Shinnecock Inlet, New York, Site Investigation Report 3, Selected Field Data Report for 1997, 1998, 1999 Velocity and Sediment Surveys

: As part of a site investigation of Shinnecock Inlet, Long Island, NY, for the Coastal Inlets Research Program, field-monitoring was conducted during 1997, 1998, and 1999. This fieldwork included ADCP current measurements and sediment sampling in the inlet channel, the Atlantic Ocean encompassing the ebb shoal, and Shinnecock Bay including the navigation channels and flood shoal. The 1997 ADCP surveys focused on the interior channel between the jetties and entrance into the bay. The majority of flood flow went into the west channel and over the flood shoal. On ebb the flow comes predominately from the west channel and impinges on the east jetty creating the interior scour hole. The 1998 and 1999 survey focused more on the ocean side of the jetties. The ebb jet follows the direction of the navigation channel cut through the ebb shoal. In the ocean area west of the west jetty a large-scale eddy seems to rotate clockwise on both phases of the tide. The end of the west jetty has a deep scour hole where the throat flow interacts with this eddy flow. Analysis of the sediment grain size distributions indicated a wide variety of depositional environments, with the coarsest material found in the high energy wave/current interaction between the jetties. Finer material was found on the seaward edge of the ebb shoal and on the landward side of the flood shoal. This combined study of currents and sediment distributions and their relationships to the inlet bathymetry provides a picture of the wave and current-induced circulation and depositional patterns active at Shinnecock Inlet.