East Tennessee experiences four small quakes within a week

by Dick Byrd, published in The Daily Times 6/1/2012
East Tennessee has experienced four small earthquakes during the past week, according to the U.S. Geological Survey.
The USGS notes that on May 26 there was a

magnitude 1.8 near Tellico Plains; magnitude 2.4 near Dayton, May 29; magnitude 1.4 near Dayton, May 30; and one magnitude 1.8 near Tellico Plains, May 31. There was also a magnitude 1.7 on May 31 near Franklin, N.C., but that one, while nearby, is considered outside the East Tennessee seismic zone.

The depth of the quakes varied from 14.2 miles to 1.2 miles below the surface. So far, no damage has been reported from any of these latest quakes. However, there is concern this region hasn’t yet seen “the big one.”
Robert Hatcher, professor of Structural Geology & Tectonics with University of Tennessee’s Department of Earth and Planetary Sciences, said the East Tennessee seismic zone “is the second most active in the Eastern U.S., behind New Madrid (Missouri-Arkansas), but we have not had an earthquake in historical times (over) 4.8, so this area gets little attention regarding the potential for large earthquakes.”
Hatcher adds the USGS rates these areas as potentially capable of producing a magnitude 7.5 earthquake.
The professor said he is involved in a research project right now supported by the Nuclear Regulatory Commission and, so far, “we have found a number of small prehistoric faults that we have concluded were produced by earthquakes of at least magnitude 6.5-7.0, but we have not yet been able to delimit their recurrence interval.”
Other scientists have studied and written about the Eastern Tennessee seismic zone, but without coming to conclusions on the future. Many noted that the depth of most of the tremors — one to 15 miles beneath the surface SEmD hampers detailed study. But they agree that the East Tennessee zone is the second most active region of the continent east of the Rocky Mountains after the New Madrid Seismic Zone.