Parameter Tree:
EARTH SCIENCE > CRYOSPHERE > GLACIERS/ICE SHEETS

Definition:
Glaciers are masses of land ice, formed by the further recrystallization of
firn, flowing continuously from higher to lower elevations. Ice sheets are a
continuous sheet of land ice that covers a very large area and moves outward in
many directions. This type of ice mass is so thick as to mask the land surface
contours, in contrast to the smaller and thinner highland ice. The continental
glacier of Greenland is sometimes called the Inland Ice. This term is often
used to describe the great ice masses that characterized the ice ages.


Reference:
American Meteorological Society Glossary of Meteorology.
http://amsglossary.allenpress.com/glossary/>