212 



Cruise of Maj; 23-24 , 1956 



On May 22, 1956, an experiment at the Hyperion outfall 

 was conducted using a radioactive tracer in the effluent. 

 Between 10 p.m. and 3 a.m. on the night of May 23-24, drift 

 cards were released over the usual series of stations in 

 Santa Monica Bay. In Figures 101 and 102 are the results of 

 these releases. 



Thirty eight per cent of all cards were recovered (95 

 out of 252). They demonstrate a modification in direction 

 of flow from the April 25 cruise. The predominant direction 

 was still inshore, but there was a moderate to strong 

 southerly component from most stations instead of a moderate 

 northerly one as on the previous cruise. With few exceptions, 

 cards from all but the northern two station lines went inshore 

 and south. A few rounded Point Vicente and were recovered 

 from Lunada Bay, Portuguese Bend, and San Pedro. From 

 Station 4257 the one card returned was from San Onofre. 

 There were no recoveries from Station 4263, as these cards 

 probably went south through San Pedro Channel and were lost. 

 Another point of evidence for a strong southerly flow from 

 the lower half of the bay is found in the fact that along 

 the three southernmost lines the percentage of recoveries 

 decreased with increasing distance from shore, from 50% to 

 10%. 



From the northern lines of stations (4248, 4249, and 4250), 

 the cards were carried more directly inshore to the area 

 between Santa Monica and Playa del Rey, but from the line just 

 below (4251, 4252, and 4253) a definite southerly drift was 

 apparent. 



