An earthquake is rated as 'major' if its magnitude on the Richter scale is in the range of

An earthquake is rated major when its Richter magnitude falls in the 7.0 to 7.9 band.

The 4.0 to 4.9 range is only a light earthquake with minor effects.

The 6.0 to 6.9 range is classed as strong, one step below major.

The 5.0 to 5.9 range is moderate, causing limited local damage.

Major quakes in the 7 band can cause serious destruction over wide areas.

Magnitudes of 8.0 and above are termed great earthquakes with catastrophic reach.