FIGURE 3-9 



TIDE-PROBABILITY CURVE— ATLANTIC CITY 



6.00- 



4.00 



f* 2.00- 



< 

 > 

 m 



-J 

 < 



0.00- 



-2.00- 



-4.00 



MHWS-j 

 MHW 



MSL 



MLW 

 MLWSH 



•oo r I 1 T 



0.00 1.00 2.00 3.00 



PROBABILITY (%) 



- 1.00 



0.50 



0.00 



-0.50 



ai 

 O 



z 

 < 

 cc 



_l 

 < 



Q 



z 

 o 



I- 

 < 



> 



UJ 



-I 



LU 



- 1.00 



4.00 



5.00 



Tide-probability curve based on statistics for Atlantic City, New Jersey (near the study area), 

 given in Ebersole (1982). The data are normalized on the right-hand axis for the local tide range. 



Abbreviations: MHWS (mean high water spring); MHW (mean high water); MSL (mean sea 

 level); MLW (mean low water); MLWS (mean low water spring); Using local MSL as datum. 



The Tuckerton marsh then does not seem to fit the model. This could be due to errors in 

 the benchmark (E55) or tidal records used for the mainland marsh. However, after verifying the 

 records with the National Oceanic and Atmospheric Administration (NOAA), we do not think 

 this is a source of error. Also, tidal data were directly recorded in the immediate vicinity of the 

 Tuckerton marsh transects at three localities as a check on each other by NOAA. The bench- 

 mark and tidal data are sufficiently modern to reflect present conditions so that subsidence or 

 other factors are unlikely to account for the observed differences. This leaves the possibility that 

 while the tidal range is less in the Tuckerton marsh, it is displaced upward as a result of impound- 

 ment of water or a difference in water flushing caused by extensive drainage canals. If this were 

 the case, it would be a significant observation indicating the indirect but important effect of 

 canalization on alteration of marsh zonation. 



80 



