DISCOVERING WINTER / THE WORK OF ICE
The Ebbs And Floes of Ice
By CHRISTINE JEFFERS
Shunpiking Magazine, Volume One, No. 10, December, 1996
ICE. HOW DOES IT EFFECT US? Myriad ways. Some of its ways we take personally (as when we slip the bruise our tailbones on it) and some, we handle with objectivity (such as using crushed ice on that bruise to reduce swelling). Yet most of us in the northern hemisphere are so used to ice that we can (and do) pass through a whole winter barely giving the ice of our environs a second thought. Unless we have to.
More often than not, we do have to. Ice commands our respect. In its unleashed proportions, ice, like the wind, the sun, and the waters, is a force eminently greater than us. Yet, it's possible for us to harness the properties of ice to vastly enhance our existence.
Some might have argued that we have gained control over ice. Well, a modicum of control, perhaps. In it's more "domestic" form, ice is relatively easy for us to regulate and manipulate, to treat ailments, preserve organic matter, and make tasty frozen foods with. We hold festivals about it, create art with it and practice sports on it; but let's not get too big for our britches.
With or without us, ice just is. Our use for the property of ice requires that we accept it as the controller. Throughout history ice has created more necessity and more challenge for mankind than we credit. The bulk of today's ice-related technology comes from our developing awareness of the power of ice. We, in our collectively humble wisdom and humanity, usually have the sense to go with the flow.
Ice can freeze naturally or it can be induced; it can freeze with our will or against; it can delight, excite and refresh us or it can frustrate, aggravate and overwhelm us. Ice can save lives and it can take lives; it can be breathtakingly beautiful to behold or it can be the most terrifying sight imaginable.
Meeting ice in its grander scale: huge mass of floating ice catch the wind, ride the current. They gain forceful momentum. Glacial scopes of ice alter the landscapes, slice through ecosystems. Nothing can stop them. A freeze descends on the north country. Then, no power on God's earth will keep a mountainside waterfall from becoming a giant needle of stalactated ice. Nor will it alter the soul-numbing beauty and bewitching peril of cold-carved ice caves below these glaciers and waterfalls. In these magnificent natural forms, ice steals our breath away, gives rise to our primal instincts, cuts us down to size. Which one of us would not believe in pure magic, spirituality, timelessness, and life beyond death when face to face with one of these phenomenon? In such proportions ice appears gold-like, all-powerful;ungiving, unforgiving.
Ah, but even ice such as this exists at the mercy of a greater force: like all things on earth, ice is ultimately at the beck and call of the global climate.
Antarctica and the North Pole remain locked in their own, present day version of an ice age. In Antarctica, as winter annually descends, a vastness of salt water ice more than twice the size of the United States forms over it. Before it thaws each spring, it has become a unique, thriving ecosystem.
As the ice ages ticked off millenniums ago, freshwater glacial ice covered much of the globe and crept over its surface like some calm, omnipotent one-celled animal. It molded and reshaped, cut rivers and lakes into flat lands, scooped out valleys, hove up mountain ranges and gave boundary to oceans. It forced migration of entire food chains; murdered as it went, but also giving birth. It was a continental emissary in mineral distribution and with all manner of plant life. Some of Nova Scotia's prettiest flowers are survivors of the last glacier on the Coastal Plain, in the southwest of the province in an area today called The Scotian Shelf. Somewhat conversely, ice's destructive force is responsible for the recurring appearances of such lovely flowers as the rosy Pinkis and milky green Water Pennyworth; they can only exist because other common, competitive plants vying for life are killed off by winter freezes and blowing ice.
Today, we can perceive many of the major features of Atlantic Canada's landscape as products of glacial activity during the Pleistocene Age. In Pleistocene times, there was a massive accumulation of ocean water in glacial ice, resulting in the increase in the bulk of glacial mass as well as lowering of sea level. From this phenomenon came vast, glacial "land bridges", which were responsible for the migration of certain hardy animal species from Asia to America across the Bering Strait. Ever wonder who were among the first to take roads less travelled? Across these "non-land" land forms created by the ice, trekked caribou, Arctic foxes and red foxes, brown bears , wolverines, musk oxen, ermine and grey wolves. All became indigenous populators of our continent.
Remember learning about glaciers and ice ages in school? In the nineteen-fifties it was being taught that we are currently enjoying an interglacial interlude between the last ice age and the next. How appalling to be forced to envision the world as we know it one day becoming an expanse of ice! Although in forty years our knowledge and understanding of the elemental world has deepened, it is still being taught that we may well be between ice ages. No one really knows for sure. But we can relax a little. The last ice age ended about ten thousand years ago now, and the known intervals between ice ages have been approximately two-hundred-fifty-million years each.
The conundrum of ice is that it can be as small as the tiniest particle of frost or as huge as Antarctica... but no matter what its dimensions, it all becomes ice through a singular process. The freezing process -- water's transition from liquid to solid -- requires a lowering of its temperature until it nears 4 degrees Celsius. At this temperature, the water molecules are moving so slowly that the spaces in between them decrease. Thus, the water density increases. Because the slow-moving molecules are so close together, each one is able to simultaneously form hydrogen bonds with four neighbouring molecules. But each water molecule is shaped geometrically; due to this, while the hydrogen bonds form, the molecules must move further apart again. This creates an open "latticework" which we perceive as ice.
As a solid, water takes up more volume than it did as a liquid. But ice, because of its crystalline structure, is not as dense as water, which is why it will float. When ice covers lakes, ponds and smaller waterways, this can actually be beneficial for submerged life forms therein. A layer of floating ice in winter tends to be protective, effectively insulating the water beneath it, keeping its temperatures at, or above, freezing. A large, deep lake will usually become thermally stratified in summer, resulting in a springtime shifting of cooler waters from the surface to lower depths. This permits year-round survival of cold-water fish at deeper levels. Freshwater fish don't freeze in winter lakes or ponds because their body fluids are considerably saltier than the fluid of there environment.
Salt water freezes at a slightly lower temperature than fresh water-28.5 degrees Fahrenheit for 1.9 degrees Celsius. The higher the water's salt content, the longer it will take to freeze.
There have been rare discoveries of fish found frozen in polar ice which, when the ice melted, revived and swam away, apparently unharmed. It is curious that salt water fish usually don't freeze even though their body fluids are less saline than sea water. When ice covers bodies of water, many cold-water species head for the lowest depths and enter a suspended state, almost seeming to hibernate. If provoked, they appear dopily lethargic, but will eventually swim off. Animal physiologists have found that the ghost fish produces a protein they've aptly named "antifreeze protein"; it secretes into the blood stream and interferes with the formation of molecular structure of ice. Several species of terrestrial frogs hibernate beneath layers of leaves, snow and ice during the winter. Their body fluids contain glycerol, an ingredient sometimes found in a car antifreeze. At present, there are questions yet to be answered as to why more aquatic life forms don't freeze when the ice above them does.
Ice (and snow) have an insulating effect on lake surfaces, acting as temperature stabilizers for the depths below. This is especially valuable to water organisms during the climatic changes of fall and spring. The stabilization of temperature provides vital time for water life to make its seasonal adjustments.
As warming occurs in the early spring, ice sheets on lakes and rivers contract, sometimes resulting in a sharp, cracking boom reverberating through the country air. This is a welcome signal to die-hard animal and bird life, whose survival depends on proximity to open waterways, and whose movements through the winters are restricted to tidal waters, a few larger lakes and fast-flowing streams. Nova Scotia's indigenous water birds -- the year-round and winter residents -- cluster towards the southwest tip of the province, where more watercourses stay clear during the winter.
Locked in the lattice of ice off our coast is the rhythm of life itself. Ecological and social environments must adapt to the dictates of ice's frigid dynamics. Fish like mackerel, capelin, herring and cod migrate out of the Gulf as the ice begins to build. White hake, red fish and lobster remain in the Gulf during winter. But the migrating fish are also followed by whales, which, if they stayed, could get stuck in the ice and perish. Similarly, people whose livelihoods depend on the maritime fisheries are at the mercy of the ebbs and flows of seasonal ice. Some fisheries are predicated on winter conditions without ice -- such as November to March lobster season off southwest Nova Scotia. Other fisheries throughout the Gulf of St. Lawrence and off the northeast coast of Newfoundland are closer by the presence of pack and drift ice until mid-May. It becomes, instead, the terrain of the seal hunt.
At tremendous cost to life and limb, much has been learned about the perils of ice at sea. Mariners and fishermen alike can cite major disasters which occurred off our eastern coast -- all attributable to the unexpected force of ice. Because of such events in our maritime history, the ice pack in the Gulf of St. Lawrence and "Iceberg Alley" in the Labrador Sea now bear witness to rigorously improved design in fishing boats, cargo ships, offshore oil rigs and other vessels.
The best-known coastal disaster of our region happened in 1912: the sinking of The Titanic. Its grim reaper? A gigantic, largely-submerged, drifting ice berg. In 1914, The Great Newfoundland Sealing Disaster occurred during a severe storm when seventy-seven seal hunters were lost on the ice in the zone known as The Front. During the same storm, ice overcame a ship called the Southern Cross, drawing it and one-hundred-seventy-seven men on board to an instant grave. Several years ago, two scallop fishing boats out of Lunenburg lost a battle to ice as spray froze heavily on their masts, keeling the vessel over.
Presently, concerns exists about the effects of pack ice on the new Fixed Link causeway between PEI and the New Brunswick mainland; how will it withstand the drift of ice year after year?
Clearly, ice in its many forms challenges all of us -- all life -- to find ways to survive. Although this challenge appears to be too much for some, it exists to the refreshment, thrill and excitement of others, and allows for perhaps limitless applications. Think for a moment about a world without ice. It's unimaginable -- for ice is a major player in the balance of our natural world.
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