GEOLOGY

Detailed explanation-1: -The answer is compressional waves. Remind them that in compressional waves particles of material move back and forth parallel to the direction in which the wave itself moves. As a compressional wave passes, the material first compresses and then expands.

Detailed explanation-2: -Primary waves (P-waves) are the fastest moving waves of an earthquake and thus are the first felt. These waves are compression waves, meaning the waves are close together and contain a great amount of pressure. This causes the rock it moves through to stretch and compress as the wave passes.

Detailed explanation-3: -P waves travel through solid and liquid, but S waves do not travel through liquid.

Detailed explanation-4: -The P wave, or primary wave, is the fastest of the three waves and the first detected by seismographs. They are able to move through both liquid and solid rock.

Detailed explanation-5: -P Waves alternately compress and stretch the crustal material parallel to the direction they are propagating. S Waves cause the crustal material to move back and forth perpendicular to the direction they are travelling.