EARTH SCIENCE CHAPTER 15

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EARTH SCIENCE CHAPTER 15 GLACIERS

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GLACIERS  Chapter 15 GLACIERS I. What is a Glacier? Mass of moving ice in charge of the most intense specialists of erosion  Types of Glaciers   Valley (elevated) Continental (Greenland, Antarctica)

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TYPES OF GLACIERS B. Valley ice sheets (Alpine icy masses) Long, moderate moving stream of ice originating in the mountains. C. Ice sheets (Continental Glaciers) Originating at the posts and growing in all headings Larger than valley or elevated icy masses. Reality: ANTARCTICA HAS THE LARGEST CONTINENTAL ICE SHEET IN THE WORLD, 1 AND A HALF TIMES THE SIZE OF THE U.S. What's more, IN SOME PLACES 4,000 METERS DEEP FACT: IF GREENLAND AND ANTARCTICA ICE SHEETS WHERE TO MELT THE SEA LEVEL WOULD RISE TO 60 METERS!

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SNOW LINE Topic 3 The Snow line  A. Definition Where changeless snow happens. More is created than melts B. Snowline versus scope Lower at more prominent scopes

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BIRTH Topic 4 Birth of a Glacier   A. Handle 1. Firn (see Fig 11-4 on p. 174) Recrystalization of snow into unpleasant grains 2. Snow to Firn to Glacial Ice

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ALPINE GLACIERS  Topic 5 Where Valley Glaciers Occur (Alpine Glaciers)   A. Areas Where mountains have elevations above snow line.

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CONTINENTAL GLACIERS Topic 6 Where Ice Sheets (Continental Glaciers) Occur A. Area Where snow line is near ocean level B. Ice tops Small ones (Iceland and Islands in Arctic Ocean) C. Mainland icy masses Antarctic icy mass (5 km thick and 1.5 m underneath ocean level) Greenland D. Nunnataks Mountain crests that venture through ice

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MOVEMENT II. Ice sheet Movement Topic 7 How Glaciers Move   A. Procedure of development 1. Weight pulls ice down 2. Softening guides oil B. Speed   1. Development From a couple cm to 3000 cm/day Faster in the center.

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CREVASSES

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HOW FAR? Subject 8 How Far Glaciers Move A. Ice fronts - Where they end (can be underneath snow line)   1. Elements figuring out Where ice dissolves as quick as it moves

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CALVING B. Calving 1. Handle When ice sheets hit ocean, close sever   2. Icy masses What you get   3. Ice racks Occur over water where ice hasn't severed yet

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TRANSPORT Topic 9 Glaciers Transport Loose Rock   A. Scope of molecule size Fine powder to mammoth boulders 

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B. Moraines - stored particles once icy mass recedes 1. Ground moraines - in icy mass before deposited   2. Parallel moraines - saved on sides of glaciers   3. Average moraines - kept on the sides of two focalizing ice sheets, coming about between the two   4. End moraines - stored at the ice front MORAINES

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EROSION  Topic 10 Glaciers Leave Their Mark   A. Depiction and arrangement   1. Striations - long parallel scratches   2. Roches moutonnees - sheep rocks   3. Cirque - half circle bowls at head of valley   4. Arête - cut edge between 2 cirques   5. Horns - aftereffect of at least 3 cirque creating a pyramid molded pinnacle

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STRIATIONS

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HORN

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CIRQUE

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ARETE

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GLACIAL VALLEY Topic 11 Recognizing Glacial Valleys A. Chilly troughs versus waterway valleys 1. U formed versus Angular B. Hanging troughs and hanging trough waterfalls SMALL ABANDONED GLACIAL VALLEY SUSPENDED ON A MOUNTAIN ABOVE THE MAIN GLACIAL VALLEY. WHAT NATURAL FEATURE DO YOU THINK WILL APPEAR WHEN A STREAM FLOWS FROM A HANGING VALLEY TO THE MAIN GLACIAL VALLEY?

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Topic 12 What Continental Glaciers Do A. Cleaned peaks versus honed ones

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DEPOSITION III. Stores By Glaciers Topic 13 Deposition Occurs Drift - all stores of ice sheets 1. Till - unsorted and unstratified (inside glacier) 2. Outwash - sorted and stratified (left in front of ice sheet)

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TILL

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OUTWASH PLAIN

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OUTWASH PLAIN

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DEPOSITION Topic 14 Glaciers Leave Moraines A. Recessional and terminal moraines - what's abandoned by an icy mass and the store left by most distant progress. B. Erratics - vast transported stones

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MORAINES

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MORAINE

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ERRATIC

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ERRATICS

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DRUMLINS Topic 15 Drumlins A. Development and depiction - long smooth kayak - formed slopes made of till delivered while propelling icy masses have keep running over prior icy moraines B. Illustrations - Southeastern Wisconsin, South of Lake Ontario, Boston, Massachusetts

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DRUMLINS

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DRUMLINS

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Topic 16 Outwash Plains and Eskers A. Outwash fields Formation and depiction - wide level ranges before ice sheets (typically prairies or farmland today) B. Eskers Formation and depiction - long winding edges where material was stored in passages inside icy mass Examples - Maine and New York

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OUTWASH PLAIN

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ESKER

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ESKER

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Topic 17 Kames, Kettles, and Deltas A . Kames 1 . Arrangement and portrayal Small cone molded slopes of sand and rock from streams on top of icy masses B . Pots 1 . Arrangement and portrayal Circular hollows on terminal moraines and outwash fields framed from vast squares of ice settling out and dissolving C. Deltas 1 . Development and portrayal When frigid streams exhaust into lakes

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KAMES

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OUTWASH PLAIN

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CIRQUE LAKES Topic 18 Lakes Made by Glaciers A. Cirque lakes 1. Arrangement When water fills the stone stunned cirque left by an icy mass 2. Cases Lake Louise, British Columbia

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CIRQUE LAKE

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KETTLE LAKES B. Pot lakes 1. Development Water from ice dissolve abandoned in pots 2. Cases Zillions of them in Minnesota and Wisconsin, also the Great Lakes

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C. Moraine – dammed lakes 1. Arrangement River valleys obstructed by cold moraines 2. Illustration Devil's Lake, Wisconsin

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ICE AGE IV. The Ice Age (NOTE OBJECTIVES A – C ON PAGE 183) Topic 19 How It Happened A. When it happened - 1,000,000 years prior, we're still in it! B. Degree - Intersection of Ohio and Mississippi waterways and as far east as NY C. North America's 3 noteworthy focuses 1. Labrador focus - east 2. Keewatin - focal 3. Cordilleran - west D. Recurrent - Advanced and retreated 4x's; 11,000 years ago was last progress

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Topic 20 Ice Age Evidence A. Limits attached to terminal moraines Terminal moraines found from New Jersey through Pennsylvania, to Indiana and past. Outwash fields are found past.

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Topic 21 Causes of Glacial Climates A. Four realities to consider 1. I million years back, Ice Age started, including 4 noteworthy advances of the ice sheets. 2. Warm interglacial periods interfered with. 3. Other ice ages have happened in the previous 600 million years. 4. In last age, ice sheets progressed and retreated in North and South sides of the equator in the meantime.

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B. Conceivable causes 1. Vitality from sun changes. 2. Volcanic movement and tidy in climate. 3. Amid mountain constructing more land was above snow line. (More land under ice, may change the atmosphere) 4. Mainlands in more seasoned arrangements may have forestalled hot and chilly water streams from blending. 5. Changes in earth's tilt.

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