Why It Matters
Have you ever had a zipper get stuck before on your back pack?
You pull and pull on the zipper but it just won’t move. Finally, with one final tug, the zipper frees itself from its obstacle and comes zooming up!
Stress along fault lines can behave a lot like a stuck zipper. Here is a simulation that the U.S.G.S. has created to show this happening along the San Andreas Fault line during the 1906 San Francisco earthquake:
How are zippers similar to fault lines at plate boundaries? Instead of us tugging at our zipper, what is tugging on the fault line?
- The San Andreas Fault line has a long history of getting stuck and then slipping. http://pubs.usgs.gov/gip/earthq3/move.html What type of stress is being experienced along this fault line? What type of fault line is the San Andreas Fault in California?
- The San Andreas Fault represents the transform plate boundary between the North American Plate and the Pacific Plate. Here is a map of California with the San Andreas Fault plotted: http://pubs.usgs.gov/gip/earthq3/where.html Make a prediction of what the shape of California will look like in the future. Trace the shape of California (by hand or digitally) and create a flip book showing the motion along the San Andreas Fault.
United States Geological Survey. http://pubs.usgs.gov/gip/earthq3/move.html