wall of the canyon, just a few kilometers away at comparable depths, show 

 northward inflow along the eastern wall. On the western wall, flow was 

 southward. The mean Eulerian currents in the canyon thus suggest a complex 

 vertical Eulerian circulation along the axis and horizontal exchange along the 

 canyon walls. 



The current fluctuations with the canyon are aligned with the canyon 

 axis. The strength of the high-frequency fluctuations (motions with periods 

 shorter than about one day) increase toward the bottom and the head of the 

 canyon. The low-frequency currents (motions which fluctuate at periods longer 

 than about two days) were strongest over the slope and weakest in the canyon. 

 Along-shelf current fluctuations over the shelf were correlated with cross- 

 shelf flow over the canyon mouth (offshelf for southwestward flow), suggesting 

 enhanced cross-shelf exchange in the region of the canyon. Fluctuations at 

 semidiurnal periods dominate the current spectra. Near the canyon head, their 

 strength changes substantially with time, indicating random generation of 

 internal wave packets. 



Similar studies in nearby Oceanographer Canyon show that currents there 

 are dominated by tidal currents and are stronger than in Lydonia Canyon. Net 

 Eulerian down-canyon flow was observed at both 200 and 600 m. 



Kinetic energy spectra clearly show different current regimes on the 

 shelf and slope and in the canyon (Figure 5). With these spectra, the current 

 fluctuations can be conveniently separated using the periods at which they 

 oscillate into low-frequency flows (periods of more than 30 hr), tidal 

 currents (diurnal and semidiurnal), inertial fluctuations, and high-frequency 

 motions (periods of 2 to 10 hr) . 



On the shelf and slope, there is a large energy component at lower 

 frequencies (2 days or more) and the fluctuations are oriented along isobaths. 

 Low-frequency currents within the canyons are oriented along the axis and are 

 weak. At all stations, there was an energy peak correlated with semidiurnal 

 tides. In the canyons, the amplitude of the tidal, inertial, and high- 



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