3.7.3 Current Speed and Direction 



The passage of Hurricane Gloria along the adjacent 

 continental shelf and over Long Island Sound significantly 

 perturbed the near-bottom current field in the vicinity of the NLON 

 disposal site. Pre-storm currents displayed a regular tidal 

 variability with peak speeds of approximately 35 cm/sec (Figure 

 3-89) . Associated directions were predominantly northeasterly 

 (030° mag) during the ebb tide and southwesterly (225° mag) on the 

 flood tide (Figure 3-90) . As Gloria approached, both current speed 

 and direction began to display irregular behavior. Over 26 

 September and into the early part of 27 September, current speeds 

 during both the flood and ebb remained similar in peak value while 

 displaying some slight increase in short-term variability. This 

 pattern was disturbed during the early morning hours of 27 

 September and the flood, which commenced at 0529 EDST in The Race 

 (Figure 2-2) , displayed a significantly reduced peak value. The 

 subsequent ebb, commencing at 1119 EDST, spanned the period during 

 which Gloria passed over the Sound and displayed significantly 

 higher peak values than those observed during the immediate 

 pre-storm period. Current directions associated with this interval 

 were also significantly perturbed with both the ebb and flood 

 displaying increased northerly components. 



Following storm passage, there was an evident suppression 

 of the tidal stream over the next 12 hr tidal cycle with peak flood 

 velocities reduced by approximately 3 0% relative to pre-storm 

 levels and a near total arrest of the ebb (approx. 2045 EDST on 27 

 September to 0530 EDST on 28 September in Figure 3-89) . This 

 absence of a significant ebb was also apparent in the direction 

 record, where values dominated by southwest to northwest components 

 prevailed over the period from 1745 EDST on 27 September to 0530 

 EDST on 28 September. This storm-associated perturbation slowly 

 relaxed over the next tidal cycle. Peak speeds during the flood 

 initiated early on the morning of 28 September (0608 EDST) 

 approached pre-storm levels observed just prior to the transit of 

 Gloria across the Sound. The following ebb, beginning at 1119 EDST 

 (28 September) , displayed peak values equal to those observed 

 during Gloria and generally well in excess of those found during 

 the pre-storm period. In contrast to the majority of the tidal 

 cycles, these high current speeds persisted over much of the ebb 

 phase resulting in generally high kinetic energy levels. This 

 event appeared to be pjrimarily associated with the relaxation of 

 the tidal system following departure of Gloria. Subsequent tidal 

 cycles displayed characteristics essentially similar to pre-storm 

 conditions. 



3.7.4 Surface Wave Characteristics 



The bottom-mounted wave and tide gage indicated that the 

 passage of Hurricane Gloria resulted in the generation of a surface 



27 



