ELGIN, S.C. — The Elgin community has been shaken by over 80 earthquakes since December 2021, and after four months of no tremors, the area has started shaking again.
“We weren't expecting anything to come back, and then these two in the last three days have reminded us it’s not over yet," said Daniel Frost, Assistant Professor at the University of South Carolina Department's of Earth, Ocean & Environmental College.
Frost has been studying the seismic activity in the area since it started.
“We went out and deployed 85 smaller seismometers," Frost said. "We retrieved those in early February of this year, and we have been analyzing the data.”
After studying the data, Frost and his collaborator, Zhingang Peng at Georgia Tech, have come up with an idea.
“Our theory is they are occurring on a fault the Eastern Piedmont fault system, which is a known fault system, not an active fault system but known," Frost said. "Any earthquakes happening on these pre-existing faults are just kind of resettling and shuffling, maybe a little of disturbance because something has changed, but it's not the kind of ongoing tectonics like on the West Coast.”
With the recent uptick in earthquakes, Frost says they have re-installed 6 seismic nodes across the town, one of which is at Elgin Town Hall. They will add 6 more next week.
"If they are in the dispersed groups as the locations were before, that doesn't fit with the fault theory," Frost said. "We want to know if these are the see same kinds of earthquakes we were having before. Are they in the same locations or a different set of locations? So far, they seem to be in different locations."
Frost said there doesn't appear to be a big risk.
“The faults are small and the size of the fault controls the size of the earthquake," Frost said. "If you have small faults, you'll never have a large earthquake, and on the East Coast, our faults are small.”