While people in some parts of California are dealing with earthquakes lately, Arkansans may think they are in the clear. But geologists say that's not the case.
In fact, large parts of Arkansas fall inside the New Madrid Seismic Zone, a fault line that has produced some of the largest earthquakes in the lower 48 states. While there hasn't been a major shaker in recent years, Martha Kopper, geohazard supervisor for the Arkansas Geological Survey, says the New Madrid fault is the most active seismic zone east of the Rockies.
"It's an area about 200 miles long by about 50 miles wide and it's located in southeast Missouri, the southern tip of Illinois, western Kentucky, western Tennessee and northeastern Arkansas," she states.
Kopper says the biggest earthquake along the New Madrid fault was in 1811 in northeast Arkansas. That quake registered a magnitude 7.7, causing major damage and loss of life.
Over the years, there have been other quakes of similar magnitude in the region, as well as smaller ones in recent years. In Arkansas, at least 15 earthquakes have occurred in the past six months, including one within the past week.
But Kopper says another big one may still be lurking out there for Arkansans. "For the New Madrid Seismic Zone, there is a 7% to 10% probability that a magnitude 7 or greater could occur within the next 50 years and a 25% to 40% chance of a magnitude 6," she states.
Kopper says individuals also have a responsibility to be ready for a disaster.
"Prepare," she urges. "You should prepare, not become laissez-faire. Don't become careless about it, because about 90% of deaths are due to buildings falling on people." Kopper says simple precautions such as attaching heavy objects to walls and removing light fixtures and fans from ceilings can make a big difference.
She also recommends putting together an earthquake survival kit that includes a first-aid kit, batteries, non-perishable food and other items, and leaving it in an easy-to-find place.