JENKINSVILLE, S.C. — Another minor earthquake has struck near the Monticello reservoir in Fairfield County, the seventh such tremor there in the last week.
The latest took place at 10:59 a.m. Monday underwater at the reservoir, according to the U.S. Geological Survey. The quake was a 2.0 magnitude and occurred at a depth of just under 0.86 miles beneath the ground surface.
At that strength, it's unlikely anyone felt it, since quakes usually have to be greater than 2.5 for them to be perceived by humans.
There was a quake just a day earlier not far from that location, and over the last week, there were five others. While it's not unusual to see quakes at this location in Fairfield County, it is unusual for there to be so many in a short amount of time. However, the South Carolina Emergency Management Division said seismologists believe these are normal background activity and are not indicators of larger earthquakes to come.
Why are there so many earthquakes in Fairfield County?
Dr. Steve Jaume told News19's Tai Wong last Friday that the reservoir itself may actually be partially to blame due to the added pressure they place on the ground below them
Jaume is with the Department of Geology and Environmental Geosciences at the College of Charleston.
"Most reservoirs don’t do this, but there are a select few around the planet -- and the Monticello Reservoir is one of them -- that experience these swarms around the reservoir," he said.
He said that the water also seeps into cracks under the lake over time adding that "some of the cracks are going to be faults."
That, in turn, makes them move more easily. At this point, it's unclear how long the small earthquakes will last, with the first of the latest six being felt last Monday and the rest happening almost daily along the east side of the lake since then.
Where do earthquakes in South Carolina typically happen?
Most earthquakes in the state happen near the coast. Approximately 70 percent of earthquakes are in the coastal plain, with most happening in the Lowcountry.
Back in 1886, Charleston was hit by a catastrophic earthquake. It had an estimated magnitude of 7.3, and was felt as far away and Cuba and New York. At least 60 people were killed, and thousands of building were damaged.
Structural damage extended hundreds of miles to cities in Alabama, Ohio, and Kentucky.
Geologists say that Charleston lies in one of the most seismically active areas in the eastern United States.