We can't dig to the Earth's core — the deepest hole ever drilled is only 12 km (Earth's radius is 6,371 km!). So how do we know what's inside? Earthquakes! When earthquakes happen, they send waves through the entire planet. By studying how these waves travel, bend, and where they can't go, scientists have mapped the Earth's interior: a solid inner core, liquid outer core, mantle, and crust. It's like using ultrasound to see inside a body, but for the whole planet!
This introduction covers X-Raying the Earth 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 1 of 14 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.
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.
Quick recall flashcards
What are P-waves?
Primary (longitudinal) seismic waves - fastest
What are S-waves?
Secondary (transverse) seismic waves - slower