 Copy the question and answer in sentences:  Why was the invention of the submersible so important in the field of oceanography? What kinds of discoveries could be made with it? Walk-In

 The submersible made it possible for oceanographers to safely go far down in the ocean, where the pressure, cold temperature and darkness made it impossible without it.  Oceanographers were able to learn about marine biology (lifeforms that live at great depths), geology (in the rocks and formation of the ocean floor) and to collect samples for chemical analysis. Answer

Write today’s title: Ocean Currents

 Discuss the following question with your table:  What would happen if a message in a bottle was placed in the ocean off the coast of a deserted island? Building Background

Speculate with your group on these questions:  Why would it move?  What causes things to move in the ocean?  How are waves formed?  Do ocean water and waves make weather and winds, or do weather and winds make waves? Would the bottle move:?

 Please do not write on the small slip of paper.  Use the questions on your small slip to guide your reading.  Please handle the textbook, “Earth’s Waters”, carefully.  Write complete sentences that repeat the question in your answer.  Be ready to share answers afterward! Find out more about ocean currents!

 What is an ocean current?  An ocean current is a mass of moving water.

 What do ocean currents distribute?  Ocean currents distribute heat and nutrients around the world.

 How do surface currents form?  Surface currents form when strong winds blow over the ocean. The winds are set into motion because of uneven heating of the Earth’s surface. The currents do not extend very deep, but they cover large areas of the surface of the water.

 What causes surface currents to “curl”?  The Earth’s rotation curls surface currents into the shape of giant clockwise whirlpools in the Northern Hemisphere (top half of the world), and into counterclockwise curls in the Southern Hemisphere.  The shapes of the continents also affect how surface currents move.

 Explain how surface currents help to moderate (even out) the global ocean temperatures.  Surface currents carry warm water away from the equator area, and cool water away from the poles. Since the water mixes and forms more even temperatures, the currents are MODERATED.

 What causes deep currents to form?  Deep currents form because of differences in water density. Dense water sinks down into the ocean, and less dense water rises back up.

 Explain how downwelling and upwelling help ocean animals.  Downwelling is the movement of water from the surface to greater depths below. It carries oxygen down from the surface (near the air).  Upwelling is the movement of water up to the surface. It brings up nutrients from the deep ocean, so ocean animals tend to live in areas where upwelling occurs.

 Use the map of currents on page.  Mark the major currents on your map, outlining their direction with a red arrow.  Color each ocean area a different color, and blend the edges (to remember that the oceans are all the same water!). Map of Ocean Currents

 Explain to the person next to you what an ocean current is, and how the direction and size of the current is determined. Check your learning!