Thursday, March 17, 2011
Further Adventures with Ice
Wow! Shirtsleeve weather today! Well into the 60s, with brilliant sun beating down on what's left of winter around here. Which is plenty. There's still nearly two miles of frazil ice jammed in the Hudson River above the Thurman bridge at Warrensburg, and Evelyn (frazil-ice expert extraordinaire) called to invite me to check out the situation with her. The solid ice holding the frazil back could break in this warmth, and if all that ice started moving at once, it would be quite dramatic. Worth the trip up to Warren County to witness. Evelyn already lives up there, so we agreed to meet at The Glen, about 8 miles upstream from the Thurman bridge. Here, the river was wide open and sparkling under a blue, blue sky.
At the Thurman bridge, we could see the jumbled frazil held back upstream, so we hiked north along the railroad bed to get a closer look at it.
Here you can see the flat solid ice with heaps of frazil pushed up on to it by the force of the current.
We could hear rushing water, and sure enough, channels of open water were coursing through the expanses of frazil ice. With the water pressure relieved this way, it's possible that the frazil won't move in a mass, but simply melt in place as the weather warms.
This photo shows one of the places (across the river) where the Schroon River joins the Hudson at Warrensburg. Is the Schroon contributing its own frazil to the masses here, or is the Hudson frazil backing up into the Schroon? I don't know.
We next drove upstream several miles to a place called Snake Rock. The frazil filled the river almost all the way here, but upstream the water was flowing open and free of ice.
Due to the configuration of the river here, the frazil collects in wide swaths along the shore, creating a particular kind of habitat called an "ice meadow," an open grassland where many rare grasses and other native plants thrive.
Our next stop was another section of ice meadow several miles upstream. Here, vast sheets of frazil had cracked on the shore as the water level had sunk beneath them. Did we dare walk out on that ice? At least, if we went through, we wouldn't drown, since the ice now rested on rock. Break a leg, maybe, but drown? No.
Alone, I wouldn't have risked it, but Evelyn has many years of experience exploring these shores, and she assured me the ice would hold us. And she was right.
Evelyn wanted to visit one more area she calls "Coney Island," a narrow, curvy part of the river where ice tends to collect in very high heaps, sometimes 20 feet high or more. We had to hike quite a distance to get here from the road, luckily most of the way along railroad tracks where the snow had been packed by snowmobilers. But leaving the tracks to make our way through the woods to the shore, I found myself floundering knee-deep in snow many times, despite wearing snowshoes. There's still lots of snow cover left to melt into the waterways and create lots of drama as the waters rise. But today the river was well within its banks, and Evelyn noted that the frazil had not collected here in the quantities it has in other years. That's one thing about frazil -- it's often full of surprises!
On the way home, I found some very high heaps of frazil on the banks along Golf Course Road. The photo doesn't provide the perspective, but I'm guessing the head of a six-foot man would come about half way up the side of that ice cliff.
I know I've shown photos of Small Winter Stoneflies before, but this guy was quite a bit larger than them. I'll bet it's the spring-emerging variety, joining those other unsung harbingers like Skunk Cabbage and Turkey Vultures to assure us that yes, indeed, the winter will soon be over.