Existing Glaciers of the United States (Classic Reprint)

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Excerpt from Existing Glaciers of the United States The formation of glaciers in any region depends primarily on the fact that the amount of snow precipitated during a term of years exceeds the amount dissipated by melting and evaporation. In this manner snow bank of broad extent are formed, the lower portions of which become compacted into ice. The change from snow to ice is known to result from pressure, and as ice is mobile under pressure, either by reason of its inherent plasticity or as a result of regelation, the weight of this mass tends to change its form, and it thus acquires motion, which takes the direction of least resistance. The essential characteristic of glaciers seems to be that they result from the consolidation of snow in regions of secular accumulation, i. Above the snow-line, and ¿ow to regions of dissipation, i. Below the snow-line. From these primary conditions result a multitude of second ary phenomena. For convenience of reference we will divide glaciers into alpine and continental, not that the two classes are alway distinct and separable, but for the reason that typical examples of each are well characterized and capable of specific description. Variations occur in each class which may suggest minor subdivisions. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.