APPENDIX B 

 EROSION AND ACCRETION AT NAUSET BEACH, CAPE COD 

 1. Storm Erosion . 



a. Storm of February 1972 . 



(1) Description . The most severe storm encountered during the 8-year 

 monitoring period (1970-1977) occurred 18 to 20 February 1972. Because of its 

 intensity and long duration, the storm caused extensive damage along beaches 

 from Long Island to New England. Storm surge reached its greatest height in 

 the early morning hours of 19 February 1972. Surge levels of 1.3 to 1.4 meters 

 were reported on Cape Cod (Pore, 1973). The peak storm surge was nearly coinci- 

 dent with high tide which intensified shore damage. Shipboard observers reported 

 waves from 3.0 to 3.5 meters during the storm (Pore, 1973). 



(2) Impact . Profile surveys were made in the study area on 14 February 

 1972, 4 days before the storm, and again on 6 March 1972, 14 days after the 

 storm. Though a survey was conducted relatively soon after the storm, it should 

 be noted that significant changes in the shore and beach may occur inmiediately 

 following severe storms. For example, Birkemeier (1979) recently studied beach 

 changes during an 18 to 20 December 1977 storm on Long Beach, New Jersey. He 

 found that about one-half of the material eroded from the beach during the storm 

 was returned to the beach within 2 days. The February and March 1972 profile 

 surveys provide data on the storm impact on dunes during early stages of devel- 

 opment. Figure B-1 depicts the prestorm and poststorm profiles on the spit. 

 Major accretion of sand occurred along the seaward shore of profiles 1 to 4. 



In this area, the beach advanced from 15 to 40 meters. Though data are incom- 

 plete for profile lines 8 and 10, there appeared to be some erosion along 

 profile lines 5 to 10, up to 15 meters at profile line 9. 



During the storm the beachgrass plots (profile lines 1, 2, 5, 6, 9, and 10) 

 were buried with overwashed sand. Plot 1 was buried by 0.3 to 0.7 meter, plot 

 3 by 0.03 to 0.7 meter, and plot 5 by 0.2 to 0.5 meter of sand. Plants were 

 observed emerging in all plots by April 1972. It was not possible to measure 

 the overall survival of the buried plants because bare areas were replanted in 

 April 1972 in keeping with study objectives to provide complete plant cover in 

 these areas. However, American beachgrass did emerge through at least a 0.3- 

 meter washover deposit in plot 2 and did survive saltwater inundation. 

 S.P. Leatherman and P.J. Godfrey (Institute for Man and Environment, National 

 Park Service Cooperative Research Unit, University of Massachusetts, personal 

 communication, 1979) have recently made similar observations on Nauset Beach. 

 However, they note that saltwater inundation and overwash during the growing 

 season can cause total mortality in American beachgrass stands. The growing 

 season for American beachgrass is roughly from March through November (R. Zaremba, 

 Institute for Man and Environment, University of Massachusetts, personal commu- 

 nication, 1979) . 



Crest elevations in the fenced plots were nearly 1 meter higher than the 

 beachgrass plots before the storm. Consequently, less overwash occurred in 

 these plots. The only major overwash occurred in plot 2. About 30 meters of 

 the fencing in plot 2 had been damaged by a storm during the previous year. 

 The earlier damage probably provided a natural pathway for overwash during the 



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