Mount Rainier Part 15

Mount Rainier stands, in round numbers, 10,000 feet high above its immediate base, and covers 100 square miles of territory, or one-third of the area of Mount Rainier National Park. In shape it is not a simple cone tapering to a slender, pointed summit like Fuji Yama, the great volcano of j.a.pan. It is, rather, a broadly truncated ma.s.s resembling an enormous tree stump with spreading base and irregularly broken top. Its life history has been a varied one. Like all volcanoes, Rainier has built up its cone with the material ejected by its own eruptions--with cinders and bombs (steam-shredded particles and lumps of lava), and with occasional flows of liquid lava that have solidified into layers of hard, basaltic rock. At one time it attained an alt.i.tude of not less than 16,000 feet, if one may judge by the steep inclination of the lava and cinder layers visible in its flanks.

Then a great explosion followed that destroyed the top part of the mountain, and reduced its height by some 2,000 feet. The volcano was left beheaded, and with a capacious hollow crater, surrounded by a jagged rim.

Later on this great cavity, which measured nearly 3 miles across, from south to north, was filled by two small cinder cones. Successive feeble eruptions added to their height until at last they formed together a low, rounded dome--the eminence that now const.i.tutes the mountain's summit. It rises only about 400 feet above the rim of the old crater, and is an inconspicuous feature, not readily identifiable from all sides as the highest point. In fact, so broad is the mountain's crown that from no point at its base can one see the top.

The higher portions of the old crater rim, moreover, rise to elevations within a few hundred feet of the summit, and, especially when viewed from below, stand out boldly as separate peaks that mask and seem to overshadow the central dome. Especially prominent are Peak Success (14,150 feet) on the southwest side, and Liberty Cap (14,112 feet) on the northwest side.

The alt.i.tude of the main summit has for many years been in doubt.

Several figures have been announced from time to time, no two of them in agreement with each other; but all of these, it is to be observed, were obtained by more or less approximate methods. In 1913 the United States Geological Survey, in connection with its topographic surveys of the Mount Rainier National Park, was able to make a new series of measurements by triangulation methods at close range. These give the peak an elevation of 14,408 feet, thus placing it near the top of the list of high summits of the United States. This last figure, it should be added, is not likely to be in error by more than a foot or two and may with some confidence be regarded as final. Greater exactness of determination is scarcely practicable in the case of Mount Rainier, as its highest summit consists actually of a mound of snow the height of which naturally varies somewhat with the seasons and from year to year.

This crowning snow mound, which was once supposed to be the highest point in the United States, still bears the proud name of Columbia Crest. It is essentially a huge snowdrift or snow dune, heaped up by the westerly winds. Driving furiously up through the great breach in the west flank of the mountain, between Peak Success and Liberty Cap, they eddy lightly as they shoot over the summit and there deposit their load of snow.

The drift is situated at the point where the rims of the two summit craters touch, and represents the only permanent snow ma.s.s on these rims, for some of the internal heat of the volcano still remains and suffices to keep these rock-crowned curving ridges bare of snow the better part of the year. It is intense enough, even, to produce numerous steam jets along the inner face of the rim of the east crater, which appears to be the most recently formed of the two. The center of this depression, however, is filled with snow, so that it has the appearance of a shallow, white-floored bowl some 1,200 feet in diameter. Great caverns are melted out by the steam jets under the edges of the snow ma.s.s, and these caverns afford shelters which, though uninviting, are not to be despised. They have proved a blessing to more than one party that has found itself compelled to remain overnight on the summit, saving them from death in the icy gales.

That Mount Rainier should still retain so much of its internal heat is not surprising in view of the recency of its eruptions. It is known to have been active at intervals during the last century, and actual record exists of slight eruptions in 1843, 1854, 1858, and 1870.

Indian legends mention a great cataclysmal outburst at an earlier period.

At present the volcano may be regarded as dormant and no apprehension need be felt as to the possibility of an early renewal of its activity. The steam jets in the summit crater, it is true, as well as the hot springs at the mountain's foot (Longmire Springs), attest the continued presence of subterranean fires, but they are only feeble evidences as compared with the geysers, the steam jets, and the hot springs of the Yellowstone National Park. Yet that region is not considered any less safe to visit because of the presence of these thermal phenomena.

In spite of Mount Rainier's continued activity until within the memory of man its sides appear to have been snow clad for a considerable length of time. Indeed, so intense and so long-continued has been the eroding action of the ice that the cone is now deeply ice-scarred and furrowed. Most of its outer layers, in fact, appear already to have been stripped away. Here and there portions of them remain standing on the mountain's flanks in the form of sharp-crested crags and ridges, and from these one may roughly surmise the original dimensions of the cone. Mere details in the volcano's sculpture, these residual ma.s.ses are, some of them, so tall that, were they standing among ordinary mountains, they would be reckoned as great peaks. Particularly noteworthy is Little Tahoma, a sharp, triangular tooth on the east flank, that rises to an elevation of 11,117 feet. In its steep, ice-carved walls one may trace ascending volcanic strata aggregating 2,000 feet in thickness that point upward to the place of their origin, the former summit of the mountain, which rose almost half a mile higher than the present top.

Nor is the great crater rim left by the explosion that carried off the original summit preserved in its entirety. Peak Success and Liberty Cap are the only two promontories that give trustworthy indication of its former height and strength. Probably they represent the more ma.s.sive portions on the southwest and northwest sides, respectively, while the weaker portions to the east and south have long since crumbled away under the heavy ice cascades that have been overriding them for ages. Only a few small rocky points remain upon which the snows split in their descent. The most prominent, as well as the most interesting, is the one on the southeast side, popularly known as Gibraltar Rock. Really a narrow, wedge-shaped ma.s.s, it appears in profile like a ma.s.sive, square-cut promontory. The trail to the summit of the mountain pa.s.ses along its overhanging south face and then ascends by a precipitous chute between ice and rock. It is this part of the ascent that is reputed as the most precarious and hazardous.

From the rim points downward the ice cover of the cone divides into a number of distinct stream-like tongues or glaciers, each sunk in a great hollow pathway of its own. Between these ice-worn trenches the uneroded portions of the cone stand out in high relief, forming as a rule huge triangular "wedges," heading at the sharp rim points and spreading thence downward to the mountain's base. There they a.s.sume the aspect of more gently sloping, gra.s.sy table-lands, the charming alpine meadows of which Paradise Park and Spray Park are the most famous. Separating these upland parks are the profound ice-cut canyons which, beyond the glacier ends, widen out into densely forested valleys, each containing a swift-flowing river. No less than a dozen of these ice-fed torrents radiate from the volcano in all directions, while numerous lesser streams course from the snow fields between the glaciers.

Thus the cone of Mount Rainier is seen to be dissected from its summit to its foot. Sculptured by its own glacier mantle, its slopes have become diversified with a fretwork of ridges, peaks, and canyons.

The first ice one meets on approaching the mountain from Longmire Springs lies in the upper end of the Nisqually Valley. The wagon road, which up to this point follows the west side of the valley, winding in loops and curves along the heavily wooded mountain flank, here ventures out upon the rough bowlder bed of the Nisqually River and crosses the foaming torrent on a picturesque wooden bridge. A scant thousand feet above this structure, blocking the valley to a height of some 400 feet, looms a huge shapeless pile of what seems at first sight only rock debris, gray and chocolate in color. It is the dirt-stained end of one of the largest glaciers--the Nisqually. From a yawning cave in its front issues the Nisqually stream, a river full fledged from the start.

The alt.i.tude here, it should be noted, is a trifle under 4,000 feet (elevation of bridge is 3,960 feet); hence the ice in view lies more than 10,000 feet below the summit of the mountain, the place of its origin. And in this statement is strikingly summed up the whole nature and economy of a glacier such as the Nisqually.

A glacier is not a mere stationary blanket of snow and ice clinging inert to the mountain flank. It is a slowly moving streamlike body that descends by virtue of its own weight. The upper parts are continually being replenished by fresh snowfalls, which at those high alt.i.tudes do not entirely melt away in summer; while the lower end, projecting as it does below the snow line, loses annually more by melting than it receives by precipitation, and is maintained only by the continued accession of ma.s.ses from above. The rate at which the ice advances has been determined by Prof. J. N. Le Conte, of the University of California. In 1903 he placed a row of stakes across the glacier, and with the aid of surveying instruments obtained accurate measurements of the distances through which they moved from day to day. He found that in summer, when the movement is greatest, it averages 16 inches per day. This figure, however, applies only to the central portion of the glacier--the main current, so to speak--for the margins necessarily move more slowly, being r.e.t.a.r.ded by friction against the channel sides.

The snout of the Nisqually Glacier, accordingly, is really composed of slowly advancing ice, but so rapid is the melting at this low alt.i.tude that it effectually counterbalances the advance, and thus the ice front remains essentially stationary and apparently fixed in place.

Actually, it is subject to slight back and forward movements, amounting to a foot or more per day; for, as one may readily imagine, fluctuations in snowfall and in temperature, above or below the normal, are ever likely to throw the balance one way or another.

A glacier may also make periodic advances or retreats on a larger scale in obedience to climatic changes extending over many years. Thus all the glaciers on Mount Rainier, as well as many in other parts of the world, are at present, and have been for some time, steadily retreating as the result of milder climate or of a lessening in snow supply. Only so recently as 1885 the Nisqually Glacier reached down to the place now occupied by the bridge, and it is safe to say that at that time no engineer would have had the daring to plan the road as it is now laid. In the last 25 years, however, the Nisqually Glacier has retreated fully 1,000 feet.

Evidences of similar wholesale recession are to be observed at the ends of the other glaciers of Mount Rainier, but the measure of their retreat is not recorded with the precision that was possible in the case of the Nisqually Glacier. Eyewitnesses still live at Longmire Springs who can testify to the former extension of the Nisqually Glacier down to the site of the wagon bridge.

As one continues the ascent by the wagon road a partial view of the glacier's lower course is obtained, and there is gained some idea of its stream-like character. More satisfying are the views from Paradise Park. Here several miles of the ice stream (its total length is nearly 5 miles) lie stretched out at one's feet, while looking up toward the mountain one beholds the tributary ice fields and ice streams, pouring, as it were, from above, from right and left, rent by innumerable creva.s.ses and resembling foaming cascades suddenly crystallized in place. The turmoil of these upper branches may be too confusing to be studied with profit, but the more placid lower course presents a favorable field for observation, and a readily accessible one at that.

A veritable frozen river it seems, flowing between smooth, parallel banks, half a mile apart. Its surface, in contrast to the glistening ice cascades above, has the prevailingly somber tint of old ice, relieved here and there by bright patches of last winter's snow. These lie for the most part in gaping fissures or creva.s.ses that run athwart the glacier at short intervals and divide its body into narrow slices.

In the upper course, where the glacier overrides obstacles in its bed, the creva.s.ses are particularly numerous and irregularly s.p.a.ced, sometimes occurring in two sets intersecting at right angles, and producing square-cut prisms. Farther down the ice stream's current is more sluggish and the creva.s.ses heal up by degrees, providing a united surface, over which one may travel freely.

Gradually, also, the glacier covers itself with debris. Angular rock fragments, large and small, and quant.i.ties of dust, derived from the rock walls bordering the ice stream higher up, litter its surface and hide the color of the ice. At first only a narrow ridge of such material--a moraine, as it is called--accompanies the ice river on each side, resembling a sharp-crested embankment built by human hands to restrain its floods; but toward the lower end of the glacier, as the ice wastes away, the debris contained in it is released in ma.s.ses, and forms brown marginal bands, fringing the moraines. In fact, from here on down it becomes difficult to tell where the ice of the glacier ends at the sides and where the moraines begin.

The lower part of the glacier also possesses a peculiar feature in the form of a debris ridge about midway on its back--a medial moraine.

Most of the way it stretches like a slender, dark ribbon, gradually narrowing upstream. One may trace it with the eye up to its point of origin, the junction of the two main branches of the glacier, at the foot of a sharp rock spur on the mountain's flank.

In the last mile of the Nisqually's course, this medial moraine develops from a mere dirt band to a conspicuous embankment, projecting 40 feet above the ice. Not the entire body of the ridge, however, is made up of rock debris. The feature owes its elevation chiefly to the protective influence of the debris layer on its surface, which is thick enough to shield the ice beneath from the hot rays of the sun, and greatly r.e.t.a.r.ds melting, while the adjoining unprotected ice surfaces are rapidly reduced.

A short distance above the glacier's terminus the medial moraine and the ever-broadening marginal bands come together. No more clear ice remains exposed, irregular mounds and ridges of debris cover the entire surface of the glacier, and the moraine-smothered ma.s.s a.s.sumes the peculiar inchoate appearance that is so striking upon first view.

In utter contrast with the glacier's dying lower end are the bright snow fields on the summit in which it commences its career. Hard by the rock rim of the east summit crater the snows begin, enwrapping in an even, immaculate layer the smooth sides of the cinder cone. Only a few feet deep at first, they thicken downward by degrees, until, a thousand feet below the crater, they possess sufficient depth and weight to acquire movement. Occasional angular creva.s.ses here interrupt the slope and force the summit-bound traveler to make wearying detours.

Looking down into a gash of this sort one beholds nothing but clean snow, piled in many layers. Only a faint blue tinges the creva.s.se walls, darkening but slowly with the depth, in contrast to the intense indigo hue characteristic of the partings in the lower course of the glacier. There the material is a dense ice, more or less crystalline in texture; here it is scarcely more than snow, but slightly compacted and loosely granular--what is generally designated by the Swiss term "neve."

For several thousand feet down, as far as the 10,000-foot level, in fact, does the snow retain this granular consistency. One reason for the slowness with which it compacts is found in the low temperatures that prevail at high alt.i.tudes and preclude any considerable melting.

The air itself seldom rises above the freezing point, even in the middle of the day, and as a consequence the snow never becomes soft and mushy, as it does at lower levels.

When snow a.s.sumes the mushy, "wet-sugar" state, it is melting internally as well as at its outer surface, owing both to the water that soaks into it and to the warming of the air inclosed within its innumerable tiny pores (which tiny air s.p.a.ces, by the way, give the snow its brilliant whiteness). Snow in this condition has, paradoxical though it may sound, a temperature a few tenths of a degree higher than the melting point--a fact recently established by delicate temperature measurements made on European glaciers. It is this singular fact, no doubt, that explains how so many minute organisms are able to flourish and propagate in summer on the lower portions of many glaciers. It may be of interest to digress here briefly in order to speak of these little known though common forms of life.

Several species of insects are among the regular inhabitants of glaciers. Most of them belong to a very low order--the Springtails, or _Thysanura_--and are so minute that in spite of their dark color they escape the attention of most pa.s.sers-by. If one looks closely, however, they may readily be observed hopping about like miniature fleas or wriggling deftly into the cavities of the snow. It seems to incommode them but little if in their acrobatic jumps they occasionally alight in a puddle or in a rill, for they are thickly clad with furry scales that prevent them from getting wet--just as a duck is kept dry by its greasy feathers.

Especially plentiful on the lower parts of the Rainier glaciers, and more readily recognized, are slender dark-brown worms of the genus _Mesenchytraeus_, about 1 inch in length. Millions and millions of them may be seen on favorable days in July and August writhing on the surface of the ice, evidently breeding there and feeding on organic matter blown upon the glacier in the form of dust. So essential to their existence is the chill of the ice that they enter several inches, and sometimes many feet below the surface on days when the sun is particularly hot, reappearing late in the afternoon.

Mention also deserves to be made of that microscopic plant _Protococcus nivalis_, which is responsible for the mysterious pink or light, rose-colored patches so often met with on glaciers--the "red snow" of a former superst.i.tion. Each patch represents a colony or culture comprising billions of individuals. It is probable that they represent but a small fraction of the total microflora thriving on the snow, the other species remaining invisible for lack of a conspicuous color.

To return to the frigid upper neves, it is not to be supposed that they suffer no loss whatever by melting. The heat radiated directly to them by the sun is alone capable of doing considerable damage, even while the air remains below the freezing point. At these high alt.i.tudes the sun heat is astonishingly intense, as more than one uninitiated mountain climber has learned to his sorrow by neglecting to take the customary precaution of blacking his face before making the ascent. In a few hours the skin is literally scorched and begins to blister painfully.

At the foot of the mountain the sun heat is relatively feeble, for much of it is absorbed by the dust and vapor in the lower layers of the atmosphere, but on the summit, which projects 2 miles higher, the air is thin and pure, and lets the rays pa.s.s through but little diminished in strength.

The manner in which the sun affects the snow is peculiar and distinctive. Instead of reducing the surface evenly, it melts out many close-set cups and hollows, a foot or more in diameter and separated by sharp spires and crests. No water is visible anywhere, either in rills or in pools, evaporation keeping pace with the reduction. If the sun's action is permitted to continue uninterrupted for many days, as may happen in a hot, dry summer, these snow cups deepen by degrees, until at length they a.s.sume the aspect of gigantic bee cells, several feet in depth. Snow fields thus honeycombed may be met with on the slopes above Gibraltar Rock. They are wearisome to traverse, for the ridges and spines are fairly resistant, so that one must laboriously clamber over them. Most exasperating, however, is the going after a snowstorm has filled the honeycombs. Then the traveler, waist deep in mealy snow, is left to flounder haphazard through a hidden labyrinth.

Of interest in this connection is the great snow cliff immediately west of Gibraltar Rock. Viewed from the foot of that promontory, the sky line of the snow castle fairly bristles with honeycomb spines; while below, in the face of the snow cliff, dark, wavy lines, roughly parallel to the upper surface, repeat its pattern in subdued form.

They represent the honeycombs of previous seasons, now buried under many feet of snow, but still traceable by the dust that was imprisoned with them.

The snow cliff west of Gibraltar Rock is of interest also for other reasons. It is the end of a great snow cascade that descends from the rim of the old crater. Several such cascades may be seen on the south side of the mountain, separated by craggy remnants of the crater rim.

Above them the summit neves stretch in continuous fields, but from the rim on down, the volcano's slopes are too precipitous to permit a gradual descent, and the neves break into wild cascades and falls.

Fully two to three thousand feet they tumble, a.s.sembling again in compact, sluggish ice fields on the gentler slopes below.

Of the three cascades that feed the Nisqually Glacier only the central one, it is to be observed, forms a continuous connection between the summit neves and the lower ice fields. The two others, viz. the one next to Gibraltar and the westernmost of the three, terminate in vertical cliffs, over great precipices of rock. From them snow ma.s.ses detach at intervals and produce thundering avalanches that bound far out over the inclined ice fields below. Especially frequent are the falls from the cliff near Gibraltar. They occur hourly at certain times, but as a rule at periods of one or more days.

From the westernmost cascade avalanches are small and rare. Indeed, as one watches them take place at long intervals throughout a summer one can not but begin to doubt whether they are in themselves really sufficient to feed and maintain so extensive an ice field as lies stretched out under them. Surely much more snow must annually melt away from the broad surface of that field, exposed as it lies to the midday sun, than the insignificant avalanches can replace. Were they its only source of supply, the ice field, one feels confident, would soon cease to exist.

The fact is that the ice field in question is not dependent for its support on the avalanches from above. It may receive some contributions to its volume through them, but in reality it is an independent ice body, nourished chiefly by direct snow precipitation from the clouds. And this is true, in large measure, of all the ice fields lying under the ice cascades. The Nisqually Glacier, accordingly, is not to be regarded as composed merely of the cascading neves, reunited and cemented together, but as taking a fresh start at these lower levels. Improbable though this may seem at first, it is nevertheless a fact that is readily explained.

The winter snows on Mount Rainier are heaviest in the vicinity of its base; indeed, the snowfall at those low levels is several times greater than that on the summit. This in itself may seem anomalous. So accustomed is one to think that the snowfall on high mountains increases with the alt.i.tude that it seems strange to find a case in which the opposite is true. Yet Mount Rainier stands by no means alone in this regard. The Sierra Nevada and the Andes, the Himalayas and the Alps, all show closely a.n.a.logous conditions.

In each of these lofty mountain regions the precipitation is known to be heaviest at moderate alt.i.tudes, while higher up it decreases markedly. The reason is that the storm clouds--the clouds that carry most of the rain and snow--hang in a zone of only moderate elevation, while higher up the atmosphere contains but little moisture and seldom forms clouds of any great density.

In the Rainier region the height of the storm clouds is in large measure regulated by the relief of the Cascade Range; for it is really this cooling mountain barrier that compels the moisture-laden winds from the Pacific Ocean to condense and to discharge. It follows that the storm clouds are seldom much elevated above the sky line of the Cascade Mountains; they cling, so to speak, to its crest and ridges, while the cone of Mount Rainier towers high above them into serener skies. Many a day may one look down from the summit, or even from a halfway point, such as Camp Muir (10,062 feet), upon the upper surface of the clouds. Like a layer of fleecy cotton they appear, smothering the lower mountains and enveloping the volcano's base.

Clouds, it is true, are frequently seen gathering about the mountain's crown, usually in the form of a circular cap or hood, precursor of a general storm, but such clouds yield but very little snow.

No accurate measurements have been made of the snowfall at the mountain's foot, but in the Nisqually Valley, at Longmire Springs, the winter snows are known often to exceed 20 feet in depth. The summer heat at this low level (2,762 feet) is, of course, abundantly able to remove all of it, at least by the end of May. But higher up every thousand feet of elevation suffices to prolong appreciably the life of the snowy cover. In Paradise Park, for instance, at alt.i.tudes between 5,000 and 6,000 feet, huge snowdrifts enc.u.mber the flowering meadows until far into July. Above an alt.i.tude of 6,000 feet permanent drifts and snow fields survive in certain favored spots, while at the 7,000-foot level the snow line, properly speaking, is reached. Above this line considerable snow remains regularly from one winter to the next, and extensive ice fields and glaciers exist even without protection from the sun.

It is between the 8,000 and 10,000 foot levels, however, that one meets with the conditions most favorable for the development of glaciers. Below this zone the summer heat largely offsets the heavy precipitation, while above it the snowfall itself is relatively scant.

Within the belt the annual addition of snow to the ice fields is greater than anywhere else on Mount Rainier. The result is manifest in the arrangement and distribution of the glaciers on the cone. By far the greater number originate in the vicinity of the 10,000-foot level, while those ice streams which cascade from the summit, such as the Nisqually, are in a sense reborn some 4,000 feet lower down.