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Columbia Icefield Parks Canada Photo

Columbia Icefield Parks Canada Photo. Earth’s Frozen Water. Ice Ages. There have been 7 major periods when glaciers covered much of the Earth Most recent was about 11,000 years ago. Frozen Water. Covers 10% of the Earth ¾ of the Earth’s water. Types of Frozen Water.

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Columbia Icefield Parks Canada Photo

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  1. Columbia Icefield Parks Canada Photo Earth’s Frozen Water

  2. Ice Ages • There have been 7 major periods when glaciers covered much of the Earth • Most recent was about 11,000 years ago

  3. Frozen Water • Covers 10% of the Earth • ¾ of the Earth’s water

  4. Types of Frozen Water • Pack Ice • Tightly packed pieces of sea ice • Ice Flows • Small floating ice pieces • Separated from pack ice • Fast Ice • Attached to shore • Iceberg • Chunks of glacial ice that breaks off glaciers • May reach heights of 90 – 150 m above the water • 90% hidden beneath the surface • Glacier • Large moving mass of compressed ice and snow

  5. Related Terms • Glaciologist – a person who studies glaciers • Ice Cap – a large dome-shaped glacier that flows outward from it’s centre and covers a large area, especially of land • Ice Field – an upland area of ice that feeds two or more glaciers • Advancing and retreating – movement of glaciers • Arete – a mountain ridge caused by 2 or more glaciers from several directions • Cirques – a bowl shaped by erosion at the start of the valley • Moraine – ridge of material left behind by a glacier

  6. Salinity of Frozen Sea Ice • Depends on the rate of freezing • New ice: between 4-15 ppt • Sea ice is 35ppt • Over time the brine trickles down, salinity decreases • 1 year old: relatively pure

  7. Importance of Glaciers • Store a lot of freshwater • Meltwater (glacier run-off) is released in summer • Provide clues to Earth’s history • Core samples show air quality in past

  8. Columbia Icefield • Water from the Columbia Icefield • Helps run hydroelectric plants • Irrigate crops • Water crops • Largest Accumulation of Ice in Rocky Mountains • Athabasca Glacier 6 km2 • Saskatchewan Glacier 12 km2 • www.canadianencyclopedia.ca

  9. Glacial Movement • Solid weight and pressure of glacier cause the solid ice to act as a liquid and flow • Centre usually moves faster than sides • Sides slowed down by friction of rocks • Move in different ways and different speeds; depends on • Volume of ice • Slope of ground • Slope of upper ice surface • Amount of water in the ice • Amount of debris it is carrying • Temperature • Friction it encounters

  10. How Glaciers Shape the Land • Glaciers change topography by eroding, transporting and depositing rocks and debris • Moves like a bulldozer • Meltwater fills cracks and refreezes causing more rock to split

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