tide. If all these factors are in the right conjunction, any given 

 storm (even one considered "moderate") may be extremely destructive; 

 i.e., result in large beach volume changes. However, if some of these 

 factors are working against each other, such as the wind direction and 

 time of tide, the storm may have an insignificant effect on the beach. 

 A summary of storm-related data of storms which occurred during 

 the 27-month study period is given in Appendix D. 



Storms are responsible for certain beach features which are only 

 observed during and immediately after storm events. These include 

 ponding, overwash, dune scarps, peat exposure at low tide (after low- 

 intensity storms) , and tree stump exposure (at False Cape) . Generally, 

 after a particularly high-intensity storm, the entire beach profile 

 is flattened and lowered. Recovery rate appears to be proportional to 

 the duration and intensity of the storm. 



All significant beach changes can be related to storm events (and 

 poststorm recovery). However, the largest percent time of erosion is in 

 the fall (Frisch, 1977) . The two most dramatic storm events surveyed, 

 Hurricane Amy in July 1975 and the November 1975 storm, were almost equally 

 destructive. These storms came at different times of the year, and neither 

 occurred during the winter (i.e., December 21 to March 21). From the data 

 in Appendix D, it would appear that the common factors for both storms were 

 maximum wave heights greater than 1.5 meters, and a swell height (greater 

 than or equal to 1.5 meters) duration of 12 hours or more. Swells for 

 both storms were east-southeasterly and northeasterly, respectively. 

 Similar data for the other storm events did not reach this intensity. 



However, these two storms were only of moderate intensity com- 

 pared to erosional events observed along these beaches in the 1972 to 

 1974 pre-CERC study period, and this 27-month study period was a 

 time of relatively low storm-erosion activity in this area. Never- 

 theless, lack of winter storm-induced beach erosion occurrences 

 (four storms in late March and early April, two in the summer, and 

 three in the fall), despite the small sample, is indeed instructive and 

 correlates well with other studies on the east coast (Bullock, 1971; 

 Goldsmith, 1972; Goldsmith, Farrell, and Goldsmith, 1974a). If the storm 

 sample is limited to the four most erosional events (25 November, 1 July, 

 1 December, and 3 September), there does indeed appear to the fall extra- 

 tropical storm, beach-erosion period, and an early tropical storm season 

 in 1976. The appears to correlate with the data of Richardson (1977), as 

 discussed in Section V, 5. In summary, neither the beach survey data, nor 

 the storm occurrences during this study, support the "classic winter erosion 

 and summer accretion" on beaches observed on the U.S. west coast. 



