Question of an Open Sea round the Poles—Upper and under Currents of the Ocean—Cause thereof—Habits of the Whale as bearing on the Question—Dr Kane’s Discovery of an Open Sea in the Far North—Notes on the Expedition—A Bear-Hunt.
It was long and very naturally supposed that the impenetrable ice of the arctic regions extended to, and, as it were, sealed up the pole. But from time to time philosophic observers of Nature’s laws began to hint their opinion that there is an open ocean around the pole; and of late years this opinion has all but been converted into a firm belief.
Maury remarks, that like air—like the body—the ocean must have a system of circulation for its waters. And an attentive study of the currents of the sea, and a close examination of the laws which govern the movements of the waters in their channels of circulation through the ocean, will lead us irresistibly to the conclusion that always, in summer and winter, there must be, somewhere within the arctic circle, a large body of open water.
There is an under-current setting from the Atlantic, northward through Davis’ Straits, into the Arctic Ocean, and a surface-current setting out.
The fact is proved beyond a doubt by the observations of arctic explorers, who have seen immense icebergs drifting rapidly northward against a strong current. This apparent anomaly could only be accounted for by the fact that a powerful undercurrent carried them northward; and as at least seven times more of these bergs must have been under than above water, we can easily understand how the under-current, acting on the larger mass of each berg, had power to carry it against the surface-current.
This under-current is warm, while the upper-current is cold. Now we know that according to Nature’s laws, heated water, like heated air, rises to the surface, and cold water sinks to the bottom. How, then, comes this warm current to be underneath the cold, as soundings have proved it to be? It is owing to the fact that the under-current is much salter, and therefore heavier (despite its warmth), than the surface-current; which latter, being mingled with the drainage and ice-masses of the arctic regions, is comparatively fresh, and therefore light as well as cold.
The hot and salt waters of the tropics are carried north by the Gulf Stream. There are here two counteracting agents at work. Heat inclines the Gulf Stream to rise; saltness inclines it to sink. During the first part of its journey, as we know, its great heat prevails over the other influence, and it flows as a surface-current. But, at a certain point in its northward route, it meets with the cold, brackish, ice-bearing currents that flow out of the arctic basin. Having lost much of its heat (though still possessing a great deal more than the arctic currents), the saltness of the Gulf Stream prevails; it dips below the polar waters, and thenceforth continues its course as an under-current, salt, and comparatively warm.
To state the matter briefly: The hot water, which ought to keep on the surface because of its heat, is sunk by its superabundant salt; and the cold water, which ought to sink because of its cold, is buoyed on the surface because of its want of salt.
Now arises the question—what becomes of the great quantity of salt that is thus being carried perpetually into the polar basin? Manifestly it must be carried out again by the surface-current, otherwise the polar basin would of necessity become a basin of salt. The under-current must, therefore, rise to the surface somewhere near the pole, with its temperature necessarily only a little, if at all, below the freezing-point—which, be it observed, is a warm temperature for such regions. Here, then, where the warm waters from the south rise to the surface, it is supposed this open Arctic Ocean must exist.
So much for theory. Now for facts that have been observed, and that tend, more or less, to corroborate this proposition of an open polar sea. The habits of the whale have gone far to prove it. The log-books of whalers have for many years been carefully examined and compared by scientific men. These investigations have led to the discovery “that the tropical regions of the ocean are to the ‘right’ whale as a sea of fire, through which he cannot pass, and into which he never enters.” It has also been ascertained that the same kind of whale which is found off the shores of Greenland, in Baffin’s Bay, etcetera, is found in the North Pacific, and about Behring’s Straits; and that the ‘right’ whale of the southern hemisphere is a different animal from that of the northern. How, then, came the Greenland whales to pass from the Greenland seas to the Pacific? Not by the Capes Horn or Good Hope; the “sea of fire” precluded that. Clearly there was ground here for concluding that they did so through the (supposed) open sea lying beyond, or rather within, the frozen ocean.
It is true the objection might be made, that the same kind of whale which exists in the North Pacific exists also in the North Atlantic, although they never cross over to see each other. But another discovery has met this objection.
It is the custom among whalers to have their harpoons marked with date and name of ship, and Dr Scoresby, in his work on arctic voyages mentions several instances of whales having been taken near Behring’s Straits, with harpoons in them bearing the stamp of ships that were known to cruise in the Greenland seas; and the dates on the harpoons were so recent as to preclude the supposition that the said whales had, after being struck, made a voyage round the capes above mentioned,—even were such a voyage possible to them. All this does not, indeed, absolutely prove the existence of an open arctic sea, but it does, we think, prove the existence of at least an occasionally open sea there, for it is well known that whales cannot travel such immense distances under ice.
But the most conclusive evidence that we have in regard to this subject is the fact, that one of the members of Dr Kane’s expedition, while in search of Sir John Franklin, did actually, on foot, reach what we have every reason to believe was this open sea; but not being able to get their ship into it, the party had no means of exploring it, or extending their investigations. The account of this discovery is so interesting, and withal so romantic, that we extract a few paragraphs relating to it from Kane’s work.
After spending the dreary winter in the ice-locked and unexplored channels beyond the head of Baffin’s Bay, Kane found his little ship still hopelessly beset in the month of June; he therefore resolved to send out a sledge-party under Morton, one of his best men, to explore the channel to the north of their position. After twelve days’ travelling they came to the base of the “Great Glacier,” where Morton left his party, and, in company with an Esquimaux named Hans, set out with a dog-sledge to prosecute the journey of exploration.
They walked on the sea-ice in a line parallel with the glacier, and proceeded twenty-eight miles that day, although the snow was knee-deep and soft. At the place where they encamped a crack enabled them to measure the ice. It was seven feet five inches thick! And this in June. We may mention here, in passing, that Dr Kane never got his vessel out of that frozen strait, which seems to be bound by perpetual ice. He and his party escaped with their lives; but the vessel that bore them thither is probably still embedded in that ice.
Next day Morton and Hans came to a region of icebergs, which had arrested a previous sledging-party of the same expedition. “These (icebergs) were generally very high, evidently newly separated from the glacier. Their surfaces were fresh and glassy, and not like those generally met with in Baffin’s Bay,—less worn, and bluer, and looking in all respects like the face of the Great Glacier. Many were rectangular, some of them regular squares, a quarter of a mile each way; others more than a mile long.”
To pass amidst these bergs was a matter of labour, difficulty, and danger. Sometimes the sides of them came so close together, that the men could scarcely squeeze between them, and they were obliged to search for other passages; in doing which, the variation of their compass confused them. At other times, “a tolerably wide passage would appear between two bergs, which they would gladly follow; then a narrower one; then no opening in front, but one to the side. Following that a little distance, a blank ice-cliff would close the way altogether, and they were forced to retrace their steps and begin again.”
Thus they puzzled their way through, “like a blind man in the streets of a strange city;” but more difficulties awaited them beyond. After advancing many miles they were arrested by broad rents in the ice, and were obliged to diverge frequently far out of their course, or to bridge the chasms over by cutting down the ice hummocks and filling them up with loose ice, until the dogs were able to haul the provision-sledge over.
Advancing thus for several days, and encamping on the snow at night, they at last came to a spot where the ice was dangerous. “It was weak and rotten, and the dogs began to tremble.” Proceeding at a brisk rate, they had got upon unsafe ice before they were aware of it. Their course was at the time nearly up the middle of the channel; but as soon as possible they turned, and by a backward circuit reached the shore. The dogs, as their fashion is, at first lay down and refused to proceed, trembling violently. The only way to induce the terrified, obstinate brutes to get on, was for Hans to go to a white-looking spot, where the ice was thicker, the soft stuff looking dark; then calling the dogs coaxingly by name, they would crawl to him on their bellies. So they retreated from place to place, until they reached the firm ice they had quitted. A half mile brought them to comparatively safe ice, a mile more to good ice again.
In the midst of this danger they had, during the liftings of the fog, sighted open water. Soon after they saw it plainly. So many long and dreary months had these men passed since they were gladdened by the sight of open water, that they could scarcely believe their eyes; and Morton declared, that but for the birds which were seen flying about it in great numbers, he would not have believed it.
They made for the land-ice as fast as possible, and quickly gained it; but the sea-ice had cracked off and sunk so much, that the land-ice presented a wall along the whole coast o............