PPT-Glacial Erosion

Ch 15 p 277281 Glaciers Enormous masses of moving ice created by the accumulation and compaction of snow Powerful agents of erosion have carved some of the most spectacular features on Earths surface. January 21, 2011. . Glaciers act as agents of erosion and deposition to help to create unique landforms which you will study in this unit. Glacier. : A large mass of ice resting on land or floating as an ice shelf in the sea adjacent to land. Glacial Erosion. As glaciers travel over land, glacial ice can erode the underlying bedrock.. This erosion can happen by:. Plucking. A. brasion. Plucking. This occurs when melt water at the base of the glacier freezes in cracks and fractures the underlying bedrock.. , 907 Deposition:. AIM:. Erosional and Depositional systems. Do Now: In your notebooks…. 1) Define the two terms below in your own words.. 2) Explain how the two terms work together.. The movement/transport of material from one place to another. Erosive forces . Glacier. persistent . body of dense ice that is constantly moving under its own . weight.. It . forms where the accumulation of snow exceeds its ablation (melting and sublimation) over many . J. Quigley. 4/2012. Water Shapes the Land. Water Shapes the Land. The Mississippi River is like a thousand dump trucks… every year it carries more than 300 million tons of sediment to the ocean! . This sediment is being washed away from the surface of the land and is called erosion.. Prairie School. Earth Science. Glaciers: Moving Ice. When you take a handful of snow and squeeze it, you are creating a product that is similar to that of glaciers. . Glacier: fast moving, large mass of ice. . Unit 5: Gradational Processes. Ms. . Thind. Glaciers. 10% of land is covered with glacial ice.. Store 75% of the world’s freshwater. . If all land ice melted, sea level would rise approx. 70m . Glaciers: importance?. More winter snowfall than summer melt. Glacier formation is similar to sedimentary rock formation. Types of Glaciers. Valley glaciers or alpine glaciation. Ice sheets or continental glaciation. Glaciers of the world. Glacier – thick ice mass that forms over hundreds or thousands of years.. 15, 000 years ago > 30 % coverage - Today 10 % coverage. Valley Glaciers. Ice Sheets. Types of Glaciers. Valley Glaciers. Glaciers. Geologists define a . glacier. as any large mass of ice that moves slowly over land.. There are two types of glaciers:. Continental glaciers. Valley glaciers. Continental Glaciers. A . continental glacier. B. Landforms : an accumulation of till deposited by direct glacial action. Ground moraines are relatively level to gently rolling and are formed by the deposition of accumulated material beneath the Once . glacial ice exceeds a thickness of about 150 feet, the weight of the overlying ice causes . the . base of . the glacier . to become plastic and flow like a very viscous liquid. While the bottom ice responds as a plastic solid, the surface ice is very brittle. However, from the surface down to the top of the plastic portion of the glacier, the ice experiences a decrease in . Glacial transport . The image to the right shows the different ways in which material can be transported. Material that has been carried and deposited by the glacier is called moraine Different types of moraine .