Drift ice

“ Generally an ice-field is traversed by long ridges of hummocks, often 40 to 50 feet high, brought about by the collision of two fields, the irresistible pressure causing them to rise up.
The term floe is applied to pieces which are from half a mile to a mile in diameter. Pieces smaller than a floe are called drift ice. When drift ice is so extensive that its limits cannot be seen, it is called a pack, when the pieces do not touch an open pack, when they are pressed together a close pack. A patch is a collection of drift ice, the limits of which are visible. ”

“ Drift-ice was constantly passed, but fortunately so scattered as not to form any obstruction to free navigation.
On the next day we enjoyed a superb Arctic summer's day, and began to fall in with the whaling fleet on the way north to Point Barrow. Fifteen vessels were sighted and passed, most of them vessels under sail. Rounding the dangerous Blossom shoals and the Icy cape of Captain Cook, we stood to the northeast, finding generally clear water, with scattered drift-ice. Upon the floes we found great quantities of walrus, in some cases stretched at full length, sound asleep. ”

“ Helpless as we were among the floating masses, we began to look upon the floe that carried us as a protecting barrier against the approaches of others less friendly; and as the month advanced, and the chances increased of our passing into the sound, our apprehensions of being frozen up in the heart of the ice-pack gave place to the opposite fear of a continuous drift. We had seen enough, and encountered enough of the angry strife among the ice-floes in the channel, to assure us of disaster if we should be forced to mingle in the sterner conflicts of the older ice-fields of the sound. ”

“ Land-ice often remains on the coasts even during summer, and in this case there is nothing to be done but to find the open navigable waters between the extreme edge of the fast-ice and the drift-ice. Should the drift become pack-ice, the moment must be awaited when winds setting in from the land carry off the masses of ice blocking the navigation, and open a passage free from ice, or at least only partially covered with drift-ice. It is evident that navigation in coast-waters must be slow and gradual, though it has always been attended with the greatest advantages. ”

“ A floe is a detached portion of a field; a large area of floes, closely compact together, is known as pack-ice; while drift-ice is loose ice in motion, and not so firmly welded as to prevent a ship from forcing her way through the yielding fragments.
IN AN ICE-PACK, MELVILLE BAY.
This “pack-ice,” however, is the great obstacle to Arctic exploration; and frequently it presents a barrier which no human enterprise or skill can overpass. At times, it has been found possible to cut a channel through it, or it breaks up and opens a water-way through which the bold adventurer steers. ”

“ We pass out of the belt of drift-ice and after a half hour’s duration are in a sea that is clear of ice.310 Looking back upon the belt we have just left, we notice that it appears like a white strip between sea and sky. Southwards through the hazy air we see Spitzbergen’s cliffs, and westwards we can just glimpse the coast of Northeastland and the ice which covers it. Straight ahead new masses of ice begin to appear on the horizon. Is it another belt of drift-ice, or is it the border of the polar ice? ”

“ Scraping by we found ourselves almost immediately afterwards surrounded by countless masses, differing greatly in size, most of them being loose drift-ice. Our stout ship, however, still continued her course, avoiding some masses and turning off other pieces from her well-protected bows. Every mile we advanced, the ice was becoming thicker. Still on we went, threading our way through the heaving masses. At length, above the ceaseless splashing sound, a roar increasing in loudness struck our ears. ”

“ This is important to remember, because, when we examine the drift in countries where the ice, during the glacier-period, overtopped nearly all the mountains, so that few fragments could fall from them upon its surface, we find scarcely any angular boulders, while the drift is interspersed with larger fragments of this character, carried under the ice, instead of on its back. Another distinction between water-worn deposits and drift consists in the fact that the former are washed clean, while the latter always retains the mud gathered during its journey and spread throughout its mass. ”

“ The strange openings in the water of a « 124 » few hours ago are now great rivers, lined by banks of hummocks, and wreathed in frost smoke. The continually increasing wind from the northward explains this southern drift of the ice, and with it these unwelcome openings. We are stationary, and the detached ice is leaving us. ”

“ All the winter the drifting pack changes—grows by freezing, thickens by rafting, and corrugates by pressure. If, finally, in its drift it impinges on a coast, such as the western shore of the Weddell Sea, terrific pressure is set up and an inferno of ice-blocks, ridges, and hedgerows results, extending possibly for 150 or 200 miles off shore. Sections of pressure ice may drift away subsequently and become embedded in new ice. ”

“ The opening, however, of this prospective strait is choked with heavy ice and, though we are eager to push landward and examine the coast carefully, the drift-ice forces us farther and farther away from the shore-line. In our over-anxious efforts to keep the coast in sight we have pushed into an area of ice which, for a time, shatters our new hopes. ”

“ The Rescue is driven out to sea, and poor Penny is probably to the southward. Five black masses, however, their cordage defined by rime and snow, are seen with their snouts shoved into the shore of ice: cables, chains, « 76 » and anchors are covered feet below the drift, and the ships adhere mysteriously, their tackle completely invisible. Should any of us break away, the gale would carry us into streams of heavy floating ice; and our running rigging is so coated with icicles as to make it impossible to work it. The thermometer stands at 14°. ”

“ Under these conditions, the climate which would have obtained in the area of the drift exposed during the minor retreat would have been cold, and oxidation, leaching, and disintegration would have proceeded slowly. If they reached considerable depths, the time involved must have been very long. If this surface of oxidized and leached and disintegrated drift were found to reach far to the northward beneath the layer of newer and upper drift, it would indicate a great recession of the ice. ”

“ No work could be done. Blizzard and snow, snow and blizzard, sudden lulls and fierce returns. During the lulls we could see on the far horizon to the north-east bergs of all shapes and sizes driving along before the gale, and the sinister appearance of the swift-moving masses made us thankful indeed that, instead of battling with the storm amid the ice, we were required only to face the drift from the glaciers and the inland heights. The gusts might throw us off our feet, but at least we fell on solid ground and not on the rocking floes. ”

“ Those of greater bulk, taking the ground, offer a resistance against which the lesser masses can only strain and grind; but away out in the unfathomable depths of the Polar Sea there is no chance of the [Pg 192] ice ever grounding. It is always floating, and so always susceptible to the force of wind, tide, and current. Consequently it is always moving and feeling the pressure of the water below, of the grinding strain of the drift, and of the surface disturbances brought about by the constant displacement. ”

“ The motion of ice, influenced by winds, tides, and currents, keeps constantly abrading the shore-line. Any outward drift, of course, makes an irregular lane of water, which a single night converts into ice; the returning floes heap this in tables one over another; and the next outward set carries off the floes again, crowned with their new increment.
« 133 »
“The haze gathered around us about an hour after starting, and the hummocks were so covered with snow that the chasms often received us middle deep. We walked five hours and a half, making in all but eleven miles ”

“ The wind roared over the snow floes, and every thing about the vessel froze into heavy ice stalactites. Had the main floe parted, we had been carried down with the liberated ice. Fortunately, every thing held; and here we are, safe and sound. The Rescue was last seen beating to windward against the gale, probably seeking a lee under Griffith’s Island. This morning the snow continues in the form of a fine cutting drift, the water freezes wherever it touches, and the thermometer has been at no time above 17°.
“September 12, 10 P.M. Just from deck. How very dismal every thing seems! ”

“ Insulation inside and out is the subject we are now attacking.
The young ice is going to and fro, but the sea refuses to freeze over so far—except in the region of Pram Point, where a bay has remained for some four days holding some pieces of Barrier in its grip. These pieces have come from the edge of the Barrier and some are crumbling already, showing a deep and rapid surface deposit of snow and therefore the probability that they are drifted sea ice not more than a year or two old, the depth of the drift being due to proximity to an old Barrier edge. ”

“ The ice around the Fram was now over thirty feet in thickness, and, as it was constantly moving in the drift, so was it also subject to the pressure which made it heave and pile itself in great rugged broken masses. There was a constant creaking and groaning in the vast pack which made it evident that the pressure had begun. Throughout the winter it would continue, getting more and more severe as the cold became more intense. ”

“ This heavy snow-drift exceeds any thing that I had conceived, although many of my Arctic English friends had discoursed to me eloquently about their perils and discomforts. As to facing it in a stationary position, nothing human could; for a man would be buried in ten minutes. Even in reaching our little Tusculum, we tumble up to our middle, in places where a few minutes before the very ice was laid bare. The entire topography of our ice is changing constantly.
“7 P.M. ‘The wind is howling.’ Our mess begin to talk again of sleeping in boots, and the other luxuries of Lancaster Sound. ”

“ But before it can be admitted that the drift-phenomena, and the polished and engraved surfaces with which they are everywhere intimately associated, are owing to floating ice or icebergs, it must be shown that all these appearances have been produced by some agency moving from the sea-board towards the land, and extending up to the very summits of the mountains, or else that all the countries exhibiting glacial phenomena have been sunk below the ocean to the greatest height at which glacier-marks are found, and have since gradually emerged to their present level. ”

“ Wear of drift in transit.—Drift carried at the bottom of the ice is subject to notable wear. The materials in transportation abrade one another and are abraded by the bed over which they pass. Englacial drift is subject to less wear because it is commonly more scattered. Superglacial drift is worn little or none while it lies on the surface of the ice; but in so far as superglacial or englacial drift is derived from the basal load, it may show the same evidences of wear as the basal drift itself. ”

“ But that the queer life we are leading—a life of constant exposure and excitement, and one that seems more like the ‘roughing it’ of a land party than the life of shipboard—has inured us to the eccentric fancies of the ice, our position would be a sleepless one.
“September 4, 2 A.M. Was awakened by Captain De Haven to look at the ice: an impressive sight. We were fast with three anchors to the main floe; and now, though the wind was still from the northward, and therefore in opposition to the drift, the floating masses under the action of the tide came with a westward trend directly past us. ”

“ If, therefore, beneath the newer drift of any given locality there be found a lower drift, the surface of which is oxidized and leached to a considerable depth, the evidence is strong that the lower drift was exposed for a long period of time before the upper drift was deposited upon it. Within certain limits a similar result might be brought about, it is true, if the ice, after having reached a certain maximum stage of advance, were to retreat for a short distance only and there remain for a very long period of time. ”

“ The effect of constant abrasion upon the snow's surface is to harden it, and, finally, to carve ridges known as sastrugi. Of these much will be said when recounting our sledging adventures, because they increase so much the difficulties of travelling.
Even hard, blue ice may become channelled and pitted by the action of drift. Again, both neve and ice may receive a wind-polish which makes them very slippery. ”

“ This would explain what we have often noticed, a northerly drift with a westerly wind. But even with our checked progress we seem to move eastward too quickly for such a condition of things. The next probability seems to explain better our actual experience. The second explanation is, that the easterly drift of the ice is only checked by a few widely separated islands through which the pack is forced into the Weddell sea by the prevailing wind. When the sun returns, and the ice loosens its grasp on our bark, we hope to clear up this mystery. ”

“ According to the Admiralty chart, this plants us high and dry among the mountains of Cape Walsingham.
“It is evident that our rate of drift has increased. The northwest winds carried us forward eight miles a day while near the strait—a speed only equaled in a few of the early days of our escape from Lancaster Sound. What has become of all the ice that used to be intervening between us and the shore? At one time we had a distance of ninety miles: we are now close upon the coast. ”