Steps 

Time Allotment: This lesson requires approximately 5 class periods.  
Introduce the students to the Savage Earth: Restless Planet pages of the wNetStation Web companion piece for the PBS series SAVAGE EARTH (http://www.thirteen.org/savageearth/earthquakes/index.html). Allow students to explore the different types of earthquake waves. Suggest that they explore the sidebars in addition to the main article. Pay particular attention to Sidebar 3  a page about earthquakeproof buildings (http://www.thirteen.org/savageearth/earthquakes/html/ sidebar3.html). Students can continue their research by exploring Earthquake Report (http://www.newscientist.com/nplus/insight/quakes/ quakes.html) and Earthquake History (http://www.earthwaves.com/shorose/history.html). If time permits, students should conduct their own Web search for information about earthquakes and earthquakeproof buildings. Inform students that their task for the week will be to construct a model of an earthquakeresistant building. Give students The Task page, located in Organizers for Students, and assign each student a work partner.  
Use the slinky to demonstrate the different waves that cause the damaging forces of the earthquake. P , or primary, waves alternately compress and stretch the rock through which they move. pwave Demonstrate a pwave by stretching the slinky out slightly, having students hold it at each end, compressing about 10 of the slinky wires together, and then letting the wires go. Students will observe the pwave as it moves through the slinky. Then have the students at each end wiggle the slinky from side to side, like a snake wiggling, so that students can observe an s , or secondary, wave that occurs in an earthquake. swave Tell students that their building model should withstand both of these waves. Tell students that construction of models will begin the next day. Show them the materials that you have gathered for their use and discuss the minimum size requirements of their model (listed on The Task page). Ask them if there are other materials they would suggest, and have the class discuss their acceptability. (The models must simulate real buildings with various parts.)  
As a class, the students will construct the earthquake simulator: A slinky should be placed in the bottom of a box and stretched from one end to the other. It should then be covered with loose, dry sand, with the ends a little exposed so you can manipulate them. Explain that the buildings will be placed on top of this simulator for their earthquake tests. Students should begin the construction of their models. Tell them that testing will begin the next day so that all glue must be dry by the beginning of the next day's class.  
Students complete their models. Take pictures of the models before testing. If cameras are not available, students should draw their model. They must also write a paragraph explaining the design features of their model. Put one of the model buildings on the sand on top of the slinky. Test the model with a pwave by compressing links in one exposed end of the slinky and letting the wave travel the length of the buried slinky. Repeat with an swave by wiggling an end of the slinky. Take "after" pictures, or have the students draw their "after" model. Allow students to modify their designs. (Explain that an actual earthquake combines the two kinds of waves, plus other waves, but that the latter are not as easy to simulate.)  
Final testing day: Again record "before" and "after" pictures of the models. Students should write a paragraph describing the design features of their model. Discuss the features and materials that proved most successful and have students explain why they were most successful. Display all completed model evaluations. 