Geologic Controls on Regional and Local Erosion Rates of Three Northern Gulf of Mexico Barrier-Island Systems

Modification of the Quaternary stratigraphic framework of the inner-continental shelf by Holocene marine transgression: An example offshore of Fire Island, New York

“…The relatively sparse seismic-reflection data coverage results in a surface that clearly contains trackline artifacts and a relatively higher uncertainty in comparison with other maps presented. change can be significantly influenced by the antecedent geology being eroded and the availability of nearshore transgressive sand deposits (Riggs et al, 1995;Thieler et al, 1995;Schwab et al, 2000aSchwab et al, , 2013Gayes et al, 2003;Miselis and McNinch, 2006;Hapke et al, 2011;Denny et al, 2013;Twichell et al, 2013). The analysis of the lower shoreface and inner-continental shelf bathymetry, sediment distribution, bedform patterns, and seismostratigraphy presented here supports previous hypotheses and references therein) that: (A) erosion of the Pleistocene glaciofluvial and early Holocene channelfill sediment deposits offshore of Fire Island during Holocene marine transgression formed the present morphology of the inner-continental shelf and sediment distribution patterns; and (B) processes associated with ongoing marine transgression and formation of a ravinement surface yield a relatively finer grained modern sand deposit that is transported in a net westerly direction.…”

“…The evolution of coastal areas, from individual storm events to millennial time scales, is linked directly to the oceanographic processes acting on the geologic framework of the adjacent inner-continental shelf (Swift, 1976;Riggs et al, 1995;Thieler et al, 1995Thieler et al, , 2001Wright, 1995;Schwab et al, 2000aSchwab et al, , 2013Cowell et al, 2003;Miselis and McNinch, 2006;Fagherazzi and Overeem, 2007;Denny et al, 2013;Twichell et al, 2013). Fire Island, a segment of a barrier island system extending along the south coast of Long Island, New York ( Fig.…”

Inundation of a barrier island (Chandeleur Islands, Louisiana, USA) during a hurricane: Observed water‐level gradients and modeled seaward sand transport

“…The Chandeleur Islands (Figure ) are a long, low‐lying (maximum elevation < 2 m) arc of sandy, partially vegetated islands perched on the remnants of the abandoned St. Bernard lobe of the Mississippi Delta. They were formed from deltaic deposits reworked by waves into paired flanking barrier spits [ Penland et al ., ; Otvos , ; Twichell et al ., , ], but the exact nature of island genesis has been debated [ Otvos and Carter , ]. The abandoned lobe is subsiding from soil compaction [ Penland and Ramsey , ], tectonic movement [ Dokka et al ., ], and possibly from oil and gas extraction [ Morton et al ., ].…”

Coupling centennial‐scale shoreline change to sea‐level rise and coastal morphology in the Gulf of Mexico using a Bayesian network

“…These extreme rates of erosion almost certainly involve both high rates of relative SLR [Penland et al, 1988;Morton et al, 2004] and storms [Fearnley et al, 2009;Stockdon et al, 2012]. Long-term shoreline change also depends on the local sediment budget and sediment texture, such that barrier islands with less available sediment and finer sediments will erode more quickly than barriers with abundant or coarse sediment [Twichell et al, 2009;Twichell et al, 2013]. Short-term storm impacts that affect shoreline change are largely controlled by the height of dunes [Sallenger, 2000;Stockdon et al, 2007;Long et al, 2014], which controls the frequency of overwash, dune erosion, and landward barrier migration or rollover.…”