With a magnitude of at least 7.0 on the Richter Scale, the 1886 Charleston Earthquake is the largest tremor the Southeast has seen in recorded history.
Talk about starting the year on shaky ground. Over the past five months, over two dozen earthquakes have rattled South Carolina. On average, the Palmetto State sees 20 quakes per year. So, is this a cause for concern?
The Culprit: “Cluster” Quakes
Not exactly. While multiple smaller quakes can be the precursor to a bigger one, they rarely mean a major earthquake is coming. In fact, the Southeast sees dozens of smaller earthquakes, known as microquakes, every day. While there’s no sign of a devastating earthquake to come, these clusters keep on popping up. Usually, these cluster events are isolated and last no more than a week. Since December 17, 2021, the town of Elgin, located 40 miles northeast of Columbia, has been struck by 17 earthquakes. The strongest in the cluster registered a 3.3 on the Richter Scale and was felt around many Midlands communities. Earlier that year, another swarm of six microquakes rattled Jenkinsville, located 40 miles west of Elgin.
The most recent cluster of earthquakes occurred earlier this year near Elgin, SC.
A Shift in Location
While South Carolina is no stranger to earthquakes, seeing clusters so far inland is somewhat of an anomaly. Most tremors occur along the Palmetto State’s Lowcountry, which is bounded by a shallow fault line. South Carolina’s Emergency Management Division (SCEMD) says roughly 70% of South Carolina earthquakes are located in the Middleton Place-Summerville Seismic Zone, which runs through Charleston’s northwestern fringes. Geologists are not sure why this shift has occurred.
A Cataclysmic Encore?
Over 135 years ago, the strongest earthquake to ever strike the Southeast in recorded history brought historic damage to Charleston. While the exact strength is unclear, it was thought to be at least a 7.0 on the Richter Scale. Hundreds of buildings were destroyed and dozens of citizens were killed. This quake was also preceded by microquakes, known as foreshocks. Unfortunately, geologists have no way of knowing if a certain microquake is a one-off event or could be a foreshock to a bigger event. That said, it’s believed that an earthquake of that scale occurs only once every 500-600 years, so South Carolinians can breathe easier for now.
