When you think about an earthquake California probably comes to mind. But they can also happen here in the Southeast.
The CSRA sits in the middle of the North American Plate. Our earthquakes aren’t caused by the grinding of plate edges. Instead, they’re what we call intraplate earthquakes.
The key is ancient history. Deep beneath us are old cracks, or faults, formed millions of years ago. These zones of weakness can reactivate when stress builds up within the plate. Here in the Augusta area, we even have the Belair Fault running beneath us, a reminder of these buried geological structures.
So, what kind of movement happens on these faults? Across the broader Southeast, including areas influencing our seismic activity, we see a few main types. Reverse faults occur when the ground is squeezed, pushing rock layers upward. This type was significant in the powerful 1886 Charleston quake. We also see strike-slip faults, where blocks of earth slide past each other horizontally. While less common for major events in our immediate vicinity, normal faults, where the ground pulls apart, can also occur.
While we might not experience the same frequency or intensity of earthquakes as plate boundary regions, understanding that our local tremors stem from the reactivation of ancient faults due to ongoing plate stress helps explain the unique seismic character of the Augusta area.
Even though major events are rare, it’s smart to be prepared. If you feel shaking, Drop, Cover, and Hold On. Secure heavy items, have an emergency kit ready, and keep a communication plan with your family…