Wednesday, March 23, 2011

We're Sinking....

Foundation and walls cracking....water leaking through windows....

These are a few signs that people whose houses are built on sinkholes are seeing in Florida.  The land below their houses in sinking.  Some home owners are saying that their house will sink in before it will be fixed.  There is a major debate going the the Florida legislature right now to find out when insurance companies should pay for sinkhole damage.  For more information about the insurance companies seeking legislation to reduce sinkhole claims click here.

What is a sinkhole?
A sinkhole is a hole or depression in the earth's surface often associated with glacial terrain.  Sinkholes can vary in size from about 3 meters to 600 meters.  They can form gradually or can occur suddenly in rocks that naturally be dissolved by water circulating through them.  This creates voids in the rock that can cause the rock to collapse.  Many processes can lead to sinkholes.  Erosion, lowering the level of groundwater, or the collapsing of a cave can all lead to the formation of sinkholes.

Picture of a sinkhole

Check out this video catching the some of a sinkhole collapsing in Texas in 2008.


  1. Do you know if it is possible to predict where sink holes will occur or to alter the foundation of a house to be sinkhole proof?

  2. Geologists have a good idea where sinkholes are likely to form geographically, but it’s difficult to accurately predict specifically where sinkholes will occur. Ground-penetrating radar equipment can be used to create a map of the underground area, but this information provides only a clue where the voids are in the subsurface.

    Avoidance of development where sinkholes are prone is the safest strategy. There are some difficult processes that can be done that are designed so that the house will not subside.

  3. This is really fascinating. I think areas that have permafrost that is melting will begin facing similar issues.

    It's remarkable to me that insurance companies want to claim exemptions for this. Can you tell us more about that?