The Potholes in New York City Sure Are Big!

The New York Times has an interesting article today about the newly-uncovered bedrock beneath the World Trade Center:

A fantastic landscape in Lower Manhattan—plummeting holes, steep cliffsides and soft billows of steel-gray bedrock, punctuated by thousands of beach-smooth cobblestones in a muted rainbow of reds and purples and greens—has basked in sunlight this summer for the first time in millennia.

In the southeast corner of the Tower 4 site is a 40-foot deep pothole scoured by glacial meltwater 20,000 years ago.

I'm reminded of the ride Henry and I took out onto the Athabasca Glacier on our Canadian Rockies trip last year. Our tour guide was a very smart and funny Egyptian-Canadian named Sam. Sam made a point to connect the strange otherworldly scenery around us to other glacially-created sights we might be more familiar with. Sam also had an obvious love of both geology and New York City, so he kept giving examples from around the city: Long Island is a terminal moraine; the boulders in Central Park are glacial erratics, etc. I'm sure Sam would be delighted by the discovery of a glacial pothole deep under Lower Manhattan.