Earthquake waves

Science

Definition

Earthquake waves (seismic waves) are energy waves generated by the sudden release of energy along faults. The three main types are P-waves (primary, compressional), S-waves (secondary, shear), and surface waves, each traveling at different speeds and through different materials.

Examples

  • P-waves arrive first at seismograph stations because they travel fastest (through solids and liquids)
  • S-waves cannot pass through Earth's liquid outer core, which helped scientists discover it
  • Surface waves cause the most damage during an earthquake because they move the ground in rolling and side-to-side motions
Key Fact

P-waves travel ~6-8 km/s through crust; S-waves travel ~3.5-4.5 km/s; difference in arrival times helps locate the epicenter.

Related Terms

Seismology Plate tectonics Plate boundaries Tectonic plates

Study This Concept

Practice earthquake waves with free review games in these units:

Earth Science Unit 2: Plate Tectonics and Earthquakes