Stick-Slip Activity
(FEMA Activity 2.1)

Standard III

Students will understand that gravity, density, and convection move Earth's plates and this movement causes the plates to impact other Earth Systems.

Objective 02

Describe the processes within Earth that result in plate motion and relate it to changes in other Earth Systems.

Indicator c

Model the movement and interaction of plates.

Intended Learning Outcomes:

  1. Use Science Process and Thinking Skills
    1. Observe objects, events and patterns and record both qualitative and quantitative information.
    2. Evaluate, sort, and sequence data according to given criteria.
    3. Select and use appropriate technological instruments to collect and analyze data.
    4. Plan and conduct experiments in which students may:
      • Identify a problem.
      • Formulate research questions and hypotheses.
      • Predict results of investigations based upon prior data.
      • Identify variables and describe the relationships between them.
      • Plan procedures to control independent variables.
      • Collect data on the dependent variable(s).
      • Select the appropriate format (e.g., graph, chart, diagram) and use it to summarize the data obtained.
      • Analyze data, check it for accuracy and construct reasonable conclusions.
    5. Construct models, simulations and metaphors to describe and explain natural phenomena.
    6. Use mathematics as a precise method for showing relationships.
  2. Manifest Scientific Attitudes and Interests
    1. Raise questions about objects, events and processes that can be answered through scientific investigation.
  3. Demonstrate Understanding of Science Concepts, Principles and Systems
    1. Apply principles and concepts of science to explain various phenomena.
  4. Communicate Effectively Using Science Language and Reasoning
    1. Provide relevant data to support their inferences and conclusions.
    2. Use precise scientific language in oral and written communication.
    3. Use mathematical language and reasoning to communicate information.
  5. Demonstrate Understanding of the Nature of Science
    1. Understand that science investigations use a variety of methods and do not always use the same set of procedures; understand that there is not just one "scientific method."
    2. Science findings are based upon evidence.
    3. Understand that scientific conclusions are based on the assumption that natural laws operate today as they did in the past and that they will continue to do so in the future.

Summary: Students will operate a model to observe the type of motion that occurs at a fault during an earthquake and explore the effects of several variables.

Learning Objectives:

  1. Students will model the frictional forces involved in the movement of a fault.
  2. Students will measure movement, calculate averages, and plot and graph information.
  3. Students will compare and contrast the variables of fault strength and potential energy.

Materials:

  • Seismic Sleuth Master 2.1a
  • Stick-Slip Data Sheet
  • Sandpaper sheets:
    • grit 60, 120, and 400
  • Scissors
  • Strapping tape
  • Sugar cubes
  • Thumbtacks
  • Large paper clips
  • Meter stick
  • String
  • Dowel or empty paper towel tube
  • Marking pen
  • Scales
  • Pine board (1"x12"x6')
  • Protractor
  • Brick

Sequence and duration of each part of lesson:
To assure success, construct the model ahead of time and rehearse the activity. Then arrange materials for student models in a convenient place.

  • Introduction (10 minutes)
     Elicit a definition of a fault from the class, supplementing students' information as necessary until the essential elements have been covered.

    Explain to the students that when an earthquake occurs and movement begins on a fault plane, the movement will not proceed smoothly away from the focus. Any change in the amount of friction along the fault will cause the fault movement to be irregular. This includes changes along the length of the fault and with depth, changes in rock type and strength along the fault, and natural barriers to movement, such as changes in the direction of the fault or roughness over the surface of the fault plane.

    Rupture along a fault typically occurs by fits and starts, in a type of sporadic motion that geologists call stick-slip. As energy builds up, the rock on either side of the fault will store the energy until its force exceeds the strength of the fault. When the residual strength of the fault is exceeded an earthquake will occur. Movement on the fault will continue until the failure reaches an area where the strength of the rock is great enough to prevent further rupture. In this manner, some of the energy stored in the rock, but not all of it, will be released by frictional heating on the fault, the crushing of rock, and the propagation of earthquake waves.

  • Lesson Development (30 minutes):
    1. Divide the class into working groups of at least four students each. Distribute one copy of Stick-Slip Data Sheet to each group. Tell students that they are going to model a process, record data for each trial, and then vary the process, changing only one variable at a time.
    2. Allow groups to assemble their materials, then give these directions:
      • Fold each piece of 120-grit sandpaper in half lengthwise and cut, to produce eight strips of sandpaper, each 11.5 cm x 28 cm in size.
      • Wrap one of the strips around the box and secure it around the sides (not the top and bottom) with two rubber bands. Weigh and record box mass.
      • Tape the seven remaining strips of 120-grit sandpaper into one long strip. (Be sure to use tape only on the back of the sandpaper.) Now attach the sandpaper lengthwise down the center of the pine board, using two thumbtacks at each end and being sure the sandpaper is drawn tight.
      • Attach one paper clip to one of the rubber bands around the box.
      • Tie one end of the string onto another paper clip and place a mark on the string about 1 cm from the clip. Use one rubber band to join the paper clip on the box with the paper clip on the string. Tie the free end of the string around the dowel or paper towel roll.
      • Tape the meter stick onto the sandpaper strip on the board.
      • diagram Position the box at one end of the board so it is centered on the sandpaper. Use books to rise the other end of the board approximately 10 cm. Measure and record the height.
      • Gently roll the string onto the dowel until the string lifts off the paper and becomes taut. Note the location of the mark on the string relative to the meter stick. Take care to keep the dowel in the same position during rolling and measurement.
      • Continue to roll the string onto the dowel until the box moves. The box should move with a quick jumping motion. Record the new location of the mark on the string (the distance the box moved) on the data table. Continue rolling up the string and recording jump distance until the box hits the meter stick. The meter stick can be pulled upwards to allow the box to continue to be pulled.
      • Subtract the beginning measurement from the ending measurement or add up the jump measurements to find out how far the box moved. Divide by the number of jumps to calculate an average jump distance.
    3. Instruct other students in the same group to change one variable, repeat the procedure, and average the distance of the jumps. Students may vary the model by adding one or more rubber bands, adding more books to change the angle of the board, substituting the brick for the box, or using sandpaper of a different grit. If time allows, give every student a chance to operate the model with each of the variations.
    4. Ask students to complete their data sheets.
  • Conclusion (10 minutes):
    Ask the class:
    • What might the different variables represent in terms of earthquakes and landscape conditions? (Number of rubber bands- different among of energy released; angle of the aboard- steepness of the fault; sandpaper grit size- differences in the amount of force required for a fault to move- the amount of friction.) Emphasize that different faults can store different amounts of energy before they fail. Some faults have the potential for generating larger earthquakes than others.
    • Do the rubber band and string go totally slack after each movement. (No.) What does this tell you about the release of stored energy on a fault when an earthquake occurs? (No earthquake ever releases all the energy stored in the Earth at a particular point. It is because some stored energy always remains that one quake may have numerous foreshocks and aftershocks, and earthquakes recur frequently in some active areas.

  • Evaluation: Student assessment will be evaluated by the accuracy and quality of the student's work as well as the results of the activity.

    Data Sheet print as a .pdf file

    Name
    Date

      Trial 1 Trial 2 Trial 3 Trial 4 Trial 5
    Box Weight          
    Board Height          
    Sandpaper Grit          
    Beginning Distance          
    Jump 1          
    Jump 3          
    Jump 4          
    Jump 5          
    Jump 6          
    Jump 7          
    Jump 8          
    Jump 9          
    Jump 10          
    Jump 11          
    Jump 12          
    Jump 13          
    Jump 14          
    Jump 15          
    Total Distance          
    Average Distance          
FEMA: Seismic Sleuths 1-800-480-2520 P.O. Box 2021 Jessup, MD 20794-2021