Eartquakes that Occur in the United States

Earthquakes are very frightening and devastating. They are natural disasters that occur without any warning, not giving much time for preparation. Many areas of the U.S. have been struct by earthquakes which includes the Central and East Coast states, also Alaska. The National Earthquake Information center(NEIC) manages and archives earthquake information. It focuses on the risks the earthquakes have on mankind. It seeks to find and size these destructive quakes.

Earthquakes are caused by the constant motion of the earth's crust. The earth's crust is broken into pieces like a boiled egg shell. The mantle of earth is similar to the egg white , while the core of the earth is similar to the yolk. Geologists call the broken pieces of the earth plates.

In 2003, there was an earthquake referred to as the San Simeon Earthquake which occurred on December 22, with an epicenter near the Pacific Coast in central California. It had a magnitude of 6.5. It did not rupture the surface but triggered landslides and caused strong shaking. Twenty- four miles south of the epicenter in Paso Robles, there were quite a few older buildings that were damaged. One collapsed killing 2 people.

In November 2002, there was the Denali earthquake with a magnitude of 7.9. Alaska had no deaths and few injuries. Even though this was one of the largest recorded earthquakes in our nation's history, there were many landslides and road closures. Very little structural damages was made.

On January 17, 1994, Northridge, California experienced an earthquake that resulted in 60 deaths, more than 5000 injuries, and left over 25,000 people homeless. Estimated loss was $25 Billion. It had a magnitude of 6.7 and was short in duration. The main shock was estimated to have lasted 15 seconds.

It is expected that there will be larger events like these in the United States, but not solely in the West Coast. Two most severe earthquakes happened in other regions such as Charleston, South Carolina in and New Madrid, Missouri. This was a three shocker that sent shock waves all the way to the Rocky Mountains, Washington DC, and Boston.

In California the maximum size quake appears to be a magnitude of 8. Studies of the effects on rivers and creeks indicate that there were many large quakes over a range of 1500 years or so. They have a repeat interval of around 60 to 100 years. Since the last large magnitude quake was in 1906, they are due for another. All 50 states can endure an earthquake. The ones with a magnitude of 7 or above are Alaska, California, Hawaii, Missouri- Tennessee, Montana, Nevada, South Carolina, and Washington.

Sources: http://www.ig.utexas.edu/research/projects/eq/faq/usa.htm, www.fema.gov/hazard/earthquake/usquakes.shtm