59 



where E is energy density, Cg is group velocity, t^ is the bottom shear 

 stress and u^j the water particle velocity. The overbar denotes 

 time -averaging over one wave period. Defining the instantaneous shear 

 stress as 



f 



^u^KI (5.17) 



^b = ^ o 



performing the time average and integrating Eq. 5.16 yields 



H(x) = ^ (5.18) 



where 



r ^'^^"("^^ (5.19) 



3irg Cg sinh kh 



The effect of rising sea level will depend on the geometry of the 

 continental shelf. For a uniform depth where the rise in sea level does 

 not affect the shelf length, T will decrease and H at the shoreline will 

 increase. However, if the geometry is such that a rise in sea level 

 results in a wider shelf, T may tend to increase and H at the shoreline 

 will then decrease, because bottom friction has had a longer time to drain 

 energy . 



Consider a storm on a shallow continental shelf that results in the 

 conditions : 



wind speed U = 30 m/s (g/U^ = 0.01089 m''^) 



fetch length F = 50 km 

 average water depth hQ = 10 m 



