Download Earth Science introduction to convection

Earth Science lesson: Convection Currents
Big Idea: Features on the Earth’s surface, such as faults, mountain chains, volcanoes
and earthquakes are the result of what’s going on inside the earth.
What we know:
As depth increases, pressure, density and temperature increase
Show students the cornstarch models. They’ll have 10 minutes to explore, focused
on the questions on the white board. When done, they will fill out the 4 square chart
in their SNOBs, (Observations, inferences, vocab words, questions). Debrief.
Ask: What does this have to do with the earth?
Draw a model of the earth’s layers. Students add the picture to their snob. Show the
lithosphere and the asthenosphere. Show a hard-boiled egg. Ask students to
compare the egg and the earth.
Discuss the idea that the asthenosphere is “plastic”. What does this mean?
It means it is pliable like a Newtonian solid. Even though it is solid it can flow.
So what makes it flow?
Silent Demo: ball and ring
Idea: Heat makes things expand.
Now – introduce them to the lava lamps. How do they work?
We’re going to observe them to see how they work. We want to tie the idea that heat
expands things to the lava lamp, and then tie the lava lamp to the cornstarch and tie
them all to what’s going on inside he earth.
Students fill out 4 square chart again.
After they have observed, debrief. Return to the diagram of the Earth’s layers, and
draw convection currents.