Summary

Description

On May 22, 1960 (19:11 UTC), a Mw 9.5 earthquake occurred in southern Chile (39.5 S, 74.5 W). This was the largest earthquake ever instrumentally recorded. (It was not the largest in terms of dollar damage or number of deaths produced). A damaging foreshock (Mw7.3) had occurred the day before at about 10:02 UTC. The series of earthquakes that followed ravaged southern Chile and ruptured a 1,000 km section of the fault between 37 and 48 degrees South latitude. This rupture was one of the longest ever reported. The earthquake epicenters delineated the SSW-NNE fault that is on shore in the north and submarine in the south. The number of fatalities associated with both the tsunami and the earthquake has been estimated at 5,700. Reportedly there were 3,000 injured; initially there were 717 missing in Chile. Earthquake Damage Accounts The Chilean government reported that 58,622 houses were completely destroyed. Damage (including tsunami damage) was more than $500 million U.S. Dollars. The heaviest damage occurred at Puerto Montt, Valdivia, Rio Negro, Lebu, Concepcion, Maldivia, Alerce, Valdivia, Rinihue, Totoral, and Villarica. Although Chile frequently experiences earthquakes, the buildings were not built to withstand a strong earthquake. Fortunately, the large foreshocks sent people into the streets. This saved some lives, because the main shock came a few minutes after one of these large foreshocks. Many of the buildings and homes were vacant when they fell. Tsunamis The main shock produced tsunamis that were not only destructive along the coast of Chile, but which also caused numerous casualties and extensive property damage in Hawaii and Japan. Abnormal wave runup was noticeable along shorelines throughout the Pacific Ocean area. In Hawaii, 6,600 miles from the epicenter, the tsunami killed 61 and injured 282. The damage there was $75 million. In Japan, the coast of Honshu was especially ravaged. There were 138 deaths, 85 missing, 855 injured, and 1,678 homes destroyed, with a total of $50 million in damage. Reportedly there were 32 missing and presumed dead in the Phillippines. The coasts of California, New Zealand, Australia and Kamchatka were also affected. Associated Geologic Events There were several other geologic phenomena associated with this event. Subsidence caused by the earthquake produced local flooding and permanently altered the shorelines of much of the area in Chile impacted by the earthquake. Landslides were common on Chilean hillsides. Many of these rock falls and landslides occurred in the Andes. The Puyehue volcano erupted 47 hours after the main shock. Chile Earthquake History Chile has experienced other large earthquakes since the 1960 event. Both the March 3, 1985, earthquake and the July 30, 1995, earthquake, had magnitudes of about 8. Historically, magnitude 8 earthquakes in Chile occur every 10 to 25 years. Many of these earthquakes produce tsunamis that often travel far beyond the shores of Chile producing devastation. It is only a matter of time until Chile once again has a "world-class" earthquake whose impact, like the 1960 Chile event, will be felt around the world.