Slinky Seismic Waves

This activity uses one or two slinkies to model how earthquakes generate P-waves, S-waves, and surface waves. The simple demonstration helps students visualize how energy travels through the Earth and why surface waves cause the most damage during earthquakes.

1. Use one or two slinkies and refer to the links below for generating different seismic waves.

Seismic Slinky—An analogy for P & S waves - IRIS Earthquake Science:

P and S waves on a slinky - Cambridge Volcano Seismology:

📄 The slinky seismic waves demo - Earthquakelearningidea: https://www.earthlearningidea.com/PDF/304_Slinky_seismic_waves.pdf

• Add a storytelling element, such as the Japanese Namazu catfish myth, to make the demo more engaging.

• Ensure students handle slinkies carefully to avoid tangling or snapping.
• Keep slinkies clear of faces to prevent accidental injury from sudden recoil.
• Supervise closely if using metal slinkies to avoid pinching fingers.

• Why do P-waves travel faster than S-waves? (Because they rely on compression and rarefaction, while S-waves require rigidity for side-to-side motion.)
• Why can S-waves not travel through liquids? (Liquids have no rigidity, so they cannot support shear motion.)
• Why are surface waves the most destructive type of seismic wave? (They cause vertical and horizontal ground movement, damaging buildings and infrastructure.)