what is the largest earthquake ever measured
The Worldâs largest earthquake with an instrumentally documented magnitude occurred on May 22, 1960 near Valdivia, in southern Chile. It was assigned a magnitude of 9.5 by the United States Geological Survey. It is referred to as the Great Chilean Earthquake and the 1960 Valdivia Earthquake.The United States Geological Survey reports this event as the largest earthquake of the 20th Century.Other earthquakes in recorded history may have been larger, however this is the largest earthquake that has occurred since accurate estimates of magnitude became possible in the earnly 1900's.he United States Geological Survey reports this event as the largest earthquake of the 20th Century. Other earthquakes in recorded history may have been larger, however this is the largest earthquake that has occurred since accurate estimates of magnitude became possible in the earnly 1900's.