Most powerful earthquake this month rumbles through Columbia area, SC officials say

There were more tremors in the Columbia area Tuesday, as two more earthquakes were confirmed by the South Carolina Emergency Management Division.

The 2.4 magnitude earthquake recorded in the Elgin area at 12:06 p.m. was the most powerful quake to hit the Midlands this month, according to the South Carolina Department of Natural Resources Geological Survey.

The seismic activity was about 9 miles beneath the surface, according to the U.S. Geological Survey.

Six minutes later, a 2.1 magnitude earthquake occurred in the Elgin area, the S.C. Emergency Management Division said.

The second earthquake hit much closer to the surface, and was recorded at a depth of about 2 miles, the USGS reported.

These were the 30th and 31st confirmed earthquakes in Kershaw County in the past 24 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 Tuesday’s earthquakes can report it to the USGS, and more than 200 people had 90 minutes after the tremors hit.

Tuesday’s earthquakes mean at least 60 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, 62 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 87 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