With exciting footage of earthquakes, engaging graphics and interviews with seismic survey teams this programme provides a fantastic introduction to waves and how they are used. The different types of waves are illustrated and the key terminology of amplitude, wavelength, frequency and period explained through clear graphics. The video then looks at how different waves behave depending on the nature of the material they are passing through. It shows how seismic survey teams make use of these differences in velocity, absorption, refraction and reflection to find out about underlying rock structures. The program also explores how new evidence provided by the study of seismic waves has helped to develop plate tectonic theory and led to a greater understanding of earthquakes.