While Kerr and Christie were away, I assisted the camp hands in advancing to Blossom island. Our first day's work consisted in packing loads across the Hayden glacier to the wooded hills on its western border, reached during the reconnoissance described above. The weather was stormy, and a dense fog rolled in from the ocean, obscuring the mountains, and compelling us to find our way across the glacier as best we could without landmarks. Patiently threading our way among crevasses, we at length came in sight of the forests on the extremity of the mountain spur toward the west, and concluded to camp there until the weather was more favorable. We climbed the bare slope bordering the glacier, and forced our way through the dripping vegetation to an open space beside a little stream and near some aged spruce trees that would furnish good fuel for a camp-fire. We were glad of a refuge, but did not fully appreciate the fact that our tents were in a paradise of flowers until the next morning, when the sun shone clear and bright for a few hours. We hailed with delight the world of summer beauty with which we were surrounded. Our camp was in a little valley amid irregular hills of débris left by the former ice invasion, each of which was a rounded dome of flowers. The desolate ice-fields were completely shut out from view by the rank vegetation. On the slope above us, dark spruce trees loaded with streamers of moss, and seemingly many centuries old, formed a background for the floral decoration with which the ground was everywhere covered. Flowering plants and ferns were massed in such dense luxuriance that the streams were lost in gorgeous banks of bloom.
Reluctantly we returned to Floral pass for another load of camp supplies, and late in the afternoon pressed on to Blossom island, where we again pitched our tents in rain and mist, and again, when the storm cleared away, found ourselves in an untrodden paradise. Kerr and Christie rejoined us at Blossom island on July 31, and we were once more ready for an advance.
BLOSSOMISLAND.
BLOSSOMISLAND.
Our camp on Blossom island was near a small pond of water and close beside a thick grove of spruce trees on the western side of the land-mass. The tents were so placed as to secure an unobstructed view to the westward; and they were visible, in turn, to parties descending from the mountains toward the northwest, whither our work soon led us.
The sides of Blossom island are rough and precipitous. The glaciers flowing past it cut away the rocks and, as the surface of the ice-fields was lowered, left them in many places in rugged cliffs bare of vegetation. The top of the island was also formerly glaciated and in part covered with débris; but the ice retreated so long ago that the once desolate surface has become clothed in verdure. Everywhere there are dense growths of flowers, ferns and berry bushes. On the rocky spurs, thrifty spruce trees, festooned with drooping streamers, shelter luxuriant banks of mosses, lichens and ferns. There was no evidence that human hand had ever plucked a flower in that luxuriant garden; not a trace could be found of man's previous invasion. The only trails were those left by the bears in forcing their way through the dense vegetation in quest of succulent roots. Later in the season, when the berries ripened, there was a feast spread invitingly for all who chose to partake. On the warm summer days the air was filled with the perfume of the flowers, birds flitted in and out of the shady grove, and insects hummed in the glad sunlight; the freshness and beauty on every hand made this island seem a little Eden, preserved with all its freshness and fragrance from the destroying hand of man.
This oasis in a desert of ice is so beautiful and displays so many instructive and attractive features that I wish the reader to come with me up the flowery slopes and study the interesting pictures to be seen from its summit.
The narrow ravine back of our camp is festooned and overhung with tall ferns, shooting out from the thickets on either hand like bending plumes. You will notice at a glance, if perchance your youthful excursions happened to be in the northeastern states, as were mine, that many of the plants about us are old friends, or at least former acquaintances. The tall fern nodding so gracefully as we pass is anAsplenium, but of ranker growth than in most southern regions. These tall white flowers with aspiring, flat-topped umbels, looking like rank caraway plants, but larger and more showy, belong to the genusArchangelica, and are at home in the Cascade range and the Rocky Mountains as well as here. The lily-like plant growing so profusely, especially in the moist dells, with tall, slim spikes of greenish flowers and long parallel veined leaves, isVeratrum viride. These brilliant yellow monkey-flowers, bending so gracefully over the banks of the pond, are closely related to the littleMimuluswhich nods to its own golden reflection in many of the brooks of New England. That purpleEpilobrum, with now and then a pure white variety, so common everywhere on these hills, is the same wanderer that we have seen over many square miles beneath the burnt woods of Maine. These bushes with obscure white flowers, looking like little waxen bells, we recognize at once as huckleberries; in a short time they will be loaded with luscious fruit. Inviting couches of moss beneath the spruce trees are festooned and decorated with fairy shapes of brown and green, that recall many a long ramble among the Adirondack hills and in the Canadian woods. The licapods, equiseta and ferns are many of them identical with the tracery on mossy mounds covering fallen hemlocks in the Otsego woods in New York, but display greater luxuriance and fresher and more brilliant colors. That graceful little beach-fern, here and there faded to a rich brown, foretelling of future changes, is identical with the little fairy form we used to gather long ago along the borders of the Great Lakes. Asters and gentians, delicate orchids and purple lupines, besides many less familiar plants, crowd the hillsides and deck the unkept meadows with a brilliant mass of varied light. In the full sunshine, the hill-slopes appear as if the fields of petals clothing them had the prism's power, and were spreading a web of rainbow tints over the lush leaves and grasses below.
On our return to Blossom island, late in September, we found many of the flowers faded, but in their places there was a profusion of berries nearly as brilliant in color as the petals that heralded their coming. Many of the thickets, inconspicuous before, had then a deep, rich yellow tint, due to an abundance of luscious salmon berries, larger than our largest blackberries. The huckleberries were also ripe, and in wonderful profusion. These additions to our table were especially appreciated after living for more than a month in the snow. The ash trees were holding aloft great bunches of scarlet berries, even deeper and richer in color than the ripe leaves on the same brilliant branches. The deep woods were brilliant with the broad yellow leaves of the Devil's club, above which rose spikes of crimson berries. The dense thickets of currant bushes, so luxuriant that it was difficult to force one's way through them, had received a dusky, smoke-like tint, due to abundant blue-black strings of fruit suspended all along the under sides of the branches.
Let us not look too far ahead, however. Wandering on over the sunny slopes, where the gardener has forgotten to separate the colors or to divide the flower banks, we gain the top of the island; but so dense are the plants about us, and so eager is each painted cup to expand freely in the sunlight at the expense of its neighbors, that we have to beat them down with our alpenstocks—much as we dislike to mar the beauty of the place—before we can recline on the thick turf beneath and study the strange landscape before us.
The foreground of every view is a bank of flowers nodding and swaying in the wind, but all beyond is a frozen desert. The ice-fields before us, with their dark bands of débris, are a picture of desolation. The creative breath has touched only the garden which we, the first of wanderers, have invaded. The land before us is entirely without human associations. No battles have there been fought, no kings have ruled, no poets have sung of its ruggedness, and no philosopher has explained its secrets. Yet it has its history, its poetry, and its philosophy!
The mountains toward the north are too near at hand to reveal their grandeur; only the borders of the vast snow-fields covering all of these upper slopes are in view. In the deep cañon with perpendicular walls, just north of our station, but curving westward so that its upper course is concealed from view, there flows a secondary glacier which forces its terminal moraine high up on the northern slope of Blossom island, but does not now join the ice-field on the south. Streams of turbid water flow from this glacier on each side of the oasis on which we stand and unite at the mouth of a dark tunnel in the ice toward the south.
The barren gravel plain just east of our station, and at the foot of the glacier from the north, is the bed of a glacial lake which has been drained through the tunnel in the ice. On our way to Blossom island we crossed this area and found that it had but recently lost its waters. Miniature terraces on the gravel banks forming the sides of the basin marked the height to which the waters last rose, and all the slopes formerly submerged were covered with a thin layer of sediment. On the sides of the basin where this fresh lining rests on steep slopes there are beautiful frettings made by rills in the soft sediment. The stream from the glacier now meanders across this sand plain, dividing as it goes into many branches, which unite onapproaching the dark archway below. The lake is extremely irregular in its behavior, and may be filled and emptied several times in a season. The waters are either restrained or flow freely, according as the tunnel through which they discharge is obstructed or open. The lake is typical of a class. Similar basins may be found about many of the spurs projecting into the Malaspina glacier.
A little west of the glacier to which I have directed your attention there is a narrow mountain gorge occupied by another glacier, of small size but having all the principal characteristics of even the largest Alpine glaciers of the region. It is less than half a mile in length, has a high grade, and is fed by several lateral branches. Its surface is divided into an ice region below and a névé region above. It has lateral and medial moraines, ice pinnacles, crevasses, and many other details peculiar to glaciers. From its extremity, which is dark with dirt and stones, there flows a stream of turbid water. It is, in fact, a miniature similitude of the ice-streams on the neighboring mountain, some of which are forty or fifty miles in length and many times wider in their narrowest part than the little glacier before us is long. The more thoroughly we become acquainted with the mountains of southern Alaska the more interesting and more numerous do the Alpine glaciers of the third order become. Already, thousands could be enumerated.
I will not detain my imaginary companion longer with local details, but turn at once to the objects which will ever be the center of attraction to visitors who may chance to reach this remote island in the ice. Looking far up the Marvine glacier, beyond the tapering pinnacles and rugged peaks about its head, you will see spires and cathedral-like forms of the purest white projected against the northern sky. They recall at once the ecclesiastic architecture of the Old World; but instead of being dim and faded by time they seem built of immaculate marble. They have a grandeur and repose seen only in mountains of the first magnitude. The cathedral to the right, with the long roof-like crest and a tapering spire at its eastern terminus, is Mount Augusta; its elevation is over 13,000 feet. A little to the west, and equally beautiful but slightly less in elevation, is Mount Malaspina—a worthy monument to the unfortunate navigator whose name it bears. These peaks are on the main St. Elias range, but from our present point of view they form only thebackground of a magnificent picture. Later in the season our tents were pitched at their very bases, and they then revealed their full grandeur and fulfilled every promise given by distant views.
The rugged Hitchcock range bordering the distant margin of the Marvine glacier, like the mountains near at hand and the rocky island on which we stand, is composed of sandstone and shale, but presents one interesting feature, to which I shall direct your attention. The trend of the range is northeast and southwest, but the strata of which it is composed run east and west and are inclined northward. As the range is some eight miles long, these conditions would seem to indicate a thickness of many thousands of feet for the rocks of which it is composed; yet the beds were deposited in horizontal sheets of sand and mud of very late date, as will be shown farther on. But the great apparent thickness of the strata is deceptive: a nearer examination would reveal the fact that the rocks have been so greatly crushed that even a hand specimen can scarcely be broken off with fresh surfaces. More than this, the black shale, exhibiting the greatest amount of crushing, is usually in wedge-shaped masses, which, in some cases at least, are bordered by what are known as thrust planes, nearly coinciding with the bedding planes of the strata. The rocks have been fractured and crushed together in such a way as to pile fragments of the same layer on top of each other, and thus to increase greatly their apparent thickness. In the elevations before us the thrust planes are tipped northeastwardly, and it would seem that the force that produced them acted from that direction. The apparent thickness of the beds has thus been increased many times. What their original thickness was, it is not now possible to say. Similar indications of a lateral crushing in the rocks may be found in several of the mountain spurs between the Hitchcock range and Yakutat bay; but space will not permit me to follow this subject further.
Turning from the mountains, we direct our eyes seaward; but it is a sea of ice that meets our view and not the blue Pacific. Far as the eye can reach toward the west, toward the south, and toward the southeast there is nothing in view but a vast plateau of ice or barren débris fields resting on ice and concealing it from view. This is the Malaspina glacier.
On the border of the ice, just below the cliffs on which westand, there is a belt of débris perhaps five miles in breadth, which almost completely conceals the ice beneath. Portions of this moraine are covered by vegetation, and in places it is brilliant with flowers. The vegetation is most abundant on the nearer border and fades away toward the center of the glacier. Its distant border, adjacent to the white ice-field beyond, isabsolutely bare and desolate. An attempt has been made to reproduce this scene in the picture forming plate 16. The drawing is from a photograph and shows the barren débris field stretching away towards the southwest. The extreme southern end of the Hitchcock range appears at the right. In the distance is the white ice of the central part of the Malaspina glacier. Far beyond, faintly outlined against the sky, are the snow-covered hills west of Icy bay. The flowers in the foreground are growing on the crest of the steep bluff bordering Blossom island on the south.
Malaspina Glacier
Malaspina Glacier
On the moraine-covered portion, especially where plants have taken root, there are hundreds, perhaps thousands, of lakelets occupying kettle-shaped depressions. A view of one of these interesting reservoirs in the ice is given in figure 2. If we should go down to the glacier and examine such a lakelet near at hand, we should find that the cliffs of ice surrounding them are usually unsymmetrical, being especially steep and rugged on one side and low or perhaps wanting entirely on the other. But there is no regularity in this respect; the steep slopes may face in any direction. On bright days the encircling walls are always dripping with water produced by the melting of the ice; little rills are constantly flowing down their sides and plunging in miniature cataracts into the lake below; the stones at the top of the ice-cliffs, belonging to the general sheet of débris covering the glacier, are continually being undermined and precipitated into the water. A curious fact in reference to the walls of the lakelets is that the melting of the ice below the surface is more rapid than above, where it is exposed to the direct rays of the sun. As a result the depressions have the form of an hour-glass, as indicated in the accompanying section.
Beyond the bordering moraines at our feet, we can look far out over the ice-plateau and view hundreds of square miles of itsfrozen surface. At the same time we obtain glimpses of other vast ice-fields toward the west, beyond Icy bay; but their limits in that direction are unknown.
Later in the season I made an excursion far out on the Malaspina glacier from the extreme southern end of the Hitchcock range, and became acquainted with many of its peculiarities. Its surface, instead of being a smooth snow-field, as it appears from a distance, is roughened by thousands of crevasses, many of which are filled with clear, blue water. Over hundreds of square miles the surface appears as if a giant plow had passed over it, leaving the ice furrowed with crevasses. The crevasses are not broad; usually one can cross them at a bound. They appear to be the scars left by rents in the tributary ice-streams.
The stillness far out on the great ice-field is immediately noticed by one who has recently traversed the sloping surfaces of the tributary glaciers. It is always silent on that vast frozen plateau. There are no surface streams and no lakes; not a rill murmurs along its channel of ice; no cascades are formed by streams plunging into moulins and crevasses. The water produced by the melting of the ice finds its way down into the glacier and perhaps to its bottom, and must there form rivers of large size; but no indications of their existence can be obtained at the surface. The icy surface is undulating, and resembles in some respects the great rolling prairies of the west; it is a prairie of ice. In the central portion not a shoot of vegetation casts its shadow, and scarcely a fragment of rock can be found. The boundaries of the vast plateau have never been surveyed, but its area cannot be less than five hundred square miles. The clear ice of the center greatly exceeds the extent of the moraine-covered borders. It has a general elevation of fifteen or sixteen hundred feet, being highest near the end of the Hitchcock range, where the Seward glacier comes in, and decreasing from there in all directions. From the summit of Blossom island and other commanding stations it is evident that the dark moraine belts about its borders are compound and record a varied history. Far away toward the southeast the individual elements may be distinguished. The dark bands of débris sweep around in great curves and concentric, swirl-like figures, which indicate that there are complicated currents in the seemingly motionless plateau.
The Malaspina glacier belongs to a class of ice bodies notpreviously recognized, which are formed at the bases of mountains by the union of several glaciers from above. Their position suggests the name ofPiedmont glaciersfor the type. They differ from continental glaciers in the fact that they are formed by the union of ice-streams and are not the sources from which ice-streams flow. The supply from the tributary glacier is counterbalanced by melting and evaporation.
If the reader has become interested in the vast ice-fields about Blossom island, he may wish to continue our acquaintance and go with me into the great snow-fields on the higher mountains, where the ice-rivers feeding the Malaspina glacier have their sources.
LIFEABOVE THESNOW-LINE.
LIFEABOVE THESNOW-LINE.
Early on the morning of August 2, all necessary preparations having been made the day previous, we started in the direction of the great snow peak to be seen at the head of the Marvine glacier, where we hoped to find a pass leading through the mountains which would enable us to reach the foot of Mount St. Elias or to discover a practicable way across the main range into the unknown country toward the north.
All of the camp hands were with us at the start, except Stamy and White, who had been despatched to Port Mulgrave to purchase shoes. All but Crumback and Lindsley were to return to Blossom island, however, after leaving their loads at a rendezvous as far from Blossom island as could be reached in a day and allow sufficient time to return to the base-camp. Kerr and myself, with the two camp hands mentioned, were to press on to the snow-fields above. We took with us a tent, blankets, rations, an oil-stove, and a supply of coal oil, and felt equal to any emergency that might arise.
The morning of our departure was thick and foggy, with occasional showers, and the weather grew worse instead of better as we advanced. All the mountains were soon shut out from view by the vast vapor banks that settled down from above, and we had little except the general character of the glacier to guide us.
Our way at first led up the eastern border of the Marvine glacier, over seemingly interminable fields of angular débris. Traveling on the rugged moraine, some idea of which may be obtained from plate 17, was not only tiresome in the extreme, but ruinous to boots and shoes. On passing the mouth of thefirst lateral gorge (about a mile from Blossom island), from which flows a secondary glacier, we could look up the bed of the steep ravine to the white precipices beyond, which seemed to descend out of the clouds, and were scarred by avalanches; but all of the higher peaks were shrouded from view. At noon we passed the mouth of a second and larger gorge, which discharges an important tributary. We then left the border of the glacier and traveled up its center, the crevasses at the embouchures of the tributary stream being too numerous and too wide to be crossed without great difficulty.
Marvine Glacier
Marvine Glacier
In the center of the Marvine glacier there is a dark medial moraine, composed mainly of débris of gabbro and serpentine, of the same character as the medial moraine on the Hayden glacier, already briefly mentioned. Here, too, we found broad areas covered with sand cones and glacial tables. There are also rushing streams, flowing in channels of ice, which finally plunge into crevasses or in well-like moulins and send back a deep roar from the caverns beneath. The murmurs of running waters, heard on every hand, seem to indicate that the whole glacier is doomed to melt away in a single season.
Early in the afternoon we reached the junction of the two main branches of the Marvine glacier, and chose the most westerly. We were still traveling over hard blue ice in which the blue and white vein-structure characteristic of glaciers could be plainly distinguished. The borders of the ice-streams were dark with lateral moraines; but after passing the last great tributary coming in from the northeast we reached the upper limit of the glacier proper and came to the lower border of the névé fields, above which there is little surface débris. The glacier there flows over a rugged descent, and is greatly broken by its fall. At first we endeavored to find a passage up the center of the crevassed and pinnacled ice, but soon came to an impassable gulf. Turning toward the right, we traversed a ridge of ice between profound gorges and reached the base of the mountain slope bordering the glacier on the east. Our party was now divided; Christie and his companion were left searching for a convenient place to leave the cans of rations they carried, while we, who were to explore the regions above, were endeavoring to find a way up the ice-fall. A shout from our companions below called our attention to the fact that they were unable to reach the border of the glacier, where they had been directed to leave their packs, and that theyhad left them on the open ice. They waved us "good-bye" and started back toward Blossom island, leaving our little band of four to make the advance.
Descending into a deep black gorge at the border of the ice, formed by its melting back from the bordering cliffs, we clambered upward beneath overhanging ice-walls, from which stones and fragments of ice were occasionally dropping, and finally reached a great snow-bank on the border of the glacier. As the storm still continued, and was even increasing in force, we concluded to find a camping ground soon as possible and make ourselves comfortable as the circumstances would permit.
FIRSTCAMP IN THESNOW.
FIRSTCAMP IN THESNOW.
We had now reached the lower limit of perpetual snow. There were no more moraines on the surface of the glacier, and no bare rock surfaces large enough to hold a tent. The entire region was snow-mantled as far as the eye could see, except where pinnacles and cliffs too steep and rugged for the snow to accumulate rose above the general surface. A little to one side of the mouth of a steep lateral gorge we found a spot in which a mass of partly disintegrated shale had fallen down from the cliff. We scraped the fragments aside, smoothed the snow beneath, and built a wall of rock along the lower margin. The space above was filled in with fragments of shale, so as to form a shelf on which to pitch our tent. Soon our blankets were spread, with our water-proof coats for a substratum, and supper was prepared over the oil-stove.
Darkness settled down over the mountains, and the storm increased as the night came on. What is unusual in Alaska, the rain fell in torrents, as in the tropics. Our little tent of light cotton cloth afforded great protection, but the rain-drops beat on it with such force that the spray was driven through and made a fine rain within. Weary with many hours of hard traveling over moraines and across crevassed ice, and in an atmosphere saturated with moisture, we rolled ourselves in our blankets, determined to rest in spite of the storm that raged about.
As the rain became heavier, the avalanches, already alarmingly numerous, became more and more frequent: A crash like thunder, followed by the clatter of falling stones, told that many tons of ice and rocks on the mountains to the westward had sliddown upon the borders of the glacier; another roar near at hand, caused by an avalanche on our own side of the glacier, was followed by another, another, and still another out in the darkness, no one could tell where. The wilder the storm, the louder and more frequent became the thunder of the avalanches. It seemed as if pandemonium reigned on the mountains. One might fancy that the evil spirits of the hills had prepared for us a reception of their own liking—but decidedly not to the taste of their visitors. Soon there was a clatter and whiz of stones at our door. Looking out I saw rocks as large as one's head bounding past within a few feet of our tent. The stones on the mountain side above had been loosened by the rain, and it was evident that our perch was no longer tenable. Before we could remove our frail shelter to a place of greater safety, a falling rock struck the alpenstock to which the ridge-rope of our tent was fastened and carried it away. Our tent "went by the board," as a sailor would say, and we were left exposed to the pouring rain. Before we could gather up our blankets they were not only soaked, but a bushel or more of mud and stones from the bank above, previously held back by the tent, flowed in upon them. Rolling up our blankets and "caching" the rations, instruments, etc., under a rubber cloth held down by rocks, we hastily dragged our tent-cloth down to the border of the glacier, at the extremity of a tapering ridge, along which it seemed impossible for stones from above to travel. We there pitched our tent on the hard snow, without the luxury of even a few handfuls of shale beneath our blankets. Wet and cold, we sought to wear the night away as best we could, sleep being impossible. Crumback, who had been especially energetic in removing the tent, regardless of his own exposure, was wet and became cold and silent. The oil-stove and a few rations were brought from the cache at the abandoned camp, and soon a dish of coffee was steaming and filling the tent with its delicious odor. Our shelter became comfortably warm and the hot coffee, acting as a stimulant, restored our sluggish circulation. We passed an uncomfortable night and watched anxiously for the dawn. Toward morning a cold wind swept down the glacier and the rain ceased. With the dawn there came indications that the storm had passed, although we were still enveloped in dense clouds and could not decide whether or not a favorable change in the weather had occurred. We were still cold and wet and the desire to return to Blossomisland, where all was sunshine and summer, was great. Uncertain as to what would be the wisest course, we packed our blankets and started slowly down the mountain, looking anxiously for signs that the storm had really passed.
An hour after sunrise a rift in the mist above us revealed the wonderful blue of the heavens, and allowed a flood of sunlight to pour down upon the white fields beneath. Never was the August sun more welcome. The mists vanished before its magic touch, leaving here and there fleecy vapor-wreaths festooned along the mountain side; as the clouds disappeared, peak after peak came into view, and snow-domes and glaciers, never seen before, one by one revealed themselves to our astonished eyes. When the curtain was lifted we found ourselves in a new world, more wild and rugged than any we had yet beheld. There was not a tree in sight, and nothing to suggest green fields or flowery hill-sides, except on a few of the lower mountain spurs, where brilliant Alpine blossoms added a touch of color to the pale landscape. All else was stern, silent, motionless winter.
The glacier, clear and white, without a rock on its broken surface, looked from a little distance like a vast snow-covered meadow. We were about a mile above the lower limit of the snow-fields, where the blue ice of the glacier comes out from beneath the névé. The blue ice was deeply buried, and could only be seen in the deepest crevasses. Across the glacier rose the angular cliffs and tapering spires of the Hitchcock range. Every ravine and gulch in its rugged sides was occupied by glaciers, many of which were so broken and crevassed that they looked like frozen cataracts.
Cheered by the bright skies and sun-warmed air, we pushed on up the glacier, taking the center of the stream in order to avoid the crevasses, which were most numerous along its borders. Two or three miles above our first camp we found a place where a thin layer of broken shale covered the snow, at a sufficient distance from the steep slopes above to be out of the reach of avalanches. We there established our second camp after leaving Blossom island, dried our blankets, and spent the remainder of the day basking in the sunlight and gathering energy for coming emergencies.
We found the névé of the Marvine glacier differing greatly from the lower or icy portion previously traversed. Instead of ice with blue and white bands, as is common lower down, theentire surface, and as far down in the crevasses as the eye could distinguish, was composed of compact snow, or snow changed to icy particles resembling hail and having in reality but few of the properties of ordinary snow: it might properly be called névé ice. Usually the thickness of the layers varied from ten to fifteen feet. Separating them were dark lines formed by dust blown over the surface of the glacier and buried by subsequent snow-storms, or by thin blue lines formed by the edges of sheets of ice and showing that the snow surface had been melted during bright sunny days and frozen again at night. The horizontal stratification so plainly marked in all the crevasses in the névé was almost entirely wanting, or at least was not conspicuous, in the lower portion of the glacier, where, instead, we found those narrow blue and white bands already mentioned, the origin of which has been so well described and explained by Tyndall.
The center of the Marvine glacier, as in most similar ice-streams, is higher and less broken by crevasses than its borders. The crevasses at the side trend up stream, as is the case with marginal crevasses generally. In the present instance the courses of these rents could be plainly distinguished on each border of the glacier, when looking down upon it from neighboring slopes. The crevasses occur at quite regular intervals of approximately fifty feet, and diverge from the bank at angles of about 40°. In the banks of snow bordering the glacier similar crevasses diverge from the margin of the flowing glacier and trend down along its banks. The marginal crevasses and the crevasses in the bordering snow-fields, to which no special name has been given, fall nearly in line; but between the two there is a series of irregular cracks and broken snow, sharply defining the border of the moving névé.
The origin of the marginal crevasses trending up stream was explained during the study of the glaciers of Switzerland. The following diagram and explanation illustrating their development are copied from Tyndall:
"LetA Cbe one side of the glacier andB Dthe other; and let the direction of motion be that indicated by the arrow. LetS Tbe a transverse slice of the glacier, taken straight across it, say to-day. A few days or weeks hence the slice will have been carried down, and because the center moves more quickly than the sides it will not remain straight, but will bend into the formS' T'. SupposingT ito be a small square of the original slice near the side of the glacier; in the new position the square will be distorted to the lozenge-shaped figureT' i'. Fix your attention upon thediagonalT iof the square; in the lower position this diagonal,if the ice could stretch, would be lengthened toT' i'. But the ice does not stretch; it breaks, and we have a crevasse formed at right angles toT' i'. The mere inspection of the diagram will assure you that the crevasse will point obliquelyupward."29
29The Forms of Water: International Scientific Series, New York, 1875, pp. 107–108.
The explanation given above applies especially to the lower or icy portion of a glacier; above the snow-line other facts appear. When a glacier flows through fields of snow on a level with its surface, crevasses are formed in the adjacent banks. These trend down stream for the same reason that the crevasses in the glacier proper trend up stream—that is, the friction of the moving stream against its banks tends to carry them along, while the portions at a distance are stationary. Fissures are thus opened which trend in the direction in which the glacier moves. The angle made by these crevasses with the axis of the glacier is about the same as those of the marginal crevasses, but in an opposite direction. They are widest near the margin of the glacier and taper to a sharp end towards the stationary snow-banks above. The crevasses in the two series thus fall nearly in line, but are separated by a narrow band of irregularly broken snow, marking the actual border of the glacier.29
30Crevasses in snow-fields through which ice-streams flow will be mentioned again in describing the Seward glacier.
After leaving Blossom island the party was divided, and we began a new series of numbers for our camp above the snow-line, although in this narrative and on the accompanying map a single series of numbers for all the camps will be used. While in the field the camps in the snow were usually termed, facetiously, "sardine camps," in allusion to the uncomfortable manner in which we were packed in our tent at night.
ACROSSPINNACLEPASS.
ACROSSPINNACLEPASS.
The morning after reaching Camp 12 dawned gloriously bright. The night had been cold, and a heavy frost had silenced every rill from the snow-slopes above. The clear, bracing air gave us renewed energy and a firmer desire to press on. Mr. Kerr and myself made an excursion ahead, while Lindsley and Crumback brought up a load of supplies from the cache left on the glacier below Camp 11.
On gaining the center of the Marvine glacier we had a magnificent view down the broad ice-stream, bordered on either hand by towering, snow-laden precipices, and changing, as the eye followed the downward slope, from pure white to brown and black in the distance. Far below we could barely discern the wooded summit of Blossom island, beyond which stretched the seemingly limitless ice-fields of the Malaspina glacier. All about us the white slope reflected the sunlight with painful brilliancy, while the black moraines and forests below and the mists over the distant ocean, made it seem as if one was looking down into a lower and darker world.
As we advanced toward the head of the glacier we found, as on several subsequent occasions, that the nearer we approached the sources of an ice-stream the easier our progress became. Following up the center of the glacier, we learned that it curved toward the east; and after an hour or two of weary tramping we reached the great amphitheatre in which it has its source. All about us were rugged mountain slopes, heavily loaded with snow, and forming clear white cliffs from which avalanches had descended. To the westward the wall of the amphitheatre was broken, and it was apparent that we could cross its rim in that direction. Pressing onward up the gently ascending slope, we came at length to a gap in the mountains bordered on the north by a towering cliff fully a thousand feet high, and were rejoiced to find that the snow surface on the opposite side of the divide inclined westward with a grade as gentle as the one we had ascended. Looking far down the western snow-slope, we could see where it joined a large glacier flowing southward past the end of the great cliffs which extended westward from the divide. The glacier we saw in the valley below is designated on our map as theSeward glacier, in honor of William H. Seward, the former Secretary of State, who negotiated the purchase of Alaska for the United States.
The pass we namedPinnacle pass, on account of the many towering pinnacles overshadowing it. Its elevation is about four thousand feet, and at the summit it has a breadth of only two or three hundred feet. The snow on the divide is greatly crevassed, but a convenient snow-bridge enabled us to cross without difficulty. The crevasses increased in breadth with the advance of the season, and on returning from our mountain trip in September we had to climb up on the bordering cliff in order to pass the main crevasse at the summit. Some idea of the crevasses of this region may be obtained from the following figure, drawn from a photograph taken on the western side of Pinnacle pass, not far from the summit.
The cliff on the north of Pinnacle pass is really a huge fault-scarp of recent date, intersecting stratified shale, limestone, and conglomerate, with a few thin coal-seams. The strata dip toward the north at a high angle, and present their broken edges in the great cliff rising above the pass. The cliffs extend westward from the pass, and retain a nearly horizontal crest line, but increase in height and grandeur, owing to the downward grade of the glacier along their base. A mile to the westward their elevation is fully two thousand feet. The cliffs throughout arealmost everywhere bare of snow and too steep and rugged to be scaled. They form a strongly drawn boundary line in the geology of the region, and furnish the key to the structure and geological character of an extended area. All the rocks to the southward are sandstone and shale belonging to a well-defined series, and differ materially from the rocks in the fault-scarp. I have called the rocks toward the south, theYakutat system, and those exposed in the faces of the fault-scarp thePinnacle system. Directly north of Pinnacle pass, and at the base of Mount Owen, the rocks of the Yakutat system are exposed, and from their position and association it is evident that they are younger than the Pinnacle system and belong above it. If these conclusions are sustained by future investigation, they will carry with them certain deductions which are among the most remarkable in geological history. On the crest of the Pinnacle pass cliffs I afterwards found strata containing fossil shells and leaves belonging to species still living. These records of animal and plant life show that not only were the rocks of the Pinnacle system deposited since living species of mollusks and plants came into existence, but that the Yakutat system is still more recent. More than this, the upheaval of the mountains, the formation of numerous fault-scarps, and the origin of the glaciers, have all occurred since Pliocene times.
The discovery of Pinnacle pass left no question as to the route to be traversed in order to reach the mountains to the westward. We returned to Camp 12, and the following day, with Crumback and Lindsley to assist us, advanced our camp across Pinnacle pass and far down the western snow-slope.
The day we crossed the pass was bright and clear in the morning, but clouds gathered around all the higher peaks about midday, vanishing again at nightfall. As it was desirable to occupy, for topographic and other purposes, a station on the top of the cliffs overlooking Pinnacle pass, we made an effort to reach the crest of the ridge by climbing up the steep scarp just at the divide, where the cliffs are lowest. While Crumback returned to Camp 12 for an additional load and Lindsley went ahead to discover a new camping place, Kerr and myself, taking the necessary instruments, began the ascent; but we found it exceedingly difficult. The outcrops of shale in the lower portion of the cliff furnished but poor foothold, and crumbled and broke away at every step. Once my companion, losing his support, slid slowlydown the slope in spite of vigorous efforts to hold on, and a rapid descent in the yawning chasm below seemed inevitable, when, coming to a slightly rougher surface, he was able to control his movements and to regain what had been lost. Climbing on, we came to the base of a vertical wall of shale several hundred feet high, and made a detour to the left where a cascade plunged down a narrow channel. We ascended the bed of the stream, which was sometimes so steep that the spray dashed over us, and reached the base of an overhanging cliff of conglomerate composed of well-worn pebbles. Above this rose a cliff of snow fifty feet or more in height, which threatened to crash down in avalanches at any moment. One small avalanche did occur during the ascent, and scattered its spray in our faces. Had a heavy avalanche formed, our position would have been exceedingly dangerous; but by taking advantage of every overhanging ledge, and watching for the least sign of movement in the snow above, we reached without accident a sheltered perch underneath an overhanging cliff near the base of the snow. We then discovered that clouds were forming on all the high mountains, and shreds of vapor blown over the crest of the cliff above told us that further efforts would be useless. Seeking a perch protected from avalanches by an overhanging cliff, we had a splendid view far out over the sloping snow-plain toward the west and of the mountains bordering Pinnacle pass on the south. My notes written in this commanding station read as follows:
"Looking down from my perch I can plainly distinguish the undulations and crevasses in the broad snow-fields stretching westward from Pinnacle pass. Each inequality in the rock beneath the glacier is reproduced in flowing and subdued outlines in the white surface above. The positions of bosses and cliffs in the rock beneath are indicated by rounded domes and steep descents in the snow surface. About the lower sides of these inequalities there are in some cases concentric blue lines and in others radiating fissures, marking where the snow has broken in making the descent. The side light shining from the eastward down the long westerly slope reveals by its delicate shading the presence of broad, terrace-like, transverse steps into which the stream is divided. Were the snow removed and the rock beneath exposed, we should find broad terraces separated by scarps sweeping across the bed of the glacier from side to side. Similar terraces occur in glaciated cañons in the Rocky Mountains andthe Sierra Nevada, but their origin has never been explained. The glacier is here at work sculpturing similar forms; but still it is impossible to understand how the process is initiated.
"Right in front of us, and only a mile or two away, rise the cliffs, spires, and pinnacles of the Hitchcock range. Every ravine and amphitheatre in the great mountain mass is deeply filled with snow, and the sharp angular crests look as if they had been thrust up through the general covering of white. The northern end of the range is clearly defined by the east-and-west fault to which Pinnacle pass owes its origin. The trend of the mighty cliffs on the southern face, on which we have found a perch, is at right angles to the longer axis of the Hitchcock range, and marks its northern terminus both topographically and geologically.
"There is not even a suggestion of vegetation in sight. The eye fails to detect a single dash of green or the glow of a single Alpine flower anywhere on the rugged slopes. A small avalanche from the snow-cliffs above, cascading over the cliff which shelters me and only a few yards away, tells why the precipices are so bare and desolate: they have been swept clean by avalanches.
"Far down the western snow-slope I can distinguish crevasses and dirt bands in the Seward glacier, which flows southward past the range on which we sit. The marginal crevasses along the border of the glacier can clearly be distinguished. As usual, they trend up-stream and, meeting medial crevasses, break the surface of the glacier into thousands of pinnacles and tables. Along the center of the stream there are V-shaped dirt bands, separated by crevasses, which point down-stream and give the appearance of a rapid flow to the central portion of the glacier. From this distance its center has the appearance of 'watered' ribbon.
"A little toward the south of where the medial crevasses are most numerous, and at a locality where two opposite mountain spurs force the ice-stream through the comparatively narrow gorge, there is evidently an ice-fall, as the whole glacier from side to side disappears from view. The appearance of Niagara when seen from the banks of the river above the Horseshoe falls is suggested. Beyond this silent cataract, the eye ranges far out over the broad, level surface of the Malaspina glacier, and traces the dark morainal ribbons streaming away for miles from the mountain spurs among which they originate. From the extremesouthern cape of the Samovar hills there is a highly compound moraine-belt stretching away toward the south, and then dividing and curving both east and west. The central band of débris must be a mile broad. Along its eastern margin I can count five lesser bands separated by narrow intervals of ice, and on the farther side similar secondary bands are suggested, but the height of the central range almost completely conceals them from view. In the distant tattered ends, however, their various divisions can be clearly traced. Great swirls in the ice are there indicated by concentric curves of débris on its surface.
"Still farther westward there are hills rising to the height of impressive mountains, in which northward dipping rocks, apparently of sandstone and shale, similar to those forming the Hitchcock range, are plainly distinguishable. All the northern slopes of these hills are deeply buried beneath a universal covering of snow evidently hundreds of feet thick, which is molded upon them so as to reveal every swelling dome and ravine in their rugged sides. Farther westward still, beyond a dark headland apparently washed by the sea, there are other broad ice-fields of the same general character as the Malaspina glacier, which stretch away for miles and miles and blend in the dim distance with the haze of the horizon.
"Just west of the Seward glacier, and in part forming its western shore, there are dark, rocky crests projecting through the universal ice mantle, suggesting the lost mountains of Utah and Nevada which have become deeply buried by the dusts of the desert. The character of the sharp crests beyond the Seward glacier indicate that they are the upturned edges of fault-blocks similar to the one on which we are seated. Interesting geological records are there waiting an interpreter. The vastness of the mountains and the snow-fields to be seen at a single glance from this point of view can scarcely be realized. There are no familiar objects in sight with which to make eye-measurements; the picture is on so grand a scale that it defies imagination's grasp."
Searching the snow-sheet below with a field-glass, I discover a minute spot on the white surface. Its movement, slow but unmistakable, assures me that it is Lindsley returning from the site chosen for our camp to-night. Although apparently near at hand, he forms but an inconspicuous speck on the vast snow-field.