Glaciers Flashcards
(19 cards)
What is a glacier? 3
Always snowy regions
Ice and snow
slow-moving
Glaciers are classified into two main types: continental glaciers and valley glaciers.
What are the two main types of glaciers?
- Continental glaciers (ice sheets)
- Valley glaciers
Continental glaciers cover large parts of continents, while valley glaciers form in mountain ranges.
What landform is created by glaciers that erode both sides and bottom of a valley?
U-shaped valley.
This is different from V-shaped valleys, which are primarily carved by rivers.
What are cirques?
Bowl-shaped basins created by glaciers in mountain areas.
Cirques are formed as glaciers erode the landscape from multiple sides.
What are arêtes?
Sharp ridges formed when glaciers erode from multiple sides.
Arêtes are typically found in mountain ranges.
What is a horn?
A sharp mountain peak created when several cirques erode a mountain from different directions.
Horns are distinctive features of glaciated mountains.
What is an ice fall?
jagged section of broken ice
From valley glaciers
flows over steep cliffs.
Ice falls are similar to waterfalls but consist of ice.
What is calving?
The process when large chunks of a glacier break off into a body of water, creating icebergs.
Calving occurs at the glacier’s terminus.
What is pack ice? 3
floating ice
<5m
fragile.
Pack ice breaks and melts easily as it moves into warmer water.
What is an ice cap?
A glacier that forms on relatively flat land and flows outward from the center.
Ice caps are smaller than ice sheets.
What is an ice field?
A larger area feeding multiple glaciers.
An example is the Columbia Icefield in Canada.
What are striations?
Parallel scratches on rocks caused by debris dragged along the glacier’s base.
Striations provide evidence of glacier movement.
What is till?
An unsorted mix of debris like boulders, clay, and sand left behind by glaciers.
Till is deposited over a wide area as glaciers melt.
What is a moraine?
A localized pile of glacial debris.
Moraines mark the edge of a glacier’s former position.
What are eskers?
Winding ridges of sediment deposited by meltwater rivers flowing within or beneath glaciers.
Eskers often indicate the path of former glacial rivers.
What are erratics?
Massive rocks that have been moved far from their original location by glaciers.
Erratics are not made of bedrock
What does it mean for a glacier to advance?
When ice builds up faster than it melts.
Glaciers can advance during colder periods or when snowfall increases.
What does it mean for a glacier to retreat?
When a glacier melts more quickly than it accumulates ice.
During retreat, glaciers still move forward but appear to shrink.
How do glaciers affect their surroundings? (3)
- Create flood plains by depositing sediments
- Carve basins that fill with water to become lakes
Glaciers significantly reshape the landscape as they move.
