DEFINITION OF FORMATION OF GLACIERS

Glaciers form mainly by the accumulation and compaction of

snow and are deformed by flow under the influence of gravity.

When snow falls it is very porous, and with time the pore

spaces close by precipitation and compaction. When snow

first falls, it has a density about 1/10 that of ice; after a year

or more, the density is transitional between snow and ice,

and it is called firn. After several years, the ice has a density

of 0.9 g/cm3, and it flows under the force of gravity. At this

point, glaciers are considered to be metamorphic rocks, composed

of the mineral ice.

The mass and volume of glaciers are constantly changing

in response to the seasons and to global climate changes. The

mass balance of a glacier is determined by the relative

amounts of accumulation and ablation (mass loss through

melting and evaporation or calving). Some years see a mass

gain leading to glacial advance, whereas some periods have a

mass loss and a glacial retreat (the glacial front or terminus

shows these effects).

Glaciers have two main zones, best observed at the end

of the summer ablation period. The zone of accumulation is

found in the upper parts of the glacier and is still covered by

the remnants of the previous winter’s snow. The zone of ablation

is below this and is characterized by older dirtier ice,

from which the previous winter’s snow has melted. An equilibrium

line, marked by where the amount of new snow

exactly equals the amount that melts that year separates these

two zones.

Title Post:
Rating: 100% based on 99998 ratings. 99 user reviews.
Author:

Terimakasih sudah berkunjung di blog SELAPUTS, Jika ada kritik dan saran silahkan tinggalkan komentar