5. Eroded by ice

There is a very wide range of spatial and temporal scales reflected in the types of glacial erosional landforms, from individual millimetre-wide striae that can form over a few days to fjords tens of kilometres long that require hundreds of thousands of years to develop. Erosional landforms can be discussed in categories defined by three spatial scales: microscale, macroscale, and megascale, the latter also including whole landscapes that have unmistakable glacial erosional origins. ‘Eroded by ice’ describes these different erosional forms and explains that they are rarely viewed in isolation because microscale erosional marks are superimposed on macroscale forms, which in turn are superimposed on megascale surfaces to constitute erosional landscapes.