12S 



Water 



Wind Vectors (5 m/sec^' j 



Figure 114. Variation of tem- 

 perature at depths of 61, 700, 

 850, and 1000 meters at Station 

 2988 near the northwest end of 

 Santa CataHna Basin during a 

 25-hour period. Note that tem- 

 perature at 1000 meters is some- 

 times higher than that measured 

 at other times at 850 meters. 

 From Emery (19566, Fig. 3). 



help to explain the prior find of currents as 

 great as 15 cm/sec at the floor and near the 

 centers of Santa Cruz and San Pedro Basins 

 and of 5 cm/sec in Santa Monica Basin. 

 They should also contribute greatly to the 

 mixing of basin and overlying waters, which 

 may help to explain the known complete re- 

 placement of basin waters in periods of 2 to 

 20 years. 



Tides 



Tidal Cycles 



Nearly everyone has noted the alternate 

 exposing and covering of the shore by ebb- 

 ing and flooding tide, but the chief means of 



obtaining precise information on the tidal 

 cycles is by the use of recording tide gauges. 

 Data from these records serve as a basis for 

 the prediction of future tides (Marmer, 1926, 

 1932; Anonymous, 1955) which correspond 

 very closely with those actually occurring. 

 The small differences that do exist are mostly 

 the result of variations in water density and 

 local winds. 



Diurnal tide curves of southern CaHfornia 

 are characterized by asymmetry such that 

 there is usually one cycle of greater range 

 and one of lesser range, unlike the more 

 symmetrical tide curves of the Atlantic 

 coast. This asymmetry is produced by in- 

 terference mainly between diurnal and semi- 



