Popular Science Monthly/Volume 46/November 1894/The Glaciers of Greenland
|THE GLACIERS OF GREENLAND.|
By Prof. ANGELO HEILPRIN.
THE traveler who skirts the coast of Greenland, and sufficiently far from it to permit Mm to look over the rugged cliffs which almost everywhere dip abruptly into the dark blue ocean, sees above these a long, undulating white crest, beyond which are only sky and conjecture. The white crest glistens awhile in the bright sunlight, elsewhere it disappears in the hazy mist which silently crawls over the landscape and shrouds it in a more or less permanent veil of obscurity. Between the cliffs and bluffs, whose crests rise well into the plane of respectable mountain height, soaring to three, four, and six thousand feet elevation, broad valleys open out to the sea, which here show a carpet of beautiful and inviting green, and elsewhere lie immobile beneath vast sheets of ice which have invaded them and remained possessors of the soil. In some places the ice sheets quite touch the sea, in others they mark a white line across the valley, which is at once the termination of the ice and of the vegetation which crawls up to it. These are the Greenland glaciers, whose tongues the eye readily unites with the interior ice crest, the snow parent to which they owe their birth.
In its fundamental construction a Greenland glacier is much like every other glacier; it neither agrees absolutely with nor differs essentially from the glaciers of the Alpine type. It is only in the matter of size that it can lay claim to special distinction. If the snows of Switzerland and Norway build up glaciers of possibly two, three, or four miles' width, those of Greenland are compacted into ice rivers of from two to five times this width, and exceptionally into streams with perhaps ten or even fifteen times the expanse. For full two hours we steamed abreast of the great Frederickshaab glacier (latitude 62°) and along the northeast contours of Melville Bay the eye failed to detect a break in the continuity of the ice wall for seemingly thirty miles or more. Where the eye follows a line of coast for any distance it is almost
sure to compass all the types of glaciers which belong to the land: the broad and lazy glacial plain, flattened out like a vast and continuous ice slide; the sharply pitched hanging glaciers, which, caterpillar-like, crawl down the steeper slopes at angles of twenty-five to thirty-five degrees; and the deeply fissured crevasse glaciers, whose forbidding aspect only too vividly recalls the wicked ice sheets of the Alps. These types are, however, but the expression of a common structure, modified by local conditions, and set into the particular mold which belongs to each particular region. To assume, as perhaps the greater number of geologists do, that the Greenland glaciers represent, both in their construction and workings, a distinct or individual type, is to do violence to truth.
In the many hours of silent contemplation of these vast ice sheets I often pondered the question of the possible thickness of the ice which was involved in their making. Agassiz's measurement of some eight hundred to a thousand feet in one or more of the Swiss glaciers conjured up visions of vast possibilities in the Greenland giants, yet nowhere could I satisfy myself that even that thickness which was measured in the Alps was to be found here. Perhaps in the far interior the ice may have that thickness and more, but on the tongue sheets and in their terminal walls we found no indications of it. Two or three hundred feet the ice certainly has, but how much more, if anything, I could not determine. Yet the majestic bergs which, flotilla-like, sail out from these slow-moving rivers of ice, and scatter themselves in hundreds and thousands over the blue mirror of the sea, rise in themselves full two hundred feet out of the water, and perhaps not less than seven or eight hundred feet of subaqueous anchorage gives to them that wonderful aspect of immobility which all who have seen it so much admire. Is the exact relation of the fallen berg to its parent still to be determined? Seemingly so, for it is certain that in perhaps by far the greater number of oases the height of the berg bears no distinct relation to the thickness
Surface of Verhoeff Glacier.
of the glacier of which it at one time formed a part. With my own eyes I saw but few bergs fall or being made, and these were all of insignificant dimensions. Like many of their larger sisters which undergo disruption, they lashed and foamed in the disturbed waters, rising serenely to no definite relation with the parent mass from which they parted.
The older accounts of travelers have invested the Greenland ice with a wicked sublimity particularly its own, which may be said to be in part an expression of the real terrors of the arctic regions, and in other part a mere fiction of the imagination. What in Nature could be more terrorizing than those impending bergs, fang-armed like the jaws of some antediluvian monster, and rising hundreds of feet in height, which have been made to do service in the annals of nearly all arctic navigators for a full century or more! Yet how many are there who have in fact seen these fantastic symbols of the north? In our two cruises among thousands of bergs of all conditions and sizes we saw only monuments of quiet and impressive beauty—nothing suggestive of near or immediate catastrophe. A berg would tumble here and there, another would groan under the weight of its own dismemberment, and others would, perhaps, be licking up the parts that the sea had torn from them; but whatever it was, the work was accomplished in a peaceable manner, with a seeming consciousness that it had no regret for the results. Nor, indeed, were the results of any magnitude. Travelers have graphically described the commotion in the waters produced by the fall of one of these vast ice mountains, of the cannon-like detonations which were sent out by the snapping of the ice. I should compare the sound more with that of not very intense or even distant thunder, and the agitation of the waters to the churning of a heavily plowing steamship. There are, however, times when the bergs appear in an angry mood. When the after-storm sends them forth from their havens of rest, shooting billowy foam over and through them it is then that they take on the mane of the lion. The surging waters open out in front of them like the parting in the path of a dolphin, and the bergs swing out triumphantly into the rocking sea. Vain and hopeless would then be the barring of the passage of the moving monster.
The glaciers of Greenland, like their children, have their quiet and angry moods. The flat ice sheets of the north, so firmly consolidated that for miles scarcely a trace of a crevasse is to be found, and whose inclination is such that over almost any part of them railroading could readily be made possible, typify the quiet phase of Nature—wholly different from that which is embodied in the structural form of the majority of the glaciers of the south and of those of Melville Bay, in which the crevasse character is so largely developed. The struggles of Janssen, Nördenskjold, Whymper, Peary, and Nansen would hardly be intelligible to those whose first efforts in glacial climbing were realized among the solid ice sheets of the north, whose only difficult points, as a rule, are to be found not very far from the ocean front of the ice sheet. With seemingly few exceptions all the larger Greenland glaciers are rifted at their terminal falls, but the rifting, as in all other glaciers, depends upon the slope of the bed, the extent of the ice, and the general compression or extension that it has undergone. In but few instances did we find the rifting so complete as to debar easy circumvention through zigzagging, and rarely did the crevasses have a greater vertical plunge than from thirty to forty feet, or a width exceeding ten or fifteen feet; indeed, by far the greater number were of insignificant depth and breadth, offering little difficulty in their passage to the mountaineer provided with a glacial axe.
Our first attempt to scale a Greenland glacier was made on one of the minor ice sheets debouching on the northern face of Sonntag Bay, in latitude 78°. We had with us a steel-shod Hudson Bay toboggan, on which we loaded some two hundred or two hundred and fifty pounds of traveling impedimenta, and which
Terminal Wall of Verhoeff Glacier.
we had hoped to be able to drag with us. We had selected this glacier because from our anchorage it presented to the eye an attractively gentle slope, which was apparently interrupted by but few crevasses, and a terminal ice wall of but insignificant height. Approach to the ice border soon showed, however, how erroneous had been our perspective. The ice wall, instead of being fifteen to twenty feet in height, as we had assumed, in reality rose to the respectable proportions of some sixty feet, over which arched a dome of graceful and even curve. In a few minutes some of our party had cut their way to the top, but it was made manifest that any attempt to draw our sledge over would only result in disaster to it, and we accordingly abandoned the enterprise. We repeated our efforts still the same night on a larger but more auspicious-looking glacier, and without difficulty, by climbing over the scanty lateral moraine, reached the middle of the ice. The surface, as in nearly all the Greenland glaciers, was almost entirely destitute of rock débris, the sparsely scattered bowlders which in a broken, zigzag line tottered over the flanks of the ice sheet scarcely revealing the structure of a moraine. Two miles in advance of us the ice was solid, with only knife-edge cracks to indicate where it had parted and to mark the positions of possible past crevasses. It fell easily from the center to
Looking Down into the Sun Glacier Fjord from the Ice Cap.
either side, describing that symmetrical dome which was apparent from the water front; seaward it descended with so gentle a slope that over long areas it appeared to the eye only horizontal, and elsewhere the gradient could not have exceeded five degrees. Over this surface the toboggan could be drawn without difficulty, and so few were the hummocks that guy-lines could readily be dispensed with. We were still in the cooler hours of night, or rather of the "day of night," and the sun had made but little impression upon the surface. Here and there the crisp, granular ice showed symptoms of early dissolution, and an occasional water pool marked progress to the gradually advancing hours of true day. A few foxes ventured near our tracks, and some crows winged their way landward, but these were all the signs of animal life that gave movement to the landscape. About two miles from the ice front a great pyramidal rock mountain or nunatak split the glacial stream, causing it to swell into gently rising waves and crests, which mounted terracelike one above the other, without, however, materially breaking the continuity of the surface. We found progression over this billowy surface slow and fatiguing; it was difficult to hold the toboggan in position, as the steel runners gained no purchase upon the adamant polish of the ice. It swayed from side to side, undulating like the fins of a fish, and keeping us in a constant state of adjustment. As the slope increased at an elevation of about fourteen hundred feet, crevasses gradually took the place of the fissure splits, and it was found advisable to make use of the rope. We tied ourselves together in single line, keeping about twelve feet apart. There were few crevasses of greater width than the length of our toboggan, and most of these were of insignificant depth, yet there was enough danger in them to warrant a sharp lookout. The snow bridges were particularly treacherous, and their presence was sometimes only made known through an unexpected plunge. Cautiously avoiding these so far as it was possible, and the numerous ugly holes which only too frequently interrupted our course, we finally reached the basin, eighteen hundred feet above the sea, out of which the glacier emerges. We had accomplished our mission; the great glacier lay all below us, and above were only the sky and the upper snow fields which tirelessly fade off to unite with the sky.
A pleasanter ice party than this one can hardly be conceived. With a temperature that was neither warm nor cold, and with just sufficient point in it to give to it that exhilarating quality which impels to work; with a lingering midnight sun sending its warm illumination through a seemingly endless rift of clouds and bergs; a mountain and ocean panorama of almost matchless grandeur around you; a solitude immeasurable and undefinable—these are the elements which united in an exercise to make it forever memorable.
A few days after this first experience we were called upon to do a piece of glacial work the memory of which, unfortunately, associates itself with one of those sad incidents of travel which are seemingly destined, from time to time, to break upon the rugged path of exploration. When all but ready to leave the icebound northern shores for the more hospitable havens of the south, whither we had hoped to convey, unbroken by disaster, the untarnished record of a most successful exploration, intelligence was brought to our quarters that a member of our party was missing. Mr. Verhoeff, mineralogist of the North Greenland party, had made a final excursion after new rock specimens, and from this search he never returned to meet his associates. It was to ascertain his fate that we were again summoned to those icy fields and domes whose first acquaintance we had but
Crossing a Greenland Glacier.
recently made. We suspected that our poor friend had attempted a traverse of one of the many glacial sheets which tumbled out into the sea and that disaster had overtaken him in his lonely tour. Accordingly, we instituted a close search over mountain top and valley, and day and night peered among the ice pinnacles for possible traces of the missing man. Our first search was made on the great glacier, since named the Sun Glacier, which cuts the eastern extremity of McCormick Bay, and parts the dry land which in the summer season bounds both the northern and southern shores. It was early in the evening of the 19th of August, when the elevation of the sun still marked about twenty degrees above the horizon, that we again entered the shadows of the same granite cliffs over which, only a few days before, we had so joyfully passed after our meeting with Mr. Peary on his return from his memorable journey. The scene had changed. The deep cañon, along which the eye could follow the long, lazy line of glacier for a distance of twelve to fifteen miles to its mother ice cap, looked bleak and forbidding; there was no longer that charm of the unknown about it which attracts when all Nature smiles with success. A dark cloud had settled over the landscape and for a time closed out its joys.
We approached the front wall of the glacier with caution and almost in silence, fearing lest any percussion might too hastily precipitate some of the tottering masses which were "calving" their way to sea as bergs. Like the snowy avalanches of the Alps, which are at times called to life by the clapping of the hands, so must these ice masses of the north be left to their own peaceful slumbers. Once overturned, there can be no forecasting of the commotion that might follow. A turn or two may end the scene, or it can be that it has hardly begun before the water is churned into foam.
Cutting our steps into the dome-shaped lateral margin of the glacier, we soon gained the surface, upon which walking was fairly easy and comfortable. An effort to reach the opposite side was frustrated by the numerous crevasses which cut into the median portion of the ice, and about which we were obliged to wander in a tortuous, zigzag line. Generally, however, we managed to keep on a united body, or where the fissures were of but insignificant width. For some distance the surface of the ice kept disagreeably hummocky, but after passing a feeding glacier it
Hanging Glacier of Herschel's island.
spread out in an almost horizontal glistening sheet, admirably adapted for sledging purposes and of necessity for pedestrianism. The crevasses became less and less numerous, and ultimately ceased altogether, so that a traverse could be made in any direction. A narrow, remarkably straight, and evenly defined medial moraine, more in the nature of a dirt band, with angular blocks scattered over it—so like the "archaic" illustrations which figure in the works of Forbes and Agassiz and in other old-fashioned books of geology—occupied the central axis, stretching off upward to the limit of vision. As in all the other Greenland glaciers which it was our pleasure to explore, there were no really large blocks in the moraines, and there was a complete or nearly-complete absence of glacial tables and pyramids. Here and there low mounds of gravel and stones heaped themselves up in beehive-like masses, such as have also been found on the surfaces of the glaciers of Alaska and Spitzbergen, and occasional impacts had also thrown the ice into deformed caps and rafts. There were no ice rivers worthy of the name, and such channels as still marked the courses of surface waters were of but insignificant extent.
Had our mission been different from what it really was we might have said that this glacial traveling was truly delightful. With all the beauty of the ice fields of Switzerland, and that charm of pedestrianism which an unexpected and varying change of scene carries with it, we had here the advantage of the
Glacier debouching on Plain.
many hours, the consciousness that a journey was not limited to any arbitrary separation of day from night. It was all day, albeit the sun shone for only a paltry few hours. For some time angry-looking clouds had been gathering about the blackened granite crests; the side canons poured out their fleecy hosts, and before long the wild spirits of the mountains swept demonlike across the valley of the glaciers. The few lazily falling flakes which for a half hour or so had portended evil were before long replaced by blinding sheets of snow, and for a long time, save in its elements. Nature ceased to exist. The landscape was completely blotted out from view. We were not prepared for this change, and the cold wind stung mercilessly wherever it caught an exposed surface. We muffled ourselves as best we could in our not over-generous garments, but yet it was not all solid fort. Fortunately, the storm was of only short duration, and in its wake the landscape rose resplendent in its new garb.
We had now penetrated up stream about five or six miles, and had ascended probably six hundred or seven hundred feet in that distance. At three o'clock in the morning we started upon our return. We had seen nothing, and no sound, save the echoes from the beetling cliff's of granite and trap, which here rose in impending masses two thousand five hundred or three thousand feet above us, responded to the oft-repeated shouts to which we gave utterance.
The general aspect and features of the Sun Glacier we found repeated in a still more gigantic ice sheet, the Verhoeff Glacier, which bore the final traces of our unfortunate associate and buried in its bosom the forlorn hope which carried our search for upward of seven days and nights over mountain, snow, and ice. This glacier measures two miles across its terminal wall, but in its middle course, where it is split by a giant nunatak rising hundreds of feet above the glistening sheet of ice, it expands to fully twice this width, and then recalls the broad mers de glace with which, as miniatures, we had become acquainted in the ice fields of Switzerland and Scandinavia. But here we have the flat united ice mass, with only a suggestion of crevasse to remind one that the ice is a moving body, tearing itself apart and then uniting; all appears firm and stationary, except small rills, which in serpentine courses cut shallow troughs into the surface and musically wend their way to lower levels, ultimately to join the sea. To the eye the main part of the glacier appeared almost absolutely horizontal, and probably it was the flattest of all the sheets that we examined. We were unable to determine the rate of motion, but doubtless it was exceedingly slow, perhaps averaging not more than twelve to fifteen inches in twenty-four hours. In the Sun Glacier we had determined a movement of some seven or eight inches in as many hours, but this was in a part of the glacier where the ice was badly cut by crevasses and in its more rapidly moving lower section. In some of the minor glaciers of the same region we could determine no motion at all, and possibly at that time they had come to an almost absolute standstill. While no detailed observations on the motion of the glaciers of northern Greenland have as yet been made, and therefore no safe deductions can be drawn from the fragmentary records that are now before us, it would appear, nevertheless, almost certain that the majority of the northern ice sheets are much slower in their motion than those of South and Central Greenland—a condition, indeed, that might have been inferred from the conditions of climate which govern the several regions.The Verhoeff Glacier presented one aspect in its existence
Remarkable Domed Glacier in Inglefield Gulf.
which was new in our experience. This was the wealth of vegetation upon which it trespassed and which in part took possession of the icy sea. The spot whence we mounted upon the ice, and where the lateral moraine was discharging its cargo of rock débris, was a true garden spot, luxuriant with its growth of grass, and smiling under its garniture of poppies, chickweed, potentillas, and gentians; butterflies flitted about in the bright sunshine, whose genial warmth recalled memories of a distant south. Where the great nunatak, rusty in its coat of lichen, threw off the main stream into two broadly diverging arms. the charms of glacial scenery were brought to their fullest height. There, in the midst of the ice, resplendent in the vigor of its own coloring, was a garden of grass, moss, and wild flowers—a veritable oasis in an ice wilderness. Fruitless would be the effort to depict the beauty of this scene, so wholly magical and weird did it present itself to the eye and mind. The long tufts of grass were twelve to sixteen inches in height, and all about were a wealth and profusion of flowers which would have done justice to the landscape of the full tropics.
Thus, in its quiet mood, does the Greenland glacier reveal itself in a form wholly different from that which the imagination paints it—so different, in fact, that one is tempted to ask. Does it conform to the conditions of existence which have made glaciers
Detached Fragments of Greenland Glacier. The Watch-Tower Berg.
elsewhere? It unmistakably does, and these conditions have shaped all the forms of glacier, from the tiniest to the largest, from the quietest to the most wicked, to which the region has given birth. Probably all the forms of glaciers that exist in the world are represented in Greenland, and none are found there which might be said to embody a type of structure that is unknown elsewhere. Such as they are, they are but the remains of far more extensive ice sheets which, at no very distant period back in time, plowed far into the ocean deep, shaped much of the contours of the existing land surface, and perhaps even carved a relief of mountain and valley. The traces of past glaciation are everywhere apparent on the barren or uncovered shores, and troughs or water channels, thousands of feet in depth, bight deep into the areas of continuous drift. How vast, manifestly, have been the changes which marked the landscape during and since the period of greatest ice! The period of recession seemingly still continues, but how far the results of this recession will extend can not be told.
The insignificant development of the ice cap, in its relation to the large glacial streams which radiate off from it, is so striking a peculiarity in some parts of Greenland as to have suggested the suspicion that many of the existing glaciers are merely relics of the great Ice age. Bessels, the accomplished scientist of the Polaris Expedition, indeed, gives voice to this feeling in explanation of the by no means insignificant glaciers of Herbert and Northumberland Islands, lying somewhat north of the seventy-seventh parallel of latitude, which descend from an ice cap of eighteen hundred to two thousand five hundred feet elevation. It did not appear to him probable, or even possible, that the comparatively feeble accumulation of snow which is found at this elevation could originate ice streams of the dimensions which are there found. The facts, however, show that there is no real basis for this interpretation. The snow covering of these islands belongs to themselves, and, feeble though it be, it is quite competent to explain the associated phenomena. Many of the "hanging glaciers" of Herbert Island, which descend over slopes of some thirty to thirty-five degrees, are so attenuated in their upper parts as to be almost extinguished before reaching the summer ice cap; yet basally they rapidly increase in dimensions, so that before they finally terminate they measure not less than forty to fifty feet in thickness. The slowly accumulating snows descend over the first-formed layers, whether by sliding or otherwise, and help to build up the base while they thin out the top. In all essential respects these hanging glaciers are identical in structure with the larger streams, and it is only in their narrow connection with the ice cap that they at all differ. I am indeed convinced that some of the minor glaciers have been formed without the assistance of any ice cap or of the accumulated snows of a névé basin; for such streams, which are seemingly not very numerous, the designation of ravine or couloir glaciers might, perhaps, be advantageously used.
Briefly recapitulated, the glacial phenomena of Greenland are the phenomena of all other glacial regions; they are not illustrative of new forces and involve no explanations that have not already been made familiar through the teachings of other countries.