Today we ran only the Chirp. We went back north to where we found the Upper Claiborne riddled with faults and ran an additional 7 surveys of the area. It is likely that Xenia will map the system in 3D to determine the strike and dip of the faulting. This information will help us ascertain the stress field needed to create these tectonic features.

We also ran the Chirp at the plunge pool. The plunge pool is located just south of Hickman, KY. The Mississippi River flows gently to the south at a depth of ~50 ft, then suddenly spins, churns, and visibly flows backwards! In one area a whirlpool caused a slight depression in the water surface. Now a canoe would have an extremely hard time in this area. Barge traffic navigating the river try to avoid the area. So what’s going on? The river rides over something not erodible…or at least difficult to erode. This bump in the river bottom causes the river to erode down on the downstream side of what we think is clay. And it scours! The river scours an additional 100 ft into the riverbed, eating out a hole about a football field wide, 3 football fields long and 150 ft deep. That’s the plunge pool. We ran 5 surveys across the plunge pool with the Chirp. The data was hard to interpret and will take a keen eye to figure out what’s going on.

It was a long day, but quite productive and fruitful.