The North Pole: Its Discovery in 1909 under the auspices of the Peary Arctic Club

by Robert E. Peary

These pressure ridges may be anywhere from a few feet to a few rods in height; they may be anywhere from a few rods to a quarter of a mile in width; the individual masses of ice of which they are composed may vary, respectively, from the size of a billiard ball to the size of a small house.

Going over these pressure ridges one must pick his trail as best he can, often hacking his way with pickaxes, encouraging the dogs by whip and voice to follow the leader, lifting the five-hundred-pound loaded sledges over hummocks and up acclivities whose difficulties sometimes seem likely to tear the muscles from one's shoulder-blades.

Between the pressure ridges are the old floes, more or less level. These floes, contrary to wide-spread and erroneous ideas, are not formed by direct freezing of the water of the Arctic Ocean. They are made up of great sheets of ice broken off from the glacial fringe of Grant Land and Greenland, and regions to the westward, which have drifted out into the polar sea. These fields of ice are anywhere from less than twenty to more than one hundred feet in thickness, and they are of all shapes and sizes. As a result of the constant movement of the ice during the brief summer, when great fields are detached from the glaciers and are driven hither and thither under the impulse of the wind and the tides—impinging against one another, splitting in two from the violence of contact with other large fields, crushing up the thinner ice between them, having their edges shattered and piled up into pressure ridges—the surface of the polar sea during the winter may be one of almost unimaginable unevenness and roughness.

At least nine-tenths of the surface of the polar sea between Cape Columbia and the Pole is made up of these floes. The other one-tenth, the ice between the floes, is formed by the direct freezing of the sea water each autumn and winter. This ice never exceeds eight or ten feet in thickness.

The weather conditions of the fall determine to a great extent the character of the ice surface of the polar sea during the following winter. If there have been continuous shoreward winds at the time when the increasing cold was gradually cementing the ice masses together, then the heavier ice will have been forced toward the shore; and the edges of the ice-fields farther out, where they come in contact, will have piled up into a series of pressure ridges, one beyond the other, which any one traveling northward from the land must go over, as one would go over a series of hills.

If, on the other hand, there has been little wind in the fall, when the surface of the polar sea was becoming cemented and frozen over, many of these great floes will have been separated from other floes of a like size and character, and there may be stretches of comparatively smooth, young, or new, ice between them. If, after the winter has set in, there should still be violent winds, much of this thinner ice may be crushed up by the movement of the heavier floes; but if the winter remains calm, this smoother ice may continue until the general breaking up in the following summer.

But the pressure ridges above described are not the worst feature of the arctic ice. Far more troublesome and dangerous are the "leads" (the whalers' term for lanes of open water), which are caused by the movement of the ice under the pressure of the wind and tides. These are the ever-present nightmare of the traveler over the frozen surface of the polar ocean—on the upward journey for fear that they may prevent further advance; on the return journey for fear they may cut him off from the land and life, leaving him to wander about and starve to death on the northern side. Their occurrence or non-occurrence is a thing impossible to prophesy or calculate. They open without warning immediately ahead of the traveler, following no apparent rule or law of action. They are the unknown quantity of the polar equation.

Sometimes these leads are mere cracks running through old floes in nearly a straight line. Sometimes they are zigzag lanes of water just wide enough to be impossible to cross. Sometimes they are rivers of open water from half a mile to two miles in width, stretching east and west farther than the eye can see.

There are various ways of crossing the leads. One can go to the right or the left, with the idea of finding some place where the opposite edges of the ice are near enough together so that our long sledges can be bridged across. Or, if there are indications that the lead is closing, the traveler can wait until the ice comes quite together. If it is very cold, one may wait until the ice has formed thick enough to bear the loaded sledges going at full speed. Or, one may search for a cake of ice, or hack out a cake with pickaxes, which can be used as a ferry-boat on which to transport the sledges and teams across.

But all these means go for naught when the "big lead," which marks the edge of the continental shelf where it dips down into the Arctic Ocean, is in one of its tantrums, opening just wide enough to keep a continual zone of open water or impracticable young ice in the center, as occurred on our upward journey of 1906 and the never-to-be-forgotten return journey of that expedition, when this lead nearly cut us off forever from life itself.