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STRAIT - A relatively narrow waterway between two larger bodies of water. 

 See also SOUND. 



STREAM - (1) A course of water flowing along a bed in the earth. (2) A 

 current in the sea formed by wind action, water density differ- 

 ences, etc. (Gulf Stream). See also CURRENT, STREAM. 



SURF - The wave activity in the area between the shoreline and the 

 outermost limit of breakers. 



SURF BEAT - Irregular oscillations of the nearshore water level, with 

 periods of the order of several minutes. 



SURF ZONE - The area between the outermost breaker and the limit of 

 wave uprush. (See Figures A-2 and A-5.) 



SURGE - (1) The name applied to wave motion with a period intermediate 

 between that of the ordinary wind wave and that of the tide, say 

 from 1/2 to 60 minutes. It is of low height; usually less than 

 0.3 foot. See also SEICHE. (2) In fluid flow, long interval 

 variations in velocity and pressure, not necessarily periodic, 

 perhaps even transient in nature. (3) See STORM SURGE. 



SURGING BREAKER - See BREAKER. 



SUSPENDED LOAD - (1) The material moving in suspension in a fluid, being 

 kept up by the upward components of the turbulent currents or by 

 colloidal suspension. (2) The material collected in or computed 

 from samples collected with a suspended load sampler. (A suspen- 

 ded load sampler is a sampler which attempts to secure a sample 

 of the water with its sediment load without separating the sedi- 

 ment from the water.) Where it is necessary to distinguish 

 between the two meanings given above, the first one may be called 

 the "true suspended load". 



SWALE - The depression between two beach ridges. 



SWASH - The rush of water up onto the beach face following the breaking 

 of a wave. Also UPRUSH, RUNUP. (See Figure A-2.) 



SWASH CHANNEL - (1) On the open shore, a channel cut by flowing water in 

 its return to the parent body (e.g., a rip channel). (2) A sec- 

 ondary channel passing through or shoreward of an inlet or river 

 bar. (See Figure A-9.) 



SWASH MARK - The thin wavy line of fine sand, mica scales, bits of sea- 

 weed, etc., left by the uprush when it recedes from its upward 

 limit of movement on the beach face . 



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