however, indicate qualitatively the trend over the period. Variance larger 
than the mean shows that some of the profiles prograded while others were 
eroded over the time interval between profiles. 
The criteria for selecting the storms in Table 2 were based on those 
events that showed a significant change in the average beach volume, which 
could be attributed to a single event. This required that the storm be 
closely bracketed by surveys. An attempt was made to select storms distributed 
by season and over the entire period of the survey record. Of the 15 events 
that met these criteria, four which caused extensive erosion are discussed 
below. The results of an additional severe winter storm were previously re- 
ported by DeWall, Pritchett, and Galvin (1977). Each of the selected storms 
occurred during seasons other than summer. This is because widely spaced 
summer surveys did not meet the selection criteria and, as shown in Figure 
5, few storms occur during the summer months. 
(1) Refraction of Storm Waves. Strong onshore winds and low pressure 
enhance normal water levels and combine with storm-generated waves to cause 
coastal flooding and erosion. The direction and rate of net littoral trans- 
port cannot be determined from the beach profile data alone. Previous studies 
of the motion of the Long Beach Island inlets have concluded that a nodal zone 
exists in the vicinity of Barnegat Inlet with transport north of the zone to- 
ward the north and south of the zone toward the south (U.S. Army Engineer 
District, Philadelphia, 1974). However, no detailed studies are available 
which show the location of the node, its migration pattern, or the rate and 
direction of littoral drift along the length of the island. Studies which 
hope to answer these and other questions are being conducted (Dr. G. Ashley, 
Rutgers University, New Brunswick, New Jersey, personal communication, 1979). 
Summary wave information was available from the wave gage at Steel 
Pier, Atlantic City, New Jersey,for most of the study period (Thompson, 1977). 
This provided height and period statistics, but did not provide directional 
information necessary for computation of sand transport. Wave data were also 
available from the Summary of Synoptic Meteorological Observations (SSMO), 
Volume 3 (U.S. Naval Weather Service Command, 1975). These are not appropriate 
for calculations of sand transport because they are at-sea observations and do 
not give precise directional information. They are also biased toward low wave. 
conditions since reporting ships attempt to avoid severe weather by resched- 
uling or rerouting. Local visual observations were collected as part of the BEP 
at selected profile line locations from 1968 to 1974. These provide estimates of 
wave height, period, and direction. According to these sources, storm waves 
generated by northeasters may develop periods of 8 to 12 seconds. 
Storm winds approach Long Beach Island from the northeast, east, and 
southeast in that order of frequency of occurrence (U.S. Army Engineer District, 
Philadelphia, 1974). Wave refraction diagrams were developed for waves approach- 
ing from these directions in order to determine if local topographic features 
caused wave focusing or other effects along the island and to obtain qualitative 
estimates of the locations of energy concentration under various conditions of 
offshore wave approach. Interpretation of these results should not be heavily 
relied upon since many assumptions are made about the waves and their behavior 
that do not apply to the prototype situation. Monochromatic, linear waves are 
34 
