MadSci Network: Earth Sciences |
Modeling Earthquakes A nice and simple way to model earthquakes for a group of middle school students would be to build a little town model with a strike-slip fault running through the center of town. A strike-slip fault is the type of crack in the Earth’s crust that allows pieces of land to slide past one another, from side to side. For example, pretend that you are standing on one side of a strike-slip fault and your friend stood facing you on the opposite side. If an earthquake occurred, you would see your friend move to your left or right. And your friend would see you move either left or right. This is the type of fault that causes earthquakes in California (the San Andreas Fault). Another way to imagine this type of fault is to put your hands together, with your thumbs touching and your palms facing downward so that you are looking at the back of both of your hands. Now, move your right hand forward and notice that your thumbs are no longer next to each other. The line between your two thumbs is a strike-slip fault. If you have two pieces of cardboard (or something similar), place them next to each other, but don’t glue them together. Then build a town on top of the two pieces of cardboard. I would recommend that you don’t glue the pieces of your town down. That way, when the earthquake happens, you can set it back up again for more earthquakes. In your town, you could include a few houses and a little shopping area, a park, a school, whatever you’d like. I would recommend putting a fence that runs across your fault (between the two pieces of cardboard) and maybe some people talking to each other from across the fault line. Then, when you are ready for the earthquake to happen, simply push one piece of cardboard forward quickly a few inches. See what happens to your town! The most noticeable things should include the fence no longer being straight and the people having moved apart from each other. If you build the town correctly, you could get buildings to collapse when the earthquake happens. There is room for a lot of creativity here. Another way of creating the effects of an earthquake beneath your town is by making a "shake table". The United States Geological Society (USGS) has some good information on how to build one. Then put your town on top of it and watch the earthquake go! See: http://mceer.buffalo.edu/education/exercises/shtable.asp Also check out this USGS web page for more ideas: http://earthquake.usgs.gov/4kids/
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