APPENDIX L: DATA SUMMARY FOR THE STORM OF 19 DECEMBER 197 7 



1. The 19 December 1977 storm was a major event causing significant 

 and consistent erosion at Long Beach Island and Ludlam Beach. Since surveys 

 were conducted during the waning stages of the storm, a good record of the 

 storm's impact was obtained. Birkemeier (1979) reported on the beach changes 

 caused by this storm and included additional data taken 2 days later and data 

 from a beach in North Carolina. 



2. As can be seen on the synoptic weather map, this storm developed 

 off the southeastern United States moving first northward and then almost due 

 east, forced out to sea by a blocking high-pressure system. Peak high tide 

 at Atlantic City was 1.4 m above msl with an associated 1.0-m surge. Visual 

 observations during the storm recorded maximum breaking wave heights ranging 

 from 3 m at Long Beach Island to 2.3 m at Ludlam Beach. As shown in Figure 

 L3 , incident waves measured in 11 m of water reached nearly 3 m in height at 

 Ludlam Beach. 



3. Erosion was consistent along both islands with almost all profile 

 lines eroding. The pattern of erosion differed between the two localities. 

 Long Beach Island eroded the most by losing -21.1 m^/m, the foreshore 

 flattened and the shoreline actually accreted on one-half of the lines for a 

 median change of 1.6m. Apparently, the material simply shifted or "rotated" 

 from the foreshore "across" the shoreline to the offshore. Considerable dune 

 erosion occurred as shown in Figure L6 . Recovery was fast. Birkemeier 

 (1979) showed some 51 percent of the material had returned to the foreshore 

 by 22 December. 



4. The volume changes at Ludlam Beach were similar with a median 

 erosion of -17.6 m^/m; however, unlike at Long Beach Island, the foreshore 

 slope remained the same and the shoreline retreated -8.8 m. Basically the 

 beach face lowered and retreated. The lowering is obvious in the before and 

 after photos shown in Figure L9. Surveys a day later showed no significant 

 recovery. 



5. Tables and figures are arranged according to predicted and actual 

 water levels, hindcasted wave data, profile comparisons, shoreline and slope 

 changes, unit volume changes, and distribution of unit volume changes. 



LI 



