WAVE AGE 



WAVE CHARAaERISTICS 



1. Wave crest; 2. Wavelength; 3. Direction of wave travel; 4. Height; 

 5. Wave trough; 6. Still water level; 7. Depth; 8. Ocean bottom 



with speed dependent upon the properties of the 

 medium. 



2. A ridge, deformation, or undulation of the 

 surface of a liquid. 



wave age — The state of development of a wind- 

 generated sea surface wave, conveniently ex- 

 pressed by the ratio of wave speed to wind speed. 

 Wind speed is usually measured at about 25 feet 

 (8 meters) above still water level. (5) 



wave base — The depth at which wave action ceases 

 to stir tlie sediments. ( 2 ) 



wave celerity — Tlie magnitude of wave speed. 



wave crest — The highest part of a wave. Also 

 that part of the wave above still water level. 

 (61) {See figure for wave.) 



wave crest length — (or crest width) . The length 

 of a wave along its crest. (61) (See figure 

 for wave.) 



wave decay — The change which waves undergo 

 after they leave a generating area (fetch) and 

 pass through a calm, or region of lighter or op- 

 posing winds. In the process of decay, the sig- 

 nificant wave height decreases and the signifi- 

 cant wavelength increases. (61) 



wave deltas — See washovers. 



wave direction — The direction from which a wave 

 approaches. (61) (See figure for wave.) 



wave filter — See filter. 



wave forecasting — The theoretical determination 

 of future wave characteristics, usually from ob- 

 served or predicted meteorological phenomena. 

 (61) 



wave front — The leading side of a wave. (68) 

 (See figure for refraction diagram.) 



wave generation — 1. The creation of waves by nat- 

 ural or mechanical means. 



2. In wave forecasting the growth of waves 

 caused by a wind blowing over a water surface 

 for a certain period of time. The area involved 

 is called the generating area or fetch. 

 (61) 



wave group — A series of waves in which the wave 

 direction, wavelength, and wave height vary 

 only slightly. (61) 



wave height — The vertical distance between a 

 wave crest and the preceding wave trough. 

 See also significant wave height. (61) {See 

 figure for wave.) 



wave height coefficient — The ratio of the wave 

 height at a selected point in shallow water to 

 the deepwater wave height. The refraction co- 

 efficient multiplied by the shoaling factor. ( 61 ) 



wave hindcasting — The calculation from historic 

 synoptic wind charts of the wave characteristics 

 that probably occurred at some past time. (61) 



wave interference — The phenomenon which re- 

 sults when waves of the same or nearly the same 

 frequency are superposed. It is characterized 

 by a spatial or temporal distribution of ampli- 

 tude of some specified characteristic differing 

 from that of the individual superposed waves. 

 (6) 



wavelength — 1. The distance between correspond- 

 ing points of two successive periodic waves in 

 the direction of propagation, for which the os- 

 cillation has the same phase. Unit of measure- 

 ment is meters. 



Note : The wavelength of monochromatic radi- 

 ant energy depends on the refractive index of 

 the medium. Unless otherwise stated, values of 

 wavelengths are those in air. (8) 



2. The horizontal distance between points on 

 two successive waves measured perpendicularly 

 to the wave crest, (^^ee figure for wave.) (61) 



wavelength of sound — The distance between cor- 

 responding points of adjacent sound waves; 

 measurement is determined by the ratio of speed 

 to frequency. 



wave level — The position of the sea surface above 

 or below a reference plane at any specific time in 

 the tide cycle. 



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