HNNUfiL 81 

 RNNUflL 80 



1.0- 3.0- A.O- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 11.0- 12.0- M.O- 17.0- 

 2.9 3.9 4.9 5.9 6.9 7.9 8.9 9.9 10.9 11.9 13.9 16.9 LONGER 

 PERIOD, SEC 



Figure 18. 1981 and 1980 wave period 

 distributions for gage 625 



distribution for gage 625. The most frequently occurring periods were 6, 8, 



and 10 sec (see Table 6). During storms when H was greater than 2 m, 



""o 

 the periods ranged from 6 to 17 sec, although most were between 6 and 12 sec. 



This variation can in general be attributed to the distance of the wave- 

 generation area from the pier; i.e., storms far offshore, say 500 km or more, 

 tend to produce 12-sec or longer wave periods, while more local storms produce 

 shorter periods. Based on the occurrence of periods longer than 10 sec, swell 

 from distant generating areas may have accounted for approximately 20 percent 

 of the conditions at the coast. During October through December, 6 sec wave 

 periods occurred most frequently, while during April through June more than 

 30 percent of the wave periods were 8 sec (Figure 19). 



76. With the exception of July through September, wave period distri- 

 butions were consistent between 1980 and 1981. January through March tended 

 to have longer (greater than 8 sec) periods, while during October through 

 December, 6-sec locally generated seas predominated. A large difference was 

 observed during July through September, when there were fewer 8-sec and more 

 wave periods greater than 10 sec (Figure 20). 



44 



