The following article, “ON THE TREMENDOUS CONCUSSIONS OF THE FIELDS OF ICE,” in the Arctic Sea, is extracted from Mr. Scoresby’s valuable Memoir on “Polar Ice” in the Wernerian Society’s Transactions.
“The occasional rapid motion of fields, with the strange effects produced on any opposing substance, exhibited by such bodies, is one of the most striking objects this country presents, and is certainly the most terrific. They not unfrequently acquire a rotatory movement, whereby their circumference attains a velocity of several miles per hour. A field, thus in motion, coming in contact with another at rest, or more especially with a contrary direction of movement, produces a dreadful shock. A body of more than ten thousand millions of tons in weight,[38] meeting with resistance, when in motion, the consequences may possibly be conceived!
“The weaker field is crushed with an awful noise: sometimes the destruction is mutual. Pieces of huge dimensions and weight are not unfrequently piled upon the top, to the height of twenty or thirty feet, whilst doubtless a proportionate quantity is depressed beneath. The view of those stupendous effects in safety, exhibits a picture sublimely grand, but where there is danger of being overwhelmed, terror and dismay must be the predominant feelings. The whale-fishers at all times require unremitting vigilance to secure their safety, but scarcely in any situation, so much as when navigating amidst those fields. In foggy weather they are particularly dangerous, as their motion cannot then be distinctly observed. It may easily be imagined, that the strongest ship can no more withstand the shock of the contact of two fields, than a sheet of paper can stop a musket ball. Numbers of vessels, since the establishment of the fishery, have been thus destroyed. Some have been thrown upon the ice; some have had their hulls completely torn open; and others have been buried beneath the heaped fragments of the ice.
“In the year 1804, I had a good opportunity of witnessing the effects produced by the lesser masses in motion. Passing between two fields of bay-ice, about a foot in thickness, they were observed rapidly to approach each other, and before our ship could pass the strait, they met, with a velocity of three or four miles per hour; the one overlaid the other, and presently covered many acres of surface. The ship proving an obstacle to the course of the ice, it squeezed up on both sides, shaking her in a dreadful manner, and producing a loud grinding, or lengthened and acute tremulous noise, accordingly as the degree of pressure was diminished or increased, until it had risen as high as the deck. After about two hours, the velocity was diminished to a state of rest; and, soon afterwards, the two sheets of ice receded from each other nearly as rapidly as they had before advanced. The ship, in this case, did not receive any injury; but had the ice been only half a foot thicker, she would probably have been wrecked.
“In the month of May of the present year (1813) I witnessed a more tremendous scene. Whilst navigating amidst the most ponderous ice which the Greenland seas present, in the prospect of making our escape from a state of besetment, our progress was unexpectedly arrested by an isthmus of ice, about a mile in breadth, formed by the coalition of the point of an immense field on the north, with that of an aggregation of floes on the south. To the north field we moored the ship, in the hope of the ice separating in this place. I then quitted the ship, and travelled over the ice to the point of collision, to observe the state of the bar which now prevented our release. I immediately discovered that the two points had but recently met; that already a prodigious mass of rubbish had been squeezed upon the top, and that the motion had not abated. The fields continued to overlay each other with a majestic motion, producing a noise resembling that of complicated machinery, or distant thunder. The pressure was so immense, that numerous fissures were occasioned, and the ice repeatedly rent beneath my feet. In one of the fissures, I found the snow on the level to be three and a half feet deep, and the ice upwards of twelve. In one place, hummocks had been thrown up to the height of twenty feet from the surface of the field, and at least twenty-five feet from the level of the water; they extended fifty or sixty yards in length, and fifteen in breadth, forming a mass of about two thousand tons in weight. The majestic unvaried movement of the ice—the singular noise with which it was accompanied—the tremendous power exerted—and the wonderful effects produced—were calculated to excite sensations of novelty and grandeur, in the mind of even the most careless Spectator!
“Sometimes these motions of the ice may be accounted for. Fields are disturbed by currents—the wind—or the pressure of other ice against them. Though the set of the current be generally towards the south-west, yet it seems occasionally to vary; the wind forces all ice to leeward, with a velocity nearly in the inverse proportion to its depth under water; light ice consequently drives faster than heavy ice, and loose ice than fields: loose ice meeting the side of a field in its course, becomes deflected, and its re-action causes a circular motion of the field. Fields may approximate each other from three causes: First, If the lighter ice be to windward, it will, of necessity, be impelled towards the heavier; secondly, As the wind frequently commences blowing on the windward side of the ice, and continues several hours before it is felt a few miles distant to leeward, the field begins to drift before the wind can produce any impression on ice, on its opposite side; and, thirdly, Which is not an uncommon case, by the two fields being impelled towards each other, by winds acting on each from opposite quarters.
“The closing of heavy ice, encircling a quantity of bay ice, causes it to run together with such force, that it overlaps wherever two sheets meet, until it sometimes attains the thickness of many feet. Drift ice does not often coalesce with such a pressure as to endanger any ship which may happen to be beset in it: when, however, land opposes its drift, or the ship is a great distance immured amongst it, the pressure is sometimes alarming.”
No. VI.
On the approximation towards the Poles, and on the possibility of reaching the North Pole. From Mr. Scoresby’s paper in the Wernerian Society’s Transactions.
“We have already remarked, that the 80th degree of north latitude is almost annually accessible to the Greenland whale-fishers, and that this latitude, on particular occasions, has been exceeded. In one of the first attempts which appears to have been made to explore the circumpolar regions, in the year 1607, Henry Hudson penetrated the ice on the north-western coast of Spitzbergen to the latitude of 80° 23´ N. In 1773, Captain Phipps, in “a voyage towards the North Pole,” advanced, on a similar track, to 80° 37´ of north latitude. In the year 1806, the ship Resolution of Whitby, commanded by my father, (whose extraordinary perseverance and nautical ability are well appreciated by those in the Greenland trade, and proved by his never-failing success,) was forced, by astonishing efforts, through a vast body of ice, which commenced in the place of the usual barrier, but exceeded its general extent, by at least a hundred miles. We[39] then reached a navigable sea, and advanced without hindrance, to the latitude of 81½ north, a distance of only 170 leagues from the pole; which is, I imagine, one of the most extraordinary approximations yet realized.”