Untitled Flashcards Set

Calving Glacier

A glacier with a terminus that ends in a body of water (river, lake, ocean) into which it calves icebergs.

Cirque Glacier

A small glacier that forms within a cirque basin, generally high on the side of a mountain.

Hanging Glacier

A glacier that originates high on the wall of a glacier valley and descends only part of the way to the surface of the main glacier.

Ice Cap

A dome-shaped accumulation of glacier ice and perennial snow that completely covers a mountainous area or island.

Ice Sheet

A thick, subcontinental to continental-scale accumulation of glacier ice and perennial snow that spreads from a center of accumulation.

Piedmont Glacier

A fan or lobe-shaped glacier, located at the front of a mountain range, formed when valley glaciers flow onto a plain.

Polar Glacier

A glacier with a thermal regime in which ice temperatures always remain below the freezing point.

Temperate Glacier

A glacier with a temperature regime in which liquid water coexists with frozen water during part or all of the year.

Valley Glacier

A glacier that flows within the walls of a mountain valley, also known as an Alpine Glacier.

Albedo

The proportion of the incident light or radiation that is reflected by a surface.

Ablation

The loss of ice and snow from a glacier system through various processes such as melting and runoff.

Accumulation

The addition of ice and snow into a glacier system from processes including precipitation and firnification.

Advance

An increase in the length of a glacier compared to a previous point in time.

Amundsen Sea Embayment

A sea in western Antarctica that has contributed to around 40% of sea level rise.

Antarctic Circumpolar Current (ACC)

An ocean current flowing clockwise around Antarctica.

Arete

A jagged, narrow ridge that separates two adjacent glacier valleys or cirques.

Basal Sliding

The act of glacier sliding over the bed due to meltwater under the ice acting as a lubricant.

Bergschrund

A large crevasse that develops at the head of a glacier where ice pulls away from the bedrock wall.

Calving

The process by which pieces of ice break away from the terminus of a glacier.

Chatter Marks

Small, closely spaced grooves or scars formed in bedrock by rocks frozen in basal ice.

Cirque

A bowl-shaped, amphitheater-like depression eroded into the head of a glacier valley.

Debris Cone

A mound of debris-covered ice, with a thick enough sediment cover to protect the ice from melting.

Dendrochronology

The study of tree rings to provide information about the glacial and climatic history of an area.

Disarticulation

The process where large blocks of ice detach from the thinning terminus of a glacier.

Drumlin

An elongated ridge of glacial sediment sculpted by ice moving over the bed of a glacier.

Erratic

A rock transported a significant distance by a glacier and deposited by melting of the ice.

Esker

A steep-sided sediment ridge that forms within a subglacial or englacial stream channel.

Fjord

A glacially eroded U-shaped valley that extends below sea level and connects to the ocean.

Firn

An intermediate stage in the transformation of snow to glacier ice, more dense than fresh snow.

Glacial Lake

An accumulation of standing liquid water on, in, or under a glacier.

Glacier

A large, perennial accumulation of ice, snow, rock, and sediment moving down slope under its own weight.

Milankovitch Cycles

Cyclical variations in Earth's orbit and axial tilt that influence climate over long time spans.

Moraine

Unstratified and unsorted deposits of sediment that form through direct action or contact with glacier ice.

Nunatak

A mountain peak or ridge that pokes through the surface of an ice field or glacier.

Retreat

A decrease in the length of a glacier when more ice is lost to melting and/or calving.

Tidewater Glacier

A glacier with a terminus that ends in a body of water influenced by tides.

U-Shaped Valley

A valley with a parabolic cross-section, steep walls, and a broad flat floor formed by glacier erosion.

Varve

A pair of sedimentary layers that form in an annual cycle due to seasonal weather changes.