Monday 10/30/2007 Ocean Currents

Oceanography Ocean Currents are large masses of water that move from one place to another. Surface Currents are driven by friction between ocean water and wind that blows across the surface.

a. Surface currents are caused by the wind and a. Surface currents are caused by the wind and move in huge circular current systems called gyres. Five major Gyres: – North Pacific Gyre – South Pacific Gyre – North Atlantic Gyre – South Atlantic Gyre – Indian Ocean Gyre b. Because of the earth's rotation, currents north of the equator are deflected to the right (clockwise), and currents south of the equator are deflected to the left (counter clockwise). This is called the Coriolis Effect Key Point

Monday 10/30/2007

c. When gyres move away from the equator they carry heat to areas of the earth that would otherwise be cooler. http://www.youtube.com/watch?v=SdgUyLTUYkg&NR=1 i.e. The Gulf Stream & the Eastern United States

Monday 10/30/2007 Activity 1 1) Draw & Label the five major gyers of the world. (Page 449). Label this map "Surface Currents" 2) Use a different color for warm and cold currents. 3) On the second map, draw and color the deep ocean conveyor belt. 4) Label this map "Deep Ocean Currents“ (Page 453) http://videos.howstuffworks.com/howstuffworks/3885-ocean-waves-video.htm

Monday 10/30/2007

2. Deep Ocean Currents are caused. by differences in density of ocean 2. Deep Ocean Currents are caused by differences in density of ocean water. a. When sea water becomes colder or has more salt it becomes more dense and sinks to the ocean floor. This results in the mixing water deep in the oceans. b. By moving large amounts of warm water away from the equator these currents also help to moderate temperature around the world.

c. When fluids circulate because of temperature differences it is known as thermal convection. ex. Hot Air Balloons ex. Earth’s Mantle d. These also help to carry heat around the globe. - this is known as the global conveyer belt. e. Seawater takes much longer to make the whole trip through the deep water system then the surface currents. Up to 500 years.

Activity 2 Differences Differences In Common Use a thinking map to compare and contrast Surface Currents & Deep Ocean Currents Use Chapter 16.1 to add additional facts. At least 5 differences and 5 Similarities Differences Differences In Common Key Words Key Words