The buried Hudson Channel on the seismic records in the region east of Sandy Hook has 

 a subsea depth of 300 feet (Fig. 5) in contrast to the channel depth of over 700 feet at 

 Tarrytown, New York. (Worzel and Drake, 1959.) Because of the general north-south 

 alignment of the subaerial Hudson Valley and because of both the great width and depth of 

 the entire Hudson River Valley it is reasonable to assume that the valley acted as a conduit 

 for glacial ice during Pleistocene times, at least as far south of the terminal moraines across 

 Staten Island, in which the glaciers advanced and retreated a number of times. The resulting 

 glacial scour was responsible for deepening the Hudson Valley into a fjord which has since 

 been partially filled by typical fluvial and glacial sediments. The base of the Hudson Channel 

 on seismic line 37 (Fig. 5) exhibits a flat-bottomed, U-shaped lateral profile (typical 

 glaciated valley) in contrast to more typical V-shaped profiles (typical fluvial valley) of the 

 channel on the outer shelf. (Knott and Hoskins, 1968.) The channel profile and 300-foot 

 depth suggest the possibility that glaciers transgressed south of the Long Island-Staten Island 

 terminal moraine, were funneled through The Narrows and flowed for an indefinite distance 

 out onto the Continental Shelf. If this suggestion were correct it could provide the 

 mechanism to explain why the Hudson is the best developed of any submarine 

 channel-canyon system on the Atlantic shelf. To provide further evidence to either prove or 

 disprove this idea, and in general to further document the exact course, maximum channel 

 relief, and nature of channel fill, more high resolution seismic records and deep cores are 

 needed on the inner shelf to tie with seismic work done by Ewing, Pichon, and Ewing 

 (1963), and Oser (1969) on parts of the outer shelf. 

 3. Effects of Man. 



a. Ocean Disposal of Spoil Material. An interesting feature on the bathymetric chart of 



the New York Inner Bight (Fig. 4) is the presence of several conical, topographically 

 positive, sea floor features located in what was a clearly defined Hudson Channel depression 

 on the 1845 chart. (See Figure 9.) These features are situated about 6 miles southeast of the 

 New York Harbor entrance and have about 30 feet of relief relative to the surrounding sea 

 floor. Their isolated nature and circular form in plan view sets them apart from the natural 

 sea floor morphology. The 1845 chart,based on lead-line sounding data, shows clear contour 

 expression of the Hudson (submarine) Channel as it makes its transition from the 

 Continental Shelf to the Lower Bay entrance, and ultimately through The Narrows to 

 connect with the Hudson Valley. Comparison of Figure 4 with Figure 9 shows little net 

 change in contour placement for the inner shelf except for the region around the channel 

 head. 



An isopach map (Fig. 10) of bathymetry differences from both the 1845 and 1934 

 charts shows the location and magnitude of accretion that has taken place during 90 years. 

 The minimum isopach line limits the maximum bathymetrical areal extent of material 

 accumulation and shows an irregular outline, is elongated in a northwest-southeast direction, 



32 



