Shaking returns as most powerful earthquake this month hits Columbia area overnight

It had been nearly a week since the last confirmed earthquake hit the Columbia area, but that streak was snapped Sunday night when the rumbling returned to the Midlands.

A 2.3 magnitude earthquake was recorded in the Lugoff area at 8:42 p.m., the South Carolina Emergency Management Division reported. It was recorded about 1.5 miles beneath the surface, according to the U.S. Geological Survey.

A few hours later, another earthquake was confirmed early Monday morning, according to DNR.

The first earthquake was the most powerful quake — so far — this month, according to the South Carolina Department of Natural Resources Geological Survey. It surpassed a quake that was downgraded from a 2.4 to a 2.2 magnitude after being confirmed near Elgin on July 19.

Monday’s seismic activity was recorded 3:01 a.m., according to the USGS. The 2.1 magnitude earthquake was about 1.3 miles beneath the surface.

These were the 32nd and 33rd confirmed earthquakes in Kershaw County in the past 30 days, according to the South Carolina Department of Natural Resources.

Both 3.5 and 3.6 magnitude earthquakes on June 29 were included in that flurry of tremors and aftershocks. Those were the two largest quakes to hit South Carolina in nearly a decade. A 4.1-magnitude quake struck McCormick County in 2014.

Anyone who felt the earthquakes can report them to the USGS.

The two most recent earthquakes mean at least 62 have been detected in the Palmetto State since the start of 2022, according to South Carolina DNR. All but five of the quakes have been in the Midlands.

In all, 64 earthquakes have hit the Columbia area since a 3.3 magnitude quake was recorded on Dec. 27, 2021, according to the South Carolina Department of Natural Resources.

No major damage or injuries have been reported from any of the recent quakes.

Earthquakes that register 2.5 magnitude or less often go unnoticed and are usually only recorded by a seismograph, according to Michigan Technological University. Any quake less than 5.5 magnitude is not likely to cause significant damage, the school said.

It is typical for South Carolina to have between six and 10 earthquakes a year, the S.C. Geological Survey previously reported. There have been 89 earthquakes in South Carolina since Jan. 18, 2021, according to the S.C. Department of Natural Resources.

An explanation for the recent outburst has eluded scientists.

Some experts have theorized there’s a link between the Wateree River and the earthquakes northeast of Columbia. They said the combination of the single moderate earthquake in December and high water levels in the Wateree River during parts of this year have contributed to the earthquakes.

Other possible causes that have been discussed include digging and blasting at mines, water seeping through the ground from lakes, or other changes in weight or pressure underground, The State previously reported. But no one has settled on the single cause for the Midlands’ shaking.

The state Department of Health and Environmental Control said that mining activity is not likely to be the cause of recent earthquakes, as mines in the Elgin area are shallow.

Elgin, located about 20 miles northeast of Columbia and situated on a fault line, has been experiencing an unusual earthquake “swarm” for the past several months, leaving some residents feeling uneasy. The series of quakes might be the longest period of earthquake activity in the state’s history, officials said last week. But officials have said they don’t believe the spate of minor earthquakes is an indicator that a bigger quake could be on the way.

“Though the frequency of these minor earthquakes may alarm some, we do not expect a significantly damaging earthquake in South Carolina at this time, even though we know our state had them decades ago,” South Carolina EMD Director Kim Stenson said in a news release. “Now is the time to review your insurance policies for earthquake coverage, secure any items in your home that may become hazards during a tremor, and remember to Drop, Cover, and Hold on until the shaking passes. These are the precautions South Carolinians can take to properly prepare for earthquakes.”

The strongest earthquake ever recorded in South Carolina — and on the East Coast of the U.S. — was a devastating 7.3 in Charleston in 1886.

That quake killed 60 people and was felt over 2.5 million square miles, from Cuba to New York, and Bermuda to the Mississippi River, according to the Emergency Management Division.

Reported earthquakes in SC in 2021-22