A Glacial MS (glacier) is a zone where a huge amount of snow is
accumulated creating areas of permanet ice (areas of high lattitude or
altitude). This accumulation flows down, draging sediments, to areas with
higher temperature, where it melts.
There are different types:
- Alpine (mountain, valley) glacier: A glacier head (cirque) is formed in high altitude areas and the glacier flows downhill (like an ice river)
- Continental glacier (ice sheet): Large extensions of ice in high lattitude areas.
- Hanging glaciers: Similar to alpine glaciers but smaller, running at a different level and ending on a bigger one.
A mountain glacier has different parts:
- Cirque: wide place on the top where snow is accumulated
- Tongue: ice river that flows downhill
- Moraine: mass of rocks dragged by the ice in its way down the mountain. Moraines can be:
- Lateral. Formed on the sides of the glaciar.
- Rogen. Under the ice, in touch with the ground.
- Medial moraine. Union of lateral moraines in the confluence of two glaciers.
- End or terminal. It´s formed where the glacier melts
Some geological
effects associated to a glacier are:
- Crevasse: fracture zone in a glacier
- Serac: huge block or column of ice
The glacier shapes the land relief in several ways:
- Glacial erratic: piece of rock that differs from the size and type of rocks that are native to the area in which it rests
- Sheepback rock: result of the glacier erosion (abrasion) process
- Glacial till: piles of glacial deposits of different types
- Esker: Long, sinuous glacial deposits
- Drumlin: hill formed by the sediments draged by the glacial ice
- Tarn (ibón in the Pyrenees): lake formed in when the glacier finds a basin.
- Horn: mountain with a pyramidal shape eroded by different glaciers.
- Glacier valley: U-shaped valley with steep walls formed by glacial erosion.
- Hanging valleys: They are those that flow at a different height than the principal, and this one cut its walls.
- Fiord: glacier valley filled of sea water
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