Glaciers Chapter 3 Section 4 Pages 91-95

Objective: Describe the causes and types of glaciers, how they impact land features, and analyze their role in earth’s history. Glacier: Any large mass of ice that moves slowly over land. Continental Glacier: Glacier that covers much of a Continent or large island. Ice Age: Times in the past where continental glaciers Have covered large parts of the Earth’s surface. Valley Glaciers: Long, narrow glacier between mountains In valleys.

Glaciers can form only in an area where more snow falls than melts. Once the depth of snow and ice reaches more than 30 to 40 meters, gravity begins to pull the glacier down hill. The 2 processes by which glaciers erode the land are… Plucking: When glaciers pick up rocks as it flows over land. Abrasion: Glaciers drag rock along Earth’s surface. When glaciers melt, it deposits the sediment it eroded from the land, creating various landforms. Till: Mixture of sediments a glacier deposits directly On Earth’s surface.

Moraine: A ridge of till deposited at the edge of a glacier. Kettle: A small depression that forms when a chunk of ice is left in glacial till. When the glacier melts it fills with water and becomes a small pond or lake.