As a seismologist with extensive experience in the study of seismic waves, I can provide you with information on the speeds at which P waves and S waves travel. P waves, also known as primary waves, are the fastest seismic waves. They are compressional waves that can travel through both solid and liquid materials, which means they can move through the Earth's crust, mantle, and even the outer core. The speed of P waves can vary significantly depending on the material they are traveling through. Generally, P waves travel at speeds ranging from about 4 km/sec in the upper crust to over 7 km/sec in the lower mantle. read more >>

Even though they are slower than P-waves, the S-waves move quickly. Typical S-wave propagation speeds are on the order of 1 to 8 km/sec. The lower value corresponds to the wave speed in loose, unconsolidated sediment, the higher value is near the base of Earth's mantle.read more >>