addition, with the predominant wave direction during this time period being 

 from the east (northeastward of shore normal) , it is not unreasonable to assume 

 that the bar also extended farther to the southwest, beyond the limits of the 

 study area. The trough-filling and platform development on the southwest end 

 may have resulted from transport from the southwest, in a manner similar to that 

 of the northeast September storm, or perhaps from net downcurrent accumulation 

 from northeasterly currents and bar-shielding of easterly waves. 



Accretion on the outer flank of the disposal bar and shore-parallel rebuild- 

 ing of the bar between mid-September and mid-October are of special importance 

 to the general concept of sediment redistribution as a response to storm trans- 

 port. Sediment redistribution in this case resulted in a volume increase in the 

 inshore and offshore zones. Profile shapes indicate little evidence for erosion 

 of the beach and inner profile with sediment transfer to the outer profile. 

 Sediment simply seems to have been added to the inshore zone and innermost part 

 of the offshore zone. This suggests that storm levels were not sufficient to 

 cause much seaward displacement of sediment from the inner profile, or that if 

 seaward displacement did occur, poststorm recovery was extremely rapid. High 

 poststorm recovery rates for transport from the offshore to the inshore are not 

 supported, though, by other profile studies (Nordstrom and Inman, 1975). Thus, 

 it is likely the source of the added sediment may have been from some alongshore 

 location or from within the offshore region. During storms, the disposal bar 

 acted as a storm bar, promoting longshore transport and lateral extension of 

 the bar itself. 



5. Wind- and Wave-Driven Longshore Currents. 



Wind may have a significant effect on moving sediment in the coastal zone, 

 both outside and within the surf zone. It is generally acknowledged that the 

 wave-driven longshore current is often modified by other currents in the near- 

 shore system, e.g., wind-driven and tidal currents (Komar, 1976a, p. 198). De- 

 pending on whether the wave-driven longshore current and wind-driven current are 

 in the same or opposite directions, a higher or lower speed resultant longshore 

 flow should ensue. 



Longshore current speed correlates with breaker height and angle of wave 

 breaking (Bowen, 1969; Longuet-Higgins, 1970; Thornton, 1971) as well as with 

 other variables (Komar, 1976a) . The LEO data for this study site show that 

 although relatively higher velocity longshore currents (e.g., > 30 centimeters 

 per second) sometimes occurred in association with high waves and lower angles 

 of wave breaking, there was not always a positive association between current 

 velocity and observed breaker conditions (viz, height, period, and angle of 

 breaking) (Fig. 10). In fact, many of the longshore current speeds > 30 centi- 

 meters per second were associated with relatively low breaker heights (< 0.6 

 meter). In most cases, the occurrence of higher speeds, especially those during 

 nonstorm conditions, was apparently associated with the development of a local 

 sea with wind and wave directions at a low angle to the coast. Maximum long- 

 shore speeds developed in conjunction with a sustained local sea, but not nec- 

 essarily large breaker conditions, or developed during a storm when winds pro- 

 duced large waves breaking at a low angle, e.g., the northeaster of 14 to 16 

 September. Similarly, Galvin and Nelson (1967) reported that from a compilation 

 of 352 longshore current observations, the highest longshore current speeds were 

 wind-aided. Thus, local seas and associated wind-driven currents appear to be 

 instrumental in producing higher velocity longshore current speeds, and therefore 



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