What type of seismic waves travel fastest through the Earth?

P-waves, or primary waves, are seismic waves that travel fastest through the Earth. These waves are characterized by their ability to move through both solid and liquid materials, which allows them to propagate rapidly through the Earth’s interior. They compress and extend the material they travel through, creating areas of compression and rarefaction, much like how sound waves travel through air.

The speed of P-waves is typically around 5 to 8 kilometers per second in the Earth's crust, making them the first waves detected by seismographs after an earthquake occurs. Their speed is due to the fact that they travel through the bulk of the Earth’s material, establishing a rapid mode of transportation for seismic energy.

In contrast, S-waves, which are secondary waves, travel slower than P-waves and can only move through solid materials. Surface waves, including Rayleigh waves, travel even more slowly than both P-waves and S-waves, propagating along the Earth's surface and usually causing the most damage during an earthquake.