Geography 2152F/G Lecture 6: HAZARDS LECTURE 6
3 Nov 2017
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Document Summary
The climate system: climate is a function of the interaction of many (cid:494)spheres(cid:495), atmosphere: gases, hydrosphere: oceans, large bodies of water (70%, lithosphere: plate tectonics, orogeny, cryosphere: glaciers, ice sheets, snow cover areas, biosphere: vegetation, animals, humans. The last glacial period: all of canada was covered with ice 18000 years ago (except for northern. Yukon: lower sea levels at that time exposed the bering land bridge. Climate in recent history: there has been a rapid rise in temperature over the past 100 years, this corresponds to human industry and the increase of greenhouse gases. There are four general causes: variations in solar radiation, changes in composition of atmosphere, changes in earth(cid:495)s surface, variations in earth(cid:495)s orbit. Ice cores: the width of an ice layer provides insight on the temperature and snowfall of that year, each year, a new layer of ice forms, bubbles of air are trapped in the ice, dendrochronology.
