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Glossary of Glacier Terminology

Barren Zone

An area of fresh, vegetation-free bedrock around the margin of a retreating glacier that documents the recent loss of ice.


South-looking photograph showing a recently exposed bare bedrock barren zone on the south margin of South Sawyer Glacier in July 2001, Tongass National Forest, Coast Mountains, Alaska. Note the subglacial stream tunnel adjacent to the glacier margin.

Bergschrund

A single large crevasse or series of sub-parallel crevasses that develop at the head of a glacier. The location where ice pulls away from the bedrock wall of the cirque against which it accumulated. In winter, the crevasse fills with snow. In spring or summer, it reopens. (Originally a German term)


Northwest-looking oblique aerial photograph showing a bergschrund composed of several nested series of crevasses, located in the higher elevation accumulation area of the Fairweather Range, west of Mount Fairweather, Glacier Bay National Park, Alaska. The mid-ground field of view is ~ 1.5 miles wide.

Bergy Seltzer

A crackling or sizzling similar to that made by soft drinks or seltzer water but louder. The sound made as air bubbles formed at many atmospheres of pressure are released during the melting of glacier ice. Also called Ice Sizzle.


Northwest-looking photograph showing a part of the calving terminus of Holgate Glacier, Kenai mountains, Kenai Fiords National Park, Alaska, with a dense concentration of 'brash ice' floating in front of the terminus. This melting releases air bubbles that cause bergy seltzer.

Southeast-looking oblique aerial photograph showing an unnamed, meandering braided stream and delta. Individual stream channels have been filled by glacial meltwater high in rock flour from Hidden Glacier. Russell Fiord Geological Wilderness, St. Elias Mountains, Tongass National Forest, Alaska.

Braided Stream (Anastomizing Stream)

A stream that is characterized by a complex network of branches that continuously separate and reunite. Streams braid when they have a much greater sediment load than they can carry. Also called an Anastomosing Stream.


South-looking photograph showing diamond-shaped bars and meandering braided stream channels, East Fork Toklat River, Alaska Range, Denali National Park, Alaska.

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