waves and winds occurring during winter stomas,, It is not the purpose of 

 this memorandum to give more than a brief background of the problem in order 

 to indicate the part which refraction plays in the observed phenomena „ Space 

 will not be taken to recount the many local theories, mostly unsound, but 

 frequently difficult to refute, which effectively prevented remedial measures 

 until a satisfactory explanation was developed „ 



>Vave action at Santa Barbara is generally light, the breakers seldom 

 exceeding 3 feet The wave period appears to be greater than at points on 

 the exposed coast north of Point Conception but there are no measurements to 

 prove this,, The waves are unusually regular in height and period, and are 

 generally long-crested, the breaking of a single crest being frequently evi- 

 dent for a mile or more,, The crests are always at a slight angle with the 

 shore, the breaker appearing first at the westerly end of the crest and 

 developing eastward „ A current runs steadily from west to east in the surf 

 zone and for a considerable distance seaward of the breaker line., 



There are several features of the situation at Santa Barbara which 

 seemed peculiar „ In the first place, the rate of accumulation at the break- 

 water seemed large in view of the relatively light wave action observed,, 

 Few accurate determinations of rates of drift were available for comparison, 

 but the few approximate determinations previously made, such as the average 

 growth of the westerly tip of Long Island, were of the same magnitude and 

 every circumstance of the Santa Barbara surf and waves suggested that the 

 littoral drift there should be much smaller than on Long Island „ The answer 

 to this problem was that at Santa Barbara there was every reason to expect 

 the sand movement to be easterly almost continuously throughout the year. 

 A second unusual feature was that the waves always seemed to break at the 

 same angle in spite of the fact that they obviously must approach from many 

 different directions, as determined by winds <> The refraction diagrams 

 showed that from any westerly bearing between north and south the waves 

 would be refracted in such manner. that the crests would occupy the same 

 position at the end of the breakwater, within the accuracy of visual obser- 

 vation o The only effect of variations in initial wave direction would be a 

 variation in height after refraction. The third effect demonstrated by the 

 refraction diagrams was that there would be filtering effect, the long- 

 period waves being refracted more than those of short-period „ This effect 

 probably accounts for the apparent increase of wave period over that north 

 of Point Conception, and the relative regularity in height and period „ 



Figure 5 shows a 10-second wave approaching from the southwest,, Or- 

 thogonals to the wave, fronts on this diagram have been drawn to show the 

 extent of the spreading of the wave energy,, This wave system shows an 

 increase in crest length off Santa Barbara for waves passing the west end 

 of San Miguel Island in the ratio 10 to 1 over the length in the open 

 ocean, and the length of crest of breaker is more nearly 20 to 1 (i e , 

 K^ =* 0o22) Waves passing between San Miguel and Santa Rosa Islands' show 

 so great an increase in crest length that their effect could not be noticed 

 in the larger waves passing west of San Miguel Island. A portion of the 

 same system would pass around the other islands but the increase in length 

 would be even greater „ 



