The growth of ice crystals as a function of depth and time in polar firn and glacier ice has been investigated at a number of locations in Antarctica and Greenland. Thin sections of snow and ice were used to measure crystal size variations. Crystal growth rates are strongly temperature dependent with growth being very much retarded at the lower englacial temperatures. At Camp Century, Greenland, where the firn temperature is -24C (constant below 10 m depth) crystals grow approximately 23 times faster than at Plateau Station, Antarctica, where the in situ temperature is -57C. (Author).

This updated and expanded version of the second edition explains the physical principles underlying the behaviour of glaciers and ice sheets. The text has been revised in order to keep pace with the extensive developments which have occurred since 1981. A new chapter, of major interest, concentrates on the deformation of subglacial till. The book concludes with a chapter on information regarding past climate and atmospheric composition obtainable from ice cores.