This time it really was an earthquake.

The crowd at a USC football game at Williams-Brice Stadium was so loud a week ago that the South Carolina Emergency Management Division playfully tweeted “No. That’s not an earthquake in the Midlands.”

But there was no joking Sunday night, when a 2.5 magnitude earthquake was confirmed in the Columbia area at 9:33 p.m., the S.C. Emergency Management Division said.

The earthquake that the U.S. Geological Survey confirmed was in the Elgin area – about 20 miles east of Columbia – had social media buzzing. It’s possible many people reported feeling the quake because it occurred so close to the surface, hitting at about 0.01 miles underground, according to the USGS.

This was the first seismic activity in South Carolina since a 1.3 magnitude quake was recorded in the Elgin area on Oct. 14, according to the South Carolina Department of Natural Resources. In the 24 hours prior to Sunday’s earthquake, two others were confirmed in neighboring Georgia, according to the USGS.

There have been 43 confirmed earthquakes in Kershaw County since the end of June, according to the South Carolina DNR.

Sunday’s quake was the most powerful recorded in South Carolina since a pair were confirmed on June 29. On that day, two earthquakes – one a 3.5 magnitude and the other 3.6 – 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 Sunday’s earthquake can report it to the USGS. Through 5 a.m., more than 1,000 people said they felt the tremors and shaking or heard rumbling.

The most recent earthquake means at least 74 have been detected in the Palmetto State since the start of 2022, according to South Carolina DNR. All but seven of the quakes have been in the Midlands.

In all, 74 earthquakes have hit the Columbia area since a 3.3-magnitude quake was recorded Dec. 27, 2021, according to the DNR.

The S.C. Emergency Management Division said Sunday’s earthquake was classified as a micro quake, according to the Modified Mercalli Intensity Scale.

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 101 earthquakes in South Carolina since Jan. 18, 2021, according to DNR.

During a town hall to address the earthquakes, state geologist Scott Howard said as many as 200 smaller tremors might have gone unnoticed and unrecorded.

Why the increase in earthquakes?

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 a single moderate earthquake in December and high water levels in the Wateree River during parts of this year have contributed to the earthquakes. But no one has settled on the single cause for the Midlands’ shaking.

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. 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 previously 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 state EMD.2022