Glacier morphology
From Wikipedia, the free encyclopedia
Glacier morphology, or the form a glacier takes, is influenced by temperature, precipitation, topography, and other factors. Types of glaciers range from massive ice sheets, such as the Greenland ice sheet or those in Antarctica, to small cirque glaciers perched on a mountain. Glaciers types can be grouped into two main categories, based on whether or not ice flow is constrained by the underlying bedrock topography.
[edit] Unconstrained
Ice sheets and ice caps cover vast areas and are unconstrained by the underlying topography. The main distinction between the two is area, with ice caps covering areas less than 50,000 square kilometers, while ice sheets span larger areas.[1]
Ice sheets and ice caps can be classified further, with ice domes located in the accumulation zone in the higher altitude portions. Ice streams rapidly channel ice flow out to the sea or ocean, where it may feed into an ice shelf. At the margin between ice and water, ice calving takes place, with icebergs breaking off.
[edit] Constrained
An icefield covers a relatively large area, usually located in mountainous terrain. Often, nunataks poke through the surface of icefields. Ice flow within icefields is influenced by the underlying bedrock topography. Valley glaciers and cirque glaciers are also constrained and influenced by topography.
[edit] References
- ^ Introduction to Glaciers. National Park Service.
