seismic waves

The study of seismic waves has lead to our understanding of teh structure of the earth. There are 2 types of seismic waves. Primary and secondary, also known as P waves and S waves.

(Primary) P-waves

• P waves are longitudinal like sound

• P waves are faster than S-waves

• When a P-wave passes the ground it is vibrated in the direction the wave is propagating

• P waves travel through both solids and liquids

(Secondary) S-waves

• S waves are transverse like light

• S waves can only travel through solids

• As a transverse/S wave passes the ground it is vibrated perpendicular to the direction that the wave is propagating

• S waves are slower than P waves

Understanding Earth

We can use these waves to study the interior of the earth. Since P waves can pass through solids and liquid the can go all the way through earth, however S-waves cannot pass through the liquid outer core.