19: Glacial Systems
Some of the most magnificent landscapes on Earth are created by the action of glaciers. Throughout much of our geologic history, great sheets of ice have waxed and waned across the Earth's surface. Glaciers in high mountains have created a craggy landscape of sharp ridges, amphitheater-like depressions, and hanging valleys occupied by spectacular waterfalls. Over the flatter plains of the Earth, ice sheets over a mile thick advanced, plowing over and burying the surface in a great thickness of glacial sediment. Once retreated, the glaciers left sinuous ridges, streamlined hills, and a pocked marked surface of depressions and lakes.
By the end of this chapter you should be able to:
- Describe the various theories for ice ages.
- Describe the process of glacial ice formation and construct a diagram showing the zones of accumulation and ablation of a glacier.
- Describe how glaciers move.
- Differentiate between continental, alpine, and piedmont glaciers.
- Describe the factors that control and explain the processes of fluvial erosion, transportation, and deposition.
- Describe features formed from continental and alpine glaciers.
- Identify glacial landforms from a topographic map.
- Describe the impact of climate change on glacial processes and landforms.