split hill esker
Copyright Geological Survey of Ireland 2006.

Eskers are long, sinuous, low ridges of stratified sand and gravel which were formed by the deposition of sediment from meltwater streams running underneath an ice sheet. Eskers are steep-sided, and are usually to be found running at or near right angles to the ice front. The term 'esker' comes from the Irish 'eiscir', meaning a ridge.

In Ireland , eskers rarely exceed 20-25 metres in height and about 40 metres in width. Eskers are commonplace in   midlands where they appear to run toward ‘end-moraines’ that represent the position of ice fronts. Here eskers are up to 10-15km in length (much smaller than in Finland where eskers up to 200km long are to be found).