the pre-storm period; the longer term, lower frequency trends were 

 simply related to varying streamflow inputs. Such data provided 

 little indication of any tendency for the storm to produce large 

 spatial scale homogeneity. 



The effects of storm-associated surface wave generation 

 were essentially confined to the period of storm passage (-12 

 hours) by the geomorphology of Long Island Sound. The long, narrow 

 configuration and the east-west orientation of this basin limit 

 significant wave generation to a relatively well-defined range of 

 wind conditions. These conditions were satisfied during the 

 initial stages of Gloria when south to southeasterly winds 

 prevailed. For the eastern Sound, these wind directions result in 

 relatively large overwater distances, or fetch, favoring maximum 

 wave generation. As the storm proceeded to the north, however, 

 fetch progressively decreased with the wind shift to the southwest. 

 As a result, kinetic energy levels associated with the surface wave 

 field also decreased, reducing the transport competence of the 

 local velocity field. In the absence of these supplemental 

 energies, materials suspended during storm passage settled rapidly, 

 and ambient suspended material concentrations quickly returned to 

 pre-storm levels. 



The response of the suspended material field to the 

 storm-associated perturbations of the local tidal system appeared 

 to consist of two primary elements. First the surge-associated 

 retardation of the tidal stream affected both current speed and 

 direction, modifying the interaction between these flows and those 

 induced by the local surface wave field. The net result of this 

 modification was reflected in the well-defined, discrete character 

 of the storm-associated peak in near-bottom suspended material 

 concentrations. This rapid increase in concentration was clearly 

 representative of a system in which transport energies were 

 confined to the storm period and were abruptly terminated following 

 storm passage. Such a response appeared consistent with both the 

 surface wave and current speed data. The virtual absence of 

 factors other than wave-current interactions sufficient to 

 contribute to the storm perturbation makes this a particularly 

 valuable set of data for any efforts to analytically model sediment 

 resuspension in the Sound. 



In addition to modifying wave-current interactions, 

 storm-associated perturbations in the local tidal system also 

 altered the tidal heigfit and phase relations. These perturbations 

 were most likely responsible for the secondary peak in near-bottom 

 suspended material concentrations which was observed approximately 

 12 hours after the direct storm peak. As noted, this secondary 

 peak appeared to be the result of offshore advection of materials 

 suspended during the storm within the inshore areas. The fact that 

 this secondary spike was essentially coincident with the increase 

 in velocity levels and displays maximum suspended sediment 

 concentrations that were independent of peak current speeds tends 



36 



