Major Funding The Laura Moore Cunningham Foundation



Glaciers: Glossary

A

ablation zone
the area of a glacier where it loses ice and snow through melting, evaporation, calving and wind action
accumulate
to gain or add mass
accumulation zone
the area of a glacier where it gains new snow and ice
alpine glacier
a glacier that forms in high mountains and is confined by mountain terrain
altitude
elevation; vertical distance from sea level
arête
sharp mountain ridge formed when two glaciers meet
atmosphere
the layer of gases (air) that surrounds the earth

B

bedrock
the solid rock under a glacier or ice sheet

C

calving
the process by which pieces of ice break off from glaciers and fall into water to become icebergs
cirque
a bowl-shaped hollow or basin near the head of a valley or mountainside resulting from glacial erosion. If filled with water, this is known as a tarn or a cirque lake
cirque glacier
a glacier that occupies basins near ridge crests, having a characteristic circular shape with its width often greater than its length
compacted
tightly pressed
compressed
weighed down, squashed, pressed together into less space or volume
crevasse
an open crack in a glacier's surface
cryosphere
the earth system that contains frozen water in the form of sea ice, lake or river ice, snow cover, glaciers, ice caps, ice sheets and frozen ground (permafrost)
currents
the continuous, predictable, directional movement of seawater

D

debris
broken, jumbled rock and soil fragments
dense
solid, thick, tightly packed with few air pockets
deposition
the process by which glaciers deposit and leave behind the rocks, gravel and sediments that were once frozen in their ice

E

equilibrium line
the area on a glacier where accumulation and ablation are balanced
erosion
the process by which Earth's materials are worn down and transported through natural causes such as wind, water and glacial ice
evaporate
when a liquid dissolves into a gas due to heat or sunlight

F

firn
compact snow that lasts more than a year and is covered by the next winter's snowfall, an intermediate stage between snow and ice
freshwater
water that is drinkable – not saltwater

G

glacial erractics
boulders deposited by glaciers far from their original source
glacial surge
a short period of time in which a glacier may move 10 – 100 times faster than normal
glacial till
material (gravel, sand, rocks, soil) deposited by glacial ice
glaciation
the process of a glacier carving out a landscape

H

head
the top of an alpine glacier
horn
a pyramid-shaped peak chiseled by three or more glaciers, such as the Matterhorn in the Swiss Alps
hydroelectric power
a form of renewable energy that uses the power of moving water to generate electricity

I

Ice Age
an era of cold temperatures when ice covers large parts of the earth. The last Ice Age ended about 11,000 years ago.
ice cap
large expanse of glacial ice with a slightly domed shape that spreads out in all directions, found in the north and south polar regions. Ice caps are similar to ice sheets but cover less than 20,000 sq. miles (50,000 sq. km).
ice core
samples of ice from deep within glaciers that provide information about past climates in their trapped air bubbles, revealing temperature, atmosphere composition, and previous climate changes
ice sheet
a huge mass of glacial ice that covers more than 20,000 square miles (50,000 square kilometers). Ice sheets cover most of Antarctica and Greenland.
ice shelf
permanent floating sheet of ice connected to a land mass, found along Arctic and Antarctic coastlines
ice stream
parts of an ice sheet that move faster than the sheet as a whole
iceberg
floating pieces of ice that have broken off from land-based ice shelves or glaciers
isolated
remote; far away from humans and buildings

L

light spectrum
visible light, which is part of the electromagnetic spectrum, includes seven colors of different wavelengths. Glacial ice absorbs red and reflects blue.

M

marine ecosystem
all of the living and non-living factors that interact in a saltwater ocean environment
moraine
material left behind by a glacier, such as rocks, gravel, soil and sand

P

piedmont glacier
a glacier that flows into a flat, lowland area and spreads out

R

rock flour
rocks crushed by glaciers into fine powder that often gives meltwater a milky, grayish apperance

S

satellite imagery
pictures taken from satellites
striations
scratches or grooves in bedrock caused by glaciers

T

terminus
the end, snout, or leading edge of a glacier
tidewater glacier
a glacier that terminates in the ocean

U

u-shaped valley
a valley with steep sides and a rounded bottom, created by a glacier moving through it and eroding the landscape

V

valley glacier
an alpine glacier whose flow is confined by valley walls

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