World’s largest and most powerful earthquake

The World’s largest and most powerful earthquake ever recorded, rating 9.5 on the moment magnitude scale occurred on May 22, 1960 near Valdivia, in southern Chile. It is referred to as the “Great Chilean Earthquake” and the “1960 Valdivia Earthquake”. Its resulting tsunami affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, southeast Australia, and the Aleutian Islands in Alaska.

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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.

The epicenter was near Lumaco some 570 kilometres (350 mi) south of Santiago, with Temuco being the closest large city, while Valdivia was the most affected city. The tremor caused localised tsunamis that severely battered the Chilean coast, with waves up to 25 metres (82 ft). The main tsunami raced across the Pacific Ocean and devastated Hilo, Hawaii. Waves as high as 10.7 metres (35 ft) were recorded 10,000 kilometres (6,200 mi) from the epicenter, and as far away as Japan and the Philippines.

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The death toll and monetary losses arising from such a widespread disaster are not certain. Various estimates of the total number of fatalities from the earthquake and tsunamis have been published, with the USGS citing studies with figures of 2231, 3000, or 5700 killed and another source uses an estimate of 6,000 dead. Different sources have estimated the monetary cost ranged from US$400 million to 800 million (or 2.9 to 5.8 billion in 2011 dollars, adjusted for inflation).

Ground motion from this earthquake destroyed and damaged many buildings. The Chilean government estimated that about 2,000,000 people were left homeless. It was fortunate that the earthquake occurred in the middle of the afternoon and was preceded by a powerful foreshock. That foreshock frightened everyone from their buildings, placing them outside when the main earthquake occurred.

Most of the damage and deaths were caused by a series of tsunamis that were generated by the earthquake. These waves swept over coastal areas moments after the earthquake occurred. They tore buildings from their foundations and drowned many people.

The 1960 Chilean earthquake was actually a series of strong earthquakes that affected Chile between 21 May and 6 June 1960. The first was the Concepción earthquake and the strongest was the Valdivia earthquake.

This is one of the few earthquakes that has killed large numbers of people at distant locations. Tsunamis generated by the earthquake traveled across the Pacific Ocean at a speed of over 200 miles per hour. Changes in sealevel were noticed all around the Pacific Ocean basin.

Fifteen hours after the earthquake a tsunami with a runup of 35 feet swept over coastal areas of Hawaii. Many shoreline facilities and buildings near coastal areas were destroyed. Near Hilo, Hawaii, 61 people were reported killed by the waves.

In California, many small boats were damaged as the waves swept through marinas. At Crescent City, a wave had a runup of about 5 feet and caused damage to shoreline structures and small boats.