The effect of coastal landform development on decadal-to millennial-scale longshore sediment fluxes: Evidence from the Holocene evolution of the central mid-Atlantic coast, USA

The behavior of siliciclastic coastal systems is largely controlled by the interplay between accommodation creation and infilling. Factors responsible for altering sediment fluxes to along open-ocean coasts include cross-shore mobilization primarily from tidal currents storms as well changes in alongshore transport rates moderated changing wave conditions, river inputs, artificial shoreline hardening modification, natural trapping updrift landforms. This paper focuses on latter relationships. To address understudied interactions landforms downdrift behavior, we quantify volume trapped Assateague-Chincoteague-Wallops barrier-island complex Virginia, USA coast relate these volumes coastal-system behavior. During last ca. 2250 years, barriers 216 million m3 sand through growth beach- foredune-ridge systems. A period (ca. 400 190 years ago) reduced/no progradation Chincoteague Assateague islands corresponds with sequestration flood-tidal deltas. finding emphasizes important control inlets coasts. Rapid historical spit elongation during has an average 681,000 yr?1 sand; this occurred coincident erosion/migration at long-term >3 m yr?1. Historical elongating southern Island progradational beach ridges northernmost Wallops Islands are equivalent least 60% estimated regional longshore rates. We therefore propose that associated refraction primary drivers barrier erosion, while storminess sea-level rise secondary forcings change affecting equally entire chain. Global context provided a compilation similar sinks, which indicates incorporated into end sandy plains (108 m3), but annual six times greater than those most mainland-attached, However, Wallops, two islands, incorporate broadly large strandplains. Our findings emphasize need account multi-decadal management efforts sandy,