What is the biggest earthquake that has ever happened?
One of the largest earthquakes ever was the Chile event of 22 May 1960 with moment magnitude of 9.5 Mw. Other large earthquakes include Lisbon, 1 November 1755, magnitude 8.7 Ms; Assam, 12 June 1897, magnitude 8.7 Ms; Alaska, 28 March 1964, moment magnitude 9.2 Mw. Although the magnitude scale is open ended, the strength of the crustal rocks prior to fracturing limits the upper magnitude of earthquakes.
