A FIELD DATA ASSESSMENT OF CONTEMPORARY MODELS OF BEACH CUSP FORMATION

Cusp formation was observed during an instrumented, daily profiled, ti me series of a reflective beach in Canaveral National Seashore, Florid a on January 5, 1988. The monitored cusp embayment formed by erosion o f the foreshore and the cusp series had a mean spacing of approximatel y 28 m. During this time, inshore fluid flows were dominated by two st anding edge waves at frequencies of 0.06 Hz (primary) and 0.035 Hz (se condary) whereas incident waves were broadbanded at 0.12-0.16 Hz. Dire ctly measured flows (and indirectly estimated swash excursion) data su pport both the standing wave subharmonic model (GUZA and INMAN, 1975) and the self-organization model (WERNER and FINK, 1993) of cusp format ion in this study.