Small earthquake recorded Tuesday

Published 3:58 pm Tuesday, January 3, 2023

A low-magnitude earthquake was recorded in southern Putnam County on Lake Sinclair Tuesday morning, according to Baldwin County Emergency Management Agency Director Wayne Johnson.

Registering at a 2.3 on the Richter scale, the quake was confirmed by the United States Geological Survey (USGS) to have hit at 10:13 a.m. USGS has the epicenter right in the middle of the lake between Cay and Lakewood Drive just over the Baldwin-Putnam County line. That section of lake runs right alongside Highway 441. The earthquake’s depth was recorded at about 1.2 miles below the Earth’s surface. 

Residents around the lake area took to Facebook to say they felt the earthquake shortly after it occurred, but no damage had been reported. 

Earthquakes, especially ones of Tuesday’s magnitude, aren’t all that uncommon in this area. After another 2.3 magnitude quake in late March 2019, The Union-Recorder spoke to Georgia College & State University geography professor Dr. Doug Oetter for intel about local quakes. 

“The Oconee River valley occupies an area that has probably been a drainage area for a long, long time — we’re talking like 10s or 100s of millions of years since the Appalachian Mountain chain started forming almost 300 million years ago,” Oetter said in 2019. “Oftentimes, rivers occupy places that had, for whatever reason, some sort of a geologic fault (crack in the bedrock) underneath it. That crack has probably been there for over 100 million years.”

He said that every so often the fault can slip and cause movement which is felt at the surface as an earthquake. The presence of Lake Sinclair can help create earthquake-favorable conditions on occasion.

“After a significant rain, especially if Georgia Power is holding onto their water, the level can come up and the rainwater can help lubricate things down underneath,” Oetter added. “The weight of the reservoir is one of the things that can help move those sediments around along that old fault. They have a name for it called, ‘reservoir-induced earthquakes.’ The ones we’ve seen tend to be focused in and around the lake. They usually tend to come when there’s a high water level at the lake, and a lot of them came on the heels of a significant precipitation event … People tend to forget how much water weighs.”

According to USGS, there are an estimated 1.3 million earthquakes that range from 2.0 to 2.9 on the Richter scale each year. Ones in that range are often felt by people around its point of origin, but they don’t usually produce any damage. Noticeable shaking of indoor objects and rattling occurs at 4.0 and up, and damage becomes more likely if an earthquake reaches 5.0.