

 10 yr 



200 



ALONGSHORE DISTANCE S — N (km) 

 + 50 yr O 100 yr 



300 



400 



500 yr 



Figure 9. Alongshore variation in total tidal height at various return 

 intervals (modified from Myers 1975 and Ho and Tracey 1975) 



the Wisconsin age. Sea level rise curves show a definite break in slope to a 

 much slower rate of rise about 4,000 years BP. Along the South Carolina coast 

 Colquhoun and Brooks (1986) postulate a curve (Figure 10), which shows an epi- 

 sodic rise and fall of sea level since 4,000 years BP. This curve, based on a 

 combination of archeological and geological (C14) dating, shows a slow overall 

 rise in sea level to present day. 



19. Examination of tide gage data in the vicinity of the study area 

 shows a highly variable but steady overall rise in relative sea level during 

 the recent past (Figure 11). Since the late 1920' s, relative sea level at 

 Charleston Harbor, South Carolina, has risen approximately 15 cm. General 

 trends in long-term eustatic (15,000 years BP) rise and present relative rise 

 along the study area coincide, suggesting continued sea level rise for the 



23 



