Glacial landsystems: modelling glacial processes and landforms

Modelling glacial processes and landforms

David J. A. Evans is a glacial geomorphologist with global experience of glaciers and their landscape impacts. Here he explains how a ‘landsystem’ approach allows us to use our understanding of present landforms to interpret past evidence of glaciation. The link between process and landform, and the understanding of glaciers as systems, is key to AS and A-level. This article puts this knowledge into context and introduces the landsystem model

David Evans

Photograph 1 Push moraines on the foreland of Skaftafellsjökull, Iceland. These have been constructed annually as the glacier has actively receded since the 1950s. In the middle of the moraine field they are so close that they form a set of superimposed ridges. These are from the early 1990s when many Icelandic glaciers underwent readvances or stillstands

Glacial landsystems are models of various characteristic forms that the glacial system can take. They are areas in which recurring patterns of topography, soils and vegetation reflect the underlying geology, geomorphological processes and climate. Landsystems are often used in the study of glacial geomorphology to classify different types of glaciated terrain (e.g. lowland, plateau, mountain valley, icesheet beds) according to their characteristic sediments and landforms.

Landsystem models link landforms and processes, and so can be used to develop process-form models (Box 1 and Figure 1). Understanding the links between processes and landforms is central to the idea of the landscape system in geography AS and A-level. This article explains how the landsystem approach is a key tool in developing understanding of the functioning of the glacial landscape system.