Chapter 8

disturbing force

the energy that causes waves to form

ocean waves

an air-water interface that creates movement of air across the ocean surface

atmospheric waves

an air-air interface that creates movement of different air masses

internal waves

an orbital wave that moves along interface between fluids of different density

longitudinal waves

a wave phenomenon when particle vibration is parallel to the direction of energy propagation

transverse waves

a wave in which particle motion is at right angles to energy propagtion

orbital waves

a wave phenomenon in which energy is moved along the interface between fluids of different densities

crest

the portion of an ocean wave that is displace above the still-water level

trough

the part of an ocean wave that is displaced bwlow the still-water level

still water level

the horizontal surface halfway between creats and trough of a wave

wave height

the vertical distance between a crest and the adjoing trough

wavelength

the horizontal distance between two corresponding points on successive waves, such as from crest to crest

wave steepness

ratio of wave height to wavelength

wave period

the elapsed time between the passage of two successive wave crests past a fixed point

frequency

the number of wave crests passing a fixed locaion per unit of time

circular orbital motion

the motion of water particles caused by a wave as the wave is transmitted through water

wave base

the depth at which circular orbital motion becomes negligible

deep-water waves

an ocean wave traveling in water that has a depth greater than one-half the average wavelength

wave speed

the rate at which a wave travels

shallow-water waves

a wave on the surface having a wavelength of at least 20 times water depth

transitional waves

a wave moving from deep water to shallow water that has a wavelength more than twice the water depth but less tahn 20 times the water depth

capillary waves

an ocean wave whose wavelength is less than 1.74 cm

gravity waves

a wave for which the diminant restoring force is gravity

sea

a portion of the ocean where waves are being generated by wind

Beaufort Wind Scale

a standardized wind scale tha describes the appearance of the sea surface from dead calm conditions to hurricane-force winds

fully developed sea

the maximum average size of waves that can be developed for a given wind speed when it has blown in the same direction for a minimum duration over a minimum fetch

swell

a free ocean wave by which energy put into ocean waves by wind in the sea is transported with little energy loss across great stretches of ocean to the margins of continents where the energy is released in the surf zone

wave train

a series of waves from the same direction

wave dispersion

the separation of waves as they leave the sea area by wave size

decay distance

the distance over which waves change from a choppy 'sea' to uniform swell

constructive interference

a form of wave interference in which two waves come together in phase to produce a greater dispacement from the still-water line than that produced by either of the waves alone

destructive interference

a form of wave interference in which two waves come together out of phase and produce a wave with less displacement than the larger of the two waves would have produced alone

mixed interference

a pattern of wave interference in which there is a combination of constructive and destructive interference

surf beat

an irregular wave pattern caused by mixed intereference that results in a varied sequence of larger and smaller waves

surf zone

the nearshore zone of breaking waves

shoaling

to become shallow

spilling breaker

a type of breaking wave that forms on a gently sloping beach, which gradually extracts the energy from the wave to produce a turbulent mass of air and water that runs down the front slope of the wave

plunging breaker

impressive curling breakers that form on moderately sloping beaches

surgin breaker

a compressed breaking wave that builds up over a short distance and surges forward as it breaks

surfing

the sport of riding on the crest of along the tunnel of a wave

refreaction

the process by which the part of a wave in shallow water is slowed down, causing the wave to bend and align itself nearly parallel to the shore

orthogonal lines

a line constructed perpendicular to a wave front and spaced so that the energy between lines is equal at all times

wave reflections

a process that reflects waves back into the ocean with little loss of energy

standing waves

a wave, the form of which oscillates vertically without progressive movement

tsunami

a seismic sea wave

spalsh waves

a long-wavelength wave created by a massive object or series of objects falling into water

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