Which waves travel through Earth's interior and are among the first to arrive after an earthquake?

Which waves travel through Earth's interior and are among the first to arrive after an earthquake?

• A. Surface waves
• B. Body waves
• C. Tidal waves
• D. Atmospheric waves

Answer: (B)

Waves that travel through Earth's interior are called body waves. After an earthquake, energy moves through the planet as these waves, and the fastest among them reach seismographs first. The quickest type is the P-wave, which compresses and expands the material as it moves and can travel through both solids and liquids, so it passes through the entire interior. After P-waves, S-waves follow; they shear the ground side to side and can only move through solids, arriving later than P-waves. In contrast, surface waves travel along the surface and typically arrive later, even though they can cause strong shaking near the epicenter. So, the waves that travel through the interior and are among the first to arrive are body waves, especially the fast P-waves.

Waves that travel through Earth's interior are called body waves. After an earthquake, energy moves through the planet as these waves, and the fastest among them reach seismographs first. The quickest type is the P-wave, which compresses and expands the material as it moves and can travel through both solids and liquids, so it passes through the entire interior. After P-waves, S-waves follow; they shear the ground side to side and can only move through solids, arriving later than P-waves. In contrast, surface waves travel along the surface and typically arrive later, even though they can cause strong shaking near the epicenter. So, the waves that travel through the interior and are among the first to arrive are body waves, especially the fast P-waves.