Sam's Flight Over Yanert Glacier, AK (Early Spring, 2010)

Sam stands beside the airplane that he will fly over the Yanert Glacier in.

Sam sits inside the plane and talks to Greg the pilot.

A picture of the Yanert Fork, the feature formed by the Yanert Glacier meltwater. This feature can be described as an outwash plain and the water flowing through it can be called glaical milk. This water flows into the Nenana River.

A small meltwater lake at the terminus (end) of the Yanert Glacier. The Yanert Glacier can be seem in the mountains in the middle of the picture.

Another view of the meltwater lake.

A close up of the meltwater lake. The lake appears to be frozen. Notice the water channels that provide water to the lake in the summer at the bottom of the image.

A view of the Yanert Glacier and surrounding mountains.

A close up of the glacier's surface that shows surface moraines (mounds of gravel and dirt) and small meltwater ponds.

Surface moraines on the Yanert Glacier.

The Yanert Glacier and surrounding mountain peaks.

A close up of well developed crevasses on the Yanert Glacier.

A view up the Yanert Glacier into the mountain peaks.

What are you looking at?

Some glacial terms

Crevasse: A crack in a glacier caused by rapid extension. Crevasses over 10 m deep would be healed by internal flow, but much deeper crevasses can be maintained by continued tension.

(Kame) Delta: A deposit, often triangular, formed where a glacial stream entered into a proglacial lake.

Glacier: A mass of ice that originates on land, usually having an area larger than one tenth of a square kilometer; many believe that a glacier must show some type of movement; others believe that a glacier can show evidence of past or present movement.

Glacial milk: A term used to describe a sediment laden glacial stream. The stream described is usually laden with silt particles that are a result of glacial abrasion.

Glacial till: Accumulations of unsorted, unstratified mixtures of clay, silt, sand, gravel, and boulders; the usual composition of a moraine. It is deposited directly by glacier ice and is sometimes reworked by water after deposition.

Moraine: A mound, ridge, or other distinct accumulation of glacial till. These can occur at the terminus (end) of the glacier (terminal moraine), along the sides of the glacier (lateral moraines) or on the surface of the glacier towards its middle (medial moraine).

Meltwater: Water that has its origin from the melting glacier. It flows downslope, away from the glacier and may form a pro-glacial lake if it is empounded or become part of an outwash plain if there is sufficient water.

Outwash Plain: A plain of glaciofluvial deposits of stratified drift from meltwater-fed, braided, and overloaded streams beyond a glacier’s morainal deposits.

Pro-glacial: Pro-: a prefix meaning "in front of". Refers to the area immediately adjacent to a glacier, often affected by outwash and by ice- or moraine-dammed lakes.

Trim line: A clear boundary line on the wall of a glacier valley that delineates the maximum recent thickness of a glacier. It may be a change in the color of the bedrock, indicating the separation of weathered from unweathered bedrock; the limit of a former lateral moraine or other sediment deposit; or the boundary between vegetated and bare bedrock.

To find out more about glaciers and glacier terms go to the National Snow and Ice Data Center, the United States Geological Survey and the Montana State University Glacier Glossary.

All of the above definitions come from these sources.