag outline.
What does an arête look like?
An arête is a thin, jagged crest that separates—or that once separated—two adjacent glaciers. These rugged ridgelines often look like serrated knives or saw blades, with steep sides and a sharp crest. The low points on the serated surface are known as cols.
Are aretes Continental or Alpine?
arête, (French: “ridge”), in geology, a sharp-crested serrate ridge separating the heads of opposing valleys (cirques) that formerly were occupied by Alpine glaciers. It has steep sides formed by the collapse of unsupported rock, undercut by continual freezing and thawing (glacial sapping; see cirque).
What are holes left by glaciers called?
A kettle (also known as a kettle lake, kettle hole, or pothole) is a depression/hole in an outwash plain formed by retreating glaciers or draining floodwaters. The ice becomes buried in the sediment and when the ice melts, a depression is left called a kettle hole, creating a dimpled appearance on the outwash plain.
What is a corrie and tarn?
Corries form in hollows where snow can accumulate. When ice in a corrie melts, a circular lake is often formed at the bottom of the hollow. This is known as a tarn, eg Red Tarn on the eastern flank of Helvellyn (see left).
What causes arête?
An arête is a knife-edge ridge . It is formed when two neighbouring corries run back to back. As each glacier erodes either side of the ridge, the edge becomes steeper and the ridge becomes narrower. Glaciers erode backwards towards each other, carving out the rocks by plucking and abrasion.