prominently in the sediment budget analysis of Caldwell (1966), and the 
morphology and dynamics of the spit have been extensively studied by 
researchers associated with Rutgers, The State University of New Jersey (e.g., 
Allen 1981a,b; Allen and Nordstrom 1977a; Nordstrom et al. 1982; Phillips, 
Psuty, and McCluskey 1984). Kondolf (1978) and Gares (1981) present accounts 
of the history and geology of Sandy Hook. The annotated bibliography by 
Gorman (1988) contains a comprehensive list of references on Sandy Hook. 
18. By definition, as a spit, Sandy Hook is an accretionary feature. 
Numerous researchers have concluded that the majority of sediment originally 
forming the spit was derived from erosion of the northern 30 km of the New 
Jersey barrier island shore, along which the predominant longshore drift is to 
the north (CE 1954, Caldwell 1966). Sandy Hook Lighthouse, originally built 
30 m from the northern tip in 1764 (cf. Kondolf 1978, p 35), now lies some 
2 km inland. Allen (1981a) performed budget analyses for the time intervals 
1953-1976 and 1971-1978 and concluded, on the basis of aerial photographs, 
that Sandy Hook had an average material loss of 270,000 cu m/year in the 
interval 1971-1978. 
19. Removal of potential updrift sources of littoral material due to 
seawall and revetment construction is probably the major cause of erosion 
along Sandy Hook. An additional factor may be convergence of wave energy due 
to refraction (Allen 1981a). Caldwell (1966) assumed that groins have caused 
limited sand starvation at Sandy Hook. However, it should be noted that 
groins have a finite trapping capacity; once the limit of trapping of a groin 
field is reached, sand transported alongshore is expected to pass through the 
field. 
20. Researchers at Rutgers University have termed the 2-km-long region 
of Sandy Hook just north of Sea Bright (more precisely, north of Highland 
Beach) the "critical zone," because of its susceptibility to erosion. The 
critical zone is of interest to the present project since the numerical model 
of shoreline change had to be calibrated for this area (cf. Part IV). 
Nordstrom et al. (1982, p 6) state that the average shoreline recession rate 
along the critical zone for the period 1943-1972 was 5.3 m/year and for 1973- 
1982, 30 m/year obtained mainly on the basis of aerial photograph interpreta- 
tion. Survey data available in the present study give a recession rate of 
8.2 m/year with a standard deviation of 0.97 m for the interval 1971-1982. 
Both data sets indicate significant erosion. Differences in recession rates 
16 
