3.8 magnitude earthquake hits north central Indiana

This map from the U.S. Geologic Survey shows the epicenter of the earthquake. The blue areas indicate a higher intensity than the purple areas.

An earthquake about 5 miles below the ground hit north central Indiana shortly before sunrise on 30 december 2010.

The U.S. Geological Survey reported a 3.8 magnitude earthquake centered 5 miles southeast of Greentown, Ind., at 7:55:21 a.m. the same day. The agency had initially reported the quake as a 4.2 magnitude. It occurred about 3 miles below the ground, the geological survey reported.

The epicenter is "highly irregular, extremely rare, unprecedented,” John Steinmetz, director of the Indiana Geological Survey at Indiana University, told the Star Press at Muncie.

The Indiana Geological Survey had no records of an earthquake this size in Central Indiana ever. Steinmetz said he needed more time to research when — if ever — central Indiana had been the center of even a more minor earthquake.

The last major earthquake in Indiana on April 18, 2008, had a magnitude of 5.2 and was the strongest to hit the state in 40 years. The epicenter of that 5:37 a.m. quake, seven miles below the Earth's surface, was near West Salem, Ill., about 125 miles southwest of Indianapolis, according to the U.S. Geological Survey. That quake was considered to be associated with the midwest New Madrid fault.

Central Indiana is home to a faultline, the Fortville Fault, which runs through Madison and Hancock counties. But Steinmetz said it was too premature as of 9 a.m. to determine whether the quake originated on the Fortville Fault.

The geological survey received reports of people feeling the quake as far away as southern Wisconsin; the western suburbs of Chicago; Toledo, Columbus and Cincinnati, Ohio; Grand Rapids, Mich.; and central Kentucky.

Source:Indiastar