A loud explosion heard Saturday in some parts of Orangeburg County remained a mystery Monday.

The explosion was reportedly heard in the Eutawville, Cope, Cordova and Norway areas, causing the ground to shake.

"It was significant," Orangeburg County Chief Fire Operations Officer Teddy Wolfe said, noting he heard it from his residence in Eutawville. "I would like to know what it was."

The Orangeburg County Fire District, however, did not receive any reports of a fire or explosion.

The South Carolina Department of Natural Resources State Geologist Charles William "Bill" Clendenin Jr. said there were no reports of earthquake activity that came across his desk for Saturday.

The South Carolina Emergency Management Division and the Orangeburg County Emergency Services Department said they did not receive any reports either.

The Columbia National Weather Service meteorologist Dan Miller said there have been no reports of earthquakes in the state over the last seven days, according to the United States Geological Survey's National Earthquake Information Center.

"My guess it was a sonic boom," Miller said, though he says he has no confirmation of such. He said there are a number of air bases in the area, including North Auxiliary Air Field and Shaw Air Force Base, making the probability of the noise being a sonic explosion a possibility.

A sonic boom is the sound associated with the shock waves created by an object traveling through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding much like an explosion.