Florida Sinkhole Highlights State's Geologic Instability 206
An anonymous reader writes "Last Thursday night, a sinkhole took the life of a man (TV news video, with ad) while he slept in his home in Seffner FL, near Tampa. While human fatalies are rare, sinkholes are so common in Florida that the insurance industry successfully lobbied the state lawmakers to pass legislation in 2011 making it more difficult for homeowners to claim sinkhole damages. The bedrock in Florida is limestone, a weakly soluble mineral formed from calcified deposits of sea creatures tens of millions of years ago. Above the limestone is a clay layer called the Hawthorn Formation which shields the limestone from ground water; and above the clay is sand. However, the protective clay layer is thin or nonexistent in some areas of Florida, particularly in the middle part of the state near the Gulf coast, where caves and sinkholes are common. Geologists say that human activity, particularly construction and irrigation, can trigger sinkholes by destabilizing the landscape above caverns by drawing down water tables and massing structures above them."
Florida state website about it (Score:5, Informative)
The state's Department of Environmental Protection has a nice collection of sinkhole resources [state.fl.us], including a database of incidents, and a poster with a map [state.fl.us].
Re:What's The Tech Angle? (Score:5, Informative)
Some tech input will show up regardless of what's in TFS/A. General science articles are always welcome for me at any rate. Regarding this topic, here's a good photo gallery: Notable sinkholes from around the globe [baltimoresun.com].
Re:Aquafilter pumping (Score:5, Informative)
Aquifer. I don't think this is connected to groundwater pumping.
It can be the start of a sink hole. Drawing out too much water can make the aquifer collapse. It can create a void where rain water flows into washing away the collapsed parts of the aquifer creating an actual void. With broken water lines they can form in days or weeks this one could have taken years. What's scary is they used to be rare events but they are getting more common so something has changed. Just building housing developments changes the flow of water with unknown effects. Most seem to happen along coastal areas, say 20 or 30 miles of the ocean so drained aquifers and redirected water would be the likely causes. look at it this way, aquifers have been stable for thousands of years then we remove billions of gallons from them in a few decades and don't expect a problem? Think of them as big water beds. What happens to your water bed when the water drains out? Now picture it with porous rock only you stick a hose in and start intermittently flushing water in and out. When there was water in the rock it would buffer the affect of the new water but now it flushes freely through the voids washing parts away. Parts of Florida are a ticking time bomb. Personally I think the bigger problem is brackish water flooding the aquifers. The aquifers are retreating at several feet a year so eventually the fresh water will all be miles inland. All those private wells will be pumping sea water.
Re:Who would have thought (Score:5, Informative)
it was a great idea to start building homes on swamp land?
This doesn't have anything to do with swampland really, rather it has to with the limestone that makes up the base of Florida. Same with really anywhere there's limestone, Ontario, Michigan, parts of Quebec, large swaths of the NE US. Some places are more stable than others and don't have to worry about it. And there's no much you can do in some cases, and while the limestone is thick where I live several hundred feet there have been huge sink holes.
Re:Pretty clever (Score:4, Informative)
Because the state requires that you pay for insurance to drive legally.
Only if you don't have the money to cover the minimum liability. If you do have money, as long as it is set aside in one of couple ways so it can't disappear before needed, you don't need insurance to drive.
Are you speaking just of Florida? Because it's different in every state. Here in Georgia you have to have liability coverage at minimum to legally operate a vehicle, even if you have thousands in a savings account named "just in case I'm a bad driver". There was a time when you didn't have to have insurance in Alabama, but a few years ago they mandated minimum liability insurance coverage as well.
I'm normally not keen on the government telling us how to live our lives, but having mandatory liability coverage is a no-brainer for the vast majority of poor and middle-class citizens who simply can't be assumed to be responsible enough to have a personal insurance savings plan, and can't afford a huge payout if they do cause an accident. I'd rather pay $50/month to insure that I won't be sued and bankrupted because I made a mistake driving, than bank that money and hope that I've saved up enough to fight said lawsuit.
On the other side of the coin, I'd much rather the person who hits me has liability coverage, so their insurance company takes care of me instead of leaving me to chase after their assets in court. Also, I wouldn't be surprised if states without mandatory liability coverage have more hit-and-run accidents than other states.