South Carolina coast extends from Bull Island to Seabrook Island. Majority of the area of South Carolina Coast is heavily developed. This developed area comprises of great population, large tourism industries and infrastructures. Local economies are totally dependent on the health of the shoreline. Local residents are severely affected by the damage and property loss due to severe storm and coastal erosion. To minimize the damage and to successfully manage coastal resources it is very essential to understand the factors that control coastal erosion and transportation of sediments.
Severity of this problem can be understood by the fact that Hunting Island which is located in South Carolina over past 140 years has lost sand at a rate of 130,000 cubic meters per year approximately. Shoreline moved back 5 to 7 meters per year from 1920 to 1971. This rate of erosion in comparison to together islands is very high and a cause of economic loss for the region.
Several studies and surveys have been conducted to understand the factors responsible factors erosion. According to the studies it is known that beaches respond quickly to changing waves conditions. Particularly, if waves are formed by combination of large and short height wave periods. This process enhances transportation of sediments towards sea. Due to high boat traffic load in this coast similar type response has been observed. Section of Spartina with its roots can retain tides but it dislodges during periods of heavy boat traffics. Shorelines which are exposed to the to heavy boat traffic are more susceptible to erosion. South Carolina Department of Natural Resources (SCNDR) has received numerous complains from landowners about this persisting problem.
One of the major natural reasons responsible for the erosion of the beach is that at different sections of the beach depth is higher which produces larger waves which hits sand hardly, as a result of which erosion rate is increased. At South Carolina Coast different rates of erosion are observed at different sections. Higher depths at some sections may the reason of different erosion rates.
Surveys have shown that near South Carolina Coast there are special ocean currents present. These currents are also responsible for severe erosion. Ocean currents are forcing sand at the bottom of the sea to move in southeastern direction. As a result of this movement sand has been deposited in southeastern part of the bay. On Hunting Island it is seen that waves break to south and north which means that rather than deposition of sand on to the beach, it is carried by currents.
Another factor contributing in erosion is the proximity and size of shoals. Sedimentary formation of coastal plain of South Carolina range from late Cretaceous to recent. Mostly it consists of unconsolidated sand, marl, gravel and limestone which are deposited on granite surface, gneiss and schist.
Another reason which plays most significant role in erosion is geology of South Carolina coast. Sea floor mapping has revealed that in majority of area significant lack in sediment deposition has been observed. According to the collected data cretaceous tertiary strata (which are pre ice deposits and were formed 145 to 1.8 million year ago) are folded, dipped towards southeast and are incised by networks of filled channels. According to the results of surveys trend and location of the channels are controlled by the differential erosion of underlying strata. Older underlying units and younger channel fill deposits are trimmed due to unconformity (break in deposition or geological record due to improper deposition or erosion), which eroded during several sea level cycles.
Sea level rise is also one major factor responsible for high erosion rate. Rise in sea level is caused by melting glaciers and expanding ocean water, which erodes beaches, is harmful for wild life and increase flooding. One foot rise in sea level could erode 100-200 foot swath of South Carolines coastline3 (U.S Global Change Research Program). Sea level rose by 9 inches at Charleston, South Carolina, during last century. According to studies by 2100 this rise is likely to reach 19 inches.
Wind and water are most prominent role players in erosion. All other factors are not them self responsible for erosion but rather use wind or water as a medium to erode. Ocean currents are also combination of wind and water. To minimize erosion due to wind and water, The National Park Service has forbidden visitors from walking on dunes and are also building fences to keep sand from being carried by water or wind.
Jetties and other man made structures are also responsible for erosion. Tide is low during the ebb flow, sea word directed flow is confined between jetties. This causes severe changes in ebb tidal shoals which are huge features. These features are formed towards sea of the inlet by sand transportation of tidal ebb currents.
Severity of this problem can be understood by the fact that Hunting Island which is located in South Carolina over past 140 years has lost sand at a rate of 130,000 cubic meters per year approximately. Shoreline moved back 5 to 7 meters per year from 1920 to 1971. This rate of erosion in comparison to together islands is very high and a cause of economic loss for the region.
Several studies and surveys have been conducted to understand the factors responsible factors erosion. According to the studies it is known that beaches respond quickly to changing waves conditions. Particularly, if waves are formed by combination of large and short height wave periods. This process enhances transportation of sediments towards sea. Due to high boat traffic load in this coast similar type response has been observed. Section of Spartina with its roots can retain tides but it dislodges during periods of heavy boat traffics. Shorelines which are exposed to the to heavy boat traffic are more susceptible to erosion. South Carolina Department of Natural Resources (SCNDR) has received numerous complains from landowners about this persisting problem.
One of the major natural reasons responsible for the erosion of the beach is that at different sections of the beach depth is higher which produces larger waves which hits sand hardly, as a result of which erosion rate is increased. At South Carolina Coast different rates of erosion are observed at different sections. Higher depths at some sections may the reason of different erosion rates.
Surveys have shown that near South Carolina Coast there are special ocean currents present. These currents are also responsible for severe erosion. Ocean currents are forcing sand at the bottom of the sea to move in southeastern direction. As a result of this movement sand has been deposited in southeastern part of the bay. On Hunting Island it is seen that waves break to south and north which means that rather than deposition of sand on to the beach, it is carried by currents.
Another factor contributing in erosion is the proximity and size of shoals. Sedimentary formation of coastal plain of South Carolina range from late Cretaceous to recent. Mostly it consists of unconsolidated sand, marl, gravel and limestone which are deposited on granite surface, gneiss and schist.
Another reason which plays most significant role in erosion is geology of South Carolina coast. Sea floor mapping has revealed that in majority of area significant lack in sediment deposition has been observed. According to the collected data cretaceous tertiary strata (which are pre ice deposits and were formed 145 to 1.8 million year ago) are folded, dipped towards southeast and are incised by networks of filled channels. According to the results of surveys trend and location of the channels are controlled by the differential erosion of underlying strata. Older underlying units and younger channel fill deposits are trimmed due to unconformity (break in deposition or geological record due to improper deposition or erosion), which eroded during several sea level cycles.
Sea level rise is also one major factor responsible for high erosion rate. Rise in sea level is caused by melting glaciers and expanding ocean water, which erodes beaches, is harmful for wild life and increase flooding. One foot rise in sea level could erode 100-200 foot swath of South Carolines coastline3 (U.S Global Change Research Program). Sea level rose by 9 inches at Charleston, South Carolina, during last century. According to studies by 2100 this rise is likely to reach 19 inches.
Wind and water are most prominent role players in erosion. All other factors are not them self responsible for erosion but rather use wind or water as a medium to erode. Ocean currents are also combination of wind and water. To minimize erosion due to wind and water, The National Park Service has forbidden visitors from walking on dunes and are also building fences to keep sand from being carried by water or wind.
Jetties and other man made structures are also responsible for erosion. Tide is low during the ebb flow, sea word directed flow is confined between jetties. This causes severe changes in ebb tidal shoals which are huge features. These features are formed towards sea of the inlet by sand transportation of tidal ebb currents.
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