Kahn, J. H. , and Roberts, H. H. 1982. "Variations in Storm Response Along A 

 Microtidal Transgressive Barrier-Island Arc," Sedimentary Geology, Vol 33, 

 pp 129-146. 



Storm response along the transgressive Chandeleur barrier island arc 

 southeast of the Mississippi Delta plain is variable because of local dif- 

 ferences in sediment supply, shoreline orientation, and barrier morphology. 

 A study of the morphological impact of Hurricane Frederic (1979) affirmed 

 that tropical storms are the primary agents causing erosion and migration of 

 this barrier arc. 



Frederic's greatest impact was in the duneless southern Chandeleurs 

 where sheet-flow overwash caused flattening of the barrier profile, destruc- 

 tion of a strip of marsh 50 to 100 m wide, and shoreline retreat of 

 approximately 30 m. In contrast, overwash in the northern Chandeleurs was 

 confined between dunes in channels established by previous storms. This 

 channelized overwash breached the northern Chandeleur barriers in 19 places. 

 As Frederic passed, return flow through these channels transported overwash 

 sediment back to the nearshore zone. These ebb deposits were a source for 

 longshore drift sediments which quickly sealed storm channels, reestablishing 

 a coherent northern Chandeleur barrier arc. 



These storm response patterns may help explain long-term changes in 

 barrier morphology. During an 84-year period (1885-1969), the southern 

 Chandeleurs decreased 41 percent in area, with an average retreat rate of 9.1 

 m/yr, compared to a 15 percent increase in area and an average shoreline 

 retreat rate of 7.2 m/yr for the northern Chandeleurs. (Authors) 



Kraft, J. C. , et al. 1979. "Processes and Morphologic Evolution of an 

 Estuarine and Coastal Barrier System," in Leatherman, S. P., ed., Barrier 

 Islands: From the Gulf of St. Lawrence to the Gulf of Mexico, Academic Press, 

 New York, N.Y., pp 149-184. 



Coastal barriers in Delaware are rapidly transgressing. Wave-dominated 

 processes are the most important single factor in determining the volume of 

 sediment in motion. Availability of sediment from the continental shelf, 

 erosion of the barrier itself, and erosion of headlands determines whether or 

 not a barrier can exist and evolve. 



Studies of the internal structure of the barriers indicate that washover 

 processes and flood-tidal delta deposition are the dominant factors in the 

 landward transgression. Wind-transported sand is of secondary importance, 

 derived from the beach berm and washover fans and transported to coast 

 parallel dunes. (Authors) 



Leatherman, S. P. 1976. "Barrier Island Dynamics: Overwash Processes and 

 Eolian Transport," Proceedings of the 15th Coastal Engineering Conference, 

 American Society of Civil Engineers, pp 1958-1974. 



The northern 8 km of shoreline at Assateague Island, Maryland, are 

 presently being eroded. During storms, swash surges are able to overtop the 

 most landward (storm) berm as overwash, with deposition occurring on the 

 barren flats. Where primary barrier dunes still exist, sediment-charged 



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