Periglacial Environments

by

Hugh French

• LAST REVIEWED: 29 September 2015
• LAST MODIFIED: 29 September 2015
• DOI: 10.1093/obo/9780199363445-0038

Introduction

Periglacial environments are cold non-glacial environments characterized by frost action. They include the polar deserts and semi-deserts of the High Arctic, the extensive tundra zones of high northern latitudes, the northern parts of the boreal forests of North America and Eurasia, and the alpine zones that lie above timberline and below snowline in mid- and low-latitude mountains. To these must be added (1) the ice-free areas of Antarctica, (2) the high-elevation montane environments of central Asia, the largest of which is the Qinghai-Xizang (Tibet) Plateau of China, and (3) small oceanic islands in the high latitudes of both polar regions. Periglacial environments contain two important components of the cryosphere, namely, frozen ground and snow/sea ice. As such, periglacial environments play a critical role in global climate change through carbon and methane release associated with the thaw of perennially-frozen ground. Sea-ice issues are not considered.

The Historical Context

The term periglacial was first used by a Polish geologist, Walery von Łoziński, in 1909 to describe the angular rock-rubble surfaces formed by intense frost action that characterize the mountain summits of the Carpathian Mountains. A translation of this paper appears in a volume edited by D. J. A. Evans (Evans 1994). Subsequently, in the 1920s and 1930s, the concept of a periglacial zone was introduced to refer to the climatic and geomorphic conditions of areas peripheral to Pleistocene ice sheets and glaciers. Theoretically, this was a tundra zone that extended as far south as the tree line. In the mountains, it was a zone between timberline and snow line. Today, Łozinski’s definition is regarded as unnecessarily restricting; this is because frost-action phenomena can be completely unrelated to ice-marginal conditions. By the early 1970s, the assumptions concerning the efficacy of frost action were being seriously challenged. First, air climates were shown to be poor indicators of the relevant ground climates and observations failed to record the numerous freeze-thaw cycles thought responsible, a shortcoming compounded by a lack of moisture in many regions. Second, insufficient consideration was given to the varying susceptibility of rocks to frost action. Third, the duration and efficacy of cold-climatic conditions, both today and during the Quaternary, had not been fully considered. Julius Budel summarized the climax of traditional climatic geomorphology in Europe (Budel 1982). More recently, French 2007, a volume on periglacial environments, and French 2011, a chapter on the disciplinary context of the study of periglacial environments, provide more general global overviews.

• Budel, J. 1982. Climatic geomorphology. Princeton, NJ: Princeton Univ. Press.

  This is a translation of Klima-geomorphologie, published by Gebruder Borntraeger in 1977. Of special interest is Section 2.2 (pp. 49–119) that describes “the polar zone of excessive valley-cutting (the active periglacial region).” It includes discussion of the “the frost debris zone,” the “ice rind,” and the “taiga zone of valley-cutting.”

• Evans, D. J. A., ed. 1994. On the mechanical weathering of sandstones in temperate climates. In Cold climate landforms. 119–134. Chichester, UK: John Wiley.

  The mechanical weathering of rock by frost action is the central characteristic of periglacial environments. This is a translation of W. von Łoziński, “Über die mechanische Verwitterung der Sandsteine im gemässigten klima,” Academie des Sciences de Cracovie, Classe des Sciences Mathematiques et Naturelles 1 (1909): 1–25. A subsequent paper, published in 1912, developed the concept of a “periglacial zone.”

• French, H. M. 2007. The periglacial environment. 3d ed. Chichester, UK: John Wiley.

  DOI: 10.1002/9781118684931

  First published in 1976, the third edition is the best comprehensive monograph dealing with periglacial environments. The textbook is intended for undergraduates in geography, geology, earth sciences, and environmental sciences. Especially relevant to Periglacial Environments are pp. 31–45, to Perennially-Frozen Ground (Permafrost) are pp. 83–215, to Processes and Landforms of Periglacial Environments are pp. 49–82 and pp. 248–279, to Periglacial Landscapes are pp. 216–247, and to Periglacial Environments and Human Occupancy are pp. 351–387.

• French, H. M. 2011. Periglacial environments. In The SAGE handbook of geomorphology. Edited by K. J. Gregory and A. S. Goudie, 393–411. London: SAGE.

  This chapter discusses the disciplinary context within which periglacial environments are studied. It is argued that geocryologists, Quaternary scientists, and cold-climate geomorphologists all have legitimate and overlapping interests.