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19 Cards in this Set
- Front
- Back
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How much of all Earth's water is salt water?
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96.5%
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How much of all Earth's water is freshwater?
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2.5%
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How much of all freshwater is locked away in the cryosphere?
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69%
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How much of all freshwater is underground?
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31%
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How much freshwater is available for potential use?
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1.2% although some of this is ground ice.
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What is the water balance equation?
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precipitation = stream flow + evapotranspiration +/- changes in storage
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What is the residence time of oceans and seas?
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4000 years
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What is the residence time of soil and why?
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2 weeks to a year as it quickly moves to the rock underneath and can be transpired by plants.
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Name a water store in South Africa
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Guarani Basin
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How much of the Earth's surface does oceans cover?
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72% of the planets surface.
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Name the two major ice sheets and what is the percentage of freshwater ice they hold?
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Greenland and Antarctic sheets contain 99% of the freshwater ice on Earth.
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What are ice caps and give an example of one.
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Thick layers of ice that are smaller than 50,000km2. e.g. The Furtwangler Glacier is the last ice cap in Africa and is melting rapidly.
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What are Alpine Glaciers?
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Thick masses of ice found in deep valleys or upland hollows. About 15,000 glaciers in the Himalayas form a unique reservoir supporting the Ganges and other perennial rivers.
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What is permafrost and where is it found?
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Permafrost is ground that remains below 0 degrees Celsius for 2 consecutive years. It is found in the ice free regions of Antarctica and is melting releasing methane and carbon dioxide.
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What are Wetlands?
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Areas of soil covered by water. They are the main ecosystem in the Artic, covering 60% of the total surface area.
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Describe the Ganges drainage basin.
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It is an international basin in the eastern Himalayas
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What are the sources of the River Ganges drainage basin?
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The main source is the ice melt in the summer months as there is low amounts of precipitation, only 300-600mm per year. The Himalayan mountain region encompasses about 15,000 glaciers.
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What is the output of the Ganges drainage basin?
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The mouth to the Indian Ocean.
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What is a current issue in the Ganges drainage basin caused by humans?
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Over abstraction for agricultural use so the water table isn't fully replenished even in the summer months.
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