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FitzGerald and Pendleton
New Inlet along the outer coast of Cape Cod was formed during a moderate northeast extratropical storm on 1-2 January 1987.
Figure 1.
Long-term shoreline recession and development of a hydraulic head across the barrier facilitate storm breaching of Nauset Spit.
to document the evolution of a tidal inlet (LUI et al., 1993;
hindcast studies (USACOE, 1957; BROOKS and
STAUBLE, 2001), the backbarrier system (FITZGERALD
BRANDON, 1995). Based on wave data, the net southerly
and MONTELLO, 1993; PENDLETON et al ., 2001) and,
longshore transport rate is estimated to be between 3.6 and
in particular, the development of the ebb-tidal delta. The
5.0 m3/yr (WEISHAR et al ., 1989; LUI et al ., 1993). The
intent of this paper is to discuss the conditions that led to the
net southerly movement of sand has been manifested
breaching of Nauset Spit. Next, we will describe the
historically by a southerly progradation of the Nauset Spit.
morphological evolution of the ebb-tidal delta and explain
As seen in Figure 2, prior to the formation of New Inlet the
how the inlet bypasses sediment.
end of Nauset Spit accreted southward 3.4 km between
1938 and 1986.
BACKGROUND
Northeast storms impact the Cape Cod region primarily
The southern outer coast of Cape Cod is dominated by
southerly longshore transport, which is driven by northeast
about 10 to 15 storms each year. The mean tidal range
storm waves. Sediment is sourced from glacial cliffs north
outside the inlet is 2.0 m (NOAA, 2001) and increases to
of Nauset Inlet consisting primarily of sand and fine gravel.
2.3 m during spring tide conditions. In Chatham Harbor
The deepwater wave approach is from the east-northeast
inside the inlet gage measurements indicate a mean tidal
with mean height of 1.5 m as determined from wave
range of 1.4 m.
Journal of Coastal Research, Special Issue 36, 2002
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