Why are we moving?

Robert F. Wagner School of Art and Technology

Summer Research Program for Science Teachers

August 2012

Subject: Earth Science

Unit: Plate Tectonics

Duration: 60 minutes

Introduction:

In this activity, students will be designing models to demonstrate convection current. Through scientific inquiry, students will be able to explain the process of convection that drives the plate tectonics in motion.

Aim: Why do the tectonic plates move?

Objectives:

Students will be able to

1. Demonstrate convection current using simple materials.

2. Identify Earth’s outer core as the heat source driving convection currents in Earth’s mantle.

3. Describe how convection current drives the movement of Earth’s plates.

Vocabulary: density, convection current

Materials:

Wooden blocks

Plastic and Styrofoam cups

Plastic shoebox containers with water

Food dye blue and red

Hot and cold water

Paper towels

Safety goggles

Student worksheet: Convection Current

Do Now:

If you place a raft in a lake, would it stand still in water, why or why not?

Procedure:

1.      Students are given a piece of wooden block and a container of water to observe that the wooden block cannot stand still in water because water is always moving due to convection current.

2.      Introduce concept of convection current and relate it to the real world:

a.       Hot air balloon rises because hot air is less dense than cold air.

b.      Boiling water in a pot

c.       Attic is warmer than the basement.

d.      Plate tectonic movement: point out to the students that the wooden block floating in a water bath is analogous to the layers of the Earth.  Water represents the asthenosphere where convection current occurs. Wooden block represents the plate floating on top of the asthenosphere. Diagrams below are useful visuals for understanding.

3.      Students are asked to design their own experiments using the materials given to demonstrate convection current. Students are to record their observations on the worksheet given. The procedure should be similar to the following steps (this protocol is not given to the students):

a.       Fill your plastic container half way with water.

b.      Place your plastic container on top of the four paper cups.

c.       Add two drops of food dye on the bottom of the container.

d.      Observe the food dye in the container. Complete Diagram 1: “No Heat Source”, in the Data section of this worksheet.

e.       Place a cup filled with hot water under the container where the food dye was placed.

f.       Observe the food dye in the container. Complete Diagram 2: “Active Heat Source’, in the Data section of this worksheet.

New York State Standards:

Standard 1

1.      The central purpose of scientific inquiry is to develop explanations of natural phenomena in a continuing, creative process.

2.      Beyond the use of reasoning and consensus, scientific inquiry involves the testing of proposed explanations involving the use of conventional techniques and procedures and usually requiring considerable ingenuity.

3.      The observations made while testing proposed explanations, when analyzed using conventional and invented methods, provide new insights into phenomena.

Standard 2
2. Beyond the use of reasoning and consensus, scientific inquiry involves the testing of proposed explanations involving the use of conventional techniques and procedures and usually requiring considerable ingenuity.

3. The observation made while testing proposed explanations, when analyzed using conventional and invented method, provide new insights into phenomena.

Standard 4

2.1a. Earth Systems have internal and external sources of energy, both of which create heat.

2.1k. The outward transfer of Earth’s internal heat drives convective circulation in the mantle that moves the lithospheric plates comprising Erath’s surface.