Definition of terms associated with glacier - SS1 Geography Lesson Note
A glacier is a large mass of ice that moves very slowly over land. It's like a river of ice. Glaciers form when more snow accumulates in a location than melts, evaporates, or calving into the sea. Over thousands of years, this snow compresses into ice and begins to flow under its weight
Ice:
Ice is the solid form of water. It forms when water freezes, typically at or below 0 degrees Celsius (32 degrees Fahrenheit). In the context of glaciers, ice is the primary component, and it accumulates over time, forming massive ice sheets.
Glaciations:
Glaciations refer to periods in Earth's history when there was a significant advance of glaciers. These are often associated with ice ages when the climate cools, and glaciers expand, covering more land.
Features of Glacier Erosion:
Glaciers have a profound impact on the landscape as they move. They erode the land in several ways:
- Abrasion: This occurs when the glacier's ice and the rocks embedded in it scrape against the underlying bedrock, wearing it down.
- Plucking: As a glacier moves, it can pick up rocks and sediments from the ground, incorporating them into the ice.
- Cirques: These are bowl-shaped depressions carved by glaciers in highland areas.
- U-shaped Valleys: Glaciers can transform V-shaped river valleys into U-shaped valleys through erosion.
- Hanging Valleys: Smaller valleys that join a main glacier valley but sit at a higher elevation.
- Moraines: Piles of sediment and rocks left behind by glaciers as they melt and recede.