Page 9 - The Call of Antarctica: Exploring and Protecting Earth's Coldest Continent

GLOSSARY

aurora: a natural display of light in the sky, usually occurring in polar
regions. Auroras occur when particles from the sun hit Earth’s upper
atmosphere and move under the influence of its magnetic field.
crevasse: a deep crack in a glacier or the ground
echo sounding: a detection system that uses sound waves to measure the
depth of water or ice
ecosystem: a community of living and nonliving things, including animals,
plants, water, air, and soil, that interact with and support the health of
one another
extinction: the permanent dying out of a species of plant or animal
fossil: the remains or traces of an organism that lived in the distant past.
Fossils include bones that have turned to rock and the impressions that
ancient organisms left in stone.
frazil: needlelike or featherlike crystals that form in seawater that is
beginning to freeze
glacier: a large mass of ice that flows slowly over the land
iceberg: a piece of ice that breaks off a glacier or ice shelf
ice core: a long cylindrical piece of ice used for scientific study. Researchers
use heavy machinery to drill cores and extract them from ice sheets.
ice floe: a large flat piece of floating sea ice
ice shelf: a large flat plate of ice from a glacier that extends out over
the sea
invasive species: a plant or animal species that moves or is carried to a
new place. Invasive species often crowd out or kill native species.
meteorite: large pieces of rock or metal that travel through space and
hit Earth
nilas: thin plates of clear frozen ice on seawater
ozone hole: a region of the atmosphere where the layer of ozone gas,
which protects living things from harmful rays from the sun, has thinned out.
Ozone holes are formed under cold atmospheric conditions by reactions
caused by human-made chemicals, which have now been mostly banned.
pack ice: a thick mass of ice formed from many ice floes gathered together
radar: a system for measuring the location of objects using radio waves

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