Logistics

1
Logistics

• Tutoring, anyone?
• ESCI111, ESCI112, GEOL102
• A preferred, B required
• Signup for final presentation
• Field trip?
• April 28/29 (May 5/6?)
• Local or plains?
• You MUST let me know what your facilitation plans
  are a day ahead!

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An Intro to Glacial Systems

• Present vs. past glaciation
• Glacier classification
• Glaciers and time
• Glaciers as systems
• Open vs. closed
• Energy fluxes and reservoirs
• Mass fluxes and reservoirs

3
Present vs. Past Glaciation

• Now One major (Antarctica) and one minor
  (Greenland) ice sheets
• Then - At least three major (Antarctica,
  Laurentide, Fennoscandian) and several minor
  (Greenland, Cordilleran, Patagonian ice sheets

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Present vs. PastPresent Past

• Antarctica 12,535,000 km2
• Greenland 1,726,400
• Laurentide - 147,250
• Fennoscandia - 3,800
• Rockies/AK 76,900
• Asia 115,000
• Alps 3,600
• S. America 26,500
• Australasia 1,000
• TOTAL 14,898,000

• 13,800,000
• 2,295,300
• 13,337,000
• 6,666,700
• 2,610,100
• 3,951,000
• 37,000
• 870,000
• 30,000
• 44,383,000

(After Flint, 1971)
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What do we know?

• S. Laurentide
• S. and E. Fennoscandian
• Atlantic shelvesnot
• Russia
• Cordillera
• N. Canada

X
X
X
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Glacier Classification Ice Sheets

• Ice Sheets Subcontinental in scale
• Dictate their own topography

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Ice Caps

• Ice Caps
• Local to regional in scale
• Dictate their own topography

8
Ice Caps
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Glaciers

• Variable in scale
• Controlled by existing topography

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Glacier Types

• Valley glaciers
• Lengthgtgtwidth
• Cirque glaciers
• Length width

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Glacier Types

• Niche glaciers
• Lengthltltwidth

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Ice Shelves

• Floating termini
• Nourished from upice and above
• Ablate by basal melt and calving

13
Subspecies of Glaciers - Outlet

• Outlet glacier (from ice cap or sheet)

14
Ice Fields

• Transection glacier (ice field)
• Radial flow, but topographically confined

15
Piedmont

• Piedmont glacier (unconfined at the toe)

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Piedmont
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Adjectives

• Calving
• Hanging

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Glacier Response Times

• All glaciers are, by definition, permanent.
• Each respond to climate across characteristic
  timescales.
• Ice sheets X000 years
• Ice caps X00 years
• Glaciers X0 years
• Glacierets X years

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Glaciers as Systems

• Best viewed as an open system
• Mass and energy in
• Radiation, rockfall snow
• Movement and work
• Erosion, transport, deposition
• Mass and energy out
• Long-wave radiation till, meltwater

INPUTS
OUTPUTS
Atmosphere
Atmosphere
GLACIER
Lithosphere
Lithosphere
Hydrosphere
Hydrosphere
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Glacier Systems

• IceSheets
• Glaciers