I got a little excited this afternoon with the news of Seattle's sinkhole. It sent me on a frenzy of sinkhole fascination, causing me once again to bemoan the too-short time we spent on sinkholes in Geology. With a quick (or semi-quick, considering how the internet's been treating me today) image search on Google, I found some pretty great photos.
From Wikipedia (Wikipediar: to wiki. Wikipediamos cuando necesitamos información)
A sinkhole, also known as a sink, shake hole, swallow hole, swallet, doline (in the Slovene language dolina means valley) or cenote, is a natural depression or hole in the surface topography caused by the removal of soil or bedrock, often both, by water. Sinkholes may vary in size from less than a meter to several hundred meters in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. They may be formed gradually or suddenly, and are found worldwide.
Mechanisms of formation may include the gradual removal of slightly soluble bedrock (such as limestone) by percolating water, the collapse of a cave roof, or a lowering of the water table. Occasionally a sinkhole may exhibit a visible opening into a cave below. In the case of exceptionally large sinkholes, such as Cedar Sink at Mammoth Cave National Park, USA, a stream or river may be visible across its bottom flowing from one side to the other.
That's one pothole you want to avoid on the tractor.
Wikipedia again. "Sinkholes near the Dead Sea, formed by dissolution of underground salt by incoming freshwater, as a result of a continuing sea level drop."
Surprise puddles! Watch out for the crocodiles.
Not very exciting, I know. This was our example of a sinkhole in Geology. Thor really failed on the entertainment factor during that unit.
Some poor Yankee's truck.
This is actually a cenote. Someday, during my endless travels around Latin America, I'm going to visit this place.
View from the bottom.
Florida knows how to play to its strong points.