By VICKI BROWN
South Carolina experiences about 10 earthquakes each year. They usually register between less than 1 and up to 4.1 on the Richter Scale. With two dozen seismometers buried underground throughout the state, every tremor and quake are recorded. On Monday, September 27, at 12:49 p.m., USGS data reportedly detected a 2.9 magnitude earthquake located 5.6 miles north-northwest of Ridgeville in Dorchester County.
In a video announcement, Dr. Steven Jaume, professor and geologist at the College of Charleston, reported that there was a second quake minutes after the first one. He said that quake was a 2.0 magnitude aftershock.
Nearly five hours later on that same day, at about 6:21 p.m., a third earthquake hit Dorchester County, this time in Summerville. This quake had a recorded magnitude 3.3 and occurred in the Wescott Golf Club off of Dorchester Road in Summerville. Residents throughout the Lowcountry, including portions of Berkeley County, reportedly felt the earthquake and hundreds of calls came in to local radio and television stations asking about it. No one has claimed any damage so far.
No earthquakes were reported that day in Colleton County, but Colleton does sit on a fault line.
Regardless, earthquakes are nothing new to this area.
In 1886, Charleston experienced the worst earthquake in the entire eastern United States. Because of that incident, studies by the United States Geological Survey (USGS) found that South Carolina sits on a fault line, particularly near Charleston and specifically along the neighboring city of Summerville.
That means that surrounding counties are susceptible to quakes.
According to geologists, the crust of the earth is like a factory. Old crust is constantly melted and new crust is being made, and the continents are always floating on a river of melted rock. This movement causes problems…namely earthquakes.
Earthquakes occur when rocks under the earth’s surface are being squeezed together until they pop up or collapse down, or are pulled apart causing a break. They may also be shifted and slide or grind from side to side. Then the rocks break.
It can sound like an explosion or sonic boom.
The shifting rock may not be very powerful under the surface, but as everything above it shifts too, it grows in velocity and noise. The break in the rock can then be felt and heard.
Rocks break and when the rocks move past each near the earth’s surface, it is called a faulting: coastal South Carolina sits on a fault line. Another one runs across the northern most part of Colleton County. Unfortunately, much of the Lowcountry sits on sandy soil which acts like a liquid during a quake, pushing buried cables and pipes above ground.
It’s going to happen again
While scientists still can’t predict earthquakes, they do know one thing…if an earthquake happened once in a certain area, it will happen again. And if a quake of magnitude 6 or higher destroyed Charleston and surrounding counties once, another one will definitely occur again.
According to Jaume, 70 percent of South Carolina earthquakes are located around Ravenel-Adams Run-Hollywood; at Middleton Place-Summerville; and in Bowman.
The August 31, 1886 earthquake of Charleston occurred at 9:51 p.m., registered 7.6 on the Richtor Scale, was felt from N.Y. to Cuba, lasted 35 seconds, killed 110 people, caused $23 million in damage (or $158.48 million present day), damaged 14,000 houses and destroyed 90 percent of all brick structures. The two epicenters were located 21 miles northwest of Charleston and in Ravenel, say historians and geologists from USGS.
While more recent earthquakes in the Lowcountry have not been as devastating as the 1886 quake, they have been felt and some have caused minor damage.
According to Dr. Joyce Bagwell, affectionately known as the “Earthquake Lady,” another major quake is imminent for this area. “We are past due for another major quake. As time goes by, the probability of the Lowcountry experiencing a major earthquake grows,” said Bagwell in a 1993 conference. Bagwell headed the Earthquake Preparedness Department at Charleston Southern University and monitored seismic activity in South Carolina for the United States Geological Survey for more than 20 years until her death in March 2021.
In all, there have been 18 recorded and large earthquakes in or near Charleston since 1903, all of which caused damage.
On January 23, 1903, houses were shaken violently in South Carolina/Georgia border near Savannah.
On April 19, 1907, a quake affected Charleston and went across a 26,000 square kilometer area.
On June 12, 1912, a stronger earthquake caused damage to chimneys in Summerville, impacting an area of about 90,000 square kilometers.
On January 1, 1913, the Union County area was shaken with cracks in many brick buildings and chimneys damaged.
On September 22, 1914, an earthquake hit the Summerville area, with reports of walls being displaced in local buildings.
On October 20, 1924, Pickens County was the epicenter of an earthquake that shook most of South Carolina and western North Carolina, northeastern Georgia, and eastern Tennessee.
On July 26, 1945, an earthquake centered in Lake Murray, west of Columbia, and was felt in Georgia, North Carolina, and Tennessee. No damage was noted.
On November 19, 1952, moderately strong shocks occurred near Charleston.
On October 20, 1958, moderate earthquakes awakened residents in Anderson and caused cracked and fallen plaster in walls.
On August 3, 1959, a quake caused minor damage in Charleston, Summerville, and Wadmalaw Island. Chimneys were damaged and walls cracked in homes.
On March 12, 1960, the earthquake epicenter was off the coast of South Carolina, impacting Augusta.
On April 20, 1964, a strong quake was felt in Florence, Lexington, and Richland Counties.
On May 19, 1971, several windows were broken in Bowman and Orangeburg from a magnitude 3.4 earthquake.
On July 13, 1971, two small shocks, about 3 hours apart, were felt in western South Carolina.
On November 11, 2002, areas near Seabrook Island, South Carolina experienced a magnitude 4.4 earthquake. There were no reports of damage or injuries.
On December 16, 2008, a 3.6 magnitude earthquake occurred in Dorchester County.
On Friday, February 14, 2014, an earthquake occurred in the midlands of SC. It was reported to have been a 4.1 earthquake.