North Cascade Glaciers:   Photo Glossary

Mauri S. Pelto, Director NCGCP
Nichols College, Dudley, MA 01571

Photo Glossary

Ablation Zone  Crevasses   Ice Fall Accumulation Zone
Glacial Flour Lateral Moraine Active Glacier Glacial Golf
Moraine Crevasses Statigraphy Glacial Runoff Stagnant Glacier
Terminus   Glacial Streams Proglacial Lake Ice Worms

Crevasses: Open because of  an acceleration of the glacier.  They are seldom more than 100 feet deep in the North of page

The Ablation Zone is the section of the glacier where melting dominates.  By the end of the summer this area is exposed glacier ice. top of page
The Accumulation Zone is the zone of the glacier where snowfall exceeds snowmelt. top of page
An Icefall is an area of rapid movement on a steep slope with extensive open crevassing. top of page
A Moraine is a pile of debris carried down glacier and dumped at its end-terminus or lateral margin. top of page

A Stagnant Glacier is a glacier that is not moving significantly, notice lack of crevassing. top of page
An Active Glacier is moving at reasonable pace has crevassing and is eroding its bed. top of page
Glacier Runoff such as this waterfall from the Colonial Glacier  is the melt from the entire glacier.  It is highest on warm dry days when runoff from other sources is at its lowest. top of page
Glacier Flour causes the blue green color in this Lake on Mt. Daniels.  The flour is clay sized particle resulting from the glacier eroding the rock at its base. top of page
Crevasse Stratigraphy Like reading tree rings the annual snow layers are visible in crevasses and can be used to determine annual snow accumulation. top of page
Lateral Moraines mark the edges of a glacier.  In this case the lateral moraines extend well below the terminus of the current Kennedy Glacier, marking its maximum size in the Little Ice Age.  top of page

Terminus is the end of the glacier.  top of page
Proglacial Lake is a lake beyond the terminus of a glacier. top of page

Channel cut by Supraglacial stream on the Rainbow Glacier top of page
Glacier golf is a game played with rocks and sticks across rough alpine terrain.  1995 Mt. Daniels Open.  Eventual Champion Bill Prater left examines form of Maura Pelto about too tee off over the water hazard.  top of page
Ice Worms live on glaciers appearing largely in the evening when solar radiation is at a minimum.  We found that over a billion ice worms inhabit a single glacier. top of page
Collembola- Springtails-Snow fleas: Most species of Collembola found on glaciers of the North Cascades are also found off glaciers, on snowpack, on pools of water, or in duff in the forest.  At least one kind of Collembola (here referred to as the "Behemoth" (Agrenia n.sp.)) appears to occur only on the glaciers of our region -- not off glaciers, and not in other regions.  
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