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20. Abstract (Continued) 



in determining bed form morphology and amount of crossbedding bimodality. 

 Froude number (Fr) shows good correlation with bed form type only in depths 

 less than 2 meters. 



In the intertidal^ and shallow subtidal (<2 meters MLW) zone, sand waves 

 are characterized by Umax 80 centimeters per second, large velocity asymmetry 

 (Fr = 0.15-0.25), planar crossbedding, little crossbedding bimodality, _and 

 dominant flood orientation. Cuspate megaripples are characterized by Umax 

 80 centimeters per second, small velocity asymmetry (Fr = 0.25-0.4), festoon 

 crossbedding, high crossbed bimodality, and no dominant orientation. In deep 

 subtidal (>2 meters MLW) areas, sand waves are the principal bed form. 

 They show no dominant orientation. However, where Umax exceeds 80 centimeters 

 per second, megaripples are superimposed on the sand wave form and crossbedding 

 is complex. 



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