GENERAL GEOLOGY

Detailed explanation-1: -Two kinds of waves are generated by earthquakes and travel through solid rock: In P or compressional waves, the vibration of the rock is in the direction of propagation. P waves travel fastest and are the first to arrive from the earthquake.

Detailed explanation-2: -P-waves (P stands for primary) are compressional earthquake waves that pass through the interior of the Earth.

Detailed explanation-3: -Refraction has an important affect on waves that travel through Earth. In general, the seismic velocity in Earth increases with depth (there are some important exceptions to this trend) and refraction of waves causes the path followed by body waves to curve upward.

Detailed explanation-4: -Seismic waves move outward in all directions away from their source. Each type of seismic wave travels at different speeds in different materials. All seismic waves travel through rock, but not all travel through liquid or gas.