Tuesday, January 15, 2013

Walking on Ice

Sunny and colder today, with most of our snow now gone, after days of warmth and rain.  I drove up to Moreau Lake, planning to get some aerobic exercise striding along on the wide sandy beach, under a bright blue sky.

The ice on the lake looked really iffy, with whitish opaque ice close to shore and transparent blue ice out deeper that almost looked like open water.  I wasn't planning to venture out on it, but then I saw there were fishermen out in the middle.   So I decided it must be safe.   Sort of.

It did give me a queasy feeling, being able to see down to the bottom through the ice.  But I also could tell by the depth of the cracks that the ice was thick enough to support my weight.  Still, I stayed pretty close to shore.

The milky ice was starred with these spidery formations, the origins of which remain a mystery to me.  One of my very knowledgeable friends explains them as occurring when the weight of snow pushes the ice down and water wells up through weak spots.  But hey, we haven't had a heavy snowfall since the lake froze over.  So how did these form?  I sure don't know.  Maybe just from the weight of the ice itself?  Or the rainwater on the surface?

 Here are similarly shaped formations in the transparent ice, only these "spiders" are raised, as in relief, on the surface of the ice.  It certainly looks as if they were formed by upwelling water.

Here's another mystery.  What causes all these underwater plants (I think these are Pipewort) to be uprooted?  Toward the end of autumn we find masses of them washed up on shore, and today I found masses of them embedded in the ice.  It occurred to me that muskrats or beavers could be digging them up in their lodge-building excavations,  but why do we find this phenomenon only certain times of year.  And why now?  When we walked on the ice last week we did not see these masses of plants.

One thing is for sure:  ice does amazing things for which I have no explanation.  Although I sure do like to speculate!  For example, what is it about this particular stretch of beach that causes the ice here to always be filled with bubbles, and almost always melted close to the shore?   It's a muddy, marshy stretch of beach, rather than a hard sandy or rocky shore, so perhaps there's some kind of constant composting going on that produces heat and gas.  This photo shows a pock-marked surface to the ice, as if big bubbles formed as the water was freezing, leaving pits in the ice when the bubbles broke.  There are also lots of silvery bubbles embedded in the ice.

Here's one of those bubbles.  Looks a bit like a jellyfish.

One last mystery confronted me on my way home along Spier Falls Road.   What are all those red shrubs out there on this little island in the Hudson?  I often explore this island for wildflowers during the summer, so I should know what grows out there.  Both Red Osier and Silky Dogwood have bright red stems, but these shrubs seem too low-growing to be either dogwood.  Ah, but then I remembered what the beavers had done to all the azaleas on a neighboring island.  Perhaps these red stems are new growth from dogwood stumps that were gnawed to the ground last summer.  I'll have to test my theory next spring when I once again put in for a paddle.

Theoretically, I could paddle the Hudson right now, since most of the ice is gone from this section of the river.  But no, I think I'll wait.

1 comment:

Virginia said...

I'm glad you said why you knew the ice was safe. It looked a little scary. That "jellyfish" photo looked like someone's footprint that froze into the ice :) I remember one year, here in Albany, when we were skating on our nearby pond during a clear snowless period, we could see fish swimming underneath! Amazing.