High Quality Content by WIKIPEDIA articles! South Carolina earthquakes occur with the greatest frequency along the central coastline of the state, in the Charleston area. South Carolina averages 10–15 earthquakes a year below magnitude 3 (FEMA). At a 7.3 magnitude, the Charleston Earthquake of 1886 was the largest quake to ever hit the Southeastern United States. This earthquake killed 60 people and destroyed much of the city. Aftershocks, some of them large enough to be damaging by themselves, continued for years.