Cryosphere glossary
esker
a sinuous ridge of sedimentary material (typically gravel or sand) deposited by streams that cut channels under or through the glacier ice.
evaporation
the physical process by which a liquid or solid substance is transformed to the gaseous state; the opposite of condensation; in meteorology, evaporation usually is restricted in use to the change of water from liquid to gas, while sublimation is used to the change from solid to gas as well as from gas to solid.
evaporation fog
fog formed as a result of evaporation of water that is warmer than the air.
excess ice
the volume of ice in the ground which exceeds the total pore volume that the ground would have under natural unfrozen conditions.
extending flow
when glacier motion is accelerating down-slope.
extensive discontinuous permafrost
(1) (North American usage) permafrost underlying 65 - 90% of the area of exposed land surface (2) (Russian usage) permafrost underlying 70 - 80% of the area of exposed land surface.
fabric
soil micromorphology.
fall wind
a cold wind blowing down an incline; a kind of katabatic wind.
false ogives
bands of light and dark on a glacier that were formed by rock avalanching.
fast ice
Ice that is anchored to the shore or ocean bottom, typically over shallow ocean shelves at continental margins; fast ice is defined by the fact that it does not move with the winds or currents. Also known as landfast ice.
Image
Note: This is land fast ice.
Michael Van Woert, National Oceanic and Atmospheric Administration/Department of Commerce
field
a region of space at each point of which a given physical or mathematical quantity has some definite value; for example, a gravitational field, magnetic field, or electric field; and, in meteorology, a pressure field, temperature field, etc; if the quantity specified at each point is a vector quantity, the field is said to be a vector field.
finger rafting
a process by which currents or winds push around thin ice so they slide over each other.
Image
Nilas showing finger rafting.
Antarctic Sea-Ice Processes and Climate (ASPeCt)
firn
rounded, well-bonded snow that is older than one year; firn has a density greater than 550 kilograms per cubic-meter (35 pounds per cubic-foot); called névé during the first year.
firn limit
the minimum elevation of firn lying on a glacier surface; each year's firn line marks a glacier's annual equilibrium line; also called firn line.
firn line
the minimum elevation of firn lying on a glacier surface; each year's firn line marks a glacier's annual equilibrium line; also called firn limit.
firn water table
the height of meltwater within saturated firn that is trapped over ice in a glacier.
firnspiegel
a thin sheet of ice formed on the glacier surface by rapid refreezing of solar-heated snow or firn, usually at high elevations during spring.
first-year ice
floating ice of no more than one year's growth developing from young ice; thickness from 0.3 to 2 meters (1 to 6.6 feet); characteristically level where undisturbed by pressure, but where ridges occur, they are rough and sharply angular.
Image
Ted Maksym, United States Naval Academy
fjord
glacial troughs that fill with sea water.
flaw lead
a navigable passage between pack ice and fast ice.