Why are we moving?
Robert F. Wagner School of Art
and Technology
Summer Research Program for
Science Teachers
August 2012
Subject: Earth Science
Grade Level: 8-12
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
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.