South Carolina officials have proclaimed October 12–18 as Earthquake Preparedness Week and are urging residents to review safety plans and better understand the region's seismic risks.
Even though earthquakes may not be top of mind for many South Carolinians, tremors are more common than most realize, with 10 to 20 events occurring every year.
The majority of these quakes are not intense enough to be detected by humans, but occasionally a more significant event can be felt and even heard.
There are numerous ways to measure the magnitude of an earthquake, but most ratings are based on the amount of energy released at the source of the quake.
Magnitudes range from 0 to above 9.0, though quakes that are considered to be above a 9.0 occur about once every 100 years.
Since the start of the year, more than two dozen quakes have been detected by seismographs in South Carolina, with most occurring in the Midlands region.
The strongest was a magnitude 3.0 earthquake near Greenwood, which was powerful enough to rattle windows, knock pictures from walls and jolt the nerves of nearby residents.
To prepare South Carolinians for the possibility of a significant event, the South Carolina Emergency Management Division is leading a statewide campaign, which includes participation in a worldwide safety drill scheduled for Thursday, October 16, at 10:16 a.m.
During the drill, participants will be encouraged to drop, cover and hold on - key actions that first responders emphasize to help residents stay safe during an earthquake.
Additionally, the South Carolina Department of Insurance urges property owners to review their insurance policies to see if seismic activity is covered.
The agency says coverage can be added to an existing policy or purchased separately, with staff available to assist residents at 803-737-6180.
SCEMD also recommends that residents build emergency kits with food, water, flashlights and first-aid supplies, and ensure that heavy objects are properly secured.
Why earthquakes are common in the Palmetto State
Most earthquakes around the world occur along the boundaries of tectonic plates, but South Carolina sits well within the interior of the North American Plate.
According to seismologists, quakes that occur within a plate are known as intraplate earthquakes.
The most widely accepted theory by seismologists is that old fault systems lie beneath the surface and are occasionally reactivated by regional stress.
According to SCEMD, about 70% of the state’s earthquakes occur in the Middleton Place–Summerville Seismic Zone, located northwest of Charleston.
The region was the epicenter of one of the East Coast's most powerful earthquakes - a magnitude 6.9 to 7.3 event that struck on August 31, 1886.
The catastrophic quake damaged or destroyed more than 2,000 buildings, toppled church steeples and claimed dozens of lives.
At the time, damages were estimated between $5 million to $10 million, but experts say if a similar quake were to occur today, total losses could exceed $20 billion, with hundreds of fatalities.
