dynamic planet

Ablation Moraine

Mound or layer of moraine in the ablation zone of a glacier

Ablation Season

Period during which glaciers lose more mass than they gain.

Ablation Zone

Area or zone of a glacier where snow and ice ablation exceed accumulation.

Accumulation Area

Area of a glacier where more mass is gained than lost.

Accumulation Season

Period during which a glacier gains more mass than it loses.

Accumulation Zone

Area of a glacier where more mass is gained than lost.

Advance

When a mountain glacier’s terminus extends farther down valley than before.

Alpine Glacier

A glacier that is confined by surrounding mountain terrain.

Arête

Sharp, narrow ridge formed as a result of glacial erosion from both sides.

Band Ogives

Alternate bands of light and dark on a glacier.

Basal Sliding

The sliding of a glacier over bedrock.

Bergschrund

Crevasse that separates flowing ice from stagnant ice at the head of a glacier.

Branched-Valley Glacier

Glacier that has one or more tributary glaciers that flow into it.

Catchment Glacier

A semi permanent mass of firn formed by drifted snow behind obstructions.

Chattermarks

Striations left on the surface of exposed bedrock caused by glacial movement.

Cirque

Bowl shaped or amphitheater usually sculpted by a cirque glacier.

Cirque Glacier

Glacier residing in basins near ridge crests.

Cold Glacier

Glacier in which most of the ice is below the pressure melting point.

Compression Flow

Flow that occurs when glacier motion is decelerating down-slope.

Constructive Metamorphism

Snow metamorphism that sharpens the corners of an ice crystal.

Crevasse

Open fissure in the glacier surface.

Crevasse Hoar

Ice crystals that develop in glacial crevasses by sublimation.

Dead Ice

Part of a glacier that has ceased to flow.

Dirt Cone

Cone-shaped formation of ice covered by dirt.

Drain Channel

Preferred path for meltwater to flow from the surface.

Drift Glacier

A semi-permanent mass of firn formed by drifted snow.

Drumlin

Remnant elongated hills formed by historical glacial action.

Dump Moraine

A mound of moraine formed from rocks that fall off the ice.

End Moraine

An arch-shaped ridge of moraine found near the end of a glacier.

Equilibrium Zone

Zone of a glacier where precipitation equals melting.

Esker

Sinuous ridge of sedimentary material deposited by streams.

Extending flow

When glacier motion is accelerating down-slope.

False ogives

Bands of light and dark on a glacier formed by rock avalanching.

Fjord

Glacial troughs that fill with seawater.

Foliation

Layering in glacier ice caused by stress and deformation.

Forbes bands

Alternate bands of light and dark thought to be from different flow rates.

Forel stripes

Shallow, parallel grooves on a melting ice crystal.

Geyser

Fountain that develops when water is forced up to the glacier surface.

Glacial advance

When a glacier's terminus extends farther downvalley.

Glacial Erratic

Boulder swept from its place of origin by glacier movement.

Glacial grooves

Grooves cut into bedrock by gravel carried by glacial ice.

Glacial retreat

Position of a glacier's terminus moves farther upvalley.

Glacial striations

Grooves or gouges cut into bedrock by glacial ice.

Glacial till

Unsorted mixtures of clay, silt, sand, and gravel deposited by glaciers.

Glacial trough

A large U-shaped valley formed by glacial erosion.

Glaciated

Land covered in the past by any form of glacier.

Glacier

A mass of ice that originates on land.

Glacier cave

Cave of ice formed by meltwater beneath a glacier.

Glacier fire

Strong reflection of the sun on an icy surface.

Glacier flood

A sudden outburst of water released by a glacier.

Glacier flour

Fine powder created by glacier scraping over bedrock.

Glacier ice

Well-bonded ice crystals compacted from snow.

Glacier mill

Nearly vertical channel in ice formed by flowing water.

Glacier pothole

Potholes formed at the bottom of glaciers through erosion.

Glacier remainie

A glacier reconstructed from other glacier material.

Glacier snout

The lowest end of a glacier.

Glacier sole

The bottom of the ice of a glacier.

Glacier table

A rock that resides on a pedestal of ice.

Glacier terminus

The lowest end of a glacier.

Glacier toe

The lowest end of a glacier.

Glacier trough

U-shaped valleys transformed from V-shaped stream valleys.

Glacieret

A very small glacier.

Glacierized

Land overlaid at present by a glacier.

Ground moraine

Continuous layer of till near the edge of a retreating glacier.

Hanging glacier

A glacier that terminates near the top of a cliff.

Hanging valley

A valley formed by a small glacier with a higher valley bottom.

Headwall

A steep cliff, usually the uppermost part of a cirque.

Horn

A peak thinned and eroded by glacial cirques.

Ice apron

A mass of ice adhering to a mountainside.

Ice cap

A dome-shaped mass of glacier ice spreading in all directions.

Ice cave

Cave of ice formed by meltwater underneath a glacier.

Ice covered

Land overlaid at present by a glacier.

Ice divide

The boundary separating opposing flow directions of ice.

Ice quake

A shaking of ice caused by crevasse formation.

Ice sheet

A dome-shaped mass of glacier ice covering terrain.

Ice stream

A current of ice flowing faster than surrounding ice.

Ice-cemented glacier

A rock glacier with interstitial ice below the surface.

Ice-cored glacier

A rock glacier with a buried core of ice.

Icefall

Part of a glacier with rapid flow and chaotic surface.

Ice field

A mass of glacier ice similar to an ice cap.

Jokulhlaup

A large outburst flood that usually occurs when a glacial lake drains.

Lateral moraine

Ridge-shaped moraine deposited at the side of a glacier.

Marginal crevasse

Crevasse near the side of a glacier formed as it moves past walls.

Medial moraine

Ridge-shaped moraine in the middle of a glacier.

Meltwater conduit

Channel that drains meltwater out of a glacier.

Moraine

A mound or ridge formed by glacial till.

Moraine shoal

Glacial moraine that has formed a shallow place in water.

Moulin

A channel in ice formed by flowing water.

Mountain glacier

A glacier confined by surrounding terrain.

Negative mill

A geyser that forces water up to the glacier surface.

Niche glacier

Very small glacier that occupies gullies on north-facing slopes.

Nunatak

A rocky crag surrounded by a glacier.

Ogives

Alternate bands of light and dark ice on a glacier surface.

Outburst flood

Any catastrophic flooding from a glacier.

Outlet glacier

A valley glacier that drains an inland ice sheet.

Paternoster lakes

A series of tarns connected by a stream.

Piedmont glacier

Large ice lobe spread over surrounding terrain.

Polar glacier

A glacier entirely below freezing except for a thin layer at the surface.

Pothole

Channel formed in ice by flowing water.

Push moraine

Moraine built out ahead of an advancing glacier.