IB Oceans and their Coastal Margins<br />B1 – Introduction to Oceans<br />
World’s Oceans<br />
Distribution of Oceans<br />The world’s oceans are referred to collectively as the “world ocean”.<br /> Boundaries that se...
Water in the Oceans<br />Volume – 1.185 billion cubic kilometres<br />97.3% of all water on the planet.<br />Chemical comp...
Ocean Currents<br />Two types of ocean currents:<br />Surface Ocean Currents<br />Deep Ocean Currents<br />What do current...
Ocean currents occur because there is very little friction between the ocean waters and the solid earth.<br />As the earth...
Deep Ocean Currents <br />
Deep Ocean Currents<br />Deep Ocean Currents occur between the ocean bottom and 400m below the surface.<br />Created by di...
Surface Currents<br />
Surface Currents<br />Surface currents are driven by the wind.<br />World’s prevailing winds create giant circular current...
Major Ocean Currents<br />
Ocean Gyres<br />Gyre – any large system of rotating ocean current.<br />Gyres are caused by the Coriolis effect – planeta...
Ocean Currents Affect Temperature<br />Warm Currents carry water Polewards and raise the air temperature of the maritime e...
What is this image showing? Why?<br />
Questions<br />Why does the chemical composition of the oceans remain fairly constant over time? (hint: think inputs / out...
www.oceanmotion.org<br />
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L1 introduction to oceans

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L1 introduction to oceans

  1. 1. IB Oceans and their Coastal Margins<br />B1 – Introduction to Oceans<br />
  2. 2. World’s Oceans<br />
  3. 3. Distribution of Oceans<br />The world’s oceans are referred to collectively as the “world ocean”.<br /> Boundaries that separate the oceans are arbitrary and blurred.<br />Size of oceans varied from largest to smallest:<br />Pacific<br />Atlantic<br />Indian<br />Southern<br />Arctic<br />
  4. 4. Water in the Oceans<br />Volume – 1.185 billion cubic kilometres<br />97.3% of all water on the planet.<br />Chemical composition of water in each of the oceans is very similar from place to place -> varies little from year to year.<br />Inputs to Ocean Water<br />Water (from rivers, glaciers, rain)<br />Chemicals (dissolved mineral <br />
  5. 5. Ocean Currents<br />Two types of ocean currents:<br />Surface Ocean Currents<br />Deep Ocean Currents<br />What do currents do?<br />Regulate the world’s climate.<br />Important for marine life.<br />
  6. 6. Ocean currents occur because there is very little friction between the ocean waters and the solid earth.<br />As the earth rotates the water moves differently to the solid crust and the lighter atmosphere.<br />Surface currents move at 9km per hour, deep currents move at 1km per hour.<br />
  7. 7.
  8. 8. Deep Ocean Currents <br />
  9. 9. Deep Ocean Currents<br />Deep Ocean Currents occur between the ocean bottom and 400m below the surface.<br />Created by difference in water density.<br />Cold or salty water is more dense than warm or less salty water.<br />One cycle of the ocean conveyor belt can take 1,000 years to complete.<br />
  10. 10. Surface Currents<br />
  11. 11. Surface Currents<br />Surface currents are driven by the wind.<br />World’s prevailing winds create giant circular currents in the major ocean basins.<br />Subtropical high pressure areas at 30 degrees latitude. <br />Combination of friction and coriolis force water does not create exactly parallel to the wind direction.<br />Coriolis Force – created by the rotation of the earth. <br />Water pulls to the right in the northern hemisphere<br />Water pulls to the left in the southern hemisphere.<br />
  12. 12. Major Ocean Currents<br />
  13. 13. Ocean Gyres<br />Gyre – any large system of rotating ocean current.<br />Gyres are caused by the Coriolis effect – planetary motion along with friction.<br />There is a major Gyre for each ocean system.<br />
  14. 14. Ocean Currents Affect Temperature<br />Warm Currents carry water Polewards and raise the air temperature of the maritime environments where they flow.<br />Cold currents carry water towards the equator and so lower the temperature of coastal areas.<br />Main ocean currents follow a circular pattern.<br />
  15. 15. What is this image showing? Why?<br />
  16. 16. Questions<br />Why does the chemical composition of the oceans remain fairly constant over time? (hint: think inputs / outputs)<br />Outline the impact of ocean currents on the climatic differences between the eastern and western sides of continents.<br />
  17. 17. www.oceanmotion.org<br />

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