SAFETY AND HEALTH

Duane Friend

Illinois earthquake — hey, it could happen

A major earthquake in Illinois is something most people don't worry about. Floods, tornadoes, and other natural disasters that frequently occur in the state are given more concern. Earthquakes are something most people relate to the West Coast.

What are the chances of a powerful earthquake happening in the Midwest? According to many scientists, it's about a 9 in 10 chance within the next 50 years. The reason for this is because of a region in the boot heel of Missouri, where huge geologic forces are at work.

Known as the Reelfoot Rift, this geologic feature is located near New Madrid, Mo. Millions of years ago, the earth's crust attempted to pull apart in this area. This is something that occurs on many parts of the earth, and is the process that helped form the Atlantic Ocean. In the case of the Reelfoot Rift, the separation was not successful. It did, however, create many breaks, or faults, within the earth's crust.

Underground forces push on these faults, causing parts of the crust to move. Faults are not restricted to this location, however. Several faults are located in Illinois, especially in the southern part of the state. Earthquakes have also been caused by movement of these faults, with one of most notable occurring as recently as 1968.

A series of huge earthquakes, centered on the New Madrid area, occurred during 1811 and 1812. While the area was sparsely populated, the energy created by one of the quakes was enough to make church bells ring in Boston, and changed the course of the Mississippi River. Sensitive equipment has recorded hundreds of small quakes during the last few decades.

"How would a major earthquake affect Illinois?"

How would a major earthquake affect Illinois? Obviously, those closer to the origin would see and feel more damage. People living anywhere south of a St. Louis to Terre Haute line could experience widespread damage. In addition, those living in the Illinois and Mississippi river valleys could see damage extending farther north, since earthquake energy could travel easily through these areas. Central and Northern regions of the state could experience moderate damage, depending on the strength of the earthquake.

Several things can be done to minimize earthquake damage in the home. Anchor free standing bookcases, cabinets and appliances to walls. Secure ceiling lights, suspended ceilings and lights to the permanent structure of your house. Water heaters should be secured to a nearby wall. All gas appliances should be fitted with flexible connections and a breakaway shutoff device. Unreinforced masonry chimneys and concrete walls should be braced. Anchor bolts or steel plates can be added between the home and foundation. In addition, houses with cripple walls, a short wall between the top of the foundation and first floor, should be braced with sheathing.

During an earthquake, if you are in your house, drop to the floor, take cover under a desk or table, and hold onto it while the earthquake is taking place. Protect yourself from falling objects.

In outdoor situations, try to get to an open area as quickly and safely as possible. Drop to the ground until the quake has subsided. If driving, carefully pull to the side of the road, being sure to stay away from bridges, overpasses, power lines or other falling hazards. Remain inside the vehicle, below window level.

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.

Duane Friend is the natural resources management educator at the Springfield Extension Center. For more information you can write to him at Springfield Extension Center, P.O. Box 8199, Springfield, IL 62791-8199. Telephone him at (217) 782-6515 or send e-mail to friendd@mail.aces.uiuc.edu.

14 ILLINOIS COUNTRY LIVING | www.aiec.org