P-waves: Primary (longitudinal) seismic waves that can travel through both solids and liquids. They are the fastest seismic waves.
S-waves: Secondary (transverse) seismic waves that can only travel through solids. They cannot pass through liquids.
Seismograph: An instrument that detects and records seismic waves, used to study earthquakes and Earth's interior.
S-wave shadow zone: The region on the far side of Earth from an earthquake where no S-waves are detected, proving the outer core is liquid.
P-wave shadow zone: A partial shadow zone (105°–140° from the earthquake) where P-waves are absent due to refraction at the core boundary.
This definitions covers Key Definitions within Seismic Waves for GCSE Physics. Revise Seismic Waves in Waves for GCSE Physics with 13 exam-style questions and 15 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 7 of 14 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
Practice questions for Seismic Waves
What type of wave is a P-wave (primary seismic wave)?
State two differences between P-waves and S-waves in terms of how the particles move and what materials they can travel through.