One of the largest earthquakes in history occurred in the New Madrid Seismic Zone on Feb. 7, 1812. The earthquake exceeded the magnitude of California's Great 1906 San Francisco Earthquake. Scientists believe it would have registered greater than magnitude 7.5. The New Madrid Seismic Zone is located in Southeastern Missouri, Northeastern Arkansas, Western Tennessee, Western Kentucky and Southern Illinois. Southwestern Indiana and Northwestern Mississippi are also close enough to receive significant shaking from large earthquakes occurring in the zone. The New Madrid Seismic Zone is the most active seismic area in the United States east of the Rocky Mountains. More than 200 small earthquakes occur each year along this zone.
Nearly 200 years of population growth in the region, which includes metropolitan areas such as St. Louis and Memphis, means that a repeat of the 1812 earthquake could cause considerably more damage. "A similar size earthquake occurring along this zone in this century has the potential to significantly impact Missouri," according to Dave Overhoff, geo-hazards geologist with the Missouri Department of Natural Resources
. Because of the proximity to the New Madrid Seismic Zone, portions of the St. Louis area are at risk for damages or injuries from a major earthquake.
Last weekend, geologists with the Missouri Department of Natural Resources met with State Farm Insurance executives at the department's St. Louis regional office to accept a check for $26,000 in support of an earthquake hazard mapping project under way at the department's Division of Geology and Land Survey in Rolla.
The partnership between the department and State Farm Insurance will further the department's work to create detailed surficial materials maps for the Greater St. Louis area. Surficial materials mapping comprises the first phase of an earthquake hazard map. The hazards maps will identify the various areas at higher and lower risk for ground acceleration or amplified ground shaking. All the information and maps generated by the project will be made available to anyone interested in this type of information.
The St. Louis Area Earthquake Hazards Mapping Project is a cooperative effort by the Department of Natural Resources, the Missouri University of Science and Technology Natural Hazards Mitigation Institute, the Illinois Geological Survey, the Central U.S. Earthquake Consortium emergency managers, Central United States Earthquake Consortium State Geologists and the U.S. Geological Survey in Memphis.
"We are pleased to partner with State Farm Insurance on this important project," said Mimi Garstang, Division of Geology and Land Survey director and state geologist. "The additional funds will supplement federal and state dollars contributing to this effort. Predicting an earthquake is nearly impossible, but we do know that portions of the St. Louis region have varying degrees of risk. Engineers, developers, emergency planners and responders and the general public can make better decisions once this project is completed."
When damaging earthquakes occur, movement of the ground seldom is the actual cause of death or injury. Most casualties result from partial building collapses, falling objects and debris, such as toppling chimneys, falling bricks, ceiling plaster and light fixtures. "When we know where the areas of highest risk are located, we can work to minimize this type of impact," said Garstang.