4 Nov 90 @ 1900 hr 



g» 0.042 

 | 



ST 003S 

 °'°^ " northward 



0.021 



9 9 9 

 Cyclic Alongshore Wavenumber (m 4 ) 



Log Variance Density (cm m +2/Hz) 



Figure 21 . Ay/ spectrum from 4 Nov 1 990 in 8-m depth. 



The rectangular boxes mark variance peaks, with 

 shading indicating the log variance density within 

 the half-power bandwidth, shown as the box 

 width (Oltman-Shay 1991; Oltman-Shay et al. 

 1992) 



(Figure 22). Correlation analysis of the entire data set clearly showed that up- 

 coast and downcoast progressive edge wave variance was dependent on the 

 propagation direction of the incident swell. Incident waves from south of shore 

 normal generated progressive edge waves traveling northward (cf. Figures 23a 

 and 23d). Similarly, incident waves from the north produced progressive edge 

 waves moving southward (cf. Figures 23b and 23c). Swell and edge waves 



Chapter 4 Field Observations 



43 



