Not surprisingly, most people think of California when they think of earthquakes, but only one of the ten strongest earthquakes in North America occurred in the Golden State.
The New Madrid Fault System lies in the Mississippi River Valley, extending 150 miles southward from Charleston, MO and crossing five state lines. In 1811, and three months later in 1812, it produced quakes so powerful that tremors were felt in over 15 states, reaching from Canada to New Orleans. Church bells rang in Boston over 1,000 miles away; forests were leveled; and the course of the Mississippi River was temporarily reversed.
If an earthquake the size of the New Madrid Quake occurred there today, tremors would be felt through half of the United States, and damage could be expected in 20 states or more. The damage to pipe and gas lines, subway tunnels, railroads, and waterways would literally stop productivity in the Midwest and Eastern United States and could produce losses 20 times those caused by the Northridge, CA earthquake in 1994.
Charleston SC was struck by a 7.1 magnitude earthquake in 1886. It killed 60 people and damaged almost every building in the city.
In March 1964, an earthquake measuring 9.2 on the Richter Scale struck Alaska, causing massive landslides, huge fissures that raised and lowered structures as much as ten feet and waves as high as 65 meters at Valdez Inlet. The California earthquakes that struck Northern California in 1989 and Southern California in 1994 lasted less than 30 seconds. In Alaska, the ground shook for a full five minutes!
Two of the most destructive earthquakes in history occurred in California. The Loma Prieta earthquake, centered about 100 kilometers south of San Francisco, killed 63 people, injured 3,800 and caused $8 billion in property damage. Five years later the Northridge earthquake in Southern California’s San Fernando Valley caused 60 deaths, 7,000 injuries and caused $43 billion in property damage of which $16.6 billion was insured.
Neither of these catastrophes can be fairly characterized as ‘The Big One.’ The US Geological Survey and the Southern California Earthquake Center released a study in May, 2005, warning that an earthquake on the Puente Hills fault under Los Angeles could kill 18,000 people and cause $250 billion in property damage. If the 1906 San Francisco Earthquake occurred today, it would cause economic damages of $400 billion, according to some estimates.
The Loma Prieta and Northridge earthquakes were tragedies of major proportions, from which the affected areas have yet to fully recover, but neither caused a collapse of the American economy. The same cannot be said for a truly catastrophic earthquake that could strike at any time.
Learn more about America’s vulnerability to earthquakes: