52 terms

Marine Science 10

C= √(gd)
relationship of velocity (C), the acceleration due to gravity (g), and water depth (d) for shallow-water waves
C= L/T
relationship of velocity (C), wavelength (L), and period (T) for deep-water waves; velocity increases as wavelength increases. typically measured in meters per second
capillary wave
a tiny wave with a wavelength of less than 1.73 centimeters (0.68 inch), whose restoring force is surface tension; the first type of wave to form when the wind blows
constructive interference
the addition of wave energy as waves interact, producing larger waves
deep-water wave
a wave in water deeper than one-half its wavelength
destructive interference
the subtraction of wave energy as waves interact, prudicing smaller waves
separation of wind waves by wavelength (and therefore wave speed) as they move away from the fetch (the place of their formation). dispersion occurs because waves with long wavelengths move more rapidly than waves with short wavelengths
disturbing force
the energy that causes a wave to form
the uninterrupted distance over which the wind blows without a significant change in direction, a factor in wind-wave development
forced wave
a progressive wave under the continuing influence of the forces that formed it
free wave
a progressive wave free of the forces that formed it
fully developed sea
the theoretical masximum height attainable by ocean waves given wind of a specific strength, duration, and fetch. longer exposure to wind will not increase the size of the waves
gravity wave
a wave with wavelength greater than 1.73 centimeters (0.68 inch), whose restoring forces are gravity and momentum
group velocity
speed of advance of a wave train; for deep-water waves, half the speed of individual waves within the group
addition or subtaction of wave energy as waves interact; also called resonance
internal wave
a progressive wave occurring at the boundary between liquids of different densities
in ocean waves, the circular pattern of water particle movement at the air-sea interface. orbital motion contrasts with the side-to-side or back-and-forth motion of pure transverse or longitudinal waves
orbital wave
a progressive wave in which particles of the medium move in closed circles
plunging wave
a breaking wave in which the upper section topples forward and away from the bottom, forming an air-filled tube
progressive wave
a wave of moving energy in which the wave form moves in one direction along the surface (or junction) or the transmission medium (or media)
restoring force
the dominant force trying to return water to flatness after formation of a wave
rogue wave
a single wave crest much higher than usual, caused by constructive interference
simultaneous wind waves of many wavelengths forming a chaotic ocean surface. sea is common in an area of wind wave origin
sea state
ocean wave conditions at a specific place and time, usually stated in the Beaufort scale
pendulum-like rocking of water in an enclosed area; a form of standing wave that can be caused by meteoroological or seismic forces, or that may result from normal resonances excited by tides
seismic sea wave
tsunami caused by displacement of earth along a fault. (earthquakes and seismic sea waves are caused by the same phenomenon)
shallow-water wave
a wave in water shallower than 1/20 its wavelength
spilling wave
a breaking wave whose crest slides down the face of the wave
standing wave
a wave in which water oscillates without causing progressive wave forward movement. there is no net transmission of energy in a standing wave
Stokes drift
a small net transport of water in the direction a wind wave is moving
storm surge
an unusual rise in sea level as a result of the low atmospheric pressure and strong winds associated with a tropical cyclone. onrushing seawater precedes landfall of the tropical cyclone and causes most of the damage to life and property
the confused mass of agitated water rushing shoreward during and after a wind wave breaks
surf beat
the pattern of constructive and destructive interference that causes successive breaking waves to grow, shrink, and grow again over a few minutes' time
surf zone
the region between the breaking waves and the shore
mature wind waves of one wavelength that form orderly undulations of the ocean surface
transitional wave
waves that travel through water deeper than 1/20 their original wavelength but shallower than one-half their original wavelength
long-wavelength, shallow-water wave caused by rapid displacement of water
disturbance caused by the movement of energy through a medium
wave crest
highest part of a progressive wave above average water level
wave diffraction
bending of waves around obstacles
wave frequency
the number of waves passing a fixed point per second
wave height
vertical distance between a wave crest and the adjacent wave troughs
wave period
the time it takes for successive wave crests to pass a fixed point
wave reflection
the reflection of progressive waves by a vertical barrier. reflection occurs with little loss of energy
wave refraction
slowing and bending of progressive waves in shallow water
wave steepness
height-to-wavelength ration of a wave. the theoretical maximum steepness of deep-water waves is 1:7
wave train
a group of waves of similar wavelength and period moving in the same direction across the ocean surface. the group velocity of a wave train is half the velocity of the individual waves
wave trough
the valley between wave crests below the average water level in a progressive wave
the horizontal distance between two successive wave crests (or troughs) in a progressive wave
wind duration
the length of time the wind blows over the ocean surface, a factor in wind wave development
wind strength
average speed of the wind, a factor in wind wave development
wind wave
gravity wave formed by transfer of wind energy into water. wavelengths from 60 to 150 meters (200 to 500 ft.) are most common in open ocean