Sverdrup wave
312
Sverdrup wave a long, plane, propagating wave for which the Coriolis force on the
moving water particles is not compensated by a pressure gradient as in the
Kelvin wave, but which makes the water particles follow tracks that are ellipses
in the horizontal plane. For a Sverdrup wave it is necessary that the angular
frequency of the wave is greater than the Coriolis parameter. In a semi-enclosed
basin Sverdrup waves may be reflected and the superposition of different
waves may result in partially standing waves, which, however, are under the
influence of the Coriolis force. Such standing waves are often called Poincare
waves, although, for priority reasons, this term is sometimes used to denote
the general class of propagating plane waves.
swash -7wave approach.
S-wave (syn. secondary wave or shear wave) type of body wave (-7seismic wave) that
propagates by oscillation of the particles perpendicular to the direction of
motion (shearing motion). It does not travel through liquids. Its speed is 3.0
to 4.0 km S-i in the crust and 4.4 to 4.6 km S-i in the upper mantle. The S
stands for secondary; it is so named because it arrives later than the primary
P-wave.
swell sea waves that have left the area where they have been generated by the
wind or that have remained after the generating wind has disappeared. -7sea.
swim bladder -7gas bladder.
swimming speed the speed by which aquatic organisms can move in water is
generally related to the size of the organism. Swimming speeds in fish are
therefore often expressed in "body length per second". A distinction can be
made between maximum swimming speed, maintained only for a short time
("sprint") for escape or prey catching, and cruising speed when the animal
travels over long distances for hours or days. In many fish species cruising
speed is approximately 1 to 2 body lengths per second, while maximum
speed is approximately 4 to 10 body lengths. Some microscopic organisms,
such as the ciliate Mesodinium, can make very fast "jumps" at an estimated
velocity of more than a hundred times the body size per second, though the
absolute swimming speed is small.
symbiosis (syn. mutualism) the relationship between different species that live
together to the advantage of one of the two or both. Types of symbiosis are
commensalism (sharing food), endoecism (hiding in the host's proximity),
epizoism (living attached on the surface of the host) and inquilinism (hiding inside the host). Examples: symbiotic algae producing oxygen and organic
carbon used by the hosts such as corals, sea anemones (Actiniaria) and giant
clams; -7Polychaeta living together with a hermit crab inside a shell and feed-
312
Sverdrup wave a long, plane, propagating wave for which the Coriolis force on the
moving water particles is not compensated by a pressure gradient as in the
Kelvin wave, but which makes the water particles follow tracks that are ellipses
in the horizontal plane. For a Sverdrup wave it is necessary that the angular
frequency of the wave is greater than the Coriolis parameter. In a semi-enclosed
basin Sverdrup waves may be reflected and the superposition of different
waves may result in partially standing waves, which, however, are under the
influence of the Coriolis force. Such standing waves are often called Poincare
waves, although, for priority reasons, this term is sometimes used to denote
the general class of propagating plane waves.
swash -7wave approach.
S-wave (syn. secondary wave or shear wave) type of body wave (-7seismic wave) that
propagates by oscillation of the particles perpendicular to the direction of
motion (shearing motion). It does not travel through liquids. Its speed is 3.0
to 4.0 km S-i in the crust and 4.4 to 4.6 km S-i in the upper mantle. The S
stands for secondary; it is so named because it arrives later than the primary
P-wave.
swell sea waves that have left the area where they have been generated by the
wind or that have remained after the generating wind has disappeared. -7sea.
swim bladder -7gas bladder.
swimming speed the speed by which aquatic organisms can move in water is
generally related to the size of the organism. Swimming speeds in fish are
therefore often expressed in "body length per second". A distinction can be
made between maximum swimming speed, maintained only for a short time
("sprint") for escape or prey catching, and cruising speed when the animal
travels over long distances for hours or days. In many fish species cruising
speed is approximately 1 to 2 body lengths per second, while maximum
speed is approximately 4 to 10 body lengths. Some microscopic organisms,
such as the ciliate Mesodinium, can make very fast "jumps" at an estimated
velocity of more than a hundred times the body size per second, though the
absolute swimming speed is small.
symbiosis (syn. mutualism) the relationship between different species that live
together to the advantage of one of the two or both. Types of symbiosis are
commensalism (sharing food), endoecism (hiding in the host's proximity),
epizoism (living attached on the surface of the host) and inquilinism (hiding inside the host). Examples: symbiotic algae producing oxygen and organic
carbon used by the hosts such as corals, sea anemones (Actiniaria) and giant
clams; -7Polychaeta living together with a hermit crab inside a shell and feed-