Strike-Slip Earthquake Model (Anthony Mascolo)
Title: Strike-Slip Earthquake Model
Principle(s) Investigated: List all principles that apply to this activity.
Why do earthquakes occur - Stress and strain
Magnitude & Frequency
Seismic Waves
Faults and Fault Motion
MS-ETS1-4. Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.
Materials: Include a list of materials and sources from which they may be obtained.
Sandpaper (2-3 sheets per model)
String or twine (each model will need one short string, 10-15cm., and one long string, 20-30cm.)
Rubber-band (1 per model)
Paperclips (2 per model)
Rulers (1 per model)
Scissors
Tape
Books
Paper-bag book covers
White paper
Sugar cubes
pencils
Procedure: Give a detailed explanation of the procedure and include diagrams if possible.
Assembling Models: can be done before-hand or by the students themselves
- View diagram as instructions are followed.
- Wrap book(s) with paper-bag covering.
- Tape down sandpaper strip to a solid flat surface (like a desk).
- Attach the long string to the book. book should be able to be pulled along by the string.
- Attach sandpaper to the underside of the book.
- Tie free end of long string to the end of 1 paperclip. Loop rubber-band onto the other end of the same paper clip.
- Loop the free end of the rubber-band onto the second paperclip. Tie short string to the free end of the second paperclip.
- Tape the first paperclip to the edge of the paper strip.
- Using a ruler, place the 0cm mark at the boarder of the paperclip and the string that is pulled.continue to mark the centimeters along the short string.
Student prior knowledge: What prior concepts do students need to understand this activity?
By the time of this lab, students will have reviewed lightly covered earthquake engineering designs. This lab will be the precursor to in depth coverage of building design and earthquake preparation.
Explanation: Give a thorough explanation of the experiment or demonstration. Your explanation should be written to give your fellow teachers a solid understanding and include greater detail than what you might provide for your secondary students. Make certain to include equations whenever pertinent.
Break your students up into pairs or small groups as needed.
Opening to students: try something relevant to them.
Demonstrate how to use the strike-slip fault model.
Distribute the supplies or models.
Have the students conduct their simulations and fill out their 3+ trials (all groups should have the same # of trials).
Average out the data and have students answer questions 1-3. Go over questions 1-3.
Demonstrate sugar cube building simulation. Hand out the sugar cubes and have students answer questions 4-6.
The goal of this lab is for students to investigate the relative force needed to produce earthquakes. The sandpaper strip represents one edge of a fault line. The sandpaper-covered book represents the other edge of the fault line. Sandpaper increases the friction in the system, making it more difficult to move the book. Pulling the sandpaper-covered sled over a sandpaper strip simulates the strike-slip motion of earthquakes.
To measure the force required to pull the book along the sandpaper strip, a tension gauge is constructed.
A rubber band with a paper clip attached serves as a meter for potential energy recording. As the string is pulled, the rubber band stretches. When potential energy has built up high enough, the pulling force overcomes the friction between the book and the sandpaper strip, resulting in a "jolt" of movement. This 'jolt' is a simulation of earthquake movement.
There are various tests to run on the system, including putting sugar cube stacks on top of the book to represent "buildings." Data is collected and averaged to determine the results of various run sequences.
Questions & Answers: Give three thought-provoking questions and provide detailed answers.
Sample Questions from the Lab:
1. What does the movement of the book on the sandpaper strip represent in this investigation?
2. The movement of tectonic plates occurs all the time, but earthquakes do not. Why doesn't plate movement cause continual small earthquakes? Why do earthquakes occur every once in a while? Explain your answer.
3. Did all of the energy stored in the rubber band release when the book slipped? Do you think an earthquake releases all of the stored energy when it occurs?
4. Which sugar-cube building experienced the most damage? Why do you think this happened?
5. Which experiment resulted in the most damage? Why do you think this happened?
6. Given the results, suggest one safety tip that would reduce damage to buildings during an earthquake.
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Applications to Everyday Life: Explain (don't just list) three instances where this principle can be used to explain other phenomenon.
- Potential energy & kinetic energy: There are many different ways to experience and observe how energy builds up as potential energy before changing over to kinetic energy.
- Earthquake readiness: There are many things that you and your family can do to be better prepared in the event of a serious earthquake. Many preparations do not require an engineering degree or reconstruction of your home. Visit http://www.ready.gov/earthquakes for detailed information.
- Engineering and architecture: Architects need to be aware of the implications of the forces of nature such as earthquakes so that they leave room in the designs for proper structural engineering safety.
- San Andreas Fault: We live in the area of a major strike-slip fault and should be aware of its implications.
Photographs: Include a photograph of you or students performing the experiment/demonstration, and a close-up, easy to interpret photograph of the activity.