Earthquakes in Missouri
February is Earthquake Awareness Month in Missouri
Most Missourians are familiar with the large 1811-1812 earthquakes that occurred in the New Madrid Seismic Zone (NMSZ) in southeast Missouri. The NMSZ extends into a multi-state area, and Missouri experiences small earthquakes nearly every day. These earthquakes typically are too small to be felt but are recorded on seismographs, devices that measure the earth’s movement. While these earthquakes are more frequent in the NMSZ in southeast Missouri, they also occur on other faults located in Missouri and surrounding states. Some scientists believe there is about a 10 percent chance of a magnitude 7-8 earthquake in the New Madrid Seismic Zone in a 50 year time interval.
Earthquake Frequency in the New Madrid Seismic Zone
- Earthquake occurrences in southeast Missouri are not rare.
- Four earthquakes measuring magnitude 4.5 or greater occurred in the zone since 1974 (as of December 6, 2012).
- Sixty-eight earthquakes that measured between Magnitude 2.0 and Magnitude 3.9 shook southeast Missouri from 2009-2011.
- Two hundred thirty-six earthquakes that measured between Magnitude 2.0 and Magnitude 3.9 shook southeast Missouri in the 10-year time frame from 2000-2009.
Seismographs are instruments that record the earth's movement. The movement along the fault system in the NMSZ occurs thousands of feet below ground surface. However, because of both the extent and depth of this fault, it has the potential to cause damage and impacts across a large area of the central United States. See a map of recent earthquakes.
Missourians should be aware of the reality of earthquake hazards in our state. However, we also must understand an earthquake measuring as large as magnitude 10.5 as depicted in disaster films probably are fiction, an earthquake measuring in magnitude of 6.0 to 8.0 is a more realistic estimation of a large earthquake that may occur in our state. The most valuable lesson we can learn from watching natural disaster movies is that knowledge and preparation are key. We should channel the energy associated with an increased awareness level into positive activities that will help prepare for actual earthquake risk associated with the New Madrid Seismic Zone. The Missouri Geological Survey has worked cooperatively with the U.S. Geological Survey for several decades to increase the knowledge base about earthquakes in the central United States.
Geologic Mapping for Natural Disasters
The Missouri Geological Survey partnered with the Missouri State Emergency Management Agency (SEMA) to create two series of maps to assist Missourians in their planning and response to a disaster. The Geologic Hazards Map Series highlights the potential for geologic and natural hazards, while the Debris Management Map Series helps to provide guidance for the management of waste debris following a disaster. Mapping potential geologic hazards and determining preliminary site suitability for disposal of debris provide emergency planners and responders with vital information needed in the response of a disaster. The maps are available for viewing and downloading. Learn more.