Mild earthquake rattles Central Indiana
A minor earthquake jostled Central Indiana awake Sunday, shaking some buildings but causing no damage or injuries.The 3.6 magnitude earthquake was recorded at 8:05 a.m. and was the state's first in more than two years. Its epicenter was located about seven miles north of Shelbyville, according to the U.S. Geological Survey.Scientists who study the earth said the incident was not tied to any major fault lines and did not signal more temblors to come.Hoosiers as far north as Noblesville, as far west as Martinsville and Brownsburg and as far east as Rushville found themselves asking, "Was that what I think it was?""It didn't last long, but it sure did wake us up," said Julie Jones, a dispatcher at the Shelby County Sheriff's Department. "Our consoles were shaking, and as soon as it stopped, all the lines lit up."Tim Cooney, a mortgage banker who lives about two miles north of Shelbyville, thought it was another of the many National Guard helicopters that fly over his house.The Shelbyville Armory next to the Shelbyville Airport is home to an aviation support facility.Perhaps there was a crash, he thought."My wife felt the bed swaying, and she knew right away it was an earthquake," Cooney said. "I thought my wife was off her rocker."Jason Adams, an advertising manager who lives in an apartment complex on the Northeastside, thinks his dogs Jake and Mazzy felt the quake coming. They woke up and started barking about 7:55 a.m."They just wouldn't stop," he said. "And the next thing I knew, there was a shock wave that went through the building. I could feel the whole building move."Gary Pavlis, a professor of geological sciences at Indiana University, said the state experiences minor quakes every few years.Sunday's earthquake occurred about six miles deep, he said, in an area of structures geologists don't understand well. He said the shaking likely was set off when a rock roughly the size of a good-sized building -- six or seven stories tall -- shifted.According to the U.S. Geological Survey, about 130,000 earthquakes with a magnitude of 3 to 3.9 occur every year.In 2003, there were 1,300 earthquakes in that magnitude range in the United States, according to statistics compiled by the geological survey.The most recent earthquake in the region occurred June 28, near Troy Grove, Ill. That temblor had a magnitude of 4.2, according to the geological survey's Web site.The last recorded earthquake in Indiana occurred on June 18, 2002. The temblor registered a magnitude of 5.0 and was centered near Darmstadt, about 10 miles north of Evansville. It caused little damage.While there have been major earthquakes in Indiana territory over the past 20,000 years, Pavlis said, the chances of experiencing "the big one" are far less likely than in California."That's the perspective that people have to keep in mind," Pavlis said. "This is one of those small events that just pop off now and again that can't be related to any specific geological structures or faults."