Refraction, bottom friction, and wave breaking contribute to the observed dif- 

 ferences in height. During the most severe storms when the wave heights 

 exceed 3 m at the seaward end of the pier, the surf zone (wave breaking) has 

 been observed to extend past the end of the pier occasionally out to Gage 640. 

 This occurrence is a major reason for the differences in the distributions 

 between Gage 630 and the inshore gages for the highest 1 percent of the waves. 

 The wave height statistics for the staff gage (Gage 645), located at the land- 

 ward end of the pier, were considerably lower than those for the other gages. 

 In all but the calmest conditions, this gage is within the breaker zone. Con- 

 sequently, these statistics represent a lower energy wave climate. 



48. The distribution of wave periods for all of the gages is shown in 

 Figure 12. Although the distributions of wave periods for all gages were sim- 

 ilar, Gage 630 tended to have the lowest percentage of wave periods 10 sec or 

 longer, and Gage 645 tended to have the highest percentage of wave periods 

 less than 6 sec. 



SO-, 



GAGE 625 

 GAGE 630 

 GAGE 640 

 GAGE 645 



1.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 12.0 14.0 16.0 

 PERIOD, s 



Figure 12. Annual wave period distributions, 1985 



49. 



Temporal variation. Temporal height and period trends for 

 Gages 625 and 630 are shown in Figures 13 and 14, respectively, and are con- 

 sistent with those for Gages 640 and 645. Wave heights tended to be above the 

 annual mean during the winter months, dropping below the annual mean by the 



33 



