Figure 14. Sea level curve for the last 35,000 years (after 

 Millman and Emery 1968) 



level over the last 4,000 years has been very episodic (Figure 10). The same 

 rising sea level trend is visible on modern tide gage data (Figure 11) . 



27. Evolution of the modern coastline of South Carolina is intimately 

 linked with the present episode of sea level rise, sediment supply, bathyme- 

 try, ancient topography, and various environmental factors such as tide and 

 wave conditions. All of these factors, except for sediment supply and bathym- 

 etry, have been discussed previously for the modern coast of South Carolina. 

 Erosion, accretion, or stability measured in this report is a function of all 

 these factors. This report has briefly examined the magnitude of each factor 

 in contributing to measured erosion and accretion. 



28. Sediment supply. Present day erosion/accretion patterns of barrier 

 islands and beaches within the study area depend on sediment supply along the 

 coast. Two potential origins for sediment are fluvial input and sources on 

 the continental shelf. Meade (1982) concluded that in recent time, a decrease 

 in cropland area and improved management practices have resulted in decreased 

 soil erosion. Additionally, all of South Carolina's rivers, except for the 

 Santee (which has been dammed and diverted since 1942) , are headwatered in the 

 Coastal Plain and therefore do not have large discharges. Meade's conclusion 

 is that little sand size sediment is reaching the coast from fluvial sources. 

 Further, he estimates only 5 percent of that sand reaches the inner continen- 

 tal shelf; most sand is being trapped in estuaries and bays. This may have 

 been different in the not-too-distant past. Carver (1971) traced the origin 

 of heavy minerals along the Georgia coast to the Santee River, suggesting it 



29 



