Georgia isn’t known for having many or strong earthquakes, but on June 18, 2022, a rare 3.9-magnitude quake hit the southeast, making it the biggest quake Georgia has ever had. The quake was felt all over the state, from Atlanta to Savannah, but it didn’t hurt or damage anyone seriously. But it made people wonder about the risk and frequency of earthquakes in Georgia and along the East Coast.
How Frequently Are Earthquakes in Georgia?
The U.S. Geological Survey says that Georgia has earthquakes of magnitude 3.9 or higher about every 3 to 5 years. These earthquakes are most common in the northwest, where the Appalachian Mountains are. In 2014, a quake with a magnitude of 4.1 shook the area along the line with South Carolina. It was the least powerful earthquake in Georgia. One of the biggest earthquakes ever recorded in the state was 4.5 on the Richter scale in 1914.
But earthquakes in Georgia’s Coastal Plain, like the recent 3.9-magnitude one, are much less common and could be more damaging. The Coastal Plain is made up of solid rocks that make the earthquake waves stronger so they go farther and cause more shaking. The location of the quake was also very shallow—only 10 kilometers down—which made the ground motion stronger.
Why Do Earthquakes Happen in Georgia?
In the Eastern Tennessee Seismic Zone, which goes from northeastern Alabama to southwestern Virginia and includes Georgia, there are a lot of earthquakes. This area is a part of the Appalachian Seismic Zone, which is bigger and includes most of the eastern United States. No one knows for sure what causes the earthquakes in this area, but here are some things that could be to blame:
- When the North American and African plates crashed into each other millions of years ago, they made the Appalachians and left cracks and stresses in the rock.
- The North American plate is moving away from the Mid-Atlantic Ridge. This makes the plate stretch and thin, making weak spots that can break.
- The sun and moon’s gravitational pull can cause small earthquakes along cracks that are already there.
- The process of putting fluids into the ground, like wastewater from oil and gas production, which can raise the pore pressure and lower the friction along faults.
How Big Can Earthquakes Get in Georgia?
There was a 7.3-magnitude earthquake near Charleston, South Carolina, in 1886 that was the biggest one ever recorded on the East Coast. It killed at least 60 people and damaged thousands of buildings. A fault that runs along the coast and was formed a long time ago shook again. Scientists think that this kind of big earthquake could happen here every 500 to 1,000 years.
A similar earthquake in Georgia is not likely to happen, but it’s also not impossible. A study by the U.S. Geological Survey found that in Georgia there is a 1% chance of an earthquake with a magnitude of 6 or higher and a 4% chance of an earthquake with a magnitude of 5 or higher in the next 50 years. Depending on where they happen, how deep they go, and how long they last, these quakes could do moderate to serious harm.
How Well Does Georgia Know How to Handle Earthquakes?
Georgia does not have a thorough plan for getting ready for earthquakes like California or Alaska, which are more likely to be affected by them. There have been some steps taken, though, to make the state and its people more aware and resilient. These include
- Developing seismic danger maps and building rules that take into account the possible ground shaking and soil liquefaction in different places.
- Monitoring and studying the state’s earthquakes and fault systems by doing seismic surveys and putting in seismometers.
- Take part in the annual Great ShakeOut drill, which teaches people how to stay safe during an earthquake by holding on, dropping, and covering themselves.
- Getting people and the media to understand the risk of earthquakes and the best ways to get ready for, react to, and recover from them.
Conclusion
The records reveal that Georgia has seen several important earthquakes throughout its history, including the 3.9-magnitude quake in 2022, which was the state’s largest and strongest. The data also describes the origins and consequences of these earthquakes, as well as the seismic zones that affect the region. The data also depicts the earthquakes’ impact on individuals and infrastructure, as well as the difficulties and worries that they encountered. The data also highlights possible seismic dangers and concerns that the region may face in the future, as well as the need to be alert and prepared.