A conceptual model for spatial Grain size variability on the surface of and within beaches

A conceptual model for spatial Grain size variability on the surface of and within beaches

Gallagher, Edith (Franklin and Marshall College, Lancaster)
Wadman, Heidi (US Army Corps of Engineers)
McNinch, Jesse (US Army Corps of Engineers)
Reniers, A.J.H.M. (TU Delft Hydraulic Engineering; TU Delft Environmental Fluid Mechanics)
Koktas, Melike (Student TU Delft)

Hydraulic Engineering

2016

Grain size on the surface of natural beaches has been observed to vary spatially and temporally with morphology and wave energy. The stratigraphy of the beach at Duck, North Carolina, USA was examined using 36 vibracores (~1-1.5 m long) collected along a cross-shore beach profile. Cores show that beach sediments are finer (~0.3 mm) and more uniform high up on the beach. Lower on the beach, with more swash and wave action, the sand is reworked, segregated by size, and deposited in layers and patches. At the deepest measurement sites in the swash (~-1.4 to -1.6 m NAVD88), which are constantly being reworked by the energetic shore break, there is a thick layer (60-80 cm) of very coarse sediment (~2 mm). Examination of two large trenches showed that continuous layers of coarse and fine sands comprise beach stratigraphy. Thicker coarse layers in the trenches (above mean sea level) are likely owing to storm erosion and storm surge elevating the shore break and swash, which act to sort the sediment. Those layers are buried as water level retreats, accretion occurs and the beach recovers from the storm. Thinner coarse layers likely represent similar processes acting on smaller temporal scales.

Beach
Depth of disturbance
Grain size
Morphodynamics
Morphology
Sediment
Shore break
Storms
Stratigraphy
Swash

http://resolver.tudelft.nl/uuid:df13ed15-6581-469b-87a6-84e66393c6e6

https://doi.org/10.3390/jmse4020038

2077-1312

Journal of Marine Science and Engineering, 4 (2)

Part of the special Issue "Coastal Morphodynamics"

Institutional Repository

journal article

© 2016 Edith Gallagher, Heidi Wadman, Jesse McNinch, A.J.H.M. Reniers, Melike Koktas