Earthquake Machine

1. Earthquake Machine Mechanical Modeling to Increase Student Understanding of Complex Earth Systems Michael Hubenthal - IRIS Consortium

2. Objectives (SWBAT) • Explain earthquakes as a part of the natural Earth System • Describe global trends for Earthquake occurrence and magnitude • Interpret a Gutenberg Richter plot (Frequency vs. Magnitude) • Critically analyze an argument • Describe the importance of sharing science results with peers in the science process

3. What is an Earthquake? Write down a definition for an earthquake In small groups, discuss your definitions of an earthquake and create a consensus definition

4. Exploring with a model…

5. B EQ Machine - Lite Bulk of the Plate Top View C Elastic Properties of Earth Materials Plate has Constant Velocity Here Edge of the Plate

6. What did you observe? How would you alter your definition, to accommodate these observations?

7. Elastic Rebound Theory Distant forces cause a gradual build up of stress in the earth over tens or hundreds or thousands of years, slowly distorting the earth underneath our feet. Eventually, a pre-existing weakness in the earth--called a fault or a fault zone--can not resist the strain any longer and fails catastrophically.

9. http://quake.wr.usgs.gov/research/deformation/modeling/animations/index.htmlhttp://quake.wr.usgs.gov/research/deformation/modeling/animations/index.html

10. Key Concepts • Elastic materials can store potential energy • Earth materials are elastic though they may not seem it within our temporal and thermal scales • The Earth’s plates are constantly in motion though we can not perceive this without instruments

11. Studying Earthquake Recurrence

12. Developing arguments…. How many beads are in the box????

13. Exploring with a model…

14. Seismic Moment Mo = fault length x fault width x displacement x rigidity Moment Magnitude = Mw = log Mo/1.5 – 10.7

15. B Visualizing magnitude with the model Seismic Moment Mo = fault length x fault width x displacement x rigidity Moment Magnitude = Mw = log Mo/1.5 – 10.7

16. Group A “There are long periods of quiet between earthquakes” Group B “Most earthquakes are huge, deadly and destructive events” Develop an argument* either for or against this statement based on your experimentation with the earthquake machine. *Note: You must base our argument on minimally 30 events

17. “There are always long periods between earthquakes.”

18. “All earthquakes are huge, deadly, and destructive events”

19. Components of Prediction • When? • Where • How Big?

20. Using the data you have collected argue either for or against the following statement… “There hasn’t been an earthquake in a long time; therefore the next one must be huge.”

22. Time Predictable Slip Predictable Characteristic Stress Slip Time

23. Calaveras Fault Data (Bufe et al., 1977)

24. For a full description of the EQ Machine and a multi-period lab please visit: http://www.iris.edu/edu/lessons.htm

25. Young students ideas (Ross and Shuell, 1991) (Tsai, 2001) (Leather, 1987)

26. Conceptual shift at age 14? (Barrow & Haskings, 1996; DeLaughter et al., 1998; Libarkin et al., 2005))

27. Location of EQs & relation to plates

28. Centennial Connections During the 1906 event the earth on one side of the fault had slipped compared to the earth on the other side of the fault by up to 21 feet (7 m). Steinbrugge Collection of the UC Berkeley EERC

29. After studying the fault trace of the 1906 earthquake and regional surveys (pre/post event), Harry Fielding Reid, postulated that the forces causing earthquakes were not close to the earthquake source but very distant.

30. Event #  Time Displacement Examine page one of your data set and develop a prediction for the 26th event based on the previous 25 events.

31. Seismicity of the EQ Machine - 67 “Years”

32. Seismicity of the EQ Machine - 163 “Years”