Charleston Earthquake of 1886

On August 31, 1886 Charleston, South Carolina, experienced the most  damaging earthquake in the eastern United States.  The initial shock lasted nearly one minute.  The earthquake had a magnitude of 7.3 (Johnson, 1996) and was felt over 2.5 million square miles, from Cuba to New York, and Bermuda to the Mississippi River.  Structural damage extended several hundreds of miles to cities in Alabama, Ohio, and Kentucky.  At the time of the earthquake, many of the residents of Charleston thought it was a calamity that struck the entire world.  Many residents were surprised when they discovered it was principally their area where the majority of severe damage occurred.

Geologically, Charleston lies in one of the most seismically active areas in the Eastern United States. The seismicity in the Coastal Plain of South Carolina clusters around the cities of Summerville and Bowman, SC, known as the Middleton Place - Summerville Seismic Zone (MPSSZ). The MPSSZ seismicity appears to be occurring in two steeply dipping faults. The first fault is the deeper, northeast-trending Woodstock Fault and the second is the shallower, northwest-trending Ashley River Fault.  Recent seismic activity (November 2002; M=4.2 & 3.5) has also included an earthquake in the Atlantic Ocean off the coast of South Carolina.

Currently the MPSSZ experiences between 10 to 15 magnitude 3 or less events every year. Large events, like the 1886 earthquake, have been recorded in the oral history of the area (~1600 and 13-1400's AD).  Additionally, paleoseismic investigations have shown evidence for several pre-historic, liquefaction-inducing earthquakes in coastal South Carolina in the last 6000 years.  If the present is the key to the past, and the past is an analog for the future, then the Charleston region can expect to experience another 1886 magnitude event in the future.  (South Carolina Earthquake Education and Preparedness, College of Charleston.)