Did you know that the most powerful earthquakes ever to occur in the continental United States took place in the NMSZ during the winter of 1811-1812? Experts estimate that a similar series of earthquakes today would devastate the region, with projected damages of $60 to $80 billion!
Illinois is at risk from two major seismic zones, the Wabash Valley Seismic Zone and the New Madrid Seismic Zone (NMSZ). The Wabash Valley Zone is located between southeastern Illinois and southwestern Indiana. The New Madrid Zone is located in the Central Mississippi Valley and includes portions of the states of Alabama, Arkansas, Illinois, Indiana, Kentucky, Missouri, Mississippi, and Tennessee. During any 50-year time span, there is a 25% to 40% chance of a magnitude 6.0 or greater earthquake in this area.
A loud rumbling may be heard several seconds before the earthquake. These few seconds could provide you with the chance to move to a safer location. You may have several options.
If you are indoors, follow these steps: Drop down to the floor. Take cover under a sturdy desk, table or other furniture. If that is not possible, seek cover against an interior wall and protect your head and neck with your arms. Avoid danger spots near windows, hanging objects, mirrors or tall furniture. If you take cover under a sturdy piece of furniture, hold on to it and be prepared to move with it. If sturdy furniture is not available, kneel, sit, or stay low to the floor. Don’t use doorways as a place of safety.
If you are outside when the shaking starts, get into an open area away from trees, buildings, walls and power lines. If driving, stop safely as soon as possible. Do not stop under overpasses or bridges. Turn off the engine and turn on the radio. Stay inside your vehicle below window level until the shaking stops. Do not get out of your vehicle if downed power lines have fallen across it.
After an earthquake, check your home for possible electrical shorts, and gas or water leaks. Contact your local electric cooperative, water, or gas company if leaks are present. Obey evacuation orders from local authorities, and be prepared for aftershocks, some of which could be almost as strong as the initial quake.
For more information on Illinois and earthquakes, visit the Illinois State Geological Survey at http://www.isgs.uiuc.edu/, the Federal Emergency Management Agency at http://www.fema.gov/hazard/earthquake/eq_before.shtm , or the Central U.S. Earthquake Consortium at http://www.cusec.org/.