Folks who awakened to a rumble or boom weren't hearing things in Eastport this morning.

The U.S. Geological Survey says a magnitude 3.3 earthquake was recorded Tuesday morning about nine miles northeast of Eastport, according to the Associated Press.

Some people reported hearing a boom, while others heard a rumble.

Such earthquakes aren't unusual in Maine, the AP said.

According to the AP, the largest earthquake in 40 years registered in Maine occurred back in 2012, clocking in at 4.0 magnitude with the epicenter, about 3 miles west of Hollis Center. The largest earthquake recorded in Maine, with a recorded magnitude of 5.1, happened in 1904.