JACKSONVILLE Fla.-- They're blemishes on Florida's beautiful landscape. The depth of our state's sinkhole outbreak is best viewed from above.
In the last year alone, the cavernous monsters have gobbled up homes, resorts and, in one quick gulp, human life. The powerful force of nature is unstoppable, but understanding these hungry geological giants is the key to protection.
So what are sinkholes? Why do they happen? And could one swallow up your back yard?
Jacksonville University geologist Jeremy Stalker has been working to answer those questions for years.
"Not enough rain or too much rain are the general culprits," he said.
He says Florida's storms and droughts cause a rapid rise and fall in ground-water tables.
When the water table dries up, it leaves nothing to support the limestone above it. If there's not a lot of sediment on top of that limestone, it can cave.
In Jacksonville, geologists say we don't see as many sinkholes because we tend have a thicker layer of sediment on top of our rock.
Local insurance claims reveal at least 10 sinkholes have opened up in just the past two years, from the Westside all the way to the Saint Augustine area.
Professor Stalker showed me where a documented sinkhole forced a Jacksonville family out of their home on the Westside last year. The home may be sinking slowly, but he says sooner or later it could cave.
"One day, all of this will give way and this concrete will go in with it," he said.
It's how most sinkholes in our area are born. Stalker says there's even more that haven't been reported.
But there are warning signs.
"That's one of the first signs that there's something going on there's some kind of settling under the foundation," he said.
Cracks in your foundation are a good indicator that the ground beneath you could be moving. So are higher water bills.
"Pipes underneath your house can leak," he said. "If there's nothing there holding your pipe up, it will flex and start to leak."
Hiring an inspector with a ground penetrating radar is the only way to determine if a sinkhole is actually the culprit like it was on Gullege Drive, but any area that sits on top of limestone is susceptible, and that's anywhere in Florida, so geologists recommend you keep your eye on the ground.