KNOXVILLE, Tenn. (WVLT) Tennessee happens to be one of the top 5 states with the highest risk for sinkholes.
Sinkholes like the ones that have formed recently in Florida are caused by ground water eroding soft rock such as limestone several feet below the surface. When the limestone gets washed away enough by underground streams, the soil above can collapse, causing a sinkhole. With all the rain we are having this year here in East Tennessee, our risk for more sinkholes goes way up.
Here is a map of Tennessee showing risk for sinkholes. The blue & especially red indicates the highest risk for sinkholes to form. We have a pretty high risk compared to the western part of the state. This is mainly due to the softer rock such as limestone present underground.
What you are looking at right now are photos of the largest naturally occurring sinkhole in the world! It's called the Qattara Depression just west of Cairo, Egypt. It is about as large as Lake Ontario, over seven thousand square miles. If a sinkhole like that would open up around here, it would likely swallow most of East Tennessee!
Since sinkholes are quite frequent in the state, there are a few things you should check on if you have a house or plan on buying one. Check your insurance. Insurance companies are required to offer sinkhole protection, but you might have to ask for it. Consult with an engineer or geologist to survey the home. Instead of having rainwater just go down the gutter on the side of your home, the water can be redirected away from your home which can cut your risk.
You can look for cracks in the foundation, windows, & doors. Deep cracks in your driveway or sidewalks could also be signs. It could just be the house settling so check with an expert if you notice any of these things.