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Fig. 12.4 Major pathways of sand transport at Norderneyer Seegat, East Friesian Islands (From Nummedal and Penland 1981 ) .
Sand bypasses the inlet from west to east through ebb- and fl ood- dominant channels
wag of a dog's tail (Fig. 12.5c ). Sand delivered to the
inlet is preferentially deposited on the updrift side of
the ebb-tidal delta, which causes a defl ection of the
main ebb channel until it nearly parallels the downdrift
inlet shoreline. This circuitous confi guration of the
main channel results in ineffi cient tidal fl ow through
the inlet, ultimately leading to breaching, when a new
channel cuts through the ebb-tidal delta. The breaching
process results in a large packet of sand bypassing the
inlet. This process was captured at Capers Inlet, South
Carolina between 1917 and 1938 whereby a new main
channel breached through a marginal fl ood channel
followed by a 2-km long bar welding to Dewees Island
(Fig. 12.7 ). The truncated beach ridges on Dewees
Island and an adjacent deep channel, where the inlet
once fl owed, are evidence of this process. Truncation
of beach ridges along Capers Island attests to this same
process occurring at Price Inlet (Fig. 12.7 , FitzGerald
et al. 1978 ) .
Fig. 12.5 Major pathways of sand transport at Norderneyer
Seegat, East Friesian Islands (Modifi ed from Nummedal and
Penland 1981 ). Sand bypasses the inlet from west to east through
ebb- and fl ood- dominant channels
12.5.2.3 Inlet Migration and Spit Breaching
A fi nal mode of inlet sediment bypassing occurs at
migrating inlets whereby an abundant sand supply
and a dominant longshore transport direction cause
spit building and downdrift inlet migration (Fig. 12.5a ).
Along many coasts, as the inlet is displaced farther
12.5.2.2 Ebb-Tidal Delta Breaching
This mechanism of sediment bypassing occurs at inlets
with a stable throat position but with a main ebb chan-
nel that migrates through their ebb-tidal deltas like the
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