GLACIERS AND LANDFORMATION

WHAT IS A GLACIER? One of the hardest substances on Earth Huge long lasting mass of ice flowing over a land Moves in response to gravity and moves/flows very slowly Largest reservoir of fresh water on Earth Donjek Glacier, Yukon, Canada, 1985 Donjek Glacier, Yukon, Canada, 1985

Alpine Glaciers ALPINE GLACIERS Glacier occupying one or more valleys in an alpine region (valley glacier) Moves down the valley from the high to low elevations because of the gravitational force Moves only a few centimetres per day Helps shape the mountain walls, giving them a U-Shape A glacier that is confined by surrounding mountains Mountain glaciers are a type of alpine glacier Alpine Glaciers

CONTINENTAL GLACIERS Large span of ice that spreads out over land Ice sheet which moves under its own weight—pressure and weight Gives land a smoother appearance by eroding away sharp peaks Last ice age there was 8 million square kilometres of continental glaciers – up to 4km thick

FORMATION OF GLACIERS Snow is repeatedly frozen and thawed Causing granular ice to form Granular ice becomes dense under the enormous pressure from the glacier Lower layers of the glacier melt under the pressure and allow the glacier to move from the pressures of gravity Upper layers of the glacier are less dense and brittle, causing pieces to break off Movement of the glacier usually occurs on the downward slope—from the forces of gravity

GLACIERS IN CANADA Bear Glacier, Stewart, British Columbia, Canada Athabasca Glacier, Jasper National Park, Alberta, Canada In Canada, 2% of the country’s area is covered by glaciers/ice fields A huge quantity of freshwater is frozen in the polar ice caps Glaciers are found in the Western Cordillera and the mountains in the eastern Arctic Largest glacier in Canada is south of the Arctic—area contains 30 glaciers (300km wide and 365 meter deep in some places) Like groundwater, glaciers are excellent natural storehouses of water Canada has sold glacier pieces to Japan for money (1.5 kg bag for $30)

MOVEMENT OF GLACIERS Glacier Advancement – accumulation of snow causing increased weight and pressure to move the glacier with the help of gravity Glacier retreat– the melting/reduction of glacier growth caused by increased temperatures This movement occurred at least 4 times in the last Ice Age (100, 000 years ago, ending 6000 years ago) Climate was warm/warmer than today Change in climate could be the result of the changing tilt of the Earth’s axis

ICE MUMMIES!!! Frozen bodies due to glacial melting are known as ice mummies Found throughout the entire world – dating back to the beginning of man Body shown was found by sheep hunters in British Columbia on the slopes of a melting glacier Kwaday Dan Sinchi was the name given to the man who is said to have come from the fifteenth century