The United States Geological Survey detected a strange earthquake in Greene County about 30 miles southwest of Tuscaloosa early Tuesday morning, the agency has reported.

The quake, which was measured as a 2.6 magnitude, started just after 4 a.m.

The seismic event is bizarre because, according to the USGS, "most earthquakes in North America east of the Rockies occur as faulting within bedrock, usually miles deep." The Tuesday morning quake in Greene County was recorded at a depth of 0.3 miles, which is uncharacteristically close to the surface.

The minor earthquake is the first in the west Alabama area this year.

The event was first reported by AL.com Monday morning.