Page images
PDF
EPUB
[graphic][subsumed][merged small][subsumed]
[blocks in formation]

stand, 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 brill

[graphic][ocr errors]

FIGURE 2-View of a glacial Lakelet (drawn from a Photograph).

iant 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, is

absolutely 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.

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

FIGURE 3-Section of a glacial lakelet.

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 its

[blocks in formation]

frozen 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 not pre

« PreviousContinue »