An exposed mountain peak protruding above an ice field or glacier is called a nunatak. The word comes from the Greenlandic Inuit term nunataq, meaning a mountain or rocky feature surrounded by ice. English geological writing has used it since the 1870s.
Nunataks may be isolated peaks, ridges, or clusters of rock that rise above an otherwise continuous ice sheet. Because glaciers cover and erode the surrounding landscape, nunataks often appear jagged or pyramid-shaped. They can also serve as fixed landmarks for explorers and scientists crossing ice-covered terrain.
A nunatak is not the same as a horn or an arête. A horn is a sharply pyramidal summit carved by several cirque glaciers, while an arête is a narrow, knife-edge ridge formed between glacial valleys. A nunatak is defined primarily by its relationship to surrounding ice, regardless of its exact shape.
Nunataks can also provide rare exposed habitats. Plants, lichens, and animals may survive on them even when the surrounding ice field remains continuous.