paralleling the natural topographic expression of the Hudson (submarine) Channel. It 

 measures approximately 7 nautical miles along an east-west axis and 3 nautical miles along a 

 north-south axis. The protrusion of accumulated material extending in a southwest direction 

 toward the New Jersey mainland may be attributed to a lack of close survey control on the 

 1845 survey due to proximity of Shrewsbury Rocks, which posed a navigation hazard. 

 Another factor contributing to the anomalous protrusion may be natural sedimentary 

 accretion from the Navesink and Shrewsbury Rivers. The rivers at one time flowed directly 

 into the ocean (Fig. 9) before northward growth of the barrier island, which has since 

 diverted their discharge north into Sandy Hook Bay. 



The area of maximum thickness, corresponding to the Castle Hill area on the recent 

 chart, is about 5 nautical miles east of New Jersey, and contains more than 50 feet of fill 

 material. The 10-, 20-, and 30-foot isopach lines extend about 4 miles in a northwest 

 direction and include another conical feature. (See Figure 10.) The conical elevation 

 northeast of the channel exhibits more than 30 feet of fill and historically has been referred 

 to as Diamond Hill. Three northeast -southwest oriented sea floor profiles located in Figure 9 

 are shown in Figure 11. Some of the disparity between the 1845 and 1934 sea floor could 

 be attributed to inaccurate surveys; however, the net aggradation of the sea floor in profiles 

 A and B is unmistakably real. The lack of significant sea floor change along profile C, which 

 passes seaward of the isopached disposal area reported on here, further indicates that the 

 sand, gravel, and stone fractions of the fill along profiles A and B are stable in the present 

 oceanographic environment and have shown little movement southward toward the deeper 

 parts of the Hudson Channel. 



Conclusive proof that the Diamond Hill sea floor feature is ocean-disposed fill is available 

 from the log for Coast Guard bore hole 4 (Table 4) taken for a foundation study for the 

 Ambrose Light station. The boring is located on a flank (Fig. 5) about 600 yards southeast 

 of the main sea floor feature. The log (Table 4) describes a mixture of fill material to 16 feet 

 below the sea floor. 



Additional proof of the origin of these sea floor features and a perspective history of 

 ocean disposal of fill in waters proximal to New York City is contained in annual reports by 

 the U.S. Army, Corps of Engineers (1885—1930). Part 1 of the 1915 report was helpful in 

 providing the location, volumes and general nature of material disposed in the ocean outside 

 New York Harbor. 



To accommodate the increasing need for disposal of assorted materials the Office of 

 Supervisor of New York Harbor was established by an act of Congress in 1888. The Harbor 

 Supervisor, acting through the Office of the Chief of Engineers, was responsible for 

 designation of specific disposal sites and for ensuring that ocean disposal would not be 

 detrimental to navigation or pollute adjacent beaches. A more complete documentation of 

 establishment of authority over ocean disposal in the New York City region is discussed by 

 Pararas-Carayannis (1973). 



35 



