P waves, also known as primary or compressional waves, travel through the Earth's interior by compressing and expanding the material that they pass through. As the wave moves forward, it causes the particles of the material to vibrate back and forth in the direction of the wave movement. This movement of particles creates a series of compressions and rarefactions, which produces a characteristic push-pull motion. P waves can travel through any type of material, including solids, liquids, and gases, which is why they are the first waves detected following an earthquake.
