Chapter 15 - Periglacial Processes in Glacial Environments

Abstract

The Earth’s history is marked by dramatic swings in global climate giving rise to fluctuations between ‘greenhouse’ and ‘icehouse’ conditions; the latter marked by continental-scale ice sheets and widespread glaciation. During an ice house regime cold temperatures extend well beyond the geographic limits of glaciation creating a periglacial zone dominated by cold nonglacial processes ranging from seasonal freeze–thaw to intense frost action to permafrost. Under full glacial conditions a proglacial belt of cold nonglacial conditions will parallel the limit of active glaciation. In some cases ice-free areas may be completely surrounded by glaciers; however, most of the time it forms a broad zone that transitions from intense cold and frozen ground to progressively more temperate environments where frost action and permafrost are replaced by seasonal frost and snow. This chapter focuses on geomorphic processes and features that characterize areas dominated by periglacial conditions and their relation to glacial environments.