Glaciers
Essential Points
• Glaciers are flowing streams of ice
• Glaciers have a zone of accumulation where snowfall
exceeds losses (ablation)
• Accumulation can be due to high altitude (mountain
glaciers) or cold climate (continental glaciers)
• Glaciers have a zone of ablation where losses exceed
snowfall
• Glaciers are governed by a balance of snowfall, ice flow,
and ablation
• Glaciers retreat by melting back, not by retracting
• Glaciers produce distinctive landforms and small scale
features
Snowfall vs Melting &
Evaporation (Ablation)
Zone of Accumulation
• Mountain
• Continental (Greenland, Antarctica
Zone of Melting or Ablation
Terminus of Glacier
• Ablation = Accumulation+ Flow
Small Glacier, Antarctica
Anatomy of a Glacier
A Typical Glacial Advance and
Retreat
Mountain
Glacier
Landforms
Glacial Valley, Yosemite, California
Cirque, Oregon
Cirques, Colorado
The Mother of All Cirques, Mount Everest
Glaciated Landscape, Sierra Nevada
What it May Have Looked Like
Glacier,
Antarctica
Moraines, Colorado
Moraine, Washington
Glacier and Moraines, Peru
Continental
Glacier
Landforms
Greenland
Ice Cap
Antarctic Ice Cap
Continental Glacier, Antarctica
Glacial Deposits, Ontario
Dropstone, Ontario
Erratic, Washington
Kettles, Madison, Wisconsin
Roche Moutonnee, Wisconsin
Crescentic Gouges, Wisconsin
Chatter Marks, Wisconsin
Drumlins, Wisconsin
Buried Log, Wisconsin
Till and Outwash, Wisconsin
Sculpted Bedrock, Ontario
Antarctic Subglacial Lakes
Lake
Vostok
Essential Points
• Glaciers are flowing streams of ice
• Glaciers have a zone of accumulation where snowfall
exceeds losses (ablation)
• Accumulation can be due to high altitude (mountain
glaciers) or cold climate (continental glaciers)
• Glaciers have a zone of ablation where losses exceed
snowfall
• Glaciers are governed by a balance of snowfall, ice flow,
and ablation
• Glaciers retreat by melting back, not by retracting
• Glaciers produce distinctive landforms and small scale
features