Imagine an earthquake with millions of people crowding around. Most people don’t understand that the earthquake danger relates to time duration and not only seismic strength. This was a 6.3 on the richter scale and the light in the kitchen was swaying due to the intensity and time duration.

An earthquake that registers 5.0 on the Richter scale has a shaking amplitude 10 times greater than an earthquake that registered 4.0 at the same distance. As energy release is generally proportional to the shaking amplitude raised to the 3/2 power, an increase of 1 magnitude corresponds to a release of energy 31.6 times that released by the lesser earthquake. This means that, for instance, an earthquake of magnitude 5 releases 31.6 times as much energy as an earthquake of magnitude 4.

• Magnitude 3 = 2 gigajoules
• Magnitude 4 = 63 gigajoules
• Magnitude 5 = 2,000 gigajoules
• Magnitude 6 = 63,000 gigajoules
• Magnitude 7 = 2,000,000 gigajoules

source: internet