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To: dangus
That’s not a sinkhole; that’s a pothole.

Yes, that's in Pennsylvania, the state that makes tourist attractions out of their finest potholes.


12 posted on 02/21/2017 7:15:50 AM PST by Fresh Wind (Hillary: Go to jail. Go directly to jail. Do not pass GO. Do not collect 2 billion dollars.)
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To: Fresh Wind

When you cross over to PA from MD the secondary roads get noticeably worse.


14 posted on 02/21/2017 7:23:29 AM PST by central_va (I won't be reconstructed and I do not give a damn.)
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To: Fresh Wind
IN fairness, that "pothole" is 48 feet wide and 38 feet deep and thousands of years old.
Here's the thing:
Sand washing away under a road surface, causing that road surface to collapse is not a sinkhole; it's a pothole.
A sinkhole is what happens over thousands of years as an aquifer dissolves away limestone, and then the area above the dissolved limestone collapses. It's not a "cave collapse" because commonly there is no cave; the collapse happens when the aquifer's water level drops, and the structire of the limestone above is no longer aided by the bouyancy the aquifer's water provides.
How did the two terms get confused? When florida's aquifer was being overused starting in the 1980s, actual sinkholes started appearing in the developed areas that were withdrawing the aquifer's water.
"Natural" sinkhole:


Florida sinkhole:


Pothole:


Pennsylvania's great Natural pothole, formed by glacial erosion, not by dissolution of limestone:

26 posted on 02/21/2017 9:06:11 AM PST by dangus
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