Sinkholes; A Whole Lot of Danger

news image
Special Stories
26 Feb 2018 7:54 PM
With the ongoing flooding occurring from the Great Lakes to the Gulf Coast and more to come, it’s a good time to review why not to drive through flooded areas.  You see there is an underlying danger in parts of the country that is often lurking just below flood water that can swallow a car whole.  Sinkholes are that hidden danger and can often form under pavement or concealed by water. Sinkholes are most common in what is called “karst terrain.”  These are locations where rock below the surface can be dissolved by groundwater.  These soluble rocks can include salt beds, limestone, gypsum and other forms of carbonate rock. Take for instance areas that are underlain by limestone, a type of rock that is slowly dissolved by weak natural acids found in rain and in the pore spaces in soil. Dissolving the limestone creates underground caverns below the surface of the earth.   Over the limestone many times we find a fairly thick layer of clay mixed with sand which can remain intact and suspended above the void caused by the erosion.  One type of sinkhole that can occur is called a cover collapse sinkhole.  Basically the material above the eroding limestone has enough cohesion to hold its shape for a while, but the problem comes when this material loses that cohesion and collapses. Sinkholes can form because of extreme rainfall and because of prolonged drought.  Our recent heavy rain added a large amount of rain and weight to the surface material and from that we can see sinkholes.  In many cases the underground caverns have a thin ceiling but when the weight gets to be too much that ceiling ceiling can fail and the cavern fills in from material above. Sinkholes can also form during and after times of drought.  During droughts underground caverns that might normally be filled with water may be only partially filled. These cavities are less likely to bear the weight of the material above especially when weighted with flood waters or vehicles without collapsing. When flood water covers the road, a sinkhole or the start of one, may not be visible and bad things can happen to drivers who don’t heed the warning Turn Around, Don’t Drown. If you live in an area prone to sinkholes and water covers a section of road in your path it may be best to find another route. Meteorologist Mike Morrison
All Weather News
More
Fronts Continue To Spark Severe Weather Across the Plains

Fronts Continue To Spark Severe Weather Across the Plains

A cold front that brought record lows to the

18 Jul 2025 10:40 PM
Extreme Heat Impacts for the East Coast & South

Extreme Heat Impacts for the East Coast & South

Extreme heat continues to impact several area

18 Jul 2025 10:05 PM
Flooding Threat Remains Elevated in the East

Flooding Threat Remains Elevated in the East

A cold front pushing through the Eastern Seab

18 Jul 2025 9:10 PM
EF-2 Firenado from the Deer Creek Fire in Utah

EF-2 Firenado from the Deer Creek Fire in Utah

A fire tornado was spotted near La Sal, Utah

18 Jul 2025 7:30 AM
Tropical System Brings Flood Risk to the Central Gulf

Tropical System Brings Flood Risk to the Central Gulf

Time has run out for notable tropical develop

18 Jul 2025 3:05 AM
Heavy Rain, Flooding Threat Returns to Florida

Heavy Rain, Flooding Threat Returns to Florida

Keep the rain boots handy in Florida - heavy

13 Jul 2025 12:50 PM
Severe Storm Risk Pushes into the Great Lakes, Ohio Valley

Severe Storm Risk Pushes into the Great Lakes, Ohio Valley

Friday was another busy day with severe weath

12 Jul 2025 8:00 PM