Glaciers Glaciers v Glacier a thick mass of
- Slides: 22
Glaciers
Glaciers: v. Glacier – a thick mass of ice that forms over land from the compaction and recrystallization of snow and shows evidence of past or present flow
Types of glaciers • Valley/mountain/alpine glaciers – form in mountainous areas • Ice sheets or continental glaciers • Large scale • e. g. , Over Greenland Antarctica – Ice Caps: Small Ice sheets
Currently ice sheets cover Greenland Antarctica
Movement of glacial ice • Types of glacial movements • Plastic flow • Slipping along the ground • Zone of fracture • Uppermost 50 meters • Crevasses form in brittle ice
Movement of glacial ice • Zone of accumulation – the area where a glacier forms • Zone of wastage – the area where there is a net loss due to melting
Accumulation and Wastage Figure 6. 7
Glacial Erosion • Plucking – Gouging out and lifting of chunks of rocks • Abrasion – Striations (scratches and grooves in the bedrock)
Landforms created by glacial erosion • • • Glacial trough Hanging valley Cirque Arête Horn Fjord
Erosional landforms created by alpine glaciers
The Matterhorn in the Swiss Alps
Glacial deposits • Glacial drift • Till – material that is deposited directly by ice • Stratified drift – sediment deposited by water melting off surface of glacier
Glacial till is typically unstratified and unsorted Figure 6. 13
Close-up view of the boulder in the previous slide
Glacial deposits • Depositional features – Moraines – layers or ridges of till – Types of moraines • Lateral • Medial • End • Ground
Glacial deposits • Depositional features – Outwash plain or valley train – Kettles – Drumlins – Eskers – Kames
Glacial depositional features
Kettle lakes
• Ice Age • Began 2 to 3 million years ago • Division of geological time is called the Pleistocene epoch • Ice covered 30% of Earth’s land area
Maximum extent of ice during the Ice Age Figure 6. 22
Indirect effects of Ice Age glaciers • • Migration of animals and plants Rebounding of the crust Drop in sea level Climatic changes
Causes of glaciation • Variations in Earth’s orbit • Shape of Earth’s orbit varies • Angle of Earth’s axis changes • Axis wobbles
- Glacier terms
- Chapter 8 mass movements wind and glaciers
- Glaciers cause erosion by abrasion and
- Metamorphic rock
- Bolivia glaciers
- Arrowhead region mn
- Is a valley
- Chapter 7 glaciers deserts and wind
- Chapter 5 glaciers oceans and landscapes
- Glacial drift vs till
- Nsidc glaciers
- How ice causes erosion
- Qori kalis glacier
- Venn diagram of glacier and geyser
- Glacial processes and landforms
- Glacier plastic flow
- Pyramidal peak diagram
- Glacier view lodge courtenay
- Glacier
- Parking reservation systems
- Alpine glacier
- Glacier ile tudy
- Glacier tax prep gtp