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
3721
parallel sailing
See SAILING.
3722
parallel sounding
A system of surveying in which the MOTHER VESSEL takes soundings while following a given course; at the same time an array of satellite boat... more
A system of surveying in which the MOTHER VESSEL takes soundings while following a given course; at the same time an array of satellite boats takes soundings along parallel courses at a fixed distance from the MOTHER VESSEL. The satellite boats determine their position relative to the MOTHER VESSEL. The term is also employed when a single vessel takes multiple lines of soundings with transducers arranged at regular intervals on outriggers.
3723
parameter
A quantity which remains constant within the limits of a given case or situation.
3724
parametric
Characterizing a quantity which is influenced by the behaviour of one or more parameters.
3725
parametric latitude
See LATITUDE.
3726
paranthelion
PHOTOMETEOR of the HALO family, consi­sting of white, round, luminous spots, having a diameter slightly greater than that of the SUN, which ... more
PHOTOMETEOR of the HALO family, consi­sting of white, round, luminous spots, having a diameter slightly greater than that of the SUN, which appe­ars at 120° from it in the case of ordinary pa­ranthe­lia, and at 90° in the case of extraordi­nary paranthe­lia. The HEIGHT of the spots above the HORIZON is that of the SUN.
3727
parantiselena
PHOTOMETEOR of the HALO family, analo­gous to the PARANTHELION, the luminary being the MOON.
3728
paraselene
Optical phenome­non of the HALO family, similar to but less brilliant than the PARHELION, the luminary being the MOON.
3729
paraselenic circle
PHOTOME­TEOR of the HALO family, analogous to the PARHELIC CIRCLE, the luminary being the MOON.
3730
parhelia associated with the 22° halo
PHOTOMETEOR of the HALO family, consisting of two luminous iridescent spots which appear on the PARHELIC CIRCLE close to the SMALL HALO.
3731
parhelia associated with the 46° halo
PHOTOMETEOR of the HALO family consisting of two luminous, iridescent spots which appear on the PARHELIC CIRCLE close to the LARGE HALO.
3732
parhelic circle
PHOTOMETEOR of the HALO family, consi­st­ing of a white, horizontal circle, situated at the same angular height as the SUN.
3733
partial eclipse
See ECLIPSE.
3734
partial node
The point, line, or surface, in a STAN­DING WAVE system where some characteristic of the wave field has a minimum AMPLITUDE differing from z... more
The point, line, or surface, in a STAN­DING WAVE system where some characteristic of the wave field has a minimum AMPLITUDE differing from zero.
3735
partial tide
See TIDE.
3736
particle velocity
In ocean wave studies, the instan­taneous VELOCITY of a water particle undergoing orbi­tal motion. At the CREST, its direction is the same a... more
In ocean wave studies, the instan­taneous VELOCITY of a water particle undergoing orbi­tal motion. At the CREST, its direction is the same as the direction of progress of the WAVE, and at the TROUGH it is in the opposite direction.
3737
particular scale
See SCALE.
3738
Particularly Sensitive Sea Area (PSSA)
An area which needs special protection through action by the IMO because of its significance for recognised ecological or socio-economic or ... more
An area which needs special protection through action by the IMO because of its significance for recognised ecological or socio-economic or scientific reasons and which may be vulnerable to damage by maritime activities.  A PSSA is a type of ENVIRONMENTALLY SENSITIVE SEA AREA (ESSA).
3739
pascal
The unit of pressure in the SI SYSTEM.
3740
pass
A break in a MOUNTAIN RANGE, permitting easier passage from one side of the range to the other; also called a COL. A navigable CHANNEL leadi... more
A break in a MOUNTAIN RANGE, permitting easier passage from one side of the range to the other; also called a COL. A navigable CHANNEL leading to a HARBOUR or RIVER. Sometimes called PASSAGE. A narrow connecting CHANNEL between two bodies of water.