Using a proportionality value of 0.77 (Komar and Inman, 1970), the esti- 

 mated gross transport at Sea Crest is 1,583,400 cubic meters (2,071,000 cubic 

 yards) per year. The predicted net transport is to the south with a north-to- 

 south transport ratio of 0.43. The annual net transport to the south at Sea 

 Crest is estimated at 625,000 cubic meters (822,000 cubic yards) per year. 



6. Tides and Sea Level Rise. 



Ocean tides are semidiurnal with a spring range of 1.16 meters (3.8 feet) 

 and a mean range of 0.97 meter (3.2 feet). Water levels in Currituck Sound 

 are wind-dominated: high during periods of southwest winds, low during north- 

 east winds. Mean water level in the sound is about 0.27 meter (0.9 foot) 

 above MSL. Normal wind-induced setup is about 0.6 meter (2 feet) and setdown 

 is -0.2 meter (-0.7 foot). 



Ho and Tracey (1975) investigated the frequency and magnitude of storm 

 tides for the northern North Carolina coast. Their results for 10-, 50-, 

 100- , and 500-year return period storms are shown in Figure 26. Note that at 

 the Wright Monument, 23 kilometers south of the FRF, the expected 100-year 

 surge height is 2.77 meters. Tide frequencies ^or several classes of storms 

 are shown in Figure 27. 



ISpAA 



10 



UA 



Figure 26. 



Coastal storm surge frequencies north of Cape Lookout, North 

 Carolina. Numbers in parentheses are values in meters (from 

 Ho and Tracy, 1975). 



52 



