1. Preview Section 1 Currents Section 2 Currents and Climate
The Movement of Ocean Water
Preview
Section 1 Currents
Section 2 Currents and Climate
Section 3 Waves
Concept Mapping

2. Section 1 Currents
Bellringer
We discussed Thor Heyerdahl’s and his Kon-Tiki voyage in the beginning of Chapter 5. Look at the large map of the world that shows the different ocean currents and the origination and destination points for Heyerdahl’s voyages. Which currents would he have used to reach his destination? How might you prove your hypothesis? What kind of data would you need?
Write your answer in your science journal.

3. Objectives The Student will Describe surface currents.
Section 1 Currents
Objectives
The Student will Describe surface currents.
The Student will List the three factors that control surface currents.
The Student will Describe deep currents.
The Student will Identify the three factors that form deep currents.

4. One Way to Explore Currents
Section 1 Currents
One Way to Explore Currents
Ocean water contains streamlike movements of water called ocean currents.
Norwegian explorer Thor Heyerdahl proved his theory that ocean currents influenced human migration by using a raft that was powered only by wind and ocean currents.

5. Section 1 Currents
Surface Currents
Horizontal, streamlike movements of water that occur at or near the surface of the ocean are called surface currents.
Surface currents are controlled by three factors:
1. global winds
2. the Coriolis effect
3. continental deflections.

6. Surface Currents, continued
Section 1 Currents
Surface Currents, continued
Global Winds Winds that blow across the Earth’s surface create surface currents in the ocean. Different winds cause currents to flow in different directions.
The Coriolis Effect is the apparent curving of moving objects from a straight path due to the Earth’s rotation.

7. The Coriolis Effect Section 1 Currents
Click below to watch the Visual Concept.
Visual Concept

8. Surface Currents, continued
Section 1 Currents
Surface Currents, continued
Continental Defections When surface currents meet continents, the currents deflect, or change direction.

9. Surface Currents, continued
Section 1 Currents
Surface Currents, continued
Taking Temperature Currents are also affected by the temperature of the water in which they form.

10. Section 1 Currents

11. Section 1 Currents
Deep Currents
Streamlike movements of ocean water located far below the surface are called deep currents.
Deep currents are not controlled by wind.
Deep currents form in parts of the ocean where water density increases. The density of the ocean is affected by temperature and salinity.

12. Deep Currents, continued
Section 1 Currents
Deep Currents, continued
Formation and Movement of Deep Currents Differences in water density cause variations in the movement of deep currents.

13. Section 1 Currents

14. Bellringer Given the average yearly temperatures for the Scilly
Section 2 Currents and Climate
Bellringer
Given the average yearly temperatures for the Scilly
Isles in England and Newfoundland in Canada, can
you explain why the two locations have very
different year-round temperatures? Note their
locations on a globe, and use what you know about
the movement of ocean currents to support your
answer.
Record your thoughts in your science journal.

15. Objectives The Student will Explain how currents affect climate.
Section 2 Currents and Climate
Objectives
The Student will Explain how currents affect climate.
The Student will Describe the effects of El Niño.
The Student will Explain how scientists study and predict the pattern of El Niño.

16. Surface Currents and Climate
Section 2 Currents and Climate
Surface Currents and Climate
Warm-Water Currents and Climate Warm-water currents create warmer climates in coastal areas that would otherwise be much cooler.

17. Surface Currents and Climate, continued
Section 2 Currents and Climate
Surface Currents and Climate, continued
Cold-Water Currents and Climate Cold-water currents keep climates along a coast cooler than the inland climate year-round.

18. Surface Currents and Climate, continued
Section 2 Currents and Climate
Surface Currents and Climate, continued
Upwelling is the movement of deep, cold, and nutrient-rich water to the surface of the ocean.
The nutrients that are brought to the surface support the growth of plankton. Plankton support larger organisms, such as fish and seabirds.

19. Section 2 Currents and Climate

20. Surface Currents and Climate, continued
Section 2 Currents and Climate
Surface Currents and Climate, continued
El Niño is a change in the water temperature in the Pacific Ocean that produces a warm current.
Effects of El Niño El Niño alters weather patterns enough to cause disasters, including flash floods, mudslides, and droughts. El Niño also prevents upwelling off the coast of South America.

21. Surface Currents and Climate, continued
Section 2 Currents and Climate
Surface Currents and Climate, continued
Studying and Predicting El Niño Learning as much as possible about El Niño is important because of its effects on organisms and land.
One way scientists use technology to predict an El Niño is with a network of buoys operated by the National Oceanic and Atmospheric Administration (NOAA). The buoys are located along the Earth’s equator record data about surface temperature, air temperature, currents, and winds.