Glaciers shape the land through processes of erosion , weathering , transportation and deposition , creating distinct landforms.
What is glaciation all about?
Glaciers are made up of fallen snow that, over many years, compresses into large, thickened ice masses . Glaciers form when snow remains in one location long enough to transform into ice. ... Due to sheer mass, glaciers flow like very slow rivers.
What is glaciation in geography?
Glaciation is the formation, movement and recession of glaciers . Glaciation was much more extensive in the past, when much of the world was covered in large, continental ice sheets. ... Most of this area is under two ice sheets situated near the Earth's poles — one near the Antarctic and the other near Greenland.
What is glacial process and landforms?
As the glaciers expand, due to their accumulating weight of snow and ice they crush and abrade and scour surfaces such as rocks and bedrock. The resulting erosional landforms include striations, cirques, glacial horns , arêtes, trim lines, U-shaped valleys, roches moutonnées, overdeepenings and hanging valleys.
How does glaciation occur?
Glaciers begin forming in places where more snow piles up each year than melts . Soon after falling, the snow begins to compress, or become denser and tightly packed. It slowly changes from light, fluffy crystals to hard, round ice pellets. New snow falls and buries this granular snow.
What are 2 types of glaciers?
- Ice Sheets. Ice sheets are continental-scale bodies of ice. ...
- Ice Fields and Ice Caps. Ice fields and ice caps are smaller than ice sheets (less than 50,000 sq. ...
- Cirque and Alpine Glaciers. ...
- Valley and Piedmont Glaciers. ...
- Tidewater and Freshwater Glaciers. ...
- Rock Glaciers.
What are the effects of glaciation?
A glacier's weight, combined with its gradual movement, can drastically reshape the landscape over hundreds or even thousands of years . The ice erodes the land surface and carries the broken rocks and soil debris far from their original places, resulting in some interesting glacial landforms.
What is a glaciation mean?
The condition of being covered with glaciers or masses of ice ; the result of glacial action; Agassiz recognized marks of glaciation all over northern Europe. The process of covering the earth with glaciers or masses of ice.
Why are glaciers freshwater?
Icebergs form as a result of two main processes, producing a freshwater iceberg: Ice that forms from freezing seawater typically freezes slowly enough that it forms crystalline water (ice), which does not have room for salt inclusions. ... The glacier is made from compacted snow , which is freshwater.
What causes snowflakes to get closer to each other?
The weight of the overlying layers compacts the snow surrounding the flake , causing these flakes to nestle closer to one another. ... As the snow accumulates, the ice crystals surrounding the flake become more compressed and the air spaces between the crystals shrink.
What are 2 types of glacial erosion?
- Abrasion – as the glacier moves downhill, rocks that have been frozen into the base and sides of the glacier scrape the rock beneath. ...
- Plucking – rocks become frozen into the bottom and sides of the glacier.
What are 3 main types of glacial erosion?
Processes of Glacial Erosion
Glacial erosion involves the removal and transport of bedrock or sediment by three main processes: quarrying (also known as plucking), abrasion, and melt water erosion .
What is glacial action?
All processes due to the agency of glacier ice , such as erosion, transportation, and deposition. The term sometimes includes the action of meltwater streams derived from the ice.
What is glaciation evidence?
The most apparent evidence is of course the glacial drift itself . ... Glacial drift refers to the rock material ground up and transported by a glacier and deposited by or from the ice (till) or in water derived from the melting of ice (outwash or lake sediment).
How is till formed?
Till is derived from the erosion and entrainment of material by the moving ice of a glacier . It is deposited some distance down-ice to form terminal, lateral, medial and ground moraines.
What are some signs of glaciation in an area?
- U-Shaped Valleys, Fjords, and Hanging Valleys. Glaciers carve a set of distinctive, steep-walled, flat-bottomed valleys. ...
- Cirques. ...
- Nunataks, Arêtes, and Horns. ...
- Lateral and Medial Moraines. ...
- Terminal and Recessional Moraines. ...
- Glacial Till and Glacial Flour. ...
- Glacial Erratics. ...
- Glacial Striations.
