12+
Gallery 3

Waves and Wobbles

A yellow and red series of horizontal rods under a glass display.
A yellow and red series of horizontal rods under a glass display case. The horizontal component of the case has a yellow information panel.

Earthquakes generate three types of seismic waves, which can be simulated on springs and rods.

How it works

Use the controls to make different earthquake (seismic) waves move along the rods or spring.

Things to try or ask around the exhibit

  • Do the waves move differently?
  • What effect would each of the waves have on a building?

Background

An earthquake starts when sections of the Earth's crust are crunched together and rocks break to relieve the stress. The energy released deep underground at the break point (the focus) moves through the rocks as different types of waves. P (primary) waves are the fastest and first to be felt. S (secondary) waves travel less quickly and arrive second, but they only travel through solids, which helps scientists to deduce how Earth's sub-surface is structured. L (longitudinal) waves are a combination of Love waves and Rayleigh waves, which cause the surface of the Earth to ripple backward and forward.

Finding the science in your world

When an earthquake first hits, humans feel P waves first, followed by S waves. Sometimes, animals can hear the P waves before humans can feel them, and the animals will behave erratically (such as barking or pacing on the spot) just before humans can feel the roll of waves as an earthquake.