How are earthquake waves used to provide information about Earths interior?
Primary Waves or P waves come first and they are the quickest and travel through earth’s interior. So if there is an earthquake in China the P wave will go through the earth and onto the other side in a couple of seconds and scientists know this because only a p wave can travel through liquid, solid, and gas and the interior of the earth is made up of semi-molten rock, molten rock and solid rock so we kind or know how the earth is inside.