Earthquake
The effect of an earthquake can be measured with a seismometer. A seismometer detects the tremors of the earth and plots the tremors on a seismograph. The strength or magnitude of an earthquake can be measured using the Richter scale. The Richter scale was invented by Charles Francis Richter in 1935. The scale is numbered 0-10. A 2 on this scale is a tremor that is not easily recorded. And damage of size 5 (or more) in a wide area. The largest earthquake ever measured had a magnitude of 9.5.