Monday, December 31, 2018

Keystone Arches Trail, Chester, with Cool Ice Formations!

On December 11, the Berkshire Hikers walked along the Keystone Arches Trail in Chester, and got a tour through the Chester Railway Station and Museum with Dave Pierce. He is extremely knowledgeable and was instrumental in saving the station and putting together the museum. The building of the railroad track up a mountain, finished in 1840, had never been done before.

The West Branch of the Westfield River gorge was the easiest way up and over the mountain. The keystone arch bridges that span the river as it tumbles down through an often deep gorge are magnificent. Some of the bridges are still in use although the weight of a locomotive is now about 40 times heavier than when the bridges were built. You can see more information on the design, building, etc., on the websites linked above.

We also got a tour through the old caboose that is available to rent for overnight stays. Railroad buffs and kids, especially, love spending the night there and hearing the trains go by, still about 24 a day.

I always love the trail and seeing the tall bridges but this hike we saw something I had never seen before–ice circles. I had to do a bit of research to find out about them and still do not completely understand how they form. While walking over the first abandoned bridge, we looked down to the river below and saw a group of ice circles bobbing around. The circles were about a foot to a foot-and-a-half across with an edge of snowy-looking ice around the borders. They were moving slightly but not proceeding downstream.

View from overhead as we crossed the bridge. 
Well, that was interesting but we kept on walking to the next bridge. We ate our lunch on top of it while enjoying the warm sunshine. Then some of us walked down the 90 feet or so to the river. Underneath the bridge was a large circle of ice similar to the smaller ones except in size. This ice circle was about 10-15 ft. across and revolving lazily.

How amazing! It was revolving but not moving downstream at all!

In this closer photo, you see the buildup on the edges
and that it was very close to a perfect circle.
 So what caused the spinning ice circles that we saw in the river? Apparently they are quite rare.

Eddies have something to do with it but, it seems, melting ice can create it’s own “eddies" from the changes in temperature and density of the water as it melts off the ice and sinks into the water below causing the ice to spin. These spinning circles can actually form in lakes where presumably there is no current.

Temperature of the water and air affects the formation and melting of the ice. Also as a scientist friend told me: Water at the middle of an eddy has less energy than water at the edges, so it freezes sooner. 

Then there is the frazil ice that builds up on the edges. We saw that on both the large and small circles. Frazil ice are ice crystals that form in moving river water that is slightly below freezing temperature, supercooled. However, I'm not clear as to why they build up on top of the edges of the circles.

I'm not sure that the explanations are complete, but here are a couple of websites that have photos and information on these ice circles:

And here are more photos of the hike. Enjoy! (Some photos for this blog are from friends Janice Tassinari and Michael Wilcox.)

One side of the double-arch bridge. All the bridges
were made without mortar of any kind.
Believe it or not, those are heads of people way up there, looking down from the top of the bridge!
Lots of icicles hang from the inside of the arch.

The trail follows a deep cut into the rocks made without dynamite,
only black powder and human powered drills.

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