The U.S. Geological Survey said the 3.6 magnitude quake struck at 7:42 a.m. local time about 4 miles south of the city of Summerville.
Police Sgt. Cassandra Williams in that city said the department had received no reports of damage, but that she felt the rattling herself for a few seconds.
The epicenter was near a fault blamed for the destructive 1886 Charleston quake that killed more than 100 people.
Dennis Clark, director of the Dorchester County Emergency Management Department, told the Associated Press his office received scattered reports of pictures falling from walls and Christmas trees tipping over during Tuesday morning’s tremor.
The two injuries occurred when a pregnant woman fell during the shaking and when a child fell out of a high chair, striking its head.