files. At present, such a large data base does aot exist, at least for 

 the laeter-fflilllmeter scales of bottom photography. One area of the 

 world ocean (near AO'Zy'N and 62''20'W) has been extensively surveyed at 

 small scales and this is the location of the High Energy Benthic 

 Boundary Layer Experiment (HEBBLE) . 



The HEBBLE area falls into the large roughness province of the East 

 Coast Continental Rise which was described in Chapter 5 and illustrated 

 in Figures 5-12 and 5-13. K spectral model was generated for this large 

 area based on averaging spectral estimates from all profiles illustrated 

 on Figure 5-13. As mentioned previously, the amplitude spectrum for 

 this area consists of two segments, the lower frequency model (with a ^ 

 0.0142 m, b > -1.813) extending to wavelengths of approximately X « 3 

 km, and the higher frequency model (with a ■• 0.0602 m, b » -0.603) 

 extending from X « 3 km to X a 200 ra. 



Data collected by the Deep-Tow sonar system In the HEBBLE area were 

 provided by Scripps Institute of Oceanography. The Deep-Tow, which col- 

 lects profiles from a height of only 25-50 meters above the sea floor, 

 is able to sample bathymetry at a horizontal sample spacing of 5 meters. 

 The vehicle is positioned via a transponder navigation system which pro- 

 vides relative location to the beacons every five minutes (or approxi- 

 mately 270 meters) of track. All depths recorded by the system in this 

 area appear to be above the instrument noise level. 



Digital height data from one stereo-pair bottom photograph col- 

 lected in the HEBBLE area were provided by the University of Washington. 

 The data set consists of six horizontal and six vertical transects sam- 

 pled at 1 mm spacing. All derived spectra were virtually identical in 

 their model characteristics. 



113 



