Glaciers of North America: A Reading Lesson for Students of Geography and Geology

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Ginn & Company, 1897 - Glaciers - 210 pages

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Page 136 - The indication of a great propelling agency seemed to be just commencing at the time I was observing it. These split-off lines of ice were evidently in motion, pressed on by those behind, but still widening their fissures, as if the impelling action was more and more energetic nearer the water, till at last they floated away in the form of icebergs. Long files of these detached masses could be traced slowly sailing off into the distance, their separation marked by dark parallel shadows — broad...
Page 62 - The general course of this glacier is south, but at its extremity it bends to the eastward, apparently deflected from its course by a cliff of older felsitic rock, more resisting than the lava T'he consequence of this deflection is a predominance of longitudinal over transverse crevasses at this point, and an unusually large moraine at its western side, which rises several hundred feet above the surface of the glaciers, and partakes of the character of both lateral and terminal moraines : the main...
Page 113 - Malaspina glacier one sees that the great central area of clear, white ice is bordered on the south by a broad, dark band formed by bowlders and stones. Outside of this and forming a belt concentric with it is a forest -covered area, in many places four or five miles wide. The forest grows on the moraine, which rests upon the ice of the glacier. In a general view by far the greater part of the surface of the glacier is seen to be formed of clear ice, but in crossing it one comes first to the forest...
Page 137 - As the surface of the glacier receded to the south, its face seemed broken with piles of earth and rockstained rubbish, till far back in the interior it was hidden from me by the slope of a hill. Still beyond this, however, the white blink or glare of the sky above showed its continued extension. It was more difficult to trace its outline to the northward, on account of the immense discharges at its base. The talus of its descent from the interior, looking far off to the east, ranged from 7° to...
Page 52 - Surveying party, of which no definite account seems as yet to have been published, it may be stated that there are no proper glaciers anywhere within the limits of the United States (Alaska not included), except around the great isolated volcanic cones of the Pacific coast. There are certainly none in the higher portions of the Sierra Nevada or the Rocky Mountains, these most elevated regions having been sufficiently explored to ascertain that fact.
Page 98 - There was not a stream, not a lake, and not a vestige of vegetation of any kind in sight. A more desolate or more utterly lifeless land one never beheld. Vast, smooth snow surfaces without crevasses stretched away to limitless distances, broken only by jagged and angular mountain peaks. . . . The view to the north called to mind the pictures given by Arctic explorers of the borders of the great Greenland ice sheet, where rocky islands, known as 'nunataks,' alone break the monotony of the boundless...
Page 110 - ... and, melting the ice beneath, sink into it. When small stones and dirt are gathered in depressions on the surface of the glacier, or, on a large scale, when moulins become filled with fine debris and the adjacent surface is lowered by melting, the material thus concentrated acts as do large bowlders, and protects the ice beneath. But as the gravel rises in reference to the adjacent surface, the outer portion rolls down from the pedestal on all sides, and the result is that a sharp cone of ice...
Page 56 - An east-and-west line divides the mountain into glacier-bearing and non-glacier-bearing halves. The ascent was formerly always made upon the south side where, as stated, there are no glaciers, and this is why able scientific observers like Professor Whitney and his party should have scaled the mountain without discovering their existence.
Page 62 - The main White River glacier, the grandest of the whole, pours straight down from the rim of the crater in a northeasterly direction, and pushes its extremity farther out into the valley than any of the others. Its greatest width on the steep slope of the mountain must be four or five miles, narrowing toward its extremity to about a mile and a half; its length can be scarcely less than ten miles.
Page 136 - It was undulating about the horizon, but as it descended toward the sea it represented a broken plain with a general inclination of some nine degrees, still diminishing toward the foreground. Crevasses, in the distance mere wrinkles, expanded as they came nearer, and were crossed almost at right angles by long, continuous lines of fracture parallel with the face of the glacier. These lines, too, scarcely traceable in the far distance, widened as they approached the sea until they formed a gigantic...

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