Why are there so many earthquakes near Elgin lately?

KERSHAW COUNTY, SC — Yet another series of earthquakes has struck near the Richland and Kershaw County border, including one of the largest in recent history that rattled thousands of people in their sleep and was felt across the state.

RELATED: Another earthquake near Elgin, hours after one shook much of the Midlands

More than 20 earthquakes have reverberated in the same Midlands area since late December. The most recent was late Monday afternoon, hours after one woke people from their sleep.

“I had just fallen asleep and then I woke up to a big boom, and it just sounded like thunder, and it lasted about ten-ish seconds or so.”

Scott White, a geology professor at the University of South Carolina and the Director for South Carolina Seismic Network, said the time and location of the earthquake is the reason why so many experienced it.

RELATED: Early Monday morning earthquakes wake up parts of the Midlands

“It occurred in the middle of the night, and it’s a very quiet time,” White said. “It was a very shallow earthquake, and you tend to hear those pretty well.”

White said after the first earthquake hit the area back on December 27 and the stream of vibrations continued, his team decided to install a seismometer in the area.

“We install these machines. They are very sensitive to shaking in the ground, they’re based on the same kinds of accelerometers or acceleration devices that you might have in your cell phone, except they’re many, many, many times more sensitive to any sort of shaking,” White said.

“We try and get them as deep as we can into the earth to couple them better to the solid rock, so it won’t shake around like a lot of jelly, like loose sediments might during earthquakes,” White said. “And so, we typically have to go out, and dig a hole and pour cement in it and then put that seismometer there, level it very carefully. And, you know, we put solar panels, all of that stuff, too, to keep it powered.”

White says having this allows them to continue researching the earthquakes in an attempt to understand why this is happening and if it will continue.

“We don’t view this whole sequence as an event with aftershocks, but rather a whole sequence of little earthquakes that are progressively relieving the stress within the earth’s crust,” White said. “Over this period of time, when enough stress gets relieved, we will see the end of this series of events. The ongoing seismic sequence doesn’t reflect abnormal seismic behavior. This one’s a bit longer than most, but it could continue for several more months or maybe even a year.”

RELATED: A month into the Kershaw County quakes, experts say answers still limited