Formation of Glaciers

Glaciers form in areas where the accumulation of snow exceeds its melting and sublimation over many years. The weight of overlying snow compacts the lower layers into ice, creating a glacier.

Movement of Glaciers

Glaciers move due to the force of gravity. The ice at the base of the glacier is under pressure, causing it to deform and flow like a thick fluid. This movement can erode the land beneath the glacier and carry sediment along with it.

Erosional Features

Glaciers have a significant impact on the landscape through erosion. Some of the notable erosional features created by glaciers include:

U-shaped valleys: Glaciers widen and deepen existing V-shaped valleys into U-shaped valleys through the process of plucking and abrasion.
Glacial striations: These are scratches or grooves on bedrock caused by the movement of rocks and sediment at the base of the glacier.
Glacial cirques: These are amphitheater-like hollows formed at the head of a glacier due to erosion.
Arêtes and horns: These are sharp ridges and peaks formed by the erosion of multiple glaciers flowing in different directions.

Depositional Features

Glaciers also deposit sediments as they melt and retreat. Some of the depositional features associated with glacial activity include:

Moraines: These are ridges of till (unsorted and unstratified rock material) deposited by a glacier.
Drumlins: These are elongated hills formed by the deposition of glacial till, often indicating the direction of glacial flow.
Erratics: Large boulders that were transported and deposited by glaciers, often in areas with different underlying rock types.
Eskers: Long, winding ridges of sand and gravel deposited by streams flowing in tunnels within or beneath a glacier.

Effects of Glacial Activity

The effects of glacial activity are far-reaching and have contributed to shaping the Earth's surface over millions of years. Glacial erosion and deposition have created some of the most iconic landscapes on the planet, from fjords and coastal cliffs to vast plains and rolling hills.