1 On the basis of these observations on sediment texture and current 



2 observations, there seems to be a correlation between Georges Bank 



3 canyon shape and the energy level of the canyon, so that large canyons, 



4 large, long canyons, with a deep mouth at the shelf, at the 200 meter 



5 isobath where the canyon cuts the shelf, with a deep mouth, fairly long, 



6 and steep walls at the canyon mouth, those canyons seemed to be the most 



7 energetic. 



8 The moderate-energy canyons are not as long, generally have a 



9 shallower mouth, and the walls are less steeply angled at the mouth, and 



10 so on, in the lower-energy canyons down to canyons like Heeltapper, 



11 which are really embayments of the slope, are even shorter and 



12 shallower, and have less steep walls. 



13 So that based on observations in more than half of these canyons, 



14 I've categorized them as to their energy level so thatOceanographer, 



15 Hydrographer, and Gilbert, all of which we have observations on the 



16 canyon axis where we see bedforms and clean sand--by the way, the canyon 



17 axis is--the nature of the canyon axis is a real good indicator of the 



18 nature of the canyon's energetics. 



19 They all are classified as high-energy canyons, even though 



20 Gilbert's a little short, but has a deep mouth. The moderate-energy 



21 canyons would be Lydonia, Powell, Welker, and Veatch. Low-energy 



22 canyons would be Heeltapper, Dog Body, Shallop [name unclear], Atlantis, 



23 and Alvin Canyons. 



24 I'd like to sum up with this overhead, if you can read it, where 



25 we have a comparison between the different canyon energy levels here so 



26 that these are generalizations, so that in high-energy canyons with a 



27 length of 13 to 25 kilometers, this is from the head of the canyon to 



28 shelf break, where the canyon passes through the 200-meter isobath, the 



29 depth at their mouth, the deepness of their mouth, is from the 750 to 



30 1,000 meters, and the angles of their walls at the mouth are 15 to 35 



31 degrees. 



32 So, on the rims of these canyons we would have shelf sand and 



33 gravel, which is rippled, sand would be in transit to the walls, 



34 transported by tidal currents and this westward current that we've 



41 



