Paperback
-
PICK UP IN STORECheck Availability at Nearby Stores
Available within 2 business hours
Related collections and offers
Overview
Product Details
| ISBN-13: | 9780199837809 |
|---|---|
| Publisher: | Oxford University Press |
| Publication date: | 05/30/2012 |
| Pages: | 232 |
| Product dimensions: | 6.00(w) x 9.10(h) x 0.50(d) |
About the Author
Read an Excerpt
Chapter One
The Nature
of the Place
In the Arctic your sense of location and time are likely to go haywire. In our familiar temperate and equatorial latitudes we speak of north, south, east, and west, the familiar cardinal directions. At the North Pole, all directions are south. The meaning of time as the notion is used in our temperate latitudes diminishes the farther north one goes, until it is virtually irrelevant: Because the meridians (longitude circles) converge at the Pole, so do the time zones. What time of day is it at the Pole, where you could place your foot in all the world's time zones at the same instant? At the Pole the Sun rises once a year and sets once a year, the Moon rising and setting once a month.
The long periods of darkness during winter and long periods of sunlight in summer in the polar regions—and to a lesser extent in the temperate regions—are caused by the fact that the plane on which the Earth rotates, the equatorial plane, is at an angle to the plane on which the Earth revolves around the Sun, the plane of the ecliptic. The angle of tilt between the two planes is 23.5 degrees. The moment when the Sun is farthest south is on December 22, known as the winter solstice. On this day the entire region north of latitude 66° 30' N is in total darkness. Conversely, on June 21 each year, the summer solstice, the same region has twenty-four hours of daylight. The North Pole itself has six months of daylight from about March 21, the vernal equinox, to September 21, the autumnal equinox, and six months of darkness fortherest of the year. The Arctic Circle is defined as the latitude 66° 30' N, a convenient division between the Arctic and the North Temperate Region south of it.
A different kind of map is needed in the Arctic. The conventional map we are most familiar with is called a Mercator, or modified Mercator, projection (after the sixteenth-century cartographer). The trouble with any map is that it has to represent a three-dimensional object, the planet, on a two-dimensional surface. and so it must distort part of the world. The simplest of Mercator projections arises, figuratively, from the exercise of placing a cylinder around the world, touching it at the equator, with its axis in a north-south direction. If you project out from the center of the Earth through every point on the Earth's surface and onto the cylinder, then unwrap the cylinder, you have a Mercator projection. It gives a pretty good representation of things at tropical and temperate latitudes, but it is of little use at the higher latitudes. There everything is out of proportion, much too large, with Greenland, for example, being larger than all of North America, and in the extreme, the North Pole is off the map altogether—out at infinity.
For polar regions, most maps in use today are centered at the North Pole, and all the directions (called azimuths) and distances are true from the Pole. These maps are called azimuthal equidistant projections. The latitudes are circles around the Pole, and the longitudes radiate out from the Pole. Such maps are made arithmetically, unlike Mercator maps, which are geometric projections. But, of course, an azimuthal equidistant projection is perfectly accurate only at the pole; elsewhere it produces its own distortions, which are larger the farther you get from the pole. To get a true idea of the sizes of the Earth's landforms and oceans, and a real sense of their directional relationship to each other, there is nothing like a globe.
The Arctic Ocean is roughly circular in form, with its center slightly offset from the North Pole. It is relatively isolated from the deep waters of the world and surrounded by a sequence of landmasses. Starting from the northern shores of Greenland and proceeding clockwise are Ellesmere Island, with Devon and Baffin Islands to the south; the Canadian Archipelago; the shores of northwestern Canada; Alaska; then around to the vast extent of Siberia, with the islands of Novosibirskye, Novaya Zemlya, Franz Josef Land, and Svalbard (formerly Spitzbergen) offshore; and ending with northern Europe (specifically Finland and Norway).
These Arctic lands—most of them, at least—are underlain by what is called permafrost. Except for a thin layer that melts in the summer, called the active layer, the extreme cold of the Arctic has permanently frozen the ground to depths of 800 to 1,500 feet, and even deeper in Siberia. To the south, in what is called the subarctic, the permafrost can be up to 400 feet deep, and farther south it underlies great layers of peat and boggy areas. Since continuous permafrost totally cuts off drainage underground, shallow lakes are common throughout the Arctic landmasses, and in warmer months standing water is home to legendary swarms of blackflies and mosquitoes. During the summer, waterlogged soil flows downhill over frozen ground, creating long, smooth slopes in areas where mountains do not rise from the land. Much of the exposed rock of the northern parts of the Arctic is broken up by frost into angular boulders.
To return to the ocean, the major bathymetric (deepwater) feature of the central Arctic is the Lomonosov Ridge, which divides the deepwater basin of the Arctic into two parts, the European Basin, in the Eastern Hemisphere, and the Canadian Basin in the western hemisphere. Surrounding the Arctic Ocean are several seas, considered separate mainly because their ice cover is seasonal, unlike the permanent ice pack of the central Arctic.
The lands bordering the Arctic Ocean are sparsely populated by nomadic peoples. Until very recently, hunting was the only way to make a living in such a northerly climate. Plant life is nonexistent in areas of permanent ice, and the tundra and other exposed surfaces are not friendly to the kind of plants that normally sustain humans. Agriculture is, of course, virtually impossible. About a million people live in the Arctic, more than half of them in Siberia. The Inuit (formerly called Eskimos, a name given them by others) number about a hundred thousand, inhabiting a broad expanse from Greenland through northern Canada to Alaska. That nearly a million people do inhabit the Arctic year round is astonishing, what with the extreme harshness of the climate and the desertlike bleakness of the landscape. Indeed, the Arctic is a desert—a cold desert—because virtually all its fresh water is locked up as ice and annual precipitation measures only 6 to 9 inches, making it a place of practical aridity.
The polar climate is a result, in great part, of the heat imbalance of the spheroidal Earth. Given the angle at which the Sun's rays strike the Earth, more radiant energy is received near the equator than at the poles. Furthermore, much of the radiant energy that does reach the polar regions is reflected back into the atmosphere and beyond by polar snow and ice. The global tendency is to redress the heat imbalance, to redistribute the heat dynamically by means of the general circulation of the atmosphere. Generally, warmer and less dense air at the equator rises and moves toward the poles, while colder and denser air at the poles sinks and moves toward the equator. This would create two separate cells of circulating air—as if a wide sleeve were wrapped around the earth north and south of the equator. But the Earth rotates, spinning on its axis, and this causes each pole-to-equator system to break up into three separate circulation cells: one is polar, the next is at midlatitude (called the Ferrel cell), and one is equatorial (called the Hadley cell).
The Earth's rotation creates what is called the Coriolis force, which dictates that air in the Northern Hemisphere, which moves north if it is warm or south if it is cold, is also deflected to the right of its north-south motion. In the Southern Hemisphere, the effect is opposite; air is deflected to the left. So when cold, dense air at the North Pole sinks and moves south, it is deflected to its right, or in a westerly direction, creating winds that are called polar easterlies. (Winds are designated by the direction they flow from rather than to.)
In the Hadley cell in the Northern Hemisphere—the cell nearest the equator—warm, less dense air rises and flows northward as it is replaced by colder air from the north, so here too the north-moving air is deflected to the west by the Coriolis force, creating the northeast trade winds.
What happens in the cell in the middle, the Ferrel cell? Air is rising at the southern boundary of the polar cell and descending at the northern boundary of the Hadley cell. At the Earth's surface here, the air is moving north and is deflected to its right (the east), creating what are called the prevailing westerlies. Much of the United States lies under the midlatitude Ferrel cell with its prevailing westerlies, which is why weather tends to come from the west. In the Southern Hemisphere the cold air comes from the south instead of the north, but direction of the Coriolis force is flopped as well, the results being polar easterlies, prevailing westerlies, and southeast trade winds—much the same as in the north.
The value of these circular patterns for the Atlantic Ocean in the days of sailing vessels is obvious: Ships sailed from Europe with the northeast trade winds blowing from astern, propelling the square-riggers across the water steadily. They could then head north on the Gulf Stream and back to Europe on the prevailing westerlies. But there were traps for the unwary. At the equator, as we have noted, warm air rises. Some flows north, some south, creating the two trade winds. In between, the air flows weakly and horizontally at the Earth's surface; this is called the intertropical convergence zone or, to sailors of wind-driven vessels, the doldrums. Similarly, the winds are also weak between the equatorial and midlatitude cells—a zone called the horse latitudes. As in the doldrums, ships were often becalmed there, and the crews jettisoned any expendable cargo, presumably including horses, to lighten the load they had to tow behind rowboats.
At the North Pole the winds are generally calm, increasing in magnitude away from it. Table 1 shows the frequency distribution of wind speeds over the central Arctic Ocean. They are not high as a rule, averaging 9 to 11 miles per hour. They are highest in April and May, but never more than 33 miles per hour.
During the Arctic's sunless winters the skies are typically clear and it is extremely cold; January temperatures over the pack ice average -22° to -33°F. In summer, when with the return of solar radiation come melting snow and ice and the resultant open water, temperatures are held near the freezing point for water (32° F), and it is likely to be damp and foggy. Annual precipitation, as noted, is about 6 to 9 inches, falling mostly in summer and early fall. Typically the landmasses lying around the Arctic Ocean are somewhat warmer than this in both summer and winter.
Just as Arctic winds rarely achieve high speeds, the ocean currents tend to be stately. The vertical structure of the ocean currents is determined, as one would expect, by the density of the masses of water, with denser water flowing in under less dense water. Density is determined by the water's temperature and its salinity, with salinity being more important than temperature. The colder and saltier the water, the denser it will be. Much of the water flowing into the Arctic Ocean is a warm and saline undercurrent, flowing along the coast of Norway and referred to as the Norwegian Current. The major outflow is the surface transport of the East Greenland Current south through the Fram Strait.
Within the Arctic Ocean water circulation is governed, in part, by the Lomonosov Ridge; in the Western Hemisphere the clockwise gyre of water north of the Canadian Archipelago is called the Beaufort Gyre. In the eastern hemisphere, the Transpolar Drift System flows across from Siberia to the Fram Strait. Off Siberia, the flow averages about 1 to 1.5 miles a day, increasing to about 4 to 5.5 miles a day in the narrower causeway of the Fram Strait.
The Arctic sea ice is always on the move. It follows the drift of the underlying ocean currents and the changes in the direction and speed of the wind. For polar explorers and Pole seekers, the most important feature of the Arctic—the single feature that needed most to be understood—was the structure and drift of this shifting, ever-changing ice pack. The ice never completely covers the Arctic Ocean, because differential motion, fracturing, and melting all lead to open waters. Some of these are narrow, roughly linear leads, ranging in width from yards to a mile, and some are broader polynyas, which can be thousands of square miles in diameter. The frequent deformation of the pack ice breaks up the otherwise uniform expanse into irregular shapes called floes, which are separate platforms of ice. Other important features are pressure ridges, formed when ice is compressed with enough force to crumble it into rows of elevated ice several yards in height and also extending some distance down into the water below. Pressure ridges are ubiquitous, and on average there are four ridges some thirty yards in height to climb over or detour around for every mile one treks across. The pack ice, then, is extremely difficult terrain, and it extends all the way to the Pole. The native populations never had any interest in going into the polar region until paid by European explorers to do so.
At its southern boundaries the ice has a seasonal growth-and-decay cycle, nearly doubling in extent from the summer to the winter. During the summer melt period water percolates through the ice, and when winter approaches, the ice is left with a rolling, hummocky surface that adds to the difficulty in crossing it. The only relatively smooth and undeformed ice one encounters in the Arctic is first-year ice, formed at the edges of the ice pack and about two yards thick. Multiyear ice tends to be about three yards thick and may be tens of years old. In September, when the ice is at its minimum extent, the ice pack is confined mostly to the Arctic Ocean, with only a small amount reaching into the Greenland, Kara, and Barents Seas and the Canadian Archipelago. At this time virtually no ice is to be seen in the Bering Sea, Hudson Bay, the Sea of Okhotsk, and Baffin Bay. On the other hand, in March, when the ice is at its maximum, it covers the Arctic Ocean, the waters around the Canadian Archipelago, and large portions of other peripheral seas and bays. Through the eons, this schedule has varied as the Northern Hemisphere has experienced long periods of unusual warmth or unusual cold.
For polar explorers a century ago, the movement of the pack ice was as important to know as the location, height, and extent of pressure ridges. In simple terms, you can't know what direction you need to go to reach, say, the North Pole, if you don't know which way the ice you're going to cross is drifting. Today, thanks to the placement of drifting manned stations on the ice pack by Russians, Canadians, and Americans over the past sixty-odd years, we have a fairly good picture of these motions. The ice generally follows the direction of the Beaufort Gyre and the Transpolar Drift System, but it can be quite erratic, sometimes doubling back on itself. It travels about four miles a day, sometimes less, sometimes as much as two miles more per day.
Finally there is the matter of navigation and bearings out on the Arctic ice pack. The early explorers did not have the advantage of satellite navigation. They couldn't even avail themselves of then-conventional celestial navigation, in which one measures the angle from the horizon to a star at a given moment in time. From the intersection of two or more such lines from two or more star sightings, and with the aid of the Nautical Almanac, a catalogue of star positions, your location is given. To use this technique both the horizon and the stars (or planets) have to be visible simultaneously, limiting celestial navigation to early evening and early morning. On the polar ice pack in summer, however, the horizon is visible but no stars are; in winter the stars twinkle but there is no horizon to be seen in the dark.
In this situation you have to rely on a less accurate system, determining the height of the Sun above the horizon at local apparent noon, which calls for a series of Sun sights until the maximum elevation has passed. Through appropriate tables, the Sun's elevation can be translated into your latitude, and the time of the local apparent noon (the Sun's maximum height in he sky) translates directly into one's longitude. (Until the invention of the chronometer at about the time of the Renaissance, there was no way to determine longitude, and explorers setting out in earlier times simply couldn't know where they were.)
These Sun sights are all very well in much of the world, but as you approach the Pole there is little change in the Sun's elevation, and the concept of local apparent noon loses its meaning. Magnetic compasses are of minimal value in the polar latitudes, since the magnetic pole undergoes large and somewhat unpredictable variations. It is currently in the vicinity of latitude 76° N and longitude 100° W, but these locations not only are indefinite but change irregularly over a period of years. It is preferable to get an estimate of geographic south from the Sun's position at its maximum elevation.
With the unpredictable vagaries in the drift of the ice pack, it is essential to take daily readings at noon. Dead reckoning—deducing position from your direction and speed—without considering the drift of the ice can lead only to huge but unrealized errors, and it often did in the long history of Arctic exploration.
Imagine, then, being an explorer four hundred or even a thousand years ago, not knowing any of this as you proceed northward past the waters and landforms of your known world in a small, seaworthy craft into a world inhabited (but only sparsely) by strange creatures in the sea—seals, walruses, narwhals with their unicornlike single horns, the occasional seabird arrowing off through the mist, strange ice forms floating in the fog like cosmic rubble and rising steeply above you, distant black-and-white shores soon lost to sight in the gathering frozen night....
The Arctic has been described as bleak, beautiful, terrifying, depressing. It has driven Europeans into madness; worse, it has claimed lives with a carelessness that denies, for some, the presence of a loving God. One of its most eloquent troubadours, Barry Lopez, has trekked its length and breadth and found a wisdom "that lies in the richness and sanctity of a wild landscape, what it can mean in the unfolding of a human life, the staying of a troubled human spirit." He speaks of the North and its exploration as a continuing movement through uncharted waters, "an expression of fear and accomplishment, the cusp on which human life finds its richest human expression."
A magical kingdom, one might say.
Table of Contents
PrefacePrologue: the Nature of the Place
PART ONE: Ultima Thule
Chapter One: Sea Lungs, Godly Commerce, and Projections
Chapter Two:Frizadores for Cathay and Polar Bears
Chapter Three: Fool's Gold, Hooch, and Mutiny
PART TWO: The Myth of the Open Polar Sea
Chapter Four: Connubial Fidelity and the Vicar of Wakefield
Chapter Five: Open Seas and Closed Minds
Chapter Six: Anything is Good that Don't Poison You
PART THREE: Racing for the Pole
Chapter Seven: Three Faces of Ambition
Chapter Eight: Amateurs, Pros, and Cons
Chapter Nine: From Polar Larks to Canary-Watching
PART FOUR: The New Arctic
Chapter Ten: Albedo, Winds, and Other Culprits
Chapter Eleven: Animals: Changing the Guard
Chapter Twelve: Boom and Bust on the New Frontier
Chapter Thirteen: Who Owns the Arctic?
Chapter Fourteen: Global Predictions