Three conditions are necessary to form a glacier: (1)
Cold local climate (polar latitudes or high elevation)
. (2) snow must be abundant; more snow must fall than melts, and (3) snow must not be removed by avalanches or wind.
What are the two basic types of glaciers and where are they found?
The two basic types of glaciers are
Valley Glaciers
(found in valleys that were once streams) and Ice Sheets (found on large regions of land).
What are the two general categories of glaciers?
Glaciers are often called “rivers of ice.” Glaciers fall into two groups:
alpine glaciers and ice sheets
. Alpine glaciers form on mountainsides and move downward through valleys. Sometimes, alpine glaciers create or deepen valleys by pushing dirt, soil, and other materials out of their way.
What is the criteria for a glacier?
While there is no global standard for what size a body of ice must be to be considered a glacier, USGS scientists in Glacier National Park use the commonly accepted guideline of
0.1 square kilometers (about 25 acres)
as the minimum size of a glacier.
What are the two basic types of glacial ice movement?
The two types of glaciers are:
continental and alpine
. Continental glaciers are large ice sheets that cover relatively flat ground. These glaciers flow outward from where the greatest amount of snow and ice accumulate. Alpine or valley glaciers flow downhill through mountains along existing valleys.
What are the 4 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 is the largest type of glacier?
The largest type of glacier is
a continental ice sheet
. The definition of an ice sheet is a glacier that covers an area of over 50,000km2. These glaciers are so thick they completely conceal topographical features like mountains and valleys.
What is the smallest type of glacier?
- Cirque. smallest type of glacier; forms in small bowl-like depressions in the mountains; also called alpine glaciers.
- Valley. …
- Piedmont. …
- Ice Fields. …
- Ice Sheets. …
- Outlet. …
- Tidewater. …
- Ice Streams.
What are three zones of a glacier?
During movement there are three parts of the glacier:
The zone of basal sliding; the zone of plastic flow; and the rigid zone
. The rigid zone is brittle and sometimes is broken into crevasses. Ice sheets move with these three zones but often spread laterally rather than flow downslope.
Are glaciers found in mountains?
Most of the world’s glacial ice is found in Antarctica and Greenland, but glaciers are found on nearly every continent, even Africa. This is why most glaciers are
found either in mountainous areas or the polar regions
. …
What are the 3 main criteria for being a glacier?
Three conditions are necessary to form a glacier: (1) Cold local climate (polar latitudes or high elevation).
(2) snow must be abundant
; more snow must fall than melts, and (3) snow must not be removed by avalanches or wind.
What might make a glacier speed up or slow down?
Gravity
is the cause of glacier motion; the ice slowly flows and deforms (changes) in response to gravity. A glacier molds itself to the land and also molds the land as it creeps down the valley. Many glaciers slide on their beds, which enables them to move faster.
Where is Earth’s largest glacier?
The largest glacier in the world is the Lambert
-Fisher Glacier in Antarctica
. At 400 kilometers (250 miles) long, and up to 100 kilometers (60 miles) wide, this ice stream alone drains about 8 percent of the Antarctic Ice Sheet.
What are the two main processes by which glaciers move?
Glaciers move by a combination of
(1) deformation of the ice itself and (2) motion at the glacier base
. At the bottom of the glacier, ice can slide over bedrock or shear subglacial sediments.
What is snow that survives one melt season called?
In polar and high-altitude alpine regions, glaciers generally accumulate more snow in the winter than they lose in the summer from melting, evaporation, or calving. If the accumulated snow survives one melt season, it forms a denser, more compressed layer called
firn
.
What glaciers leave behind?
Later, when the glaciers retreated leaving behind their freight of crushed rock and sand (glacial drift), they created characteristic depositional landforms. Examples include
glacial moraines, eskers, and kames
. Drumlins and ribbed moraines are also landforms left behind by retreating glaciers.
