USC Scientist Explains South Carolina Earthquake Detection

Seismologist says state's seismic activity is 'randomly diffuse and scatter', making it hard to predict larger quakes.

Apr. 3, 2026 at 11:11am

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A high-contrast black-and-white photograph depicting the intricate inner workings of a seismometer, with various components like magnets, coils, and masses shown in sharp detail, conceptually illustrating the scientific principles behind earthquake detection.Cutting-edge seismic monitoring equipment helps scientists track South Carolina's scattered earthquake activity, though predicting larger quakes remains an elusive challenge.Piedmont Today

As small earthquakes are reported more often across parts of the Carolinas, a University of South Carolina seismologist says the state's shaking can be difficult to tie to a single fault and scientists still can't predict exactly when or where a larger quake might hit. Dr. Philip Crotwell explains how seismometers detect ground motion and how the data is used to monitor seismic activity in the region.

Why it matters

South Carolina has a known seismic hazard, but the scattered nature of the state's earthquake activity makes it challenging for scientists to forecast larger, potentially damaging quakes. Understanding how earthquake detection instruments work is crucial for preparing communities for seismic events.

The details

Crotwell said scientists understand the basic mechanics of earthquakes - stress builds along a fault until the force exceeds friction and the fault slips. However, in the Irmo area near Lake Murray, small earthquakes have fueled concern but it's hard to explain why quakes occur in one spot and not miles away. Crotwell said the seismic activity is spread out, making it difficult to pinpoint a single fault. His lab uses seismometers to detect ground motion and measure voltage changes, sending the data back to computers in near real time as part of a broader network of sensors across South Carolina.

  • Small earthquakes have been reported more often across parts of the Carolinas in recent years.

The players

Dr. Philip Crotwell

A seismologist at the University of South Carolina who studies earthquake activity in the state.

University of South Carolina

The institution where Dr. Crotwell is a seismologist and conducts research on earthquakes in South Carolina.

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What they’re saying

“We have a pretty good understanding that you have a fault, we have a frictional force and then you have shearing forces and when the forces exceed the friction it slips and we have an earthquake.”

— Dr. Philip Crotwell, Seismologist, University of South Carolina

“We know South Carolina earthquakes, but we don't have a lot of information to say why these earthquakes are happening here instead of 10 miles away or 50 miles away.”

— Dr. Philip Crotwell, Seismologist, University of South Carolina

“In South Carolina, we can't really say whether or not a larger damaging earthquake is likely or is going to happen. We can only say that South Carolina does have a seismic hazard, and we should be prepared for that.”

— Dr. Philip Crotwell, Seismologist, University of South Carolina

What’s next

Crotwell's lab will continue monitoring seismic activity across South Carolina using the network of seismometers, providing real-time data to help scientists better understand the state's earthquake patterns and hazards.

The takeaway

While scientists have a good grasp of the basic mechanics behind earthquakes, the scattered and unpredictable nature of seismic activity in South Carolina makes it challenging to forecast larger, potentially damaging quakes. Ongoing monitoring and research is crucial for helping communities prepare for the state's seismic hazards.