PPT-Glaciers Glacial Ice

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 . 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 Ice. . 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 . Chapter 7.1. At one time nearly 30% of the earth’s surface was covered in ice. . . This . period of time was referred to . as the . ice age. .. Today. , only . 10% of the earth’s surface is covered in ice. Chapter 3: Changing Climates. The Big Freeze. A cooling trend began in the Cretaceous Period and continued throughout the Tertiary Period. By the end of the Tertiary Period (1.7 . mya. ) the climate became so cold that snow began o accumulate year after year in the Polar regions. 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 . 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?. Ch 15: p 277-281. 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 Earth’s surface. Do Now:. The material seen below was left behind by a retreating glacier. Describe the sediments seen in the picture. . . Tasman Glacial Moraine, New Zealand. Formed from the accumulation of ice and snow over thousands of years. . 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. It originates on land from the accumulation, compaction, and . recrystallization. of snow. .. A glacier appears to be motionless, but glaciers move very slowly.. Glaciers are dynamic weathering . and erosional . 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 . years..