Eskers

Location of eskers throughout Canada's Arctic.

The term esker comes from the Gaelic word eiscir, meaning "ridge". Eskers are sinuous ridges of gravel that have been deposited following the retreat of a glacier and can extend for many kilometres.

The formation of eskers is linked to the drainage pattern under a glacier. As the ice melts, water flows down through the glacier and drains out the front of the ice sheet. Often, large tunnels channel substantial amounts of meltwater which deposit much glacial debris. As the ice melts, increasing amounts of debris are channelled through these tunnels and deposited on the floor. Once the glacier has completely melted, the leftover debris forms a raised ridge, an esker.

The debris that comprises eskers is usually a mixture of silts, sands, gravels, and boulders. These are usually not transported very far from their source of origin, unlike other depositional formations.