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• Found at high
• landbound ice in motion

 

• Cirque glacier -

• Valley glacier - fills

• Fjord glacier - occupies

 

 
• Piedmont glacier - broad bowl-shaped glacier

 

 
• Ice cap - covers a
• Rock glacier - composed of

Ice sheets (Continental) - continental-sized

• Ice shelves - mass of

General glacier classification based on relative T - controls

• Temperate (wet) glacier - at the higher pressure of the base of the glacier the temperature

1. characterized by a

• Polar (dry, cold) glacier - at the higher pressures of the base of the glacier

1. characterized by a

• glaciers are

 

 

 
• with burial,

 

 

Change in glacier size - Glacial Budget:

• matter of mass balance - if accumulation exceeds ablation

 

 
• generally activity at the terminus

 

 
• calving forms

Glacial Movement

• Ice moves and carries objects by

 

 
• Maximum velocities at the

 

 
• Typical rates of movement is a

 

 
• Glacier surge - unusually

 

 
 

Glaciation - the modification of the land surface by

Glacial erosion and sculpture - due to high viscosity and P of ice
 

Erosive  features (abrasion)	Glacial Striations	Scratches from rocks frozen in base of glacier
	Glacial grooves and polishing	Linear depressions or polish due to rocks and fine sand in base of glacier

 

Glaciated mountain landforms	Cirques	Bowl-like form caused by frost-wedging, plucking and abrasion
	Tarn	Small lake in a cirque
	Arete	Knife-like ridge that forms as 2 cirques erode headward
	Horn	Point that forms as >2 cirques erode headward
	Glacial Valleys (hanging valleys)	U-shaped valley formed from glacial erosion
	Fjords	Valley carved below sea level on the coast

 

Landforms from ice caps	Glacial striations	Scratches in rock that can indicate direction to center of ice cap
	Drumlins	Streamlined hill, gentle upstream, but steep downstream, depositional and erosional character

 

Transport by glaciers

• Load is

• Load tends to be concentrated along

• Much of the basal load is

Glacial Deposits

• Extremely efficient agent of

• Collectively called

• Generally

Ice-laid deposits

• Till - unsorted drift

1. Tillite - lithified till

• Glacial erratic - rock different from

 

 
• Moraine - deposits with form

 

Ground moraine - widespread drift

Terminal moraine - ridge-like accumulations at

Lateral moraine - ridge-like accumulations of     along

(100's feet high)

Medial moraine - ridge-like accumulation at

 

• Outwash - stratified sed deposited in
• Esker - sinous deposit of
•    due to

• Deposits with

1. Kame - small hill
2. Kettle - small basin

Louis Agassiz (1837) - hypothesis of continental glaciation - dramatic evidence for

Ice Age Glaciers

• During the Cenozoic the global climate has

 

 
• In the last few million years there are numerous

 

 
• 30,000 years ago

 

 
• 29% of the land

 

 
• lowering of

 

 
• deform the crust due

 

 
• earlier glaciations

1. deep sea records indicate
2. Early and late
3. Early and late\

• Little Ice Ages =

Interaction of atmosphere, earth, oceans, biosphere and sun

Glacier ages relate to

• Movement of continents

• Large scale

• Creation of mountains

• Opening/closing of

• The alternating glacial/interglacial periods

• Croll-Milankovitch theory - variation in

1. axis of rotation wabbles (23,000 year period)
2. tilt of axis (41,000 year period)
3. eccentricity of orbit (100,000 year period)

• more dust and less

1. greenhouse effects