Monday, March 20, 2006

You only think you've been cold...

kw: book reviews, nonfiction, natural science

To those who have ever overwintered in Antarctica or Kamchatka, the title above is not directed!

(prescript: I prepared this the 20th, so I am dating it then. I was ready to post it, but went on a trip before I'd copied it into here. Oh, well.)

I note that twelve days have passed without a posting. Blame a combination of my obsessiveness and the writing of Mariana Gosnell. Her book Ice, the Nature, the History, and the Uses of an Astonishing Substance is 500 pages of small text. I briefly contemplated posting about halfway through, but a day or two later was far enough long on the second half, that I just forged ahead.

Now, I can usually polish off a quarter million words in six to eight hours of reading time. Not here. The author's prose is not difficult, though it is quite straightforward and less lyrical than that of many nature writers. She writes well, but the book is so packed with ideas and information that I could read but a few pages at a time, then had to think a while.

The halfway point in the book was a seductive point to pause—if I had done so—because of a shift in the narrative. Of the 36 chapters, the first 16 present ice where it is found: capping seas, lakes, and streams; glaciating continents (at the moment, two) and high mountains; and in permafrost. The next seven chapters show how plants and animals, including humans, are impacted by ice. Five more focus more on ice in our work and play, then seven on more places ice is found: the air and space. Finally, a chapter on ice ages and a closing one on life at the north end of Lake of the Woods.

I've had a love-hate relationship with the stuff. Born in California, I saw snow only after a family move to Utah. There I learned to ski, and found I am no good at it. I did better at lunch-tray tobogganing, which I learned at college in Ohio. I also learned to ice skate, and love that, though I rarely do so any more. Now that I live on the edge of the ice belt, outdoor skating places are typically far away, and "rinks" are too costly. The eight years I lived in South Dakota were quite fun. Snow was not plowed; when it is -20°, snow is like sand. You pack it down and drive on it. Further south, snow is too close to its melting point to be safe to drive on. Thus, the ubiquitous sand-n-salt trucks, and the prevalence of body shops to repair the rust on your car.

The uniqueness of ice on Earth is that, of all the common solid materials, it alone exists close to its melting point. I imagine if Venus were a little hotter, granite would behave a little more like ice does on earth...with a big exception. Ice is the only common solid that is less dense than its liquid.

Aside: the next-most common solid that expands on freezing is the semimetal Antimony. Where ice expands 9% in volume Antimony expands about 1%, which makes it a perfect alloying element for type metal in hot-type machines such as the old Linotype™. That little expansion makes the metal squeeze into every cranny of a type slug so the letter is very clear.

I imagine if the temperature were near 1000°C (1800°F), granite mountains would creep and flow the way glaciers do. What they would creep upon is another matter. Basalt, I suppose, which melts another 600° or so higher.

To me, the most beautiful form of ice is windowpane frost. In Utah, we didn't have storm windows for our bedroom windows, so there was often a swirl of frost catching the rays of the rising sun of a winter morning. Second most beautiful, snowflakes. During the South Dakota years, I was a Geology student, and carried a hand lens all the time. I kept it on a lanyard so it would stay cold, and during November or April snows (December to mid-March, the little snow that fell was powder), I'd look at the flakes that fell on my dark blue parka. Exquisite!!

In Ice, Gosnell explains how these beauties form by direct freezing from vapor. No liquid phase occurs. Conversely, ice in stiff clothing on the clothesline in winter evaporates directly to the chill winds, and you know the clothes are dry when they become supple. While we often dry clothes that way, a quick tumble in the clothes dryer with some Bounce, or a touch of a warm iron, makes them so much nicer to put on!

We also find animals that can survive freezing, mainly because ice tends to form between cells rather than within (saltier there), so the cells evaporate much water to the growing ice while they shrink and stiffen. A frozen insect or frog is not in much danger from the freezing, but from dehydration if too much water is withdrawn from the cells. Those that must live in the coldest climes have efficient antifreezes, some that allow them to survive nearly 100 degrees of frost.
Will we soon get more intimately acquainted with Ice? Are we at the end of an Interglacial episode? Most science indicates that is the case, but the author mentions a few studies that argue it will be another 10,000 or 20,000 years until the US, northern Europe, and southern Africa are glaciated again. The more we learn, the more there is to learn. This is particularly true about Ice.

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