The Nixa Sinkhole

Little did I know that last month's post on sinkholes would be so timely. Here in Missouri, there was a collapse in the town of Nixa, in southwest Missouri. I know most of the principals involved by name, reputation, or from what the 'grapevine' tells me. First off, a series of pictures of the house that was partially destroyed, that dropped into a sinkhole 75 feet deep.

Lost in the sinkhole was the resident's garage and his Chevy Cavalier.

One of the first responders to the scene was the Nixa Fire Department. Rightly, they cordoned off the area. Geologists and other experts came to the scene at the request of the City Administrator, who also happens to be a geology graduate of Missouri State University (formerly known as Southwest Missouri State University).

There's a lot of concern right now about where the material went that was displaced when the sinkhole collapsed. Where did it go? What kind of process is being initiated here? Did the red clayey material (about 35-45 feet in thickness in other areas close to the the sink) drop into a cavern below? Is there a large cavity underneath the area, or are the residents dealing with piping of material down a joint; with a sudden loss of support in either case?

What needs to be done?

So far, there are ideas and hypotheses but little hard evidence other than the visual evidence of the sinkhole, geophysical data from resistivity measurements completed by a crew led by Mr. Peter Price of the Missouri Department of Natural Resources Division of Geological Survey, and seismic measurements that were taken by a crew led by Dr. Neil Anderson of the University of Missouri-Rolla. Dr. Doug Gouzie of Missouri State University, a karst specialist, has also weighed in with his opinions and observations. I also understand that drill holes have been completed at a "safe" distance from the sinkhole, completed to bedrock.

Response to such a catastrophe is initially a "hit-and-miss" proposition. I think that's what probably happened here. As more data is obtained, recorded, and correlated, a strategy may emerge that may protect the residents of Nixa from future collapse.

I wish all of the principals involved well with their studies. I sincerely hope they'll keep me posted as they find out more of the details, and I'll share them with you here.

Until next time,

Trenchless Geologist