1 2 NOAA Technical Report NMFS 140 



Figure 6 



Chart of the studv area showing bathymetric and geographical features. Depth contours are in meters (adapted from 

 Uchupi 1965). 



Maine. The bank slopes gentlv to the southeast and 

 south and its surface is relatively smooth except for a 

 series of sand ridges in the shallow northwest and north- 

 central sections. The sand ridges are formed by excep- 

 tionally strong tidal currents that prevail in this region. 

 Tidal currents generally flow with greatest velocity in 

 the northwest and southeast directions. Further details 

 relating to Georges Bank are contained in Emerv and 

 Uchupi (1965); Uchupi etal. (1977); Valentine (1981); 

 Butman (1982, 1987); Butman et al. (1982. 1987); 

 Backus (1987); Bourne (1987); Butman and Beardsley 

 (19X7); Cohen and Grosslein (1987); Cooper et al. 

 (1987); Emery (1987); Flagg (1987); Howart (1987): 

 Klitgord and Schlee (1987); Maciolek and Grassle 

 (1987); Michael (1987); Neff (1987); Twichell et al. 

 (1987); Uchupi and Austin (1987). 



Nantucket Shoals is a relatively shallow and topo- 

 graphic all\ uneven area southeast of Nantucket Island, 

 Massachusetts. Prim ipal irregularities are large swales 



and ridges extending in north-south and northeast- 

 southwest directions. 



The southern New England continental shelf is a 

 gentlv seaward-sloping region with rather smooth to- 

 pography. Width of the shelf is approximately 100 km 

 and the shelf break occurs at a depth of about 120 m. 

 See Garrison and McMaster ( 1966) for more details. 



The continental slope is a narrow zone along the 

 outer margin of the shelf extending from the shelf 

 break to a depth of 2,000 m. This zone has a compara- 

 tively steep gradient, but less than 5°, and the relief is 

 moderately smooth except where it is cut by submarine 

 canyons. The continental rise (2,000-6,000 m) is gener- 

 ally similar to the slope in having only gradual changes in 

 surficial topography. However, the overall gradient is sub- 

 stantially less than that for the continental slope. Consult 

 Emery (1965a), Emery and Ross (1968), Gibson et al. 

 (1968) , Schlee etal. (1979), Sheridan (1974), and Uchupi 

 et al. ( 1977) for details of topography of this region. 



