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Grade Level(s): 6-8
Introduction: Currents are moving masses of ocean water on the surface or deep within the oceans. Wind is the primary force for surface currents. Deep ocean circulation happens because of density differences within water masses. Regular intermittent currents that respond to movement of the sun and moon are called tidal currents. Tides are the actual rise and fall in local water levels. Every current, regardless of its origin, has a set and a drift (speed). Set is the true direction toward which a current flows, drift is its speed.
Learner Objectives:
- The student will be able to identify the forces that cause surface currents.
- The student will be able to explain the factors which affect deep ocean currents
Florida Sunshine State Standards: Science: SC.D.1.3.3 Math: MA.B.1.3.2.
Competency-Based Curriculum: Science: Sci. M/J3 III-4-A Math: M/J3 II-4-A
Materials:
Metal pan(10cm. X 3cm. X 7cm.)
Hair dryer
Pepper
World Map
Activity Procedures:
- Ask the students a question regarding the direction in which rivers flow (rivers flow in one direction).
- Ask how an oceans flow is similar or different than that of a river (waves and tides cause water in oceans to move up and down and into the shoreline and back to sea).
- Ask what they think would happen if someone sealed a message in a bottle, and threw it into an ocean (most likely the bottle would be found by a person from a distant place).
- How do you think that the bottle got there? Some students may know that currents carried the bottle to its present location.
- Identify to the class that large streams of water moving through an ocean is a current.
- Identify that currents can move water at the surface or deep within the ocean.
- Ask the students to distinguish between both types of currents. Surface currents, can be as deep as several hundred meters below the surface. Deep-ocean currents can be found deeper than a few hundred meters.
- Ask what causes surface currents. The wind as the driving force should be the response. To show this concept the teacher should demonstrate with a shallow pan of water, a hair dryer and pepper. Sprinkle the pepper on top of the surface of the water in the pan. Then turn on the blow-dryer and blow the pepper across the surface of the water.
- Ask if the students can make an inference about ocean currents and the flow of the pepper across the pan.
Student Assessment:
Have students demonstrate their understanding of ocean currents by writing a story describing the imaginary trip taken by a bottle which contains a message written by the student.
Activity Extensions:
Have students investigate how surface currents affect the climate of certain landmasses (Miami and the Gulf Stream would make an ideal investigation).
Home Learning Activity:
Have students investigate the Coriolis’ Effect on the moving water.
Vocabulary: density, tidal currents, set, drift
References/Related Links:
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