Randall M. Richardson 2000 Journal of Geoscience Education v48 no5 p576
This article describes an activity where the class models the behavior of S and P waves with their bodies. Have the whole class stand up together in a circle and do "the wave" as they would in a football stadium, raising their arms and lowering them as the next person raises his or hers. This is a transverse (S) wave. Then have them do a longitudinal (P) wave by having them gently grip each other's shoulders and having one pull or push the next person in line. Ask students how the direction of motion corresponds to the direction of wave propagation for the P-wave (parallel) and the S-wave (perpendicular).