ES1002  Observe animations of earthquake waves.

P waves, also called compressional waves or primary waves, move through material by squeezing and stretching the material in the same direction as the wave is moving.
S waves, also called shear waves or secondary waves, move materials at right angles to the wave direction.

  !   Click the images to see the animations. Play both movies at the same time to examine the relative speeds of the waves.
Tom Grace, TERC