Revised July 2008
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Take cover under a heavy desk, table or bench, in a supported doorway, or along an inside wall.
Earthquake preparation
During the winter of 1811–1812, a legendary series of three earthquakes, 18 tremors and hundreds of aftershocks struck southern Missouri near New Madrid. This series of disruptions is regarded as one of the largest seismic events in U.S. history. The greatest of the quakes measured 8.8 on the Richter scale and was detected in the cities of Chicago, Washington, D.C., New Orleans and parts of Canada. The energy released from the earthquake was equal to 12,000 atomic bombs the size of those dropped on Hiroshima, or 150 million tons of TNT.
Settlements in Missouri and Arkansas were devastated, the Mississippi River flowed backwards for several days. Boats capsized. An eyewitness to the New Madrid earthquake gave the following account: "The surface of the earth rose and fell like the long, low swell of the sea, tilting the trees until their branches interlocked, and opening the soil in deep cracks. Landslides swept down the steeper bluffs and hillsides. Considerable areas were uplifted, and still larger areas sunk and became covered with water emerging through fissures. High banks of the Mississippi caved in and were precipitated into the river. Sand bars and points of islands gave way, and whole islands disappeared."
Scientists estimate that an earthquake the magnitude of the 1811–1812 quakes will occur about every 670 years. Scientists agree that the New Madrid system has now stored up enough strain energy to produce an earthquake measuring 7.6 on the Richter scale, although the probability of its occurring in the near future is unknown.
The New Madrid Seismic Zone (NMSZ) is the most active seismic area in the United States east of the Rocky Mountains. According to the Missouri Department of Natural Resources Division of Geology and Land Survey, the NMSZ averages more than 200 measured events per year (magnitude 1 or greater), about 20 per month. Tremors large enough to be felt (magnitude 2.5 to 3.0) are measured annually. Every 18 months, a 4.0 or greater shock, capable of minor local damage, occurs. Events of 5.0 or greater occur about once every decade and can do significant damage and be felt in several states.
Based upon historically and instrumentally recorded earthquakes, scientists with the U.S. Geological Survey and the Center for Earthquake Research and Information at the University of Memphis now estimate that the probability of a magnitude 6.0 or greater earthquake is 25 to 40 percent in the next 50 years and there is a 7 to 10 percent probability of a repeat of the 1811–1812 earthquakes (magnitude 7.5 to 8.0) within the next 50 years.
If an event equal in magnitude to the largest 1811–1812 quake occurred today, it is estimated that the loss of life would be great and property damage would be many billions of dollars. There would be major damage near the fault system in the Missouri Bootheel, northeast Arkansas and western Kentucky and Tennessee. Significant damage is expected to extend north of St. Louis up the Mississippi River valley, up the Ohio and Wabash River valleys to near Owensboro, Kentucky, and Indiana, and down the Mississippi River valley to near Greenville, Miss. Significant damage is also expected in about 15 additional counties each in southern Illinois, western Kentucky and Tennessee, northeastern Arkansas and northwestern Mississippi and in about five counties in southeast Missouri outside the Bootheel.
This guide is designed to help you and your family plan for and survive a major earthquake. With advance preparation, the impact of an earthquake can definitely be lessened. Set aside some emergency supplies and plan with your family what to do at home during and after a disaster. You could be without help for up to 72 hours, so learn to cope for at least that long and possibly one week. Movement of the ground is seldom the actual cause of death or injury. Most injuries and casualties result from partial building collapses, falling objects and debris, such as toppling chimneys and falling bricks, ceiling plaster and light fixtures. Many of these conditions are preventable.
Because earthquakes occur without warning, it is important to take precautionary steps so you and your family can respond during this emergency.
Before the earthquake happens, be prepared by having a home emergency supply kit available. The kit should include the following supplies:
Note
Extra flashlight and portable radio batteries should be stored in the refrigerator to extend their useful life.
Note
Water can be disinfected with 5.25 percent sodium hypochlorite solution (household chlorine bleach). Do not use a solution in which there are active ingredients other than hypochlorite. Use the following proportions:
| Clean water | Cloudy water | |
|---|---|---|
| Two liters | 4 drops | 1/8 teaspoon |
| One gallon | 1/8 teaspoon | 1/4 teaspoon |
| Five gallons | 1/2 teaspoon | 1 teaspoon |
Keep pipe, top, and adjustable wrenches, bottom, handy for emergencies.
Know how to shut off gas valve.
Your main gas shut-off valve is located next to your meter on the inlet pipe. On an LP gas system, the shut-off is located at the tank.
Use a wrench to give the valve a quarter turn in either direction so that the valve runs crosswise on the pipe. The gas line is now closed.
Caution
Do not shut off gas unless an emergency exists. If gas is ever turned off, remember that all pilot lights must be relit when the gas is turned back on.
Know how to shut off the water main valve.
Locate the water shut-off valve where it enters the house. Show all family members where the valve is. Also locate the main water shut-off at the water meter.
Locate your circuit breaker, left, or pull-out cartridge fuses in fuse box, right.
Look closely at your circuit breaker box or fuse box. Locate the main cartridge fuses or circuit breaker.
Be certain you can shut off electricity if there is damage to your home electrical wiring. To properly shut down the electrical circuits in your home, turn off each breaker one at a time and then shut off the main breaker. Reverse these steps to re-energize the home’s electrical panel.
First and foremost -- keep calm. During a major earthquake, you may experience a shaking that starts out to be gentle and within a second or two grows violent and knocks you off your feet. Or, you may be jarred by a violent jolt -- as though your house is being hit by a truck. A second or two later you will experience the shaking, making it difficult (if not impossible) to move from one room to another.
If you are indoors, stay there. Take cover under a heavy desk, table or bench, in a supported doorway, or along an inside wall. Stay away from windows, bookcases, china cabinets, mirrors and fireplaces until the shaking stops.
If you are in the kitchen, turn off the stove at the first sign of shaking and quickly take cover under a counter or sturdy table, or in a doorway.
If you are in a high-rise building, get under a desk or similar heavy furniture, and stay away from windows and outside walls. Stay in the building on the same floor. Do not dash for exits because stairways may be broken or jammed with people. Don’t be surprised if the electricity goes off, or if fire alarm systems or sprinklers go on. Do not use elevators.
If you are in your car, pull to the side of the road and stop the car. Do not park under overpasses or power lines. Stay in your car until the earthquake is over. When you drive on, watch for hazards created by the earthquake, such as fallen or falling objects, downed electric wires, damaged, broken or undermined bridges, roadways or overpasses.
If water is off, emergency water supplies may be all around you -- in water heaters, toilet water tanks, melted ice cubes, canned fruits and vegetables, etc.
Do not eat or drink anything from open containers near shattered glass. Liquids may be strained through a clean handkerchief, cloth or cheesecloth if danger of glass contamination exists.
If power is off, check your freezer and plan meals to use up foods that will spoil quickly. Keep your freezer door closed and insulate the freezer with blankets or quilts to reduce cooling loss. Cook thawed frozen foods immediately if they are still cool. If in doubt about their safety, do not use them.
Use outdoor charcoal broilers for emergency cooking. Never use the cookers indoors because of fire and carbon monoxide hazards.
The potential for earthquakes in Missouri always exists. Family earthquake preparedness and what family members do during and immediately after the tremor can help minimize damage and may make a life-or-death difference.
More information
Missouri Department of Natural Resources, Division of Geology and Land Survey
111 Fairgrounds Road
Rolla, MO 65402
573-368-2100
800-361-4827
dnr.mo.gov/geology/geosrv/geores/geohazhp.htm
G1905, revised July 2008