In the past 25 years, scientists have learned that strong earthquakes in the central Mississippi Valley are not freak events but have occurred repeatedly in the geologic past. The area of major earthquake activity also has frequent minor shocks and is known as the New Madrid Seismic Zone. The NMSZ is made up of several thrust faults that stretch from Marked Tree, Arkansas to Cairo, Illinois.
Earthquakes in the central or eastern United States effect much larger areas than earthquakes of similar magnitude in the western United States. For example, the San Francisco, California, earthquake of 1906 (magnitude 7.8) was felt 350 miles away in the middle of Nevada, whereas the New Madrid earthquake of December 1811 rang church bells in Boston, Massachusetts, 1,000 miles away. Differences in geology east and west of the Rocky Mountains cause this strong contrast.We all must get better prepared for major earthquakes, and practice how to protect ourselves when they happen. You could be anywhere when an earthquake strikes: at home, at work, at school or even on vacation.
What we do now will determine our quality of life after our next big earthquake. Are you prepared to survive and recover quickly?
The Great Central U.S. ShakeOut is an annual opportunity to practice how to be safer during big earthquakes: “Drop, Cover and Hold On.” The ShakeOut has also been organized to encourage you, your community, your school, or your organization to review and update emergency preparedness plans and supplies, and to secure your space in order to prevent damage and injuries.