Our camp occupied a commanding situation. From the end of the ridge on which it was located there was a splendid view of glaciers and mountains to the eastward. The illustration forming plate 18 is from a photograph taken from that station. Toward the north, and only a few miles away, rose the bare, rugged slope of Mount Malaspina. In a wild, high-grade gorge on its western side, a glacier, all pinnacles and crevasses, tumbles down into the broad white plain below. On account of its splendid ice-fall this was named the Cascade glacier. Beyond the white plain, stretching eastward for fifteen or twenty miles, there rise the foothills of Mount Cook. Farther south, the rugged, angular summits of the Hitchcock range are in full view, and toward the north stands Mount Irving,32 which rivals even Mount Cook in the symmetrical proportions of its snow-covered slopes.
32 Named in honor of Professor Roland Duer Irving, U. S. geologist.
The surface of the vast snow-plain near at hand is gashed by many gaping fissures, but the distance is so great that these minor details disappear in a general view. Looking down over the snow, one may see the crevasses as in a diagram. They look as if the white surface had been gashed with a sharp knife, and then stretched in such a way as to open the cuts. That the snow of the névés may be stretched, at least to a limited extent, is shown by the character of these fissures. The crevasses are widest in the center and come to a point at their curving extremities. Two crevasses frequently overlap at their ends and leave a sliver of ice stretching across diagonally between them. It is by means of these diagonal bridges that one is enabled to thread his way through the crevasses.
On returning to camp in the evening, weary with a hard day's climb, a never-failing source of delight was found in the matchless winter landscape to the eastward. The evenings following days of uninterrupted sunshine were especially delightful. The blue shadows of the western peaks creeping across the shining surface were nearly as sharp in outline as the peaks that cast them. When the chill of evening made itself felt, and the dropping water and the indefinite murmurs from the glacier below were stilled, the silence became oppressive. The stillness was so profound that it seemed as though the footsteps of the advancing shadows should be audible.
On warm sunny days, however, there are noises enough amid the mountains. The snow, partially melted and softened by the heat, falls from the cliffs in avalanches that make the mountains tremble and, with a roar like thunder, awaken the echoes far and near. During our stay at Camp 15 the avalanches were sometimes so frequent on the steep mountain faces toward the north that the roar of one falling mass of snow and rocks was scarcely hushed before it was succeeded by another.
On the southward-facing cliffs of Mount Augusta, composed of schist which disintegrates rapidly, there are frequent rock avalanches. A rock or a mass of comminuted schist sometimes breaks away even in midday, although these avalanches occur most frequently when the moisture in the rocks freezes. The midday avalanches, I fancy, may be started by the expansion of the rocks owing to the sun's heat. A few stones dislodged high up on the cliffs fall, and, loosening others in their descent, soon set in motion a train of dirt and stones, which flows down the steep ravines with a long rumbling roar, at the same time sending clouds of dust into the air. If the wind is blowing up the cliffs, as frequently happens on warm days, the dust is carried far above the mountains, and hangs in the air like clouds of smoke.
It has been frequently stated that St. Elias is a volcano, and sea captains sailing on the Pacific have seen what they supposed to be smoke issuing from its summit. As its southern face is composed of the same kind of rocks and is of the same precipitous nature as the southern slope of Mount Augusta, it appears probable that what was supposed to be volcanic smoke was in reality avalanche dust blown upward by ascending air currents.
The disintegration of the mountain summits all through the St. Elias region is so great that one constantly wonders that anything is left; yet, except late in the fall, the snow surfaces at the bases of even the steepest cliffs are mostly bare of débris. The absence of earth and stones on the surfaces of the névé fields is mainly due, of course, to the fact that these are regions of accumulation where the winter's snow exceeds the summer's melting. Thus each year the surface is renewed and made fresh and clean, and any débris that may have previously accumulated is concealed.
There is another reason, however, why but little débris is found at the bases of the steep precipices. The snows of winter are banked high against these walls, but when the rocks are warmed by the return of the summer's sun the snow near their dark surfaces is melted, and leaves a deep gulf between the upward-sloping banks of snow and the sides of the cliffs. These black chasms are frequently 150 or 200 feet deep, and receive all the débris that falls from above. In this way very large quantities of earth and stones are injected, as it were, into the glacier, and only come to light again far down toward the ends of the ice-streams, where the summer's melting exceeds the winter's supply.