The largest earthquake to ever strike Georgia occurred on June 18, 2022, a rare 3.9-magnitude earthquake that struck the state’s southeast. Georgia is not known for having many or significant earthquakes. There was no notable damage or casualties resulting from the earthquake, which was felt all over the state, from Atlanta to Savannah. It did, however, bring up concerns regarding the risk and seismic activity in Georgia and the East Coast.
How frequently do earthquakes occur in Georgia?
Georgia often experiences earthquakes of magnitude 3.9 or higher every three to five years, especially in the northwest region, which is home to the Appalachian Mountains, according to the U.S. Geological Survey. A 4.1-magnitude earthquake that rocked Georgia’s border with South Carolina in 2014 was the state’s most recent earthquake of this size. A 4.5-magnitude earthquake that struck the state in 1914 was the biggest earthquake ever recorded there.
But the 3.9-magnitude earthquake that struck Georgia’s Coastal Plain recently is one of the state’s rarest and maybe most destructive earthquakes. This is because the sedimentary strata that make up the Coastal Plain intensify seismic waves, causing them to travel farther and produce greater shaking. The quake’s shallow epicenter—just 10 kilometers deep—also contributed to the strength of the ground motion.
Why do earthquakes occur in Georgia?
Georgia is situated in the Eastern Tennessee Seismic Zone, a seismically active region that stretches from southwest Virginia to northeastern Alabama. Part of the broader Appalachian Seismic Zone, which spans the majority of the eastern United States, is this zone. Although the precise reason behind the earthquakes in this area is unknown, several potential causes include:
The Appalachian Mountains were formed by the prehistoric collision of the African and North American plates, which also left behind crustal faults and stresses.
The North American plate is still moving away from the Mid-Atlantic Ridge, which is causing the plate to thin and stretch and develop weak spots that could burst.
The sun and moon’s gravitational pull has the potential to cause minor earthquakes along pre-existing faults.
the injection of liquids into the ground, such as gas and oil production wastewater, which can lower friction along faults and raise pore pressure.
In Georgia, how big can an earthquake get?
The largest earthquake to ever be recorded on the East Coast occurred in 1886, close to Charleston, South Carolina, and had a magnitude of 7.3. It resulted in thousands of buildings being damaged and at least 60 fatalities. An old fault that runs along the coast was reactivated, which is what triggered this earthquake. According to scientific estimates, there’s a 500–1,000 year chance of seeing a major earthquake in this area.
While unlikely, there is a very small chance that Georgia will have a similar earthquake. According to a U.S. Geological Survey research, there is a 1% probability that Georgia will experience an earthquake of magnitude 6 or greater in the next 50 years, and a 4% likelihood of an earthquake of magnitude 5 or higher. Depending on the location, depth, and length of the shaking, these earthquakes may inflict moderate to severe damage.
To what extent is Georgia earthquake-prepared?
In contrast to some states like California or Alaska that are more vulnerable to seismic risks, Georgia does not have a comprehensive plan for earthquake preparedness. However, a number of actions have been made to raise the state’s and its citizens’ knowledge and resilience, including:
creating building codes and seismic hazard maps that account for the possibility of soil liquefaction and ground shaking in various locations.
monitoring and researching the state’s fault systems and earthquake activity through the installation of seismometers and seismic surveys.
taking part in the yearly Great ShakeOut drill, which instructs people on how to drop, cover, and hold on in the event of an earthquake.
teaching the general public and the media about the likelihood of earthquakes and the best ways to be ready for, react to, and recover from one.
In summary
Though it was the largest earthquake to ever rock Georgia, the 3.9-magnitude earthquake that occurred in June 2022 did not cause a significant amount of damage. It was an unusual and natural occurrence that made us aware of the East Coast’s susceptibility to earthquakes. Even if there is little chance of a catastrophic earthquake occurring in Georgia, it is still necessary to be ready for anything that can happen. As stated in a tweet from the USGS, “Earthquakes don’t usually occur in the South, but they do happen.”