indications point to continuing barrier retreat along southern Long Island except in isolated spots 

 of convergence, such as updrift of inlet jetties or at the west tip of Fire Island. 



Table 3 



Relative Sea Level Trends Near Long Island 







Entire Record Series 



1950-1993 



NOAA 

 Station 



Name 



Years of 

 record used 



Trend 

 mm/year 



Error 

 mm/year 



Variability 

 mm/year 



Trend 

 mm/year 



Error 

 mm/year 



Variability 

 mm/year 



8510560 



Montauk, NY 



39 



1.85 



0.35 



28.09 



1.78 



0.38 



28.56 



8518750 



New York (the 

 Battery) 



122 



2.72 



0.07 



28.62 



2.27 



0.34 



28.40 



8516990 



Willets Pt, NY 

 (LI Sound) 



62 



2.33 



0.22 



31.54 



1.78 



0.40 



33.35 



8531680 



Sandy Hook, 

 NJ 



61 



3.84 



0.22 



30.04 



3.15 



0.37 



31.12 



Source: Statistics computed by National Oceanic and Atmospheric Administration (NOAA), downloaded from NOAA Internet 

 home page 8/6/1996. 



Sediment Grain Size Characteristics 



The most comprehensive sediment sampling program along the south coast of Long Island 

 was conducted in the 1950's by the Beach Erosion Board (Taney 1961a). Overall grain sizes 

 along the south shore of Long Island decrease in size from east to west. Taney (1961b) reports 

 that the coarsest material is found in the headland zone extending about 7 km west of Montauk 

 Point. From there west to Shinnecock Inlet, the average median diameter lies between 0.4 and 

 0.5 mm. Between Shinnecock and Moriches, the sizes display considerable variation (possibly 

 due to gravel bands or patches). Near Shinnecock, sands are slightly coarser than further 

 downdrift to the west. Statistics based on many samples collected along the barrier portion of the 

 south shore (Coney Island to east end of Shinnecock Bay) are listed in Table 4. 



Some limited grain statistics were provided by Great Lakes Dredge & Dock, Oakbrook, IL. 

 For the beach west of Shinnecock inlet (exact location unspecified), they reported fine sand with 

 a trace of gravel, d 50 = 0.74 mm and d g5 = 3.00 mm. This is surprisingly coarse, and it is likely 

 that the sample statistics were heavily influenced by the gravel portion. For underwater samples 

 below -3.3 m, fine to medium sand had d 50 = 0.43 mm and d 85 = 0.80 mm, while above the 

 -3.3-m depth, d 50 = 0.30 mm and d g5 = 0.74 mm. More samples were collected in 1995. Grain 

 size distribution curves for each sample at the profile immediately west of the inlet are shown in 

 Figure 4. 



Chapter 2 Geologic Setting and Morphologic Development 



