Answer: Masses of ice moving as sheets over the land or as linear flows down the slopes of mountains in broad trough-like valleys are called glaciers. They are formed through the processes of accumulation, compaction, and recrystallization of snow. The movement of a glacier is very slow and it moves from a few centimeters to a few meters in a day. During this movement, a glacier forms various landforms. Erosional landforms created by the movement of a glacier are the following:

• Glacial Valleys/Troughs: Glaciated valleys are trough-like and U-shaped with broad floors and relatively smooth, and steep sides.
• Cirque: These are bowl-shaped depressions found at the head of glacial valleys. For most alpine glaciers, cirques are the areas where snow first accumulated and was modified into glacial ice. A lake found in a cirque is called a tarn.
• Horns: These are pyramidal peaks that form when several cirques chisel a mountain from three or more sides. The highest peaks of the Alps (Matterhorn) and the Himalayas (Everest) are in fact horns formed through headward erosion of radiating cirques.
• Arete: These are formed as a spiky high land between two glaciers.
• Valley step: It is an abrupt change in the longitudinal slope of a glacial valley.
• Bergschrund: These form when a crevasse or wide crack opens along the headwall of a glacier; most visible in the summer when covering snow is gone.

Depositional landforms created by the movement of glaciers include:

• Till deposits: The unassorted coarse and fine debris dropped by the melting glaciers is called glacial till. Most of the rock fragments in the till are angular to subangular in form.
• Outwash plains: Streams form by melting ice at the bottom, sides, or lower ends of glaciers. Some amount of rock debris small enough to be carried by such melt-water streams is washed down and deposited. Such glaciofluvial deposits are called outwash plains.
• Moraines: They are long ridges of deposits of glacial till. Based on their orientation with the glacier, they are termed terminal moraines, lateral moraines, horse-shoe-shaped ridge, ground moraines, and medial moraines.
• Eskers: These are sinuous ridges formed as a result of the melting of ice. During summers, the water accumulates beneath the glacier and flows like streams in a channel beneath the ice. This causes very coarse materials like boulders and blocks along with some minor fractions of rock debris carried into these streams and settle in the valley of ice beneath the glacier giving rise to eskers.
• Drumlins: Drumlins are smooth oval-shaped ridge-like features composed mainly of glacial till with some masses of gravel and sand.