A local seismologist is planning his own rumble on the river.
Charles Langston, a professor of seismology at The University of Memphis, will begin blasting the New Madrid fault line to get a better understanding of the deep clay sediment that lies below the fault line.
The explosions, which will measure 2.0 on the Richter Scale, will help to determine whether the clay suppresses or amplifies the energy released by an earthquake.
Langston is acting as the principal investigator for the experiment, which should begin around late May to early June.
Langston is working with the Center for Earthquake Research and Information, and received a grant from the United States Geological Survey in January for $70,000 to begin working on the Embayment Seismic Excitation Experiment.
The experiment will be conducted in two separate locations in the New Madrid zone, one of which will be near Marked Tree, Ark., about 30 miles north of Memphis.
Holes will be dug about 150 feet into the ground in the two locations. They will then be filled with explosives. When scientists blast the explosives, numerous detectors will record the seismic activity and determine whether the clay amplified or suppressed the simulated earthquake.
“We are trying to figure out whether the motion from an earthquake is dampened out by the sediments or made larger,” Langston said.
Although the experiment has not yet begun, Langston is hypothesizing that the clay sediment will amplify the waves from the explosions.
He said, “I’ve done other research on the sediment, and I’m 90 percent convinced that the sediments will tend to amplify seismic waves. So the results, I think, will show that waves are larger during an earthquake, not suppressed.”
If Langston’s hypothesis is wrong, and the simulated earthquake waves are absorbed by the sediments, it could mean that the notorious New Madrid fault, which once caused the Mississippi River to flow backwards, is less dangerous than previously thought.
“If the sediments actually dampen out seismic waves, then we wouldn’t see much activity at our seismic stations,” Langston said. “If that’s true, then it’s likely that seismic waves would tend to be absorbed, and there would be less shaking.”
