EAS100 Lecture Notes - Lecture 21: Antarctica, Cirque Glacier, Glacier Mass Balance

50 views2 pages

For unlimited access to Class Notes, a Class+ subscription is required.

November 5 2014
ESB 3-27
Components of Glacier Motion
Ice deformation
Glacier sliding
Sediment Deformation
= Total Motion
Antartica has ~300 subglacier lakes as a result of geo-thermal heating.
Surging glaciers
Water at the surface - not a result of surface melting - high pressures
raise the ground water all the way up so the glacier 'floats'
Water reaches the bed through several methods - cravasses, geo-thermal
melting
and upstream melt sources.
Pressure from subglacier water has an angled normal force which 'pushes'
the glacier down-slope.
With high pressure from glacier + sediments, the sediments break down and
also cause increased rate of movement.
Conditions of the glacier bed predomadate the characteristics of flow.
Water pressure changes
can find 'subglacier river systems'
daily fluctuations during the summer season (high at night, low in day)
increases gradually from low after summer, high by next summer.
Less sediment deformation when water pressures are high (glacier
'floats')
More sediment deformation when water pressure is low (glacier 'drags')
The cryosphere
Snow and glaciers
Distribution of snow
Annual snow line marks boundry of areas that have snow year-
round.
The snow line varies, Lower in polar areas where temperature is
cooler,
Lower in coastal areas where there is more moisture (= more snow)
Above the snow line, there are areas where snow accumulates to
Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

Already have an account? Log in

Get access

Grade+
$10 USD/m
Billed $120 USD annually
Homework Help
Class Notes
Textbook Notes
40 Verified Answers
Study Guides
1 Booster Class
Class+
$8 USD/m
Billed $96 USD annually
Homework Help
Class Notes
Textbook Notes
30 Verified Answers
Study Guides
1 Booster Class