The timing it takes for the P/S waves to reach you. One travels through the center, and the other travels along the surface of the earth. Here's a quick rundow

The timing it takes for the P/S waves to reach you. One travels through the center, and the other travels along the surface of the earth. Here's a quick rundown: https://slcc.pressbooks.pub/physicalgeography/chapter/4-3/ https://slcc.pressbooks.pub/physicalgeography/chapter/4-3/