A Study in Ice

A Study in Ice

February 2, 2014

It was an icy day, but with no snow.  The temperatures had stayed below freezing for a good part of the winter, sometimes well below.

For several previous years, our area had been experiencing abnormally mild winters, with higher than normal temperatures and only occasional snow or ice.  When we did get a good pile of snow, it would melt by the afternoon or the next day.  Many local people got used to that as a “new normal”.  They have been doing quite a lot of grumbling this winter.

But not I.  I am happy to have a normal winter of deep cold, ice, and (often) an insulating layer of snow.  

This is what Nature has adapted to here, a place where blocks of ice were cut and harvested from the rivers years ago.  We need sustained cold to control the populations of insects and some other types of animals.  We need the snow to help protect burrowing animals, as well as tubers and roots under the ground.  We will need a good melting of snow and ice in the spring to refresh the water table, streams and ponds.

And so, I have delighted in finding out how Cottonwood Pond and its environs look during a real winter, and how it is affected.  

On the way down, I saw the lower end of the “resting log” sparkling in the winter sun.

Each cream- and tan-striped fungus had a sheen of thin ice on its fan-shaped surface.

Some even had a network of small, glass-like, sparkling crystal fingers.

The creek was not completely frozen.

 

    There were layers of ice, with water flowing beneath or between them.

 

 The action of water flow and some melting caused various designs to form.

  

Crystals formed around the inside edges of holes.

 

The new pond-like area of to the side of the creek was frozen.  Leaf piles, pushed up by rushing water during a previous flood time, rimmed the little pond.

A channel-like depression was still frozen in place within the seep, between Cottonwood Pond and the creek.

Cottonwood Pond was covered by what looked like a thick layer of ice.

Light-footed Silas took a walk all the way across.

Bubbles of many different sizes were frozen into the surface.  Why had these formed?  There were no frozen ripples this time to indicate wind stirring the water surface and adding oxygen.  Had there been much oxygen trapped below, then quickly released during a brief warming, followed by a quick, hard freeze?

Toward the north end of the pond, the bubbles tended to be smaller and to congregate in large groups.  

In places, they looked like constellations.

Some larger bubbles had collected around leaves.

Were these frozen, or still active?

They appeared to be full of very tiny bubbles, like worlds within worlds.  Or were the very tiny ones just  beneath the large ones?

Near the middle of the pond, small bubbles had formed a large ring, with a small ring of seemingly foamy, swirled bubbles in the center. 

How did this form?  Had a store of oxygen bubbled up from the mud below and then rippled out at the pond's surface?  Or could it have been released from an animal burrowed in the mud?

An area of thin ice had formed close to the root ball, sprinkled with fine dirt particles that had fallen from the ball.  Ripples had formed in the ice where rootlets dipped into the pond. 

Was there movement of the rootlets due to wind when the water was freezing?

Looking up, I saw a clear burrow high in the root ball.  Someday I will wait here and see if the animal appears.

I went to the south end of the pond.

The large crawdad chimney was frozen so hard it looked and felt like it had been in a kiln.

A paw print, showing serious claws, was frozen into the mud.

 From right to left, it was still evident where the water had rushed to the south end of the pond during the flood (the “rush area”) and pooled under the log at the edge ...

...went under the log …

… and then entered the pond.

Flow lines, resembling lines of varying elevation on a topographic map, showed how water entered the pond's south corner.  

This time, though, the flow was obstructed by a strange, clear rod shape in the ice...

Did this ice form around a stick?  I wondered if incoming water had flowed over the stick (if there was a stick there) and froze in layers as water continuously moved over it.

When we have our next thaw, I need to look at this spot again.

Did this ice form around a stick?  I wondered if incoming water had flowed over the stick (if there was a stick there) and froze in layers as water continuously moved over it.

When we have our next thaw, I need to look at this spot again.

I moved back around to the other side, to see “little pond”.

 

“Little pond” looked to be in similar condition to the larger pond, though the ice layer may have been thinner.

It also had “constellations” of many bubbles.

There was the old Stinging Nettle plant that had dipped down from the root ball top to the water..  Some very interesting ice designs had formed around it.

With the frosty conditions of the day, the tiny hairs along the nettle's stem and leaf petioles were very visible.  They would no longer sting, though, as the plant was completely dry.

“Little pond”, as seen from the southeast.

“Little pond” on the left and Cottonwood Pond to the right, to either side of the fallen tree's giant root mass.  During the flood, water had rushed over the leaves between the two ponds.

I stepped back over to the north edge of Cottonwood Pond.

Silas had walked over the pond earlier.  How thick was this ice?

I put my booted foot over the edge, set it down, and began to add pressure.

A sudden snapping, crackling sound told me to go no further.

I had broken the nice smooth surface of the pond with its constellation of bubbles.  But, I had only cracked it lightly, and the cracks spread out into a beautiful pattern …

… like a spider's web.

I was reminded of the webs I had found last summer and fall, stretched between plants near the pond, between rootlets on the root ball, and stretched over the ground.

After I cracked the ice, I noticed movement.

Bubbles in the middle of the pond, further from the “web”, began moving in a mass exodus toward the edge of the pond, coalescing into larger bubbles at the edge.

So, the bubbles were “alive”, after all.  They were not frozen.  They were floating just below the surface of ice.  That layer was thinner than I had originally thought.  

Appearances can be deceiving.

I will do more thinking about the bubbles, and why they formed as they did. 

My study of ice had shown me patterns reminiscent of other things in the world:  spider webs, topographic maps, rods, crystals, constellations, and worlds within worlds.

At the end of my visit, a sheen of sunlight lay on the icy top of Cottonwood Pond in varying degrees of brightness.

I expect that the conditions and variations of the ice will continue to fluctuate with more changes this winter, and I will be fascinated to see them.

Fresh Snow

Fresh Snow

January 16, 2014

The great snow had melted, the rains and flood had softened everything, and the first layer of ground had started to thaw – and then it froze.

One day, the pickup truck left deep ruts and was almost stuck.  The next day, the ruts were frozen.

Then, a new, fresh snow was falling.  It was a dusting, just enough to accentuate patterns of bark, leaves, water and terrain.

Even at this distance, the broken pattern of bark on the fallen Cottonwood was very clear and pronounced, as was the swirly pattern of the bark-less wood on the fallen tree to the southeast side of the pond.

The smooth, glass-like meandering line of the creek interrupted the mass of pointed leaves, sticks and dead plants.

The snow also made more obvious the newly-formed pool that was created by the fierce rush of water during the flood.

I think this pool will also be interesting to investigate throughout this new year.

 

 

 

Snow clearly defined the edges of holes and burrows, making animal hiding places easier to find.

 

This day, the creek had only occasional layers of thin ice that created ceilings over parts of the creek bed.  I remembered when the creek was covered on top with brightly colored leaves last fall.  Now. The silted-over leaves on the bottom were all muddy brown, rotting, and breaking down.

The pond was solid white, except for where dirt had fallen close to the root ball, and where mud had piled up along the north side.

The pond had sharp, frozen edges, and rows of frozen ripples near the “shore”.  These ripples were different from the ones I had seen the last time the pond was frozen.  This time, the wind must have pushed the water from the north.  Then, snow had settled in between the rows of ripples.

Here is where mud had been piling up on the north side.  Some of this pile-up was caused by the flood, but its easy to see that the pile-up further in was from dirt falling off of the root ball.  In fact, the drier, light colored section of root ball looks like it will soon drop dirt toward the middle of the pond.

A dark band of brown on the snow, just below the bottom rootlets, was finer dirt that the root ball had shaken down.  This sheltered area was where frogs gathered last summer.

 

The recent action of flood water in the seep was more visible after the snowfall.

“Little pond” below the top of the root ball.  An old Stinging Nettle plant had bowed down to the water.

 

The snow had started shortly before I went into the woods, and was still lightly falling.  There had not been enough time for animals to leave tracks.

Before heading back uphill, I looked for more patterns made by this fresh snow.

  Sycamore

 Blue Beech/American Hornbeam/Muscle Tree

A New Year at Cottonwood Pond

 

A New Year at Cottonwood Pond

January 4, 2014

A new year had begun, already with a flip-flopping of weather events.  There was a winter storm in December, followed by heavy rains and snow melt just before Christmas.  Then the temperature dipped deeply again as 2014 began.

There was ice again, though not nearly as thick as it was in early December.  

  

Looking down at Cottonwood Pond from woods' edge, I could see a cresent-shaped band of white, and a band of brown closer to the root ball.  I knew the white had to be ice.  But what was the brown layer?  A shadow?  Or was it simply an un-iced area?

First, on my way down, I investigated other things.

The creek was mostly frozen.  Since the snow melt and big rains, it had been flowing very swiftly.  Those ripples, rushes, tumbles and pools were frozen as if in stop-animation.  The water was, though, still flowing beneath the ice, but not as swiftly as before.

Piled-up debris in the stream bed showed how the powerful water had pushed leaves, twigs and mud forward, creating small dams.  The dead plant stalks near the stream were all flattened in one direction, showing where rushing water had flowed beyond its banks.

Oxygenation from rushing water created pockets and bubbles in the surface ice, the swirly patterns illustrating the flow.

 

Dead leaves were sometimes caught in the patterns.  Tulip Poplar seeds had fallen to the icy surface, to be swept away later when the ice melts.

In another section of the creek were different patterns on the ice.  Perhaps during a warmer period, some surface ice had melted a bit, trickled, and froze again, leaving evidence resembling a satellite photo of a riverine area between mountains and ocean.  But, I also found these patterns reminiscent of those made by traveling worms in the creek mud during the past spring and summer.

I approached the pond's edge to solve The Mystery of the White and Brown Bands.  The ice had developed layers of thickness.  At the edges, thin ice mingled with the crackly, crispy layer of dead leaves.  A crescent shaped band of white ice was sandwiched between two bands of bluish gray, and there was a concentration of thick white ice on the northwest end (where the pond overflow spills into the seep.)

The layers of ice are more complex than the simplicity I perceived from farther away. 

And, what of the brown band?

Speaking of deception, the brown was neither shadow nor a non-iced area.  It was … dirt. 

I had wondered before how much dirt falls from the root ball into the pond, adding to the bottom.  Now I was able to have an idea of the amount as it settled on top of the ice.

(My cat Silas had come on my woods walk with me, always just several feet from wherever I was.)

To the left, a pile of dirt seemed to have grown higher, as well as farther into the pond.  I will compare this to earlier photos sometime.  I assume that this has been pushed forward by the action of heavy rains, and added to a little at the top by dirt fallen from the root ball.

Here is a closer look at that pile of mud, situated between Cottonwood Pond and “little pond”, which can be seen on the other side of the root ball, around the corner.

Before heading around the bend, here is a particularly beautiful view of the crescents of ice and mud layers.

I went around for a full view of “little pond”, which had also been swollen by snow melt and rain, and I found it full of interesting patterns.  I would love to know how these are created.

 

The remaining snow had accentuated the deeply-furrowed texture of Cottonwood bark.

Here is where Mystery Mammal had walked across the ice of “little pond”, walked alongside the fallen tree, and then slipped under the first open spot. 

(see “Tracking”, December 2, 2013)

Silas seemed to be following a similar trail, though I knew he was not the Mystery Mammal.

Lo and behold, there were prints frozen into the mud.  One of these is, possibly, a canine print.  This would have been a good opportunity to make a cast.

Then I found more prints nearby.  These may be Raccoon, but I am not positive.

On the other side of the fallen Cottonwood, I could see where Mystery Mammal not only had gone under the tree, but where it had been wearing a trail in the weeds and mud.

I found deeper prints frozen in the mud. I did not think these were from Raccoon.  Ice crystals had formed in them, so they were probably made no later than the night before.

The mud of a Crawdad chimney was frozen, and ice crystals had developed at the entrance.  The Crawdad was likely burrowed in deep below the frost line.

I went to the south end of the pond.  Rushing water, which had traveled from up the slope during heavy rains, had gouged out and enlarged the space under the fallen log. 

(See “Flood”, December 21, 2013)

If the pond filled up further, it could back up into this space.

On the pond side of the fallen log, where rushing water had come under and through, flow patterns could be seen in the ice.  It was also evident that this “new” water, as it entered, flowed under the shelf of ice that already covered the pond. 

Gentle ripple patterns, moving away from this spot, could be seen nearby on the pond's surface.

Silas enjoyed visiting Cottonwood Pond and going on a woods walk with me.  It's going to be an exciting year, with more investigation of the goings-on at Cottonwood Pond.