Earthquakes strangely familiar
By By Connie Nowlin Managing editor
A press release from the emergency management agency verified what residents of Little Rock and Robinson Road already knew.
There have been several tremors there in recent days.
The first shake, about 6:30 p.m. Sept. 25, registered at 2.9 on the Reichter scale. The second event, about 9:30 p.m. on Sept. 29, was slightly stronger, at 3.3 on the scale. That information was sent out by the Geological Survey of Alabama in Tuscaloosa.
Residents said that their homes shook and rattled on both occasions.
Rex and Cindy McKinley from Little Rock felt the both tremors and said the second one was a much stronger. It lasted somewhere around 6-7 seconds, " a very long time when your whole house is shaking. We had objects on the mantel that vibrated to the edge and almost fell off. The sound was so loud it drowned out the TV and other noises in the house. You could even hear the tin on the roof moving. It was very scary it even had the dogs barking outside," they reported by e-mail.
Gladys Helton was outside on Sept. 25 and felt the earth move under her feet, and knew what it was because of the larger quake in 1997. That event cracked the brick and plaster in her home, but there was no damage in either event last week.
"I just hope that we don't ever have anything bad like they have in California," she said.
That is not too likely, according to geologists.
"There are several small faults at great depths below the coastal plain," said Dorothy Raymond, a geologist with the Geological Survey of Alabama. She said the plain is composed of sand and clay several miles thick, and it usually dampens the effects of shifts in the faults.
Those shifts are what cause the earthquakes.
And just like oranges in a basket, when one moves, the others shift as a result. That means that there may be a little cluster of quakes.
"It is nothing unusual, if you've had quakes in the area, you're likely to have them again in the future," said John Mich, with the Department of the Interior in Tuscaloosa.
Raymond agreed. "When one (plate) moves, the others have to readjust, they have to get comfortable with each other again," she said.
None of this points to a countdown to a larger, damaging event.
"You might not have another one for 25 or 50 years," Raymond said. "There might be a little cluster of several and then they just peter out."