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Water Systems on Earth Grade 8 Science Review 2009.

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Presentation on theme: "Water Systems on Earth Grade 8 Science Review 2009."— Presentation transcript:

1 Water Systems on Earth Grade 8 Science Review 2009

2 Properties of Water  Water is a special material. Some properties of water are:  Freezes at 0 o C  Boils at 100 o C  Density = 1.0 g/mL  Expands when frozen (ice is less dense than liquid water)  Has a HIGH HEAT CAPACITY - takes a long time to heat up or cool down  Water is a special material. Some properties of water are:  Freezes at 0 o C  Boils at 100 o C  Density = 1.0 g/mL  Expands when frozen (ice is less dense than liquid water)  Has a HIGH HEAT CAPACITY - takes a long time to heat up or cool down

3 Properties of Water  water runs across land it dissolves minerals including SALT, leading to the salinity of the oceans  Water dissolves many different solutes - it’s called the UNIVERSAL SOLVENT  We use water to clean many things: laundry, dishes, us, cars, windows, streets etc..  Because of this it is easy to pollute water  water runs across land it dissolves minerals including SALT, leading to the salinity of the oceans  Water dissolves many different solutes - it’s called the UNIVERSAL SOLVENT  We use water to clean many things: laundry, dishes, us, cars, windows, streets etc..  Because of this it is easy to pollute water

4 Properties of Fresh & Salt Water  Salt Water  97% of the Earths’ water  Not useable for drinking  Density ~ 1.03 g/ml  Freezes below 0 o C  Salt Water  97% of the Earths’ water  Not useable for drinking  Density ~ 1.03 g/ml  Freezes below 0 o C  Fresh Water ~ 3% of Earth’s water  Can be used for drinking  Density ~ 1.0 g/ml  0 o C

5 USES of Water  Drinking  Food  Cleaning  Plumbing  Gardening  Drinking  Food  Cleaning  Plumbing  Gardening  Recreation  Transportation  Industry  Farming  Many more…

6 HEAT CAPACITY & CLIMATE  Because of its high heat capacity, water has large effects on climate  LAKES & OCEANS  absorb heat energy in the summer and keep nearby climates cooler  release heat energy in the winter and keep nearby climates warmer  Because of its high heat capacity, water has large effects on climate  LAKES & OCEANS  absorb heat energy in the summer and keep nearby climates cooler  release heat energy in the winter and keep nearby climates warmer

7 HEAT CAPACITY & CLIMATE  Ocean currents:  Are WARM or COLD  Distribute heat around the globe  Affect coastal climates  Gulf Stream = warm current that takes heat from the Gulf of Mexico and warms England and other European countries  El Nino - a period reversal of Pacific Ocean currents create warmer, wetter winters in NA  Ocean currents:  Are WARM or COLD  Distribute heat around the globe  Affect coastal climates  Gulf Stream = warm current that takes heat from the Gulf of Mexico and warms England and other European countries  El Nino - a period reversal of Pacific Ocean currents create warmer, wetter winters in NA

8 Factors Affecting Ocean Currents  Convection - uneven heating of the Earth creates winds  Coriolis Effect - the rotation of the Earth affects winds and currents  Continents - large land masses deflect and change the course of currents  Convection - uneven heating of the Earth creates winds  Coriolis Effect - the rotation of the Earth affects winds and currents  Continents - large land masses deflect and change the course of currents

9 Drainage on the Land  On land, water moves downhill, due to gravity  Streams, creeks, and rivers drain into similar areas called DRAINAGE BASINS  Smaller drainage basins drain into larger basins  There are 5 major drainage basins in Canada:  Atlantic Arctic, Gulf of Mexico (Mississippi), Hudson Bay, & Pacific  On land, water moves downhill, due to gravity  Streams, creeks, and rivers drain into similar areas called DRAINAGE BASINS  Smaller drainage basins drain into larger basins  There are 5 major drainage basins in Canada:  Atlantic Arctic, Gulf of Mexico (Mississippi), Hudson Bay, & Pacific

10 Drainage on the Land  In Winnipeg, streams and creeks flow into the Red and Assiniboine Rivers  The Red drains into Lake Winnipeg  Lake Winnipeg drains into HUDSON BAY  In Winnipeg, streams and creeks flow into the Red and Assiniboine Rivers  The Red drains into Lake Winnipeg  Lake Winnipeg drains into HUDSON BAY

11 Erosion & Deposition  As water flows across the land it erodes (wears away) soils & sediments  This creates river channels  Old rivers may meander (wind) and create OXBOW LAKES  As rivers enter lakes, seas, or oceans they deposit sediments creating DELTAS  Rivers flood throughout their FLOOD PLAINS  As water flows across the land it erodes (wears away) soils & sediments  This creates river channels  Old rivers may meander (wind) and create OXBOW LAKES  As rivers enter lakes, seas, or oceans they deposit sediments creating DELTAS  Rivers flood throughout their FLOOD PLAINS

12 YOUNG & OLD RIVERS YOUNG  Fast  Straighter  Narrower  Deeper  Move large rocks/boulders YOUNG  Fast  Straighter  Narrower  Deeper  Move large rocks/boulders OLD  Slower  Meandering  Wider  Shallower  Move small rocks/sediments

13 Drainage & Flooding in Winnipeg Factors for Flooding  Red R flows north - melts upstream first  Ice jams downstream  Heavy winter snows or spring rains  Frozen ground can’t absorb moisture  Reduce vegetation Factors for Flooding  Red R flows north - melts upstream first  Ice jams downstream  Heavy winter snows or spring rains  Frozen ground can’t absorb moisture  Reduce vegetation Flood Prevention  Sandbagging  Levees, dikes  FLOODWAY  Breaking up ice jams  Diversions, ditches  Plant trees & shrubs

14 TIDES  Tides are the daily rise and fall of the ocean levels  Caused by the gravitational pull of the SUN and MOON on the Earth  Greatest tidal events on Earth occur at the Bay of Fundy in Nova Scotia - this bay has a large opening and funnels to a small end (the water piles up)  Tides are the daily rise and fall of the ocean levels  Caused by the gravitational pull of the SUN and MOON on the Earth  Greatest tidal events on Earth occur at the Bay of Fundy in Nova Scotia - this bay has a large opening and funnels to a small end (the water piles up)

15 Waves & Ice Effects  Waves on lakes and oceans are caused by winds  ICE is jagged and can cause shoreline and lake bottom erosion and gouging  Waves erode the shoreline  JETTIES, windbreaks, vegetation, stone and wire covers are ways to reduce shoreline erosion  Waves on lakes and oceans are caused by winds  ICE is jagged and can cause shoreline and lake bottom erosion and gouging  Waves erode the shoreline  JETTIES, windbreaks, vegetation, stone and wire covers are ways to reduce shoreline erosion

16 Spring & Neap Tides SPRING  LARGEST tidal events  Sun, Moon, and Earth in straight line SPRING  LARGEST tidal events  Sun, Moon, and Earth in straight line NEAP  SMALLEST tidal events  Sun, Earth, and Moon are perpendicular (ninety degrees) S E M S E M

17 Water Cycle  Water is constantly moving through the environment in the WATER CYCLE.  The main parts are: 1) Evaporation 2) Condensation 3) Precipitation  The other processes include: 4) runoff 5) surface waters 6) absorption & groundwater  Water is constantly moving through the environment in the WATER CYCLE.  The main parts are: 1) Evaporation 2) Condensation 3) Precipitation  The other processes include: 4) runoff 5) surface waters 6) absorption & groundwater

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19 Drinking Water Sources  Surface Waters - Lakes & Rivers  Winnipeg water is from SHOAL LAKE, ON  Underground - Aquifers & Spring  Desalination - ocean or sea water must have salt removed, expensive!  Glaciers & Icebergs - transport and storage problems  Surface Waters - Lakes & Rivers  Winnipeg water is from SHOAL LAKE, ON  Underground - Aquifers & Spring  Desalination - ocean or sea water must have salt removed, expensive!  Glaciers & Icebergs - transport and storage problems

20 Drinking Water Treatment An example:  Filters & screens - remove debris: sticks, rocks, fish etc.  Chemicals are added to clump small particles  Settling Tank - heavy materials sink to bottom  Sand Filter - water is filtered to remove small materials  Chemicals added - Chlorine - disinfect Fluorine - dental hygiene  Pumped to businesses, schools, homes  Filters & screens - remove debris: sticks, rocks, fish etc.  Chemicals are added to clump small particles  Settling Tank - heavy materials sink to bottom  Sand Filter - water is filtered to remove small materials  Chemicals added - Chlorine - disinfect Fluorine - dental hygiene  Pumped to businesses, schools, homes

21 Pollution Possible Entries  Sewage  Surface water  Vehicles  Groundwater  Industries Possible Entries  Sewage  Surface water  Vehicles  Groundwater  Industries Prevention Strategies  Phosphate free detergents  Use no/less chemicals  Cleanup creek/riverbanks  Maintain vehicles  Clean up oil/gas spills  Phosphate free fertilizers  Chemical free weed control  Government regulations  Consumer awareness


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