Convection Currents Modeling Lab

How do convection currents work in order to support continental drift? Convection currents transfer heat from one place to another by mass motion of a fluid such as water, air or molten rock. The heat transfer function of convection currents drives the earth’s ocean currents, atmospheric weather and geology. Geologists believe the molten rock deep within the earth circulates by convection currents (like a conveyer belt or escalator analogy). The rock is in a semi-liquid state and should behave like any other fluid, rising up from the bottom of the mantle after becoming hotter and less dense from the heat of the earth’s core. As the rock loses heat into the earth’s crust, it becomes relatively cooler and denser, sinking back down to the core. These constantly circulating cells of hotter and cooler molten rock are thought to help heat the surface. Some geologists believe convection currents within the earth are a contributing cause of volcanoes, earthquakes and continental drift. Can a model be created to explain and/or show convection currents?

Procedure

Materials: Groups ~3/4

Clear Plastic Storage Box (ie. 6 Qt (5.7 L))    

(5) Styrofoam Coffee Cups

Water Source (cool)

Microwave – heat source

Red Food Coloring – hot mantle indicator

Blue/Green Food Coloring – cool mantle indicator

(2) Disposable Pipette 

Resources

Steps:

1. Gather all necessary materials as directed.

2. Fill the storage box ~3/4 full of cool water.

3. Place the storage box on top of (4) evenly distributed yet inverted Styrofoam cups.

4. Fill the 5^th Styrofoam cup with microwaved (~ 2 minutes) hot water; wait for ~ 5 mins

5. Slide the Styrofoam cup with hot water under the storage box in the center.

6. “Carefully” extract ~ 1/2 mL of “red” food coloring with a pipette and place only 1 drop of the contents under water directly at the bottom/center of the storage box under the hot water.

7. “Carefully” extract ~ 1/2 mL of “blue/green” food coloring with a pipette and place only 1 drop of the contents under water directly at the bottom and “both” of the narrow sides of the storage box under the pillar cups

8. Observe dyes for about 5-10 minutes and note the reaction going on.

9. After answering the answer sheet, clean up all materials as directed.