United States Geological Service (USGS), it is quite easy to learn about the biggest earthquake ever recorded, which occurred near Santiago, Chile, in 1960. Known as the Great Chilean Earthquake, the quake measured an impressive 9.5 on the Richter scale. The death toll of the Great Chilean Earthquake is not known, but estimates go as high as 6,000, and the earthquake may have caused as much as 800 billion US Dollars in damage.
It is highly probable that some ancient earthquakes were of a higher magnitude, but because the Richter scale was not developed until the 1930s, it is difficult to quantitatively compare them. For example, the Lisbon Earthquake of 1755 was by all accounts quite severe, and it generated a massive tsunami which only magnified the death toll, and the Shaanxi Earthquake which occurred in China in the 1500s was the deadliest known to history, killing almost one million people. The Shaanxi Earthquake may also have been the biggest earthquake known to man, but there is simply no way to tell.
In terms of earthquakes which were studied, measured, and recorded on the Richter Scale, however, the Great Chilean Earthquake was far and away the biggest earthquake ever. Keeping in mind that the Richter Scale runs along an exponential progression, the next largest earthquake was a 1964 tremblor in Prince William Sound, Alaska, which measured 9.2. The 2004 Indian Ocean Earthquake is the next biggest earthquake ever recorded, clocking in at 9.1 on the Richter Scale and generating a formidable tsunami which damaged much of the coastline of Southeast Asia.
The risk of large earthquakes has become greatly increased since the Great Chilean Earthquake, thanks to increasing human population and the growth of megacities, and it wouldn't take the biggest earthquake ever recorded to create the most lethal earthquake ever recorded. Many huge cities happen to be located in seismically active areas, and an earthquake of major size in any of these regions could be devastating. Because earthquakes cannot be predicted or controlled, seismologists have warned communities, suggesting that they need to develop clear action plans for major quakes, as much of the damage and loss of life associated with earthquakes is caused by poor infrastructure.
That would be Chile, 1960. Same area as Darwin's quake. This helps put our recent small quakes in the Northeast in perspective.
The Largest Earthquake in the World
"Approximately 1,655 killed, 3,000 injured, 2,000,000 homeless, and $550 million damage in southern Chile; tsunami caused 61 deaths, $75 million damage in Hawaii; 138 deaths and $50 million damage in Japan; 32 dead and missing in the Philippines; and $500,000 damage to the west coast of the United States." (USGS)
"The series of earthquakes ... ravaged southern Chile and ruptured over a period of days a 1,000 km section of the fault, one of the longest ruptures ever reported. The number of fatalities associated with both the tsunami and the earthquake has been estimated to be between 490 and 5,700. Reportedly there were 3,000 injured, and initially there were 717 missing in Chile. The Chilean government estimated 2,000,000 people were left homeless and 58,622 houses were completely destroyed. Damage (including tsunami damage) was more than $500 million U.S. dollars. The main shock setup a series of seismic sea waves (tsunami) that not only was destructive along the coast of Chile, but which also caused numerous casualties and extensive property damage in Hawaii and Japan, and which was noticeable along shorelines throughout the Pacific Ocean area. There were several other geologic phenomena besides tsunamis 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. Cordón Caulle erupted forty-seven hours after the main shock. 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." (NOAA)
Valdivia, Chile (NOAA)
"Valdivia suffered catastrophic damage because of its proximity to the epicenter of the massive quake. Regional tectonic subsidence of five to seven feet occurred. There was extensive loss to agricultural lands from flooding. The horizontal ground motions, not the subsidence, caused the principal damage to structures away from shorelines and river channels. Older masonry structures were hard hit by the earthquake. However, many wood frame buildings performed well.
"The highest [tsunami] runup on the United States was at Crescent City, California. Here, the runup reached 1.7 m and the first wave arrived 15.5 hours after the tsunami was triggered. A total of $500,000 to $1,000,000 in damage was done by the tsunami to the United States west coast.
"Hilo was the hardest hit city in the Hawaiian Islands. The tsunami arrived at Hilo about 15 hours after it originated off the coast of south central Chile, 6,600 miles distant. The runup at Hilo was measured at 10.7 m. The tsunami changed into a bore as it passed the harbor entrance and advanced on to the bay front. The business district along Kamehameha Avenue and the adjoining low-lying residential areas of Waiakea and Shimmache were destroyed. Damage to property included 229 dwellings and 308 business and public buildings. Between the Wailoa and Wailuku Rivers, the water washed inland as far as the 6 m(20 ft) contour above sea level." (NOAA)
