GLACIAL PROCESSES
AND LANDFORMS
1. Formation of glacier ice
2. Glacier motion and crevasse formation
3. Glacial erosion processes and landforms
4. Landforms of glacial deposition
5. “Eiszeit”: past climates and glacial periods
Present-day snowline
LGM snowline
Source: Broecker & Denton, 1990.
2 basic types of glaciers:
Continental glaciers (ice sheets)
Alpine glaciers
Cirque glaciers
Valley glaciers
The Antarctic ice sheet: a continental glacier.
Source: University of Tokyo.
The Antarctic ice sheet: under-ice topography.
Source: University of Tokyo.
2 basic types of glaciers:
Continental glaciers (ice sheets)
Alpine glaciers
Cirque glaciers
Valley glaciers
Cirque glaciers feeding a valley glacier:
the Mer de Glace, French Alps.
Another valley glacier: Aletschgletscher, Swiss Alps.
Accumulation zone
Equilibrium line
COLDER
Ablation zone
WARMER
Alpine glacier profile and mass
balance. Source: Christopherson, 2012, p. 495.
Mer de Glace,
French Alps.
Firn/equilibrium line
Global glacier retreat.
Source: Oerlemans.
Holgate Glacier, Alaska, 1909.
Source: National Snow and Ice Data Center glacier rephotography collection.
Holgate Glacier, Alaska, 2004.
Source: National Snow and Ice Data Center glacier rephotography collection.
McCall Glacier, Alaska, 1958.
Source: National Snow and Ice Data Center glacier rephotography collection.
McCall Glacier, Alaska, 2003.
Source: National Snow and Ice Data Center glacier rephotography collection.
Glacier movement processes. Source: Christopherson, 2012, p. 496.
Internal
flow in
glacier ice.
Crevasse patterns. Source; Clowes and Comfort, 1982.
The Western
Cwm, Khumbu
icefall and
Khumbu glacier,
Mount Everest
(Source: Joe Simpson,
Dark Shadows Falling)
Everest
Lhotse
Western
Cwm
Khumbu
Icefall
Khumbu
Glacier
Cirque glaciers feeding a valley glacier:
the Mer de Glace, French Alps.
Crevasses on the Mer de Glace, French Alps.
Crevasses on an outlet
glacier of Vatnajökull,
Iceland.
GLACIAL EROSION PROCESSES
1. Plucking
2. Abrasion
Effects of glacial
plucking: formation
of a roche
moutonnee,
Lembert Dome,
Yosemite, CA.
Source: Christopherson,
2012, p. 503.
V-shaped
valley
Effects of alpine glaciation:
preglacial. Source: Christopherson, 2012, p. 498.
Horn
Arête
Truncated
spurs
Effects of alpine glaciation:
glacial. Source: Christopherson, 2012, p. 498.
Cirque
Arête
Horn
Cirques
Hanging valley
Hanging waterfall
Effects of alpine glaciation:
postglacial. Source: Christopherson, 2012, p. 498.
U-shaped valley
Cwm Idwal, North Wales
(Source: Ogwen Valley Mountain Rescue)
Cwm Idwal, North Wales
(Source: Ogwen Valley Mountain Rescue)
Cirque- Helvellyn, Lake District, UK
AreteStriding Edge, Lake
District, UK
U-shaped valley (evidence of glacial erosion)
Hanging valley- Bridalveil Falls, Yosemite
Glacier retreat above Manang, Nepal
Lateral moraines
Pro-glacial lake
Terminal moraine
Glacial outwash: Kali Gandaki Valley, Nepal
Glacial outwash: Kali Gandaki Valley, Nepal
Glacial
depositional
features.
Source: Christopherson,
2012, p. 502.
North American ice cover, 18,000 BP. Source: Christopherson, 2012, p. 510.
North American ice cover, 9,000 BP. Source: Christopherson, 2012, p. 510.
Retreat of Laurentide ice sheet. Source: Christopherson, 2012, p. 511.
Retreat of Laurentide ice sheet. Source: Christopherson, 2012, p. 511.
Retreat of Laurentide ice sheet. Source: Christopherson, 2012, p. 511.
Retreat of Laurentide ice sheet. Source: Christopherson, 2012, p. 511.
Paleolakes in
the western US,
12-30,000 BP.
Source: Christopherson, 2012,
p. 512.
Lake Bonneville
Milankovitch cycles: cyclical wobbles in the
Earth’s orbit.
Source: Houghton, 2009, p. 86; see Christopherson, 2012, p. 516-517.