Intensity of earthquake is measured on Richter scale. This is done by a device called seismograph. The Richter scale varies from 1 to 10. Earthquakes upto 4 Richter scale are weak and seldom noticed. Earthquakes up to 5.5 Richter are considered as strong and those beyond to Richter are considered as devastating. Earthquakes beyond 7 Richter are highly devastating in nature and cause large scale destruction.
