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Glossary of Glacier Terminology

Nunatak

A mountain peak or ridge that pokes through the surface of an Ice Field or a Glacier. It may separate adjacent Valley Glaciers (Greenlandic).


Northeast-looking photograph showing a well-formed sharp-peaked horn and connected arete ridge. The horn which pokes through the snow-covered Juneau Icefield is a nunatak, Tongass National Forest, Alaska.

North-looking oblique aerial photograph of the upper reaches of Sea Otter Glacier, Fairweather Range, Glacier Bay National Park, Alaska. The surface of each of the glacier's main tributaries contains several dozen band ogives.

Ogive

An arcuate, convex, down-glacier-pointing band or undulation that forms on the surface of a glacier at the base of an icefall. Two types of ogives occur: wave ogives, which are undulations of varying height and band ogives, which are alternating light- and dark-colored bands.


Southwest-looking photograph of the surface of the Vaughn Lewis Glacier, immediately below the Vaughn Lewis Icefall, Juneau Icefield, Tongass National Forest, Alaska. The surface of the central part of the glacier contains more than a dozen wave ogives.

Northwest-looking oblique aerial photograph of the terminus of Brady Glacier, Fairweather Range, Glacier Bay National Park, Alaska, which is fronted by a braided outwash plain that extends for > 4 miles. The surface is fed by numerous ice-marginal streams.

Outwash plain

A broad, low-slope angle alluvial plain composed of glacially eroded, sorted sediment (termed outwash), that has been transported by meltwater. The alluvial plain begins at the foot of a glacier and may extend for miles. Typically, the sediment becomes finer grained with increasing distance from the glacier terminus.


Northwest-looking oblique aerial photograph of the stagnant terminus of Rendu Glacier, Fairweather Range, Glacier Bay National Park, Alaska, showing a braided outwash plain fan delta that originates from a subglacial stream on the west side of the glacier.

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