Sediment delivery to marsh platforms minimized by source decoupling and flux convergence

Geophysical Research Letters
By: , and 

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Abstract

Sediment supply is a primary factor in determining marsh response to sea level rise and is typically approximated through high‐resolution measurements of suspended sediment concentrations (SSCs) from adjacent tidal channels. However, understanding sediment transport across the marsh itself remains limited by discontinuous measurements of SSC over individual tidal cycles. Here, we use an array of optical turbidity sensors to build a long‐term, continuous record of SSC across a marsh platform and adjacent tidal channel. We find that channel and marsh concentrations are correlated (i.e., coupled) within tidal cycles but are largely decoupled over longer time scales. We also find that net sediment fluxes decline to near zero within 10 m of the marsh edge. Together, these results suggest that large sections of the marsh platform receive minimal sediment independent of flooding frequency or channel sediment supply. Marsh‐centric, as opposed to channel‐centric, measures of sediment supply may better characterize marsh platform vulnerability.

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Publication type Article
Publication Subtype Journal Article
Title Sediment delivery to marsh platforms minimized by source decoupling and flux convergence
Series title Geophysical Research Letters
DOI 10.1029/2020JF005558
Volume 125
Issue 8
Year Published 2020
Language English
Publisher American Geophysical Union
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description e2020JF005558, 13 p.
Country United States
State Massachusetts
Other Geospatial Plum Island Estuary
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