Sinkholes Can Occur Anywhere in Florida

Posted on March 6, 2013

A man was killed in Florida last week when a sinkhole suddenly opened up inside the bedroom he was sleeping in. CNN reports that this sinkhole is now 20 feet wide and 50 feet deep. A couple other sinkholes have been recently found in the state, but none as large or deep as the Hillsborough County sinkhole. The Weather Channel says "sinkhole season" has just begun in Florida.

In the wake of the sinkhole story, the Florida Department of Environmental Protection issued a bulletin that shares information about sinkholes and why they are a problem for Florida. A big reason sinkholes are a potential threat for Florida residents is the limestone rock base Florida sits on.

Limestone is a rock that can form with natural void spaces called porosity. In limestone where the void spaces are connected, the rock is permeable. Porous and permeable limestone makes great aquifers and provide millions of gallons of fresh drinking water for residents and agriculture. The most significant factor in the development of sinkholes is the dissolution of the limestone underlying Florida by naturally acidic groundwater.

The bulletin says Florida can have three types of sinkholes:

In Florida one may see solution sinkholes, cover-subsidence sinkholes or cover-collapse sinkholes. The first two types will show very little topographical disturbance to the naked eye, while the third is the type which shows a abrupt change in topography and is most associated with the thought of sinkholes.

The bulletin also answers the question, "Is there a safe area of Florida where there is no chance of sinkholes?" The answer is no. The Florida Department of Environmental Protection says sinkholes could occur anywhere in the state. However, there are higher risk areas, such as Hillsborough County, which is known as "sinkhole alley."

Technically, no. Since the entire state is underlain by carbonate rocks, sinkholes could theoretically form anywhere. However, there are definite regions where sinkhole risk is considerably higher. In general, areas of the state where limestone is close to surface, or areas with deeper limestone but with a conducive configuration of water table elevation, stratigraphy, and aquifer characteristics have increased sinkhole activity.

Scientists say new technology can help reduce the danger by spotting potential problems. Shimon Wdowinksi from the University of Miamia says ground-penetrating radar can find cavities in the ground. Unfortunately, the technology is not cheap. He says it would be wise to use it before you build a house. A big problem with detecting sinkholes is when there is no subsidence before the sinkhole appears. Wdowinski says rain water contains enough acidity to dissolve limestone beneath the ground in Florida and develop caverns and voids. Take a look:

Here is another informative video about sinkholes from the U.S. Geological Survey, called "The Science of Sinkholes." Florida is not the only state where sinkholes can occur. USGS also published an article, The Science of Sinkholes. Take a look:

EARTH