Small Earthquake Near Rockford, Mercer County, Ohio
Origin Time: 13 March, 2005, 04:02:04.49 UTC
Location: 40.68º N -84.60º W
Magnitude: 2.2 mbLg
Depth: 5 km (fixed)
A small earthquake startled residents of Rockford, Mercer County, on Saturday, March 13 at 11:02 p.m. Eastern Standard Time. Felt reports were received from Rockford, north to Ohio City in Van Wert County, and from about four miles south of Rockford. All described a loud boom followed by a brief shaking. Many did not realize that it was an earthquake. The epicenter of this earthquake is near that of a 2.5-magnitude event on January 30, 2004. Both earthquakes are close to the trend of the Anna-Champaign fault, which is a major structure within the Anna or Fort Wayne Rift. This feature trends northwest from Champaign County, Ohio to Fort Wayne, Indiana. Historically, this rift zone has had many earthquakes, including damaging earthquakes on March 2 and March 9, 1937. Most of the historical earthquakes were centered in Shelby, Auglaize, and Allen Counties. Prior to the January 30, 2004 Rockford earthquake, no events had been noted so far north in Mercer County. Individuals who felt the March 13 earthquake are encouraged to submit a felt-report form. This information assists the Ohio Seismic Network in determining the extent of the area in which the earthquake was felt and potential future seismic risk.