FEMA reminds Missouri and Tennessee of New Madrid Seismic Zone
As part of earthquake preparedness, the Federal Emergency Management Agency has reached out to businesses in Memphis, Tenn., and St. Louis, Mo.--large cities near the New Madrid Seismic Zone, a FEMA official told a May 8 Senate panel.
The New Madrid zone, located in southeastern Missouri, northeastern Arkansas, western Tennessee, western Kentucky and southern Illinois, is the most active seismic area in the United States east of the Rocky Mountains. In 1811 and 1812, hundreds of earthquakes occurred there, with three large events reaching estimated magnitudes of 7.9, 7.6 and 8.0.
FEMA reached out to businesses in Memphis and St. Louis as part of its QuakeSmart initiative, timed to occur around the 200th anniversary of those earlier earthquakes, said Elizabeth Zimmermanm, deputy associate administrator for the Office of Response and Recovery, in written testimony (.pdf). She spoke before a hearing of the Senate Homeland Security and Governmental Affairs subcommittee on emergency management, intergovernmental relations, and the District of Columbia on the subject of the private sector in preparedness and emergency response.
Scientists say the New Madrid Seismic Zone is about 30 years overdue for a 6.3 magnitude earthquake and that the probability of another earthquake the magnitude of the quakes of 1811-1812 is 7 to 10 percent.
The zone is more difficult to study than seismic zones in, for example, California, since New Madrid zone is buried are "beneath 100- to 200-foot thick layers of soft river deposited soils called alluvium," notes the Missouri Department of Natural Resources.
The Missouri agency also notes that earthquakes in the zone shake and damage an area approximately 20 times greater than earthquakes in California due to the Midwest's harder, colder, drier and less fractured geology.