Have a student from each team lightly strike the tabletop with a rubber mallet on the table's front edge. Team members should observe the water and draw pictures of the waves they see in the box. Instruct students to repeat the procedure two more times, lightly striking the table on its top, then on one of the side edges of the tabletop. Tell students that the three directions in which earthquake waves vibrate determine how large the resulting sea waves will be. L waves cause the most damage and set up tsunamis.
Students can work in pairs to further demonstrate the three types of waves by using a slinky toy.
Stretch the spring to about 6 to 10 times its compressed size, with one student holding each end. The holder should hold the spring still, while the operator moves the spring as directed. To create a P wave, the operator pushes the spring directly toward the holder. To create an S wave, the operator waves the spring from side to side. To create an L wave, the operator lifts the spring up and snaps it down.