PART V: SUMMARY 



29. Field studies have shown that the infragravity band of surf-zone 

 energy is dominated by long waves that are standing in the cross shore. Some 

 of these long waves are clearly low-mode edge waves. Significant amounts of 

 the total variance in the infragravity band outside the surf zone come from 

 bounded long waves traveling with incident wind wave groups. The presence of 

 leaky and high-mode edge waves is less resolved. However, cross-shore cur- 

 rents appear to contain either or both in addition to low-mode edge waves. 



30. The importance of infragravity band motions in the nearshore is 

 unequivocally proven. On dissipative beaches these long waves dominate (80 to 

 100 percent) the surf and swash elevation and current field, with vertical 

 swash excursions of 70 percent of the incident significant wave height. Data 

 acquisition and analysis skills have overcome many difficulties in examining 

 this energy band. Researchers are now at a level of understanding that allows 

 them to begin addressing some of the more practical questions as to the actual 

 role of infragravity long wave energy in surf and swash sediment transport and 

 structure integrity. 



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