Pea Island, Oregon Inlet, and Bodie Island, North Carolina, are severely human-modified barrier-island segments that are central to an age-old controversy pitting natural barrier-island dynamics against the economic development of coastal North Carolina. Bodie Island extends for 15 km from the Nags Head–Kitty Hawk urban area to the north shore of Oregon Inlet and is part of Cape Hatteras National Seashore. Pea Island extends 19.3 km from the southern shore of Oregon Inlet to Rodanthe Village and is the Pea Island National Wildlife Refuge. Bodie and Pea Islands evolved as classic inlet- and overwash-dominated (transgressive) simple barrier islands that are now separated by Oregon Inlet. The inlet was opened in 1846 by a hurricane and subsequently migrated 3.95 km past its present location by 1989. With construction of coastal Highway 12 on Bodie and Pea Islands (1952) and the Oregon Inlet bridge (1962–1963), this coastal segment has become a critical link for the Outer Banks economy and eight beach communities that occur from Rodanthe to Ocracoke. The ongoing natural processes have escalated efforts to stabilize these dynamic islands and associated inlet in time and space by utilizing massive rock jetties and revetments, kilometers of sand bags and constructed dune ridges, and extensive beach nourishment projects. As the coastal system responds to ongoing processes of rising sea level and storm dynamics, efforts to engineer fixes are increasing and now constitute a “human hurricane” that pits conventional utilization of the barriers against the natural coastal system dynamics that maintain barrier-island integrity over the long term.

Abstract High-resolution seismic data suggest that portions of depositional sequences representing as many as 18 Quaternary sea-level highstands are preserved within 60 m of Quaternary deposits in northeastern North Carolina. Sediments deposited during at least seven of these Quaternary sea-level events have been defined within the upper 33 m in drill holes in Dare County. The complex stratigraphy was resolvable only after integrating detailed lifho-, bio- and aminostratigraphic drillhole data with a high-resolution seismic framework. High-frequency, sea-level cyclicity dominated the depositional patterns of the resulting Quaternary sediment sequences. As high-energy coastal systems moved repeatedly across the low-gradient continental shelf, sediment units that had previously been deposited in coastal and shelf environments were significantly modified. During each glacial episode, fluvial channels extensively dissected previously deposited coastal facies. Subsequent deglaciation and transgression flooded the channels, backfilling them with fluvial and estuarine sediments. The infilled channel facies were then partially truncated by shoreface erosion, which also eroded portions of previously deposited coastal sequences. During sea-level highstands, a new sequence of coastal facies was deposited over the ravinement surface cut into remnants of older and similar Quaternary sequences and the associated channel-fill systems. Thus, the resulting record consists of a series of imbricated coastal deposits of similar, but discontinuous, lithostratigraphic units with irregular geometries that only partially represent interglacial highstand deposition; the depositional sequences are highly punctuated and dominated by unconformity surfaces with extensive incised and backfilled channel deposits.