Littell's Living Age/Volume 131/Issue 1696/The Sea of Ancient Ice

From Wikisource
Jump to navigation Jump to search

From The Academy.

THE SEA OF ANCIENT ICE.

One of the very interesting subjects of investigation connected with the discoveries of the Arctic Expedition is that relating to the ancient ice met with north of Robeson Channel, which is similar to that described in Admiral Sherard Osborn's "Discovery of a North-West Passage." We used to call this ancient formation "M'Clure's ice," for want of a better name, but a special name is much needed to obviate confusion, and to distinguish this ice from ordinary old pack. The name palaeocrystic was adopted by the officers at the time; but for present purposes I will use the expression "the sea of ancient ice." By ancient I mean the ice many years old of the area about to be defined, as distinguished from the old pack-ice met with in any other sea.

It now appears that this sea of ancient ice is of much greater extent than was supposed by Admiral Sherard Osborn. We know that it extends from near the coast of North America to the northwest extremity of Prince Patrick Island, a distance of 420 miles. There is then an unknown gap of about 420 miles from Prince Patrick Island to Aldrich's furthest, which is probably occupied by islands and coastline. Thirdly, there is the coast-line discovered by Captain Nares, extending over about 300 miles from Aldrich's to Beaumont's furthest. We thus have a line extending from the American coast to Beaumont's furthest, in a north-east and south-west direction, for a distance of 1,140 miles, upon which this ancient ice rests.

The sea of ancient ice was first seen by Captain M'Clure when, on August 19, 1850, the "Investigator" ran into apparently open water off the mouth of the Mackenzie River in a north-eastern direction. But it was soon discovered that they were running into a trap in the main pack, consisting of ice of stupendous thickness, the surface rugged with the frosts and thaws of centuries, and totally unlike any ice ever met with in Baffin's Bay and adjacent seas. They ran up the blind lead in this dangerous ice for ninety miles; but, fortunately, the ship was put about in time, and escaped before the ice closed. There were no two opinions in the ship as to what would have been her fate if the floes had closed upon her.

In August, 1851, the "Investigator" passed along the west coast of Banks Island, and Captain M'Clure again had opportunities of examining the sea of ancient ice. The pack was of the same fearful description as that encountered in the offing of the Mackenzie River, at least eighty feet thick. The surface of the floes resembled rolling hills, some of them 100 feet from base to summit; and the edge of this wonderful oceanic ice rose in places from the water as high as the "Investigator's" lower yards.

Captain Collinson, in the "Enterprise," also passed along the southern flank of the sea of ancient ice, and his description agrees with that of his second in command. In the spring of 1854, when wintering at Camden Bay on the coast of North America, Captain Collinson made an attempt to travel over it with a sledge. He came upon it at a distance of about seven miles from the ship, but he found it to be of such a character as to render all travelling impracticable. His sledge was broken, one of the men fractured his thigh, and he was obliged to return after a few days. McClintock and Mecham found the same ancient ice along the west coast of Prince Patrick Island. Mecham terms this ice "tremendous;" and no one who has travelled elsewhere in the Arctic regions has ever met with similar oceanic ice. Along the coast discovered by Captain Nares the same ice was met with, not as a narrow belt along the shore, but becoming worse and more formidable to seaward, and composing the whole surface of this palaeocrystic sea.

The officers of the "Alert" had longer and better opportunities of carefully examining this most important phenomenon in physical geography than had ever been afforded to previous explorers, and their observations on this point form not the least valuable part of the results of the expedition. The ice was from eighty to one hundred and fifty feet in thickness, judging from the height of the portion above water; and the surface was rugged in the extreme. Apart from the masses of hummocks thrown up during disruptions, the surfaces of some of these ancient floes were broken into hills and dales, the hills varying from ten to fifty feet in height. This, of course, must be the result of ages of drift, and of alternate frost and thaw. The floes far out to sea were infinitely heavier than those nearer the coast. The formation of this palaeocrystic sea is analogous to the well-known course of formation of glaciers. Year by year layer after layer is added to the upper surface, the lower layers becoming harder, owing to the superincumbent weight, until they are converted into snow-ice. The method of this formation was studied by means of the huge masses, well-termed floe-bergs, which were cast upon the beach. Some of these were split by the frost, offering complete sections, which were carefully drawn. In some instances they showed lines of darker color, at distances of many feet from the existing surface, indicating sections of the pools of water and intermediate rises which, during some far-distant summer, had been on the surface.

Such a sea as this is never navigable, but there was the clearest evidence of frequent, if not annual, disruptions. The vast masses of hummocks, thirty to fifty feet high, and sometimes a quarter of a mile wide, which occur at frequent intervals and divide the ancient floes, are evidence of very violent encounters between the floes; and mud found on the ice some miles from the shore is also a proof of movement. The ice traversed by Captain Markham consisted of ancient floes of small extent and very uneven surface, separated by lofty ranges of rugged hummocks, and there were occasionally narrow streams of this year's ice, that is about five feet four inches thick, connecting the floes. The drift-wood which was found on Prince Patrick and Banks Island, and also on the scene of Captain Nares's discoveries, is likewise a proof that the palaeocrystic sea is subjected to movements the exact nature of which is uncertain; for this drift-wood must have come from the banks of Siberian, rivers.

At the same time the periodical disruption is clearly only partial; and the movement of a particular floe is but slight during one season. For there is no sufficient outlet, apparently, for the ice of this sea. The age of the ice is a sufficient proof of this. Sherard Osborn describes the sea of ancient ice as "a vast floating glacierlike mass, surging to and fro in an enclosed area of the Arctic region." It is bounded on the south by the shores of North America; on the east by Banks and Prince Patrick Islands, Grant Land, and the north coast of Greenland; and on the west by Kellett Land and other unknown obstacles north of the Siberian coast; so that it has an area of about one thousand two hundred miles both from south to north, and from east to west Its movement is slight, and the "Enterprise" and "Investigator" observed that it never moved off from the shore more than a mile or two, and then surged back again. The known outlets to the sea of ancient ice are very narrow. Fragments, forming great ice-streams, pour through Banks Strait into Melville Sound, but they never get west of Griffith Island, and are never seen in Barrow Strait. They appear to fill up McClintock Channel, which can never be navigable. Here Osborn saw them in May, 1851, and he describes the floe as of great antiquity, and as like a heavy cross sea suddenly frozen solid, the height of the solid waves being twenty-five feet. Allen Young reached Osborn's point of observation, and formed the same conclusion. He actually attempted, like Collinson, to travel across this palaeocrystic floe, but found it quite impracticable owing to the rugged nature of the ice.

Thus two explorers had attempted to tackle the ancient ice before the memorable journey of Captain Markham — namely, Sir Richard Collinson and Captain Allen Young, and they can well appreciate Captain Markham's difficulties, and the severity of the struggle he entered upon. There is another outlet for the sea of ancient ice by Robeson Channel, but it is very narrow, and the ancient and heavy floes do not get much further south than Lincoln's Bay in 82° N. Lat, or thereabouts, according to the season. The "Polaris" did not encounter them; but the "Alert" was at one time actually beset in ancient floes off Cape Lincoln, before rounding Cape Union, and was in great danger. Their size and position in the strait would vary according to the season. Fragments of the ancient ice, no doubt, stream down the south coast of Greenland and round Cape Farewell; and it would be a matter of great interest to explore the east coast from Cape Bismarck to Beaumont's furthest, in order to ascertain the limit of the sea of ancient ice in that direction, and the causes which obstruct a freer flow of the ice which now, from want of an adequate outlet, continues to grow in thickness and ruggedness.

It was over this sea that Markham and Parr attempted to force their way; and by dint of perseverance they and their gallant followers, in spite of such difficulties as no other advancing sledge-party (except those of Collinson and Allen Young) ever before encountered, achieved a position which will make their journey memorable forever. Considering the character of the ice, the distance they made good was, as Captain Nares truly says, marvellous. They advanced the Union Jack and their own standards to a point north of which no human being has ever put his foot. Clements R. Markham.