GARY HINCKS / SCIENCE PHOTO LIBRARY GARY HINCKS / SCIENCE PHOTO LIBRARY
Seismic waves. Artwork of the movement of seismic (shock) waves (arrowed) during an earthquake. Primary (P) and secondary (S) body waves travel through the Earth's crust (grey) and mantle (red) from the earthquake's focus (black circle). The speed of P and S waves is modified at the boundary of the crust and mantle, the Moho (Mohorovicic Discontinuity). The Moho is about 35 kilometres beneath the Earth's surface. Shock waves that enter the mantle travel faster than those remaining in the crust. Surface waves travel outwards from the earthquake's epicentre on the ground above the focus. It is these surface waves that cause the most damage to infrastructure.
Model release not required. Property release not required.