Historic World Earthquakes

written by Christine Regalla

The following overviews represent some of the world's most notable earthquakes. Click here to see a comparative listing of the world's strongest and deadliest earthquakes.

1960 Chile Earthquake

On May 5, 1960, what may be the world’s largest earthquake occurred off the coast of central Chile. The quake, a magnitude 9.5, resulted from a rupture along the boundary between the subducting Nazca Plate and South American Plate approximately 1000 km long and 200 km wide. This rupture, unprecedented in size, stretched along half of the southern coast of Chile. Its tremors caused widespread destruction, changes in land formations, and one of the largest tsunamis recorded in the Pacific region for over 500 years. 

The cities of Conception, Valdivia, and Puerto Montt suffered the heaviest destruction, while many smaller villages were completely destroyed. Loss of life totaled more than 2,000 in Chile, with over 3,000 injured. Damages were estimated at $550,000. Effects of the tidal wave devastated parts of the Pacific, killing 68 in Hawaii, 138 in Japan, and 32 in the Philippines, and causing millions in damages. The wave’s maximum height was 1.7 m recorded at Crescent City, California, and was strong enough to carry a 10 ton tractor out of its showroom in Hawaii.

Land deformation was evident along much of the fault. A subsidence of 2 m was seen in the coastal mountains; vertical uplifts of 0.5 m were observed along the foothills of the Andes and offshore islands were raised up to 6 m. Effects of the quake were seen as rockfalls and landslides pummeled down the slopes of the Andes, an artificial lake formed on the Rio San Pedro, and the Puyehue volcano erupted 19 days after the initial break in the fault.

1906 San Francisco Earthquake

A break 430 km long along the San Andreas Fault initiated an earthquake of magnitudde 7.7 and sparked widespread fire in the San Francisco area on April 18, 1906. The earthquake damaged large portions of the city, especially older buildings which were not structurally sound, and caused large sections of the city which had been built upon filled land to resettle and sink. The water line from the San Andreas Lake was ruptured during the quake, and when fire broke out in the city, thousands of citizens were left without a water supply to combat the flames.

1,000 people lost their lives and property destruction was estimated at $524 million, most of which was due to fire. However, the area affected by the earthquake was surprisingly small, reaching a distance of about only 600 km, and was centered around long narrow strips that paralleled the fault. A horizontal displacement of 6.4 m was measured near Pont Reyes Station, California and in many places broken fence lines and split roadways showed fouther ground movement. To this day, this earthquake remains one of the most devastating to hit the San Francisco area. The destruction that resulted from this earthquake opened the eyes of many people to the hazards of living in an earthquake zone.

See pictures at http://neic.usgs.gov/neis/eqlists/USA/1906_04_18_pics.html

1964 Good Friday Earthquake, Alaska

On March 28, 1964 a magnitude 9.2 earthquake shook the ground near Prince William Sound, Alaska for a three minute period. The quake resulted in the largest uplifts of land ever recorded in the United States. In Cape Cleare, Montague Island, the seafloor was uplifted 33 ft above its previous position, while an area of 520,000 square miles was uplifted nearly 11.5 meters. There was also significant subsidence of about 2 meters in an area covering 285,000 square miles.

The quake, whose focus lay 30 miles beneath the crust, ruptured an 800 km section of the fault. It triggered massive landslides that buried buildings in downtown Anchorage and nearby homes, disrupted water mains and gas lines, and generated a devastating tsunami which destroyed several towns along the Gulf of Alaska and affected many other areas of the Pacific. A maximum wave height of 67 meters was measured at Valdez Inlet, while areas of low water as far as the Gulf of Mexico suffered damage from seiche action. A total of $235 million in damages was incurred as a result of the quake.

see pictures at http://neic.usgs.gov/neis/eqlists/USA/1964_03_28_pics.html

see seismograph recordings at http://neic.usgs.gov/neis/eqlists/USA/1964_03_28_seismogram.html

1811-1812 New Madrid Earthquakes

A series of three earthquakes centered near New Madrid, Missouri marked the strongest mid-plate earthquakes to occur in North America. They shook the ground over much of the United States, an area two to three times larger than that of the 1960 Chile and 1906 San Fransisco earthquakes, and greatly affected the topography of the continent. Subsidence of as much as 5 meters occurred in areas, while new fissures opened and closed below the ground. Lake St. Francis, 64 km long by 1km wide, formed when a piece of sunken ground flooded with groundwater, and additional shifts in surface structure caused the Mississippi to change its course.

The first and weakest of the earthquakes occurred on December 16 with a magnitude 7.7, knocking down chimneys in cities as far as Cincinnati and Richmond. The second two, occurring on January 23 and February 7, having magnitudes of 7.6 and 7.9 respectively, hit areas of higher populations, causing damage to an area of over 100,000 square km. Although these earthquakes occurred almost two centuries ago, modern seismicity suggests that the stresses which brought them about are still at work today.

1985 Mexico City Earthquake

A slip 50 km ff the Pacific coast of Mexico along the Benioff Fault Zone resulted in one of the most damaging quakes Mexico City has ever experienced. The city, 400 km away from the epicenter, suffered major building damage and a loss of more than 10,000 lives. Because a large part of Mexico City was built on the filled land of an ancient lake bed, it experienced roughly 5 times the ground shaking of outlying areas. Many structures collapsed because of lose soil foundations, while others, located close by but on firmer foundations, withstood the shaking. A total of $4 billion in damage was done, including damage from tsunamis.

1755 Lisbon Portugal Earthquake

On the morning of November 1, 1775 thousands of citizens in Lisbon were attending mass for All Saints Day when a magnitude 8.6 earthquake stuck the Iberian Peninsula. Nearly 20% of the city’s population, about 70,000 people, died as a result of the quake, many of which were trapped in collapsing churches. Fires burned for 6 days after the initial shock and half the houses in Lisbon were ruined. Tremors from the quake were felt over much of Europe, in an area covering 3,890,000 square km, and caused damage 1,100 km away in Algiers. Even more threatening than the shaking ground was the wall of water raced toward the shore. The tsunami was measured at 4 m near Martinique, 6 m near Lisbon, and 20 m at Cadiz Spain, killing thousands along the shores. Because of the loss of life and mass destruction that occurred, this earthquake remains the most devastating tragedies Lisbon’s history.

1923 Tokyo-Yokohama Earthquake

The area around Sagami Bay, Japan began to shake on September 1, 1923 around 12 noon in what amounted to a magnitude 8.3 earthquake. A section of the fault under the bay was measured to have been displaced nearly 240 m, and although no surface faults appeared, new ridges 180 to 300 ft tall appeared on the sea floor in line with a pre-existing volcanic chain. The Baso and Sagami Peninsulas experienced a general upheaval as high as 24 feet recorded at Misaki. However, this uplift lasted only 72 hours before the ground began to sink again at rates of up to 2 feet per day. A final uplift of 5 feet was all that remained.

The large movements of ground in the Tokyo area had catastrophic consequences. A final death toll was estimated at 140,000 people, and more than half of the structures in the cities were severely damaged or ruined completely. The earthquake triggered hundreds of landslides throughout the area and generated a tsunami measuring 12 m high at Atami, where it destroyed 155 houses and killed 60 people. However, most of the damage was due to the devistating fires that swept through Tokyo and Yokohama killing over 100,000 people and leaving half the population homeless.

1976 Tangshan, China Earthquake

Considered by many to be the deadliest earthquake of the twentieth century, the July 28 1976 Tangshan earthquake brought devastation to many areas in northwestern China. The quake occurred when a 150 km section of the Tan-Lu fault system ruptured, releasing enough energy to trigger a magnitude 8.0 earthquake. The heavily populated, industrial coal-mining city of Tangshan was almost completely destroyed, killing thousands of its citizens as they slept in their homes. Peking, 16 km to the northwest, also suffered considerable damage. Total death toll estimates ranged anywhere from 250,000 to half a million.

1970 Peru Earthquake

Southern Peru experienced a magnitude 8.1 earthquake on May 31, 1970. Its epicenter was located about 600 km southeast of Lima along the boundary between the subducting Nazca plate and the South American Plate. Loss of life was estimated at 66,000 people, 200,000 were left homeless, and $530,000 in damages was incurred in the surrounding areas. Landslides and rockslides in the Andes blocked highways and engulfed homes. Many villages that were located along the coast and in the foothills of the mountains were completely destroyed, either by falling debris or rising water brought on by a 2 m tsunami. Tremors from the quake were felt through much of Peru, northern Chile, and parts of Bolivia.

Sources:  www.usgs.gov 10/17/01; www.geo.arizona.edu  10/18/01;  http://nisee.berkeley.edu 10/21/01; The new Encyclopedia Britannica vol. 17. 1998. 685; Colliers Encyclopedia vol. 8. 1996. 376; Bolt, Bruce A., Earthquakes. W. H. Freeman and Company. New York. 1999. 2-20, 292-297.