Shaking the World

GSW geology makes waves participating in large-scale seismic experiment

Georgia Southwestern recently participated in the first half of a largescale seismic experiment, called the Suwanee Suture and GA Rift basin, or SUGAR, experiment.

The principal investigators of the SUGAR experiment are Donna J. Shillington, Ph.D., from Lamont Doherty Earth Observatory and Columbia University; Daniel Lizarralde, Ph.D., from Woods Hole Oceanographic Institution; and Steven Harder, Ph.D., from the University of Texas-El Paso. Undergraduate Geology students from GSW, along with other volunteers, assisted with the experiment.

The goal of this experiment is to gain a better understanding of tectonic movement and evolution. Its focus is on the South Georgia Rift Basin, which starts in the southern part of South Carolina and extends through Georgia and into Alabama. The Suwanee Suture runs through the South Georgia Rift Basin from east to west.

The experiment has been divided into two parts: a western profile, which GSW assisted with, and an eastern profile that will be take place in 2015. These profiles, or lines, are roughly 170 miles long, and run north to south, crossing the South Georgia Rift Basin and the Suwannee suture. The western profile spans roughly from Columbus, Ga., to Valdosta, Ga., and intercepts Americus, where the field team was stationed. The eastern profile will span from Milledgeville, Ga., to around Waycross, Ga.

The experiment will provide information about the South Georgia Rift Basin by using sound waves.

“We are using sound waves to image geological features up to 40 km beneath the earth’s surface along a 300-km-long transect across southwest Georgia,” said Shillington. “The sound waves will be generated by 12 controlled blasts in deep holes and recorded on over 1000 small seismographs [devices that read sound waves].”

During Spring Break, fourteen teams of two, including GSW students, deployed the seismometers along the profile in holes that have been recently drilled. The controlled blasts were then detonated at night, far away from any houses or structures. Afterwards, the seismographs were retrieved and the data was downloaded.