Sea-level rise acceleration and the drowning of the Delaware Bay coast at 1.8 ka

Abstract

Cores from Delaware Bay tidal marshes separated by over 100 km reveal correlative transgressive overlap boundaries dated at 1.8 to 2.0 ka. Sedimentary fades at these boundaries that show strong marine influence abruptly (but conformably) overlie facies showing strong terrestrial influence. The transgressive overlap boundaries correlate with a transgression in wetland deposits of the New Jersey shore of Delaware Bay, further suggesting the occurrence of a significant regional sea-level movement. Because other mechanisms (rapid subsidence, autocompaction, rapid lateral erosion by tidal streams, and reduced sediment supply) are less likely, we propose that these transgressive facies transitions were produced by an acceleration in the rate of sea-level rise at 1.8 ka in the Delaware Bay.

Salt-marsh reconstructions of relative sea-level change in the North Atlantic during the last 2000 years

“…Datasets which cover the 81 last 700 and 1500 years in Connecticut, USA (Donnelly et al, 2004;van de Plassche, 2000 82 respectively) and AD 600-1600 in Louisiana (González and Törnqvist, 2009) provide snapshots of past 83 RSL, but it is difficult to clearly identify periods of past sea-level change from such short records. It 84 has been suggested that the regionally variable signals along the USA-Canadian margin during the 85 late Holocene may, in part, be due to changes in the strength and position of the Gulf Stream 86 (Fairbridge, 1992;Fletcher et al, 1993;Gehrels et al, 2002), in a similar way to sea-level changes 87 recorded by tide gauges over the last 50 years (Kopp, 2013;Sallenger et al, 2012). 88…”

Influence of Sediment Availability, Vegetation, and Sea Level Rise on the Development of Tidal Marshes in the Delaware Bay: A Review

“…Natural and anthropogenic changes can have a major impact on their development and health (Allen, 2000;Boorman, 1999;Kraft, Yi, and Khalequzzaman, 1992;Orson, Simpson, and Good, 1992;Vane et al, 2008;Velde and Church, 1999). The Delaware Bay and its fringe marshes are no exception to these stressors, and much work has been carried out to shed some light on the processes and interactions that govern the functioning of marshes in the Delaware Bay (Church et al, 2006;Fletcher, Knebel, and Kraft, 1992;Fletcher et al, 1993;Hartwell and Hameedi, 2006;Kearney et al, 2002;Kraft, Yi, and Khalequzzaman, 1992;Najjar et al, 2000;Orson, Simpson, and Good, 1992;Teal and Peterson, 2005) and worldwide (Cappucci et al, 2004;D'Alpaos et al, 2006D'Alpaos et al, , 2007Marani et al, 2003;Thompson et al, 2004). In addition to this fundamental research, the question has arisen of whether sea level rise and changing sediment budgets have a negative impact on the surrounding fringe of marshes in the Delaware Bay (Church et al, 2006;Kraft, Yi, and Khalequzzaman, 1992;Sommerfield and Madsen, 2003;Velde and Church, 1999).…”

The Role of Phragmites australis in Mediating Inland Salt Marsh Migration in a Mid-Atlantic Estuary

“…This strategy is intended to help offset losses of salt marsh due to coastal erosion, and when sea level rise outpaces the accretion capacity of these marshes [5]–[8]. The process of habitat change at this upland interface is well-understood over geologic time-scales [9]–[11], but there are few studies that document this process at a contemporary time-scale [12], [13]. Such information is needed to gain a realistic understanding of the contribution these upland areas will make toward offsetting salt marsh losses due to sea level rise.…”