What is the unit of measuring earthquakes?

Earthquakes are measured by the seismometer. The intensity of an earthquake is expressed on the Richter scale.

Addition information: It is a logarithm unit means if you say that the earthquake of 3 intensity is actually 10³. Richter scale rates an earthquake by the size of its seismic waves ( the shockwaves of released energy that shake the Earth) on a scale from 1 to 10. Each number on this scale is 10 times stronger than the number before it, so a 2 is 10 times stronger than a 1, a 3 is 100 times stronger, a 4 is 1,000 times stronger and so on.