. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 78 Geological processes massive discharges of sand in the surf zones of the Long Island and New Jersey coasts move toward the New York harbor mouth; these discharges have built Sandy Hook and Rockaway spits within subhistoric to historic times. However, we know almost nothing about fluid motions over the ad- jacent inner shelf, although the geologic data presented above show that currents seaward of the surf play a major role in the coastal sand bud
. Collected reprints / Atlantic Oceanographic and Meteorological Laboratories [and] Pacific Oceanographic Laboratories. Oceanography 78 Geological processes massive discharges of sand in the surf zones of the Long Island and New Jersey coasts move toward the New York harbor mouth; these discharges have built Sandy Hook and Rockaway spits within subhistoric to historic times. However, we know almost nothing about fluid motions over the ad- jacent inner shelf, although the geologic data presented above show that currents seaward of the surf play a major role in the coastal sand budget. We must specifically ask what time and .space scales of inner shelf flows are intense enough to entrain sand? Is their velocity field so structured that there are periods of significant offshore bottom flow and sand transport? Equally important is the problem of the inner shelf sand ridges, which seem to occur wherever a sewage outfall or power plant is to be located. If we wish to predict the probable behavior of these features through the design life of the structure, we must un- derstand their genesis and how they are maintained by flow. It is a truism of loose boundary hydraulics that sheared boundary flows are innately unstable, and that these instabilities tend to interact with the sub- strate to generate sand ripples, sand ribbons, sand waves, and sand dunes. The circum- stantial evidence that inner shelf sand ridges are similarly responses to flow is strong. How are they formed land maintained? As a first attempt to investigate these questions, Lavelle et al. (in press) placed 40 Aandaraa current meters at 19 stations over the Tobay Beach sand ridges of the Long Island inner shelf (Figs. 10 and 11). The meters were in place for 6 weeks dur- ing late November and December 1974; a single meter recorded for an additional 5 weeks. All meters averaged speed over 10 min and took an instantaneous direction reading during each sampling period. During the observation period
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