G L O S S A RY
All terms are explained when they are rst used in the text
but some of the more important or unusual ones are listed
here for ready reference.
ABYSS: deep ocean oor and all regions deeper than 18,000 feet
ALGAE: one of the four divisions in the plant kingdom. Simpler in struc—
ture than garden plants, algae are largely aquatic and range in size
from a single cell like the diatonz to large seaweeds such as the kelj)
ANODIC EFFECT: inuence of direct electric current on sh which tend to
move towards the positive pole or anode—see page 37
BEAM TRAWL—see tram!
BEAUFORT WIND SCALE: system originally devised by Admiral Beaufort
in the nineteenth century which classied wind forces by the amount
of sail carried by a ship. It has since been modied and expanded for
international meteorological use—see page 134
BENDS———SC€ decompression
BENTHOS: the plants and animals attached to the sea—bed or crawling on it.
BORE: tidal phenomenon which occurs when water is forced by tidal
action into large but rapidly narr0wing river estuaries. The excess water
escapes by moving upstream in a wavelike front over the river water——
see page 140
BOUNDARY WAVES—see internal waves
BRACKISH WATER: water with a salinity of less than 17,000 parts per
million (p.p.m.) and more than 500 p.p.m.
BREATHING MIXTURES—see nitrogen narcosir
CAVITATION: formation, growth and rapid collapse of gaseous and vapeur
bubbles. Cavitation can be a serious source of noise, corrosion and loss
of efciency in marine propellers—see page 197
CONTINENTAL RISE—see continental shelf
CONTINENTAL SHELF: extension of continental land mass into the ocean.
lt slopes gently with a gradient of about 1 in 500 breaking off around
the Too—fathom mark into a steeper gradient, I in 40, at the start of the
23!
All terms are explained when they are rst used in the text
but some of the more important or unusual ones are listed
here for ready reference.
ABYSS: deep ocean oor and all regions deeper than 18,000 feet
ALGAE: one of the four divisions in the plant kingdom. Simpler in struc—
ture than garden plants, algae are largely aquatic and range in size
from a single cell like the diatonz to large seaweeds such as the kelj)
ANODIC EFFECT: inuence of direct electric current on sh which tend to
move towards the positive pole or anode—see page 37
BEAM TRAWL—see tram!
BEAUFORT WIND SCALE: system originally devised by Admiral Beaufort
in the nineteenth century which classied wind forces by the amount
of sail carried by a ship. It has since been modied and expanded for
international meteorological use—see page 134
BENDS———SC€ decompression
BENTHOS: the plants and animals attached to the sea—bed or crawling on it.
BORE: tidal phenomenon which occurs when water is forced by tidal
action into large but rapidly narr0wing river estuaries. The excess water
escapes by moving upstream in a wavelike front over the river water——
see page 140
BOUNDARY WAVES—see internal waves
BRACKISH WATER: water with a salinity of less than 17,000 parts per
million (p.p.m.) and more than 500 p.p.m.
BREATHING MIXTURES—see nitrogen narcosir
CAVITATION: formation, growth and rapid collapse of gaseous and vapeur
bubbles. Cavitation can be a serious source of noise, corrosion and loss
of efciency in marine propellers—see page 197
CONTINENTAL RISE—see continental shelf
CONTINENTAL SHELF: extension of continental land mass into the ocean.
lt slopes gently with a gradient of about 1 in 500 breaking off around
the Too—fathom mark into a steeper gradient, I in 40, at the start of the
23!