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Published byMaurice Gregory Modified over 9 years ago
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What percent of the earth is covered in water or land?
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What percent of the earth’s water is salty or fresh?
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Ocean Salinity
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World Ocean Facts – which ocean is the biggest? Area (1,000,000 km²) Volume (1,000,000 km³) Average Depth (m) Maximum Depth (m) Atlantic Ocean 82.4323.639269200 Pacific Ocean 165.2707.6428211,022 Indian Ocean 73.4291.039637460 Arctic Ocean14.117.012054300
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HW: What makes the ocean salty? Think about why the highest salinity is found near equator.
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Lab Inquiry: How does temperature and salinity affect the density of ocean water?
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Oceanic Circulation Aim: Why causes the currents in the ocean?
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Vocabulary Salinity Density Upwelling Gyre Currents Thermal Expansion Coriolis Global Winds
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Why is Ocean Circulation Important? a. Transport ~ 20% of latitudinal heat between Equator and poles b. Transport nutrients and organisms c. Influences weather and climate d. Influences commerce e. Pollution is transported
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2 kinds of circulation: a.Surface driven currents are wind-driven and occur in the uppermost 100 m or less of ocean b.Deep ocean currents are caused by density changes due to salinity and temperature differences. These currents produce very slow flows in deeper waters. c.Other forces affecting currents: Coriolis effect, friction, gravity, thermal expansion, geologic shape of ocean basin and landmasses
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How fast? A few miles/hr (Gulf Stream off of Miami = 4.5 mph) How much? Total water in ocean surface circulation = about 100 Amazon Rivers (20 million m 3 /s).
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N. Atlantic Gyre S. Atlantic Gyre N. Pacific Gyre S. Pacific Gyre Indian Ocean Gyre Antarctic Circumpolar Current
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Gyres are large circular-moving loops of water Five main gyres (one in each ocean basin): North Pacific South Pacific North Atlantic South Atlantic Indian Generally 4 currents in each gyre Centered about 30 o north or south latitude Current Gyres
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ESRT Surface Ocean Currents pg. 4 Color the war currents red and the cool currents blue http://www.youtube.com/watch?v=PAQos8 COqYI&feature=player_embedded
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Surface Currents are created by: 1. Global Winds 2. Coriolis Effect 3. Solar Heating (temperature, density)
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Global Winds pg. 14 ESRT Surface currents of ocean generally mirror atmospheric circulation (wind) patterns
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equator Quito Buffalo 79 o W North Pole South Pole N Quito Buffalo equator Buffalo moves 783 mph Quito moves 1036 mph 15 o
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The Coriolis effect on Earth As Earth rotates, different latitudes travel at different speeds The change in speed with latitude causes the Coriolis effect
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Coriolis Effect a.The rotation of Earth causes a deflection (curve) of the winds and waters of the Earth. In Northern Hemisphere, curvature is to right - clockwise In Southern Hemisphere, curvature is to left – counterclockwise b. Effect lessens at equator and increases at poles Visualization of the Coriolis effect: http:// www.classzone.com/books/ear th_science/terc/content/visualizatio ns/es1904/es1904page01.cfm?chapt er_no=visualizationhttp:// www.classzone.com/books/ear th_science/terc/content/visualizatio ns/es1904/es1904page01.cfm?chapt er_no=visualization Wind: http://www.classzone.com/books/earth_s cience/terc/content/visualizations/es1905/ es1905page01.cfm?chapter_no=visualiza tionhttp://www.classzone.com/books/earth_s cience/terc/content/visualizations/es1905/ es1905page01.cfm?chapter_no=visualiza tion
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A)Idealized winds generated by air pressure differences and Coriolis Force. B)Actual wind patterns affected by land mass distribution..
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Ocean Circulation & Global Winds
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Sea Surface Temperature
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Thermal expansion Solar radiation heats the water at equator more than the poles Warm water expands and cool water contracts, creating a water bulge at the equator Gravity pulls warmer water “downhill” toward cooler water
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Ocean Salinity Increased evaporation near the equator makes the water saltier.
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Global ocean circulation that is driven by differences in the density of the sea water which is controlled by temperature and salinity.
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Thermohaline Circulation - The Ocean Conveyor
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Equatorial to polar heat transport and water flow
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LINKS: http://www.youtube. com/watch?v=w_8m w-1HYFghttp://www.youtube. com/watch?v=w_8m w-1HYFg http://www.youtube. com/watch?v=nAq9 LXLXISkhttp://www.youtube. com/watch?v=nAq9 LXLXISk http://www.youtube. com/watch?v=rR5TF WNLtOc&feature=rel atedhttp://www.youtube. com/watch?v=rR5TF WNLtOc&feature=rel ated http://www.youtube. com/watch?v=boiFo SRq1BM&feature=re latedhttp://www.youtube. com/watch?v=boiFo SRq1BM&feature=re lated
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What do Nike shoes, rubber ducks, and hockey gloves have to do with currents?
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Lost at Sea
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2004-2007 Barber’s Point
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“Great Pacific Garbage Patch” Estimate: 46,000 pieces of floating garbage/mi 2. North Pacific Subtropical Gyre
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135° to 155°W and 35° to 42°N
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North Pacific Subtropical Gyre http://http://marinedebris.noaa.gov/info/patch.html#6 Great Pacific Garbage Patch- Good Morning America 2010 http://www.youtube.com/watch?v=uLrVCI4N67M&feature=player_embedded http://www.youtube.com/watch?v=uLrVCI4N67M&feature=player_embedded http://www.youtube.com/watch?v=FrAShtolieg&feature=related
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