41 



Table 4.1. Representative Bay Superelevations (after Mehta and Philip, 

 1986) 



Cause 



Superelevation^ 

 (cm) 



Comment 



Inlet/Bay Geometry 



Sea Tide 



5-30 Effect of shallow bar is more 



important than changing geometry 

 with tide; hence seasonal and 

 episodic response 



10 



Theoretical estimate; no 

 verification; believed to be a 



small contribution compared to 



others 



Runoff 



50 



Major factor; strong seasonal 

 variation 



Salinity 



15 



Important in estuaries rather 

 than bays (no runoff) ; seasonal 

 variation 



Wind 



Waves 



Other Factors 



10-15 Local forcing and remote forcing 

 can both be equally important; 

 seasonal and episodic response 



5-10 Induced pileup behind reefs may 

 be important; seasonal and 

 episodic response 



1-30 Modification of tide during 



upland propagation and Coriolis 

 effect are significant 



^Only positive values are indicated. Superelevation can also be 

 negative, i.e. lower bay level than sea, e.g. due to offshore wind. 



