December 25, 2010
Odd Earthquakes Not Letting Up In Central Arkansas
Central Arkansas has been hit with a series of earthquakes recently, more than 500 since September 20.
According to the U.S. Geological Survey (USGS), most were hardly noticeable but one stood out prominently when it hit the Richter scale at a 4.0 on October 11.
Geologists can't say whether the quakes will end anytime soon.
Dr. Horton of the University of Memphis feels that the ample amount of earthquakes in this state is quite unusual.
"In the New Madrid Seismic Zone there's approximately 200 per year, so if we had that many in Central Arkansas in less than a month, something is going on," Dr. Horton told CNN's Sarah Hoye.
The problem is that part of central Arkansas isn't even part of the New Madrid Fault Zone, so researchers are trying to figure out what's causing all those earthquakes.
Although drilling for natural gas has been ruled out as a cause for the quakes, experts want to continue looking at salt water disposal wells, said Scott Ausbrooks, geohazards supervisor for the USGS. Disposal wells occur when drilling waster is injected back into the earth after drilling.
Even though the two areas are not connected, Horton's biggest worry is along the New Madrid Fault where he said damage from a magnitude six earthquake could be catastrophic to Mid-Southerners.
"A probability of having that in a 50-year period is about 25 to 40-percent chance," said Dr. Horton.
As exciting as it seemed when the first couple of quakes hit, residents are looking forward to the quakes dissipating.
"In the beginning, it was fun, it was neat, it was a cool thing to experience. But now we're wanting it to go away," Steve Wilson, assistant superintendent at Woolly Hallow State Park, told Hoye. "We've had all the fun we want."
There have been no reports of damage or anyone getting hurt from the earthquakes in central Arkansas. The largest earthquake along the New Madrid Fault was a 7.7 magnitude in 1811. It caused a massive upheaval of the ground and the shaking was felt all the way to New York City.
Image Caption: Map of the New Madrid Seismic Zone. Credit: USGS
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