Studied by 10 people
ablation area
the area of a glacier where more glacier mass is lost than gained
ablation hollows
depressions in the snow surface caused by the sun or warm
ablation moraine
mound or layer of moraine in the ablation zone of a glacier; the rock has been plucked from the mountainside by the moving glacier and is melting out on the ice surface
ablation season
period during which glaciers lose more mass than they gain; usually coincides with summer
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 usually coincides with winter
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; glacial advance occurs when a glacier flows down valley faster than the rate of ablation at its terminus
alpine glacier
a glacier that is confined by surrounding mountain terrain; also called a mountain glacier
arête
sharp
band ogives
alternate bands of light and dark on a glacier; usually found below steep narrow icefalls and thought to be the result of different flow and ablation rates between summer and winter
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; distinguished from a simple valley glacier that has only a single tributary glacier
catchment glacier
a semi permanent mass of firn formed by drifted snow behind obstructions or in the ground; also called a snowdrift glacier or a drift glacier
chattermarks
striations or marks left on the surface of exposed bedrock caused by the advance and retreat of glacier ice
cirque
bowl shaped or amphitheater usually sculpted out of the mountain terrain by a cirque glacier; also called a corrie or cwm
cirque glacier
glacier that resides in basins or amphitheaters near ridge crests; most cirque glaciers have a characteristic circular shape
cold glacier
glacier in which most of the ice is below the pressure melting point; nonetheless the glacier's surface may be susceptible to melt due to incoming solar radiation
compression flow
flow that occurs when glacier motion is decelerating down-slope
constructive metamorphism
snow metamorphism that adds molecules to sharpen the corners and edges of an ice crystal
crevasse
open fissure in the glacier surface
crevasse hoar
a kind of hoarfrost; ice crystals that develop by sublimation in glacial crevasses and in other cavities with cooled space and calm
dead ice
any part of a glacier which has ceased to flow; dead ice is usually covered with moraine
dirt cone
a cone-shaped formation of ice that is covered by dirt; a dirt cone is caused by a differential pattern of ablation between the dirt-covered surface and bare ice
drain channel
preferred path for meltwater to flow from the surface through a snow cover
drift glacier
a semi-permanent mass of firn formed by drifted snow behind obstructions or in the ground; also called a catchment glacier or a snowdrift glacier
drumlin
remnant elongated hills formed by historical glacial action; it is not clear exactly how they are formed and why they form only in some glaciated regions
dump moraine
a mound or layer of moraine formed along the edge of a glacier by rocks that fall off the ice; sometimes called a ground moraine
end moraine
an arch-shaped ridge of moraine found near the end of a glacier
equilibrium zone
zone of a glacier in which the amount of precipitation that falls is equal to the amount that melts the following summer
esker
a sinuous ridge of sedimentary material (typically gravel or sand) deposited by streams that cut channels under or through the glacier ice
extending flow
when glacier motion is accelerating down-slope
false ogives
bands of light and dark on a glacier that were formed by rock avalanching
fjord
glacial troughs that fill with seawater
foliation
layering in glacier ice that has distinctive crystal sizes and/or bubbles; foliation is usually caused by stress and deformation that a glacier experiences as it flows over complex terrain
forbes bands
alternate bands of light and dark on a glacier; usually found below steep narrow icefalls and thought to be the result of different flow and ablation rates between summer and winter
forel stripes
shallow
geyser
fountain that develops when water from a conduit is forced up to the surface of a glacier; also called a negative mill
glacial advance
when a mountain glacier's terminus extends farther downvalley than before; occurs when a glacier flows downvalley faster than the rate of ablation at its terminus
glacial erratic
a boulder swept from its place of origin by glacier advance or retreat and deposited elsewhere as the glacier melted; after glacial melt
glacial grooves
grooves or gouges cut into the bedrock by gravel and rocks carried by glacial ice and meltwater; also called glacial striations
glacial retreat
when the position of a mountain glacier's terminus is farther upvalley than before; occurs when a glacier ablates more material at its terminus than it transports into that region
glacial striations
grooves or gouges cut into the bedrock by gravel and rocks carried by glacial ice and meltwater; also called glacial grooves
glacial till
accumulations of unsorted
glacial trough
a large u-shaped valley formed from a v-shaped valley by glacial erosion
glaciated
land covered in the past by any form of glacier is said to be glaciated
glacier
a mass of ice that originates on land
glacier cave
a cave of ice
glacier fire
a phenomenon in which strong reflection of the sun on an icy surface causes a glacier to look like it is on fire
glacier flood
a sudden outburst of water released by a glacier
glacier flour
a fine powder of silt- and clay-sized particles that a glacier creates as its rock-laden ice scrapes over bedrock; usually flushed out in meltwater streams and causes water to look powdery gray; lakes and oceans that fill with glacier flour may develop a banded appearance; also called rock flour
glacier ice
well-bonded ice crystals compacted from snow with a bulk density greater than 860 kilograms per cubic meter (55 pounds per cubic-foot)
glacier mill
a nearly vertical channel in ice that is formed by flowing water; usually found after a relatively flat section of glacier in a region of transverse crevasses
glacier pothole
potholes formed at the bottom of glaciers through erosion caused by sand and gravel in melt-water; melt-water seeps through crevasses in the glaciers
glacier remainie
a glacier that is reconstructed or reconstituted out of other glacier material; usually formed by seracs falling from a hanging glacier
glacier snout
the lowest end of a glacier; also called glacier terminus or toe
glacier sole
the bottom of the ice of a glacier
glacier table
a rock that resides on a pedestal of ice; formed by differential ablation between the rock-covered ice and surrounding bare ice
glacier terminus
the lowest end of a glacier; also called glacier snout or toe
glacier toe
the lowest end of a glacier; also called glacier snout or terminus
glacier trough
u-shaped valleys transformed from v-shaped stream valleys due to erosion caused by passing glaciers
glacieret
a very small glacier
glacierized
land overlaid at present by a glacier is said to be covered; the alternative term glacierized has not found general favour
ground moraine
continuous layer of till near the edge or underneath a steadily retreating glacier
hanging glacier
a glacier that terminates at or near the top of a cliff
hanging valley
a valley formed by a small glacier that has a valley bottom relatively higher than nearby valleys formed by larger glaciers
headwall
a steep cliff
horn
a peak or pinnacle thinned and eroded by three or more glacial cirques
ice apron
a
mass of ice adhering to a mountainside
ice cap
a dome-shaped mass of glacier ice that spreads out in all directions; an ice cap is usually larger than an icefield but less than 50
ice cave
a cave of ice
ice covered
land overlaid at present by a glacier is said to be covered; the alternative term glacierized has not found general favor
ice divide
the boundary separating opposing flow directions of ice on a glacier or ice sheet
ice quake
a shaking of ice caused by crevasse formation or jerky motion
ice sheet
a dome-shaped mass of glacier ice that covers surrounding terrain and is greater than 50
ice stream
a current of ice in an ice sheet or ice cap that flows faster than the surrounding ice
ice-cemented glacier
a rock glacier that has interstitial ice a meter or so below the surface
ice-cored glacier
a rock glacier that has a buried core of ice
icefall
part of a glacier with rapid flow and a chaotic crevassed surface; occurs where the glacier bed steepens or narrows
ice field
a mass of glacier ice; similar to an ice cap
jokulhlaup
a large outburst flood that usually occurs when a glacially dammed lake drains catastrophically
lateral moraine
a ridge-shaped moraine deposited at the side of a glacier and composed of material eroded from the valley walls by the moving glacier
marginal crevasse
a crevasse near the side of a glacier formed as the glacier moves past stationary valley walls; usually oriented about 45 degrees up-glacier from the side wall
medial moraine
a ridge-shaped moraine in the middle of a glacier originating from a rock outcrop
meltwater conduit
a channel within
moraine
a mound
moraine shoal
glacial moraine that has formed a shallow place in water
moulin
a nearly vertical channel in ice that is formed by flowing water; usually found after a relatively flat section of glacier in a region of transverse crevasses; also called a pothole
mountain glacier
a glacier that is confined by surrounding mountain terrain; also called an alpine glacier
negative mill
a geyser; a fountain that develops when water from a conduit is forced up to the surface of a glacier
niche glacier
very small glacier that occupies gullies and hollows on north-facing slopes; may develop into cirque glacier if conditions are favorable
nunatak
a rocky crag or small mountain projecting from and surrounded by a glacier or ice sheet
ogives
alternate bands of light and dark ice seen on a glacier surface
outburst flood
any catastrophic flooding from a glacier; may originate from trapped water in cavities inside a glacier or at the margins of glaciers or from lakes that are dammed by flowing glaciers
outlet glacier
a valley glacier which drains an inland ice sheet or ice cap and flows through a gap in peripheral mountains
paternoster lakes
a series of tarns connected by a single stream or a braided stream system
piedmont glacier
large ice lobe spread out over surrounding terrain
