SHUGA 



SHORE PROFILE 



1. Offshore; 2. Shoreface or Inshore; 3. Mean high water; 

 4. Mean low woter; 5. Step; 6. Low tide shoreline; 7. High 

 tide shoreline; 8. Foreshore or Beach face; 9. Shore or Beach, 

 10. Backshore or Bockbeach; 1 1. Ordinary or Summer berm 

 12. Storm or Winter berm; 13. Beach scarp; 14. Coast, 

 15. Sea cliff; 16. Coasjiine; 17. Crest of berm; 18. Trough 

 19. Ball or Longshore bar. 



(AJTER WIEGEl, 19531 



tically by floats on the head or top rope 

 and by weights on the lead or foot rope. Fish 

 entering the open end are trapped in the apex 

 or "cod" end of the net. Lateral dimensions of 

 the net opening range from about 24 to 100 

 feet. 



shuga — Spongy white ice lumps a few centimeters 

 in diameter (about one inch), formed of sludge 

 and sometimes of anchor ice, and emerging on 

 the surface. 



Siberian anticyclone — See Siberian high. 



Siberian high — (or Siberian anticyclone). An 

 area of high pressure which forms over Siberia 

 in winter, and which is particularly apparent 

 on mean charts of sea level pressure. It is cen- 

 tered near Lake Baikal, where the average sea 

 level pressure exceeds 1,030 millibars from late 

 November to early March. 



This anticyclone is enhanced by the surround- 

 ing mountains which prevent the cold air from 

 flowing away readily. In the center of the anti- 

 cyclone the normal clockwise circulation is re- 

 placed by katabatic winds down the river 

 valleys, but to the east along the Pacific coast 

 there is a belt of very strong northerly winds. 

 In summer the Siberian high is replaced by 

 a low pressure area. See monsoon. (5) 



sieve — Wire cloth containers with mesh openings 

 graded increasingly in a fixed ratio. Coarse 

 bottom sediments such as sand are usually ana- 

 lyzed for size by sieving. 



sigma limits — The interval about the mean ex- 

 pressed in units of standard deviation. In a 

 normal distribution , 2(t limits on each side of a 

 mean include about 95 percent of the popula- 

 tion, 3<y limits include 99 percent of the popula- 

 tion. (22) 



sigma-t — (symbol o-t). A conveniently abbrevi- 

 ated value of the density of a sea water sample 

 of temperature t and salinity S : 



where p^a, n is the value of the sea water 

 density in cgs units at standard atmospheric 

 pressure. If, for example, p(s t) = 1.02648, then 

 o-i =26.48. (5) 

 sigma-zero — (symbol <jo). Sigma-t at 0°C. 

 Knudsen's Tables give values of sigma-zero as 

 a function of salinity or chlorinity, as well as 

 corrections to be applied to obtain sigma-t. 



.(5) 



signal — A disturbance which is used to carry in- 

 formation ; opposed to noise. 



signal wave — Any sound wave upon which it is 

 required to make an observation of any kind is 

 known as a signal wave, or more often, simply 

 as a signal. (28) 



signature — 1. The characteristic frequency pat- 

 tern of the target displayed by detection and 

 classification equipment. (63) 



2. The graph of pressure versus time at a 

 point as a ship passes over it. Increased water 

 velocity in the constriction between the ship and 

 the bottom of the water basin causes the pres- 

 sure variation by the Venturi effect. 



significant wave — A statistical term relating to 

 the one-third highest waves of a given group 

 and defined by the average of their heights and 

 periods. 



The composition of the higher waves depends 

 upon the extent to which the lower waves are 

 considered. Experience so far indicates that a 

 careful observer who atempts to establish the 

 character of the higher waves will record values 

 which approximately fit the definition. 



significant wave height — (or characteristic wame 

 height). The average height of the one-third 

 highest waves of a given wave group. Note 

 that the composition of the highest waves de- 

 pends upon the extent to which the lower waves 

 are considered. In wave record analysis, the 

 average height of the highest one-third of a 

 selected number of waves, this number being 

 determined by dividing the time of record by 

 the significant period. (61) 



significant wave period — An arbitrary period 

 generally taken as the period of the one-third 

 highest waves within a given group. Note that 

 the composition of the highest waves depends 

 upon the extent to which the lower waves are 

 considered. In wave record analysis, the aver- 

 age period of the most frequently recurring of 

 the larger well-defined waves in the record un- 

 der study. (61) 



sikussak — An Eskimo name for very old sea ice,. 

 resembling glacier ice trapped in a fiord, and 

 having a snow accumulation on its surface which 

 contributes to its formation and perpetuation. 

 (59) 



148 



