You'll need

  • One 500 gram packet of uncooked spaghetti strands (each about 1mm diameter) 
  • Elastic bands to hold the spaghetti bundles together 
  • One piece of A4 paper/cardboard 
  • One piece of paper 90cm wide (two A0 pages stuck together or eight A3 pages stuck together) 
  • Ruler and tape measure 
  • Safety glasses for when the spaghetti is broken

What to do

1. Divide the spaghetti strands into 3 bundles to represent different magnitude values: 

  • Bundle 1: Set aside 1 strand to represent the energy of a magnitude 5 earthquake. 
  • Bundle 2: Set aside 30 strands to represent a magnitude 6 (weighs ~9g). 
  • Bundle 3: Set aside ~900 strands to represent a magnitude 7 (weighs ~270g).

2. Cut circles of paper to represent the cross-sections of even thicker bundles of spaghetti. 

  • Cut a 16cm diameter circle to represent magnitude 8 (equivalent to 27 000 spaghetti strands).
  • Cut a 90cm diameter circle to represent magnitude 9 (equivalent to 810 000 spaghetti strands).

3. Put on safety glasses. Bend and snap the single strand of spaghetti (Bundle 1) to represent rocks being broken during a magnitude 5 earthquake. 

4. Bend and snap the bundle of 30 spaghetti strands (Bundle 2) to represent a magnitude 6 earthquake. Discuss how this requires a lot more energy to break. 

5. Take the 900 strands of spaghetti (Bundle 3) to represent a magnitude 7 earthquake. Attempt to bend and snap. This bundle, 30 times larger than the previous magnitude (30 x 30 = 900 pieces), is almost impossible to bend or snap by hand. 

6. For a magnitude 8 earthquake a bundle of 30 x 900 = 27 000 pieces of spaghetti would be needed. Instead of using a huge quantity of spaghetti this can be illustrated with a 16 cm diameter circle of paper or card (assuming that each spaghetti strand is 1mm in diameter). 

7. For a magnitude 9 earthquake a bundle of 30 x 27 000 = 810 000 pieces would be needed. Use the 90cm diameter paper circle.

What's happening

The way we describe the size of an earthquake is related to the energy released by the event and is measured using a magnitude scale.  Each whole number increase in magnitude represents a tenfold increase in measured amplitude as measured by a seismogram. 

The activity demonstrates how each whole number increase in magnitude of an earthquake represents a tenfold increase in the amplitude of waves shown on a seismogram, which equates to a 30-fold increase in energy released.

The more spaghetti that is added to your bundle, the more energy required to snap it and the greater impact when the spaghetti breaks!

In partnership

This content was developed by Geoscience Australia. 
For more instruction on this activity, please see the Geoscience Australia information sheet.