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You searched for: Start Over Topic Glaciers Remove constraint Topic: Glaciers Local Collection Name Visual Instruction Department Lantern Slides, 1900-1940 (P 217) Remove constraint Local Collection Name: Visual Instruction Department Lantern Slides, 1900-1940 (P 217)

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Description: Image Description from historic lecture booklet: "When the amount of ice developed form snow becomes great enough, it begins to move out by a sort of spreading motion from the place where it was formed. When it begins to move, it becomes a glacier. Not all snow-fields give rise to glaciers, but all glaciers have their sources in snow-fields. For convenience of reference the glaciers now known may be arranged in three classes, alpine, piedmont, and continental. These three classes are not always distinct and clearly separable, but typical examples of each may be selected that are well characterized, and differ in essential features from typical examples of each of the other classes. In each group there are conspicuous variations which suggest minor or more specific subdivisions."

Description: Image Description from historic lecture booklet: "Although ice under steady pressure slowly flows, when subjected to a decided strain it breaks, forming cracks, or crevasses in the glacier. Where the valley bottom is irregular, causing many steams in the moving ice, crevasses are especially abundant; and when the slope of the bottom is steep, the ice may become so crevassed that it is almost impossible to pass over it."

Description: Image Description from historic lecture booklet: "Another example of the Alpine type, with a terminal moraine shown in the foreground."

Description: Image Description from historic lecture booklet: "The Illecellewaet glacier. This is an inherited basin glacier, in which the inherited topography has exercised a greater influence upon the glacier form than has the auto-sculpture."

Description: Image Description from historic lecture booklet: "Many of the boulders and pebbles of the till are found to be glaciated, or marked with parallel scratches. Often they look as if engraved with a sharp need. Sometimes the scratches are deep and rough. A marked polish is seen on some stones. If we dig through the subsoil to the bed-rock, we shall often find the latter scratched in the same way, or even deeply grooved and carved into fluting's and the folding. The glacier, shod with stones at its base, drags these over the bed-rock, and thus both the moving fragments and the floor over which they move are polished and graven. The direction of the scratches corresponds to that in which the erratic boulders have been moved, and so, putting these other facts together, we have full proof that glaciers have done the work."

Description: Image Description from historic lecture booklet: "If we examine a field in Maine or New York, or norther Indiana, or Iowa, we shall find the stones, the soils, and the subsoil's often consisting of different material from the underlying bedrock. Pebbles and cobblestones, small boulders and great ones, even to hundreds of tons in weight, are scattered over the surface or buried in the finer waste. Bedrock like these loose stones may be found 10, 20, 50, or even some hundreds of miles away. these are "erratic" or strayed boulders. once moved by a glacier. as the Malaspina Glacier is now carrying stones from Mt. St. Elias to the sea-border."

Description: This is another treacherous crevasse which mountain climbers must constantly be on the lookout for.

Description: On the climb we turn aside for a look into the crevasses of Eliot Glacier in the midst of a sea of snow and ice.

Description: Image Description from historic lecture booklet: "Of the three great classes referred to above, the most widely known is the alpine type, which derives its name from the mountains of central Europe, where it was first studied. Alpine glaciers occur about high peak and on the summits and flanks of mountain ranges in many parts of the world, but reach their most perfect development in temperate regions. The Himalayas, the Alps, the mountains of Scandinavia, the Southern Alps of New Zealand, the Cordilleras, etc., furnish well-known examples. Glaciers of this type originate as a rule in amphitheaters and cirques, partially surrounded by lofty peaks and overshadowing precipices, and flow through rugged valleys leading from them as winding ice rivers which carry the excess of snow falling on the mountains into the lower regions, where a higher mean annual temperature causes it to melt. They are essentially streams of ice, formed usually by the union of many branches, and end abruptly when the drainage changes from a solid to a liquid form."