Use the “Quick Search” box to locate your required term and/or definition. The following “Search conditions” can be used to refine your search: “Contains”, “Begins with”, “Ends with”, “Equals”, “Does not contain” or “Does not equal.”
Eng ID Term Definition
3961
polarization
A condition of RADIANT ENERGY in which the VIBRATIONS take place in a regular manner, as in a straight line, circle or ellipse, in a plane p... more
A condition of RADIANT ENERGY in which the VIBRATIONS take place in a regular manner, as in a straight line, circle or ellipse, in a plane perpen­dicular to the path of travel.
3962
polarization error
See ERROR.
3963
polar orthographic projection
See PROJECTION.
3964
polder
LAND reclaimed from the SEA or other body of water by the construction of an EMBANKMENT to restrain the water. See DIKE.
3965
pole
Either of the two points of intersection of the surface of a sphere or SPHEROID and its AXIS. The origin of a system of POLAR COORDINATES. E... more
Either of the two points of intersection of the surface of a sphere or SPHEROID and its AXIS. The origin of a system of POLAR COORDINATES. Either of the two MAGNETIC POLES of a MAGNET. A long slender rod, as of timber or metal. Such a rod used for SOUNDING is called SOUNDING POLE.
3966
pole: celestial
Either of the two points of intersection of the CELESTIAL SPHERE and the extended AXIS of the EARTH, labelled N or S to indicate either the ... more
Either of the two points of intersection of the CELESTIAL SPHERE and the extended AXIS of the EARTH, labelled N or S to indicate either the north celestial pole or the south celestial pole.
3967
pole: depressed
The CELES­TIAL POLE below the HORIZON, of opposite NAME to the LATITUDE.
3968
pole: elevated
The CELESTIAL POLE above the HORIZON, agreeing in NAME with the LATITUDE.
3969
pole: geographic(al)
Either of the two points of intersection of the surface of the EARTH with its AXIS, labelled N or S to indicate either the north geographica... more
Either of the two points of intersection of the surface of the EARTH with its AXIS, labelled N or S to indicate either the north geographical pole or the south geographical pole.
3970
pole: magnetic
See MAGNETIC POLE.
3971
pole: terrestrial
One of the POLES of the EARTH. See POLE.
3972
pollution
The direct or indirect alteration of the physical, chemical, thermal, biological or radioactive properti­es of any part of the environment i... more
The direct or indirect alteration of the physical, chemical, thermal, biological or radioactive properti­es of any part of the environment in such a way as to create a hazard or potential hazard to the health, safety or welfare of any living species.
3973
polyconic projection
See PROJECTION.
3974
polygon
A non-selfintersecting, closed chain defining the boundary of an area.
3975
polynia
A water area enclosed in ICE, generally fast; this water area remains constant and usually has an oblong shape; sometimes limited to one sid... more
A water area enclosed in ICE, generally fast; this water area remains constant and usually has an oblong shape; sometimes limited to one side by the COAST. Any enclosed sea water area in PACK ICE other than a LEAD, not large enough to be called OPEN WATER. If a polynia is found in the same region every year, for example, off the MOUTHS of big RIVERS, it is called a recurring polynia. A temporary small clearing in PACK ICE which consists of small ICE FLOES and BRASH ICE in continuous local movement is called an unstable poly­nia; an opening which is flanked by large FLOES and therefore appears to be relatively stable is called a stable polynia. When frozen over, a polynia becomes an ice skylight from the point of view of the submariner.
3976
polyvinyl corer
See CORER: HYDROPLASTIC.
3977
pond
A small body of still water of artificial forma­tion, its BED being either hollowed out of the SOIL or formed by embanking and damming up a ... more
A small body of still water of artificial forma­tion, its BED being either hollowed out of the SOIL or formed by embanking and damming up a natural HOLLOW.
3978
pontoon
Floating structure, usually rectangular in shape which serves as landing, pierhead or bridge support.
3979
pool
A small body of still or standing water, perma­nent or temporary; chiefly one of natural formation. A deep or still place in a RIVER or STRE... more
A small body of still or standing water, perma­nent or temporary; chiefly one of natural formation. A deep or still place in a RIVER or STREAM. In ice terminology, any enclosed relatively small area in PACK ICE, drift ICE, other than a LEAD. See POLYNIA.
3980
porosity
The ratio of the aggregate volume of pore space in a ROCK or SEDIMENT to its total volume, usual­ly expressed as a percentage.