Ogives of the Forbes Type on Alpine Glaciers and a Study of their Origins

Abstract Ogives form beneath active ice falls whose heads are situated near or below the firn line. They consist of curved bands of alternating white, bubbly, less dense ice and darker, denser ice with fewer bubbles, extending throughout the thickness of the glacier. The difference in character is h...

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Bibliographic Details
Published in:Journal of Glaciology
Main Author: Fisher, Joel E.
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1962
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000018207
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000018207
Description
Summary:Abstract Ogives form beneath active ice falls whose heads are situated near or below the firn line. They consist of curved bands of alternating white, bubbly, less dense ice and darker, denser ice with fewer bubbles, extending throughout the thickness of the glacier. The difference in character is held to be due to the different conditions in the upper ice fall, through which the ice passes in one year at high speed. In summer the thin and shattered ice is exposed to high temperatures and melt water, while in winter the conditions are of Arctic-type throughout the thickness of the attenuated ice. A lane of ice on the Gornergletscher, originating as cold, dry snow with no melt water present, illustrates the character and origin of the white bubbly ice. The greater elevation of this cold-snow ice and the waves formed beneath the ice falls are considered to be the result of the lesser thermal conductivity and greater albedo of the white bubbly ice.