GEOLOGY

Detailed explanation-1: -P waves travel through solid and liquid, but S waves do not travel through liquid.

Detailed explanation-2: -Both P and S waves travel outward from an earthquake focus inside the earth. The waves are often seen as separate arrivals recorded on seismographs at large distances from the earthquake. The direct P wave arrives first because its path is through the higher speed, dense rocks deeper in the earth.

Detailed explanation-3: -Table 1 Properties of P-waves and S-waves P-waves pass through both mantle and core, but are slowed and refracted at the mantle / core boundary at a depth of 2900 km.

Detailed explanation-4: -Mantle rock is generally denser and stronger than crustal rock and both P-and S-waves travel faster through the mantle than they do through the crust. Moreover, seismic-wave velocities are related to how tightly compressed a rock is, and the level of compression increases dramatically with depth.