According to the USGS, a magnitude 4.6 Earthquake hit in Maine at 7:12PM on October 16th, 2012, with the epicenter approximately 5km west of Hollis Center, Maine.
Details are still emerging, but this is the first earthquake we can recall in some time. More details will be posted as they are made available.
UPDATED 10/17 @9:06AM EST – The magnitude of the earthquake was revised down to 4.0. No damage or injuries have been reported.