The most abundant source of icebergs known in the arctic regions is Baffin’s Bay. From this remarkable sea they constantly make their way towards the south, down Davis’s Strait, and are scattered abroad in the Atlantic to an amazing extent. The banks of Newfoundland are occasionally crowded with these wonderful productions of the frigid zone; beyond which they are sometimes conveyed, by the operation of the southerly under-current, as low as latitude 40° north, and even lower, a distance of at least two thousand miles from the place of their origin.
Icebergs commonly float on a base which is larger in extent than the upper surface. Hence the proportion of ice appearing above water is seldom less in elevation than one-seventh of the whole thickness; and when the summit is conical, the elevation above water is frequently one-fourth of the whole depth of the berg. Perhaps the most general form of icebergs is with one high perpendicular side, the opposite side very low, and the intermediate surface forming a gradual slope. When of such a form, captain Ross found that the higher end was generally to windward. Some icebergs have regular flat surfaces, but most usually they have different acute summits, and occasionally exhibit the most fantastic shapes. Some have been seen that were completely perforated, or containing prodigious caverns, or having many clefts or cracks in the most elevated parts, so as to give the appearance of several distinct spires. On some icebergs, where there are hollows, a great quantity of snow accumulates; others are smooth and naked. The naked sides are often filled with conchoidal excavations, of various magnitudes; sometimes with hollows the size of the finger, and as regular as if formed by art. On some bergs, pools of water occur stagnant; on others, large streams are seen oozing through crevices into the sea. In a high sea, the waves break against them as against a rock; and, in calm weather, where there is a swell, the noise made by their rising and falling is tremendous. When icebergs are aground, or when there is a superficial current running to leeward, the motion of other ice past them is so great that they appear to be moving to windward. Fields of ice, of considerable thickness, meeting a berg under such circumstances, are sometimes completely ripped up and divided through the middle. Icebergs, when acted on by the sun, or by a temperate atmosphere, become hollow and fragile. Large pieces are then liable to be broken off, and fall into the sea with a terrible crash, which, in some places, produces an echo in the neighbouring mountains. When this circumstance, called calving, takes place, the iceberg loses its equilibrium, sometimes turns on one side, and is occasionally inverted. The sea is thereby put into commotion, fields of ice in the vicinity are broken up, the waves extend, and the noise is heard to the distance of several miles; and sometimes the rolling motion of the berg not ceasing, other pieces get loosened and detached, till the whole mass falls asunder like a wreck.
Icebergs differ a little in colour according to their solidity and distance, or state of the atmosphere. A very general appearance is that of cliffs of chalk, or of white or grey marble. The sun’s rays reflected from them sometimes give a glistening appearance to their surfaces. Different shades of colour occur in the precipitous parts, accordingly as the ice is more or less solid, and accordingly as it contains strata of earth, gravel, or sand, or is free from any impurity. In the fresh fracture, greenish grey, approaching to emerald green, is the prevailing colour. In the night, icebergs are readily distinguished, even at a distance, by their natural effulgence; and in foggy weather, by a peculiar blackness in the atmosphere, by which the danger to the navigator is diminished. As, however, they occur far from land, and often in unexpected situations, navigators require to be always on the watch for them. Though often dangerous neighbours, they have occasionally proved useful auxiliaries to the whale-fishers. Their situation in a smooth sea is very little affected by the wind; under the strongest gale they are not perceptibly moved, but, on the contrary, have the appearance of advancing to windward, because every other description of ice moves rapidly past them. From the iceberg’s firmness, it often affords a stable mooring to the ship in strong adverse winds, and the fisher likewise avails himself of it when his object is to gain a windward situation more open. He moors under the lee of the iceberg, loose ice soon forces past, the ship remains nearly stationary, and the wished-for effect seldom fails to result. Vessels have, however, often been staved, and sometimes wrecked, by the fall of their icy mooring; while smaller objects, such as boats, have been repeatedly overwhelmed, even at a considerable distance, by the vast waves occasioned by such events.
All ice becomes exceedingly fragile towards the close of the whale-fishing season, when the temperate air thaws its surface, and changes its solid structure into a brittle mass of imperfectly attached columns. Bergs in this state being struck by an axe, for the purpose of placing a mooring anchor, have been known to rend asunder, and precipitate the careless seaman into the yawning chasm; whilst, occasionally, the masses are hurled apart, and fall in contrary directions with a prodigious crash, burying boats and men in one common ruin. The awful effect produced by a solid mass, many thousands, or even millions, of tons in weight, changing its situation with the velocity of a falling body, whereby its aspiring summit is in a moment buried in the ocean, can be more easily imagined than described. Though a blow with an edge-tool on brittle ice does not sever the mass, still it is often succeeded by a crackling noise, proving the mass to be ready to burst from the force of internal expansion, or from the destruction of its texture by a warm temperature. It is common, when ships moor to icebergs, to lie as remote from them as their ropes will allow, and yet accidents sometimes happen, though the ship ride at the distance of a hundred yards from the ice. In the year 1812, while the Thomas, of Hull, captain Taylor, lay moored to an iceberg in Davis’s Strait, a calf was detached from beneath, and rose with such tremendous force, that the keel of the ship was lifted on a level with water at the bow, and the stern was nearly immersed beneath the surface. Fortunately, the blow was received on the keel, and the ship was not materially damaged.
From the deep pools of water found in the summer season on the depressed surface of some bergs, or from streams running down their sides, the ships navigating where they abound are presented with opportunities for watering with the greatest ease and dispatch. For this purpose, casks are landed upon the lower bergs, filled, and rolled into the sea; but, from the higher, the water is conveyed by means of a long tube of canvas, or leather, called a hose, into casks placed in the boats, at the side of the ice, or even upon the deck of the ship.
The greater part of the icebergs that occur in Davis’s Strait, and on the eastern coast of North America, notwithstanding their profusion and immense magnitude, seem to be merely fragments of the land icebergs, or glaciers, which exist in great numbers on the coast forming the boundaries of Baffin’s Bay. These glaciers fill immense valleys, and extend, in some places, several miles into the sea; in others, they terminate with a precipitous edge at the general line formed by the coast. In the summer season, when they are particularly fragile, the force of cohesion is often overcome by the weight of the prodigious masses that overhang the sea; and, in winter, the same effect may be produced by the powerful expansion of the water filling any excavation, or deep-seated cavity, when its dimensions are enlarged by freezing, thereby exerting a tremendous force, and bursting the berg asunder. Pieces thus, or otherwise, detached, are hurled into the sea with a dreadful crash. When they fall into sufficiently deep water, they are liable to be drifted off the land, and down Davis’s Strait, according to the set of the current; but, if they fall into a shallow sea, they must remain until sufficiently wasted to float away.
Spitzbergen is possessed of every character which is supposed to be necessary for the formation of the largest icebergs; high mountains, deep extensive valleys, intense frost, occasional thaws, and great falls of sleet and snow; yet here a berg is rarely met with, and the largest that occur are not to be compared with the productions of Baffin’s Bay. The reason of the difference between Spitzbergen and Old Greenland as to the production of icebergs is, perhaps, this—that, while the sea is generally deep, and the coast almost continually sheltered by drift-ice at the foot of the glaciers, in Baffin’s Bay; in Spitzbergen, on the contrary, they usually terminate at the water’s edge, or where the sea is shallow, so that no very large mass, if dislodged, can float away, and they are, at the same time, so much exposed to heavy swells, as to occasion dismemberments too frequently to admit of their attaining considerable magnitude.
That extensive body of ice which, with occasional tracts of land, occupies the northern extremity of the earth, and prevents all access to the regions immediately surrounding the Pole, fills, it appears, on an average, a circle of above two thousand geographical miles diameter, and presents an outline which, though subject to partial variations, is found at the same season of each succeeding year to be generally similar, and often strikingly uniform. The most remarkable alteration in the configuration of the Polar ice on record, is that said to have taken place between Iceland and Greenland, in the beginning of the fifteenth century, whereby the intercourse between the Icelanders and the colonies in Greenland was interrupted; and, although many attempts have been made on the part of Denmark for the recovery of these colonies, and for ascertaining the fate of the colonists, they have not yet succeeded. In various countries, changes of climate, to a certain extent, have occurred within the limits of historical record; these changes have been commonly for the better, and have been considered as the effects of human industry, in draining marshes and lakes, felling woods, and cultivating the earth; but here is an occurrence which, if it be indeed true, is the reverse of common experience, and concerning the causes of which it is not easy to offer any conjecture.
With each recurring spring, the north Polar ice presents the following general outline. Filling the Bays of Hudson and Baffin, as well as the Straits of Hudson, and part of that of Davis, it exhibits an irregular, waving, but generally continuous line, from Newfoundland or Labrador to Nova Zembla. From Newfoundland it extends in a northerly direction along the Labrador shore, generally preventing all access to the land, as high as the mouth of Hudson’s Strait; then, turning to the north-eastward, forms a bay near the coast of Greenland, in latitude perhaps 66° or 67°, by suddenly passing away to the southward to the extremity of Greenland. The quantity of ice on the east side of Davis’s Strait being often small, the continuity of its border is liable to be broken, so as to admit of ships reaching the land; and sometimes the bay of the ice, usually occurring in the spring, in latitude 66° or 67°, does not exist, but the sea is open up the strait to a considerable distance beyond it. After doubling the southern promontory, or Cape Farewell, it advances in a north-eastern direction along the east coast, sometimes enveloping Iceland as it proceeds, until it reaches the Island of Jan Mayen. Passing this island on the north-west, but frequently inclosing it, the edge of the ice then trends a little more to the eastward, and usually intersects the meridian of London between the 71st and 73rd degree of latitude. Having reached the longitude of 5° or 6° east, in some instances as far as 8° or 10°, in the 73rd or 74th degree or north latitude, it joins a remarkable promontory, and suddenly stretches to the north, sometimes proceeding on a meridian to the latitude of 80°, at others forming a deep sinuosity, extending two or three degrees to the northward, and then south-easterly to Cherie Island, which, having passed, it assumes a more direct course a little to the southward of east, until it forms a junction with the Siberian or Nova Zemblan coast.
During the winter and spring months, the Polar ice seems closely to embrace the whole of the northern shores of Russia, to the eastward of Nova Zembla, and filling, in a great measure, Behring’s Strait and the sea to the northward of it, continues in contact with the Polar face of the American continent, following the line of the coast to the eastward, until it effects a junction with the ice in the Spitzbergen Sea, or in the great north-western bays of Hudson and Baffin, or is terminated by land yet undiscovered.