The Peach State is not typically a hotbed of seismic activity, but residents in pockets of North Georgia have been feeling some unexpected vibrations lately after the area has been jolted by five small earthquakes over the last 10 days. 

Georgia is located in the middle of the North American Plate, the vast tectonic plate that sits beneath almost all of North America, parts of the Caribbean, Greenland and much of the Atlantic Ocean. Earthquakes — particularly strong ones — are much more likely in places like California, which sit along major plate boundaries.

Still, small earthquakes are fairly common in Georgia, experts say. The state typically experiences between 10 and 20 earthquakes above magnitude 2.0 each year, said Andy Newman, professor and associate chair for Undergraduate Studies in the School of Earth and Atmospheric Sciences.

The three earthquakes at Lake Lanier’s southern end represent a “swarm” of seismic activity, but scientists say such clusters are also common.

“Generally, if you have one earthquake, the best place to guess where the next earthquake is going to occur is right near the same location,” Newman said.

(This also appeared at Macon Telegraph and Phys.org.)

Forecasters are predicting a busy Atlantic hurricane season. The projections point to a potential weather double-whammy, said Zachary Handlos, senior academic professional at the School of Earth and Atmospheric Sciences. “The forecasts are expecting a higher frequency of storms this year, potentially aligned with record-breaking years like 2020 and 2005,” he noted. “But then on top of that there's a high chance of a few major hurricanes that could be thrown in the mix of all the named storms.” 

Thirty named storms formed in 2020. Fifteen Atlantic cyclones became hurricanes in 2005 including Katrina, which caused nearly $200 billion in damage and led to more than 1,800 deaths. Both seasons were influenced by La Niña patterns, which involve the cooling of tropical Pacific waters but lead to a reduction in vertical wind shear that acts as a brake against Atlantic hurricanes. This year, warming Atlantic waters and the expected arrival of a La Niña pattern are driving expectations for a hyperactive hurricane season. “The waters are already warmer than usual in the Atlantic, and warm water is a key ingredient for kind of starting off and forming hurricanes,” Handlos said. “If you mix that trend on top of the possible La Niña setup, it's just a potential recipe for disaster.” 

Elephants use their trunks for various tasks by exploiting a remarkable range of motions. A research team has now shown that much of this dexterity can be achieved using just a small number of muscle-like actuators. Using both theoretical calculations and experiments with a simple physical model of a trunk, the researchers found that their minimal model can reproduce the complex bending and torsional motions seen in real trunks. The results might be useful in the design of “soft robotics” devices.

David Hu, professor in the School of Biological Sciences and the School of Mechanical Engineering, calls the work “a triumph of mathematics and an important step in reverse engineering the elephant trunk.” He says that the important result is in “reducing the biological complexity to three degrees of freedom.” 

Hu adds that “the big question left in my mind is this: If elephants can achieve all these 3D trunk positions with just three actuators, why does it have to have so many other muscles, and when are those used?”