###### Inside the Earth - Shake It Up!

Earthquakes and volcanoes are expressions of energy; if there were no energy, there would be no earthquakes or volcanoes. Both earthquakes and volcanoes transfer energy from Earth’s interior to its surface. Earthquakes transfer energy via seismic waves. The seismic waves transfer mechanical energy from the Earth’s interior to its surface. Volcanoes transfer heat energy from the Earth’s interior to the surface. Moving lava carries heat as well as mechanical energy. In this activity you will model the transfer of energy via seismic waves.

How well can you build an edible building that can stand up to a moderate size earthquake?That is the challenge of this activity. Read the materials and instructions carefully before you design and build your structure. Try challenging your friends or classmates to see who can design a structure that will survive the greatest earthquake model forces!

Materials:

• For the shake table:
• Two soda case boxes
• Four rubber bands
• Four toothpicks
• Approx. 40 marbles
• Stapler
• Building structure options:
• Graham crackers & frosting (example, outcome)
• Gumdrops & toothpicks/drinking straws (example, example, outcome)
• Marshmallows & straws (example)
• Olives and/or carrots and toothpicks (example, outcome)
• Marshmallows & pretzels
• Any combination of the above or any other materials you can come up with! (Make sure you get permission before using the materials.)
• Watch, stopwatch, or clock (The more detail you can measure, the better the model will be)
• Pen or pencil
• Paper

Procedure:

1. Build the shake table. Refer to the enlarged image, shown smaller above, to help you with construction if needed.
2. Cut off the sides leaving an extra 2 cm around the perimeter of one of the boxes to allow for the shaking movement.
3. Staple a rubber band to each corner of the piece of cardboard that you have just cut.
4. Insert a toothpick into each corner of the box that was not cut.
5. Place the marbles into the large box, and place the shaking tray inside.
6. Place the ends of the rubber bands over the toothpicks, and your shake table is complete!
7. You can staple the rubber bands onto the larger box, but if it is constructed as indicated, the shaking tray can be removed to place a building on it and then reconnected to the box.
8. To construct the building you can use any materials that you would like, as long as the building is made of edible parts (and you have permission from an adult.) Okay - we don't really eat toothpicks and straws, but we USE them to eat, right?
9. Your building must be at least 30 cm tall (which represents three stories.).
10. The base of the building must fit within the base of the shake table, so make sure to check this during design and construction.
11. Test your design on the shake table.
12. If you are comparing buildings with friends or classmates, make sure the same person shakes each structure. This is to ensure that the forces exerted on each construction are the same.
13. Record how many seconds your building lasted until it collapsed from the shaking.

Safety concerns: As with all science lab activities, the most important safety rule is to follow all teacher directions.

Data:
Record your observations here. What materials did you use? What did your structure look like? How many seconds did it last?

Analysis:

1. How many seconds was your building able to survive the shaking?
2. Compare the survival time of your building quake survival with the building quake survival of your friends or classmates.
3. What materials did you use in constructing the structure?
4. How did your structure's design compare to your friends or classmates?
5. Which seemed to be more important, the type of building materials used or the design of the building?
• What construction method resulted in a building that lasted the longest?
• What did all of the buildings with the best results have in common?
6. How does the shake table model a real Earthquake?
• What does the tray represent?
• What do the marbles represent?

Extension:
Describe another way that you could model the movement and interactions of the tectonic plates. What type of plate boundary/movement will you model? What materials would you need? How would you make it? With permission, use the materials to construct your model.

Snack Tectonics provides more ideas on how to model earthquakes.

This Sci-ber Text was developed by the Utah State Board of Education and Utah educators.