Formation and development of beach cusps on Del Monte Beach, Monterey, California

Abstract

Observations and measurements were made daily on Del Monte Beach in order to develop a quantitative description of the parameters affecting tlie formation of beach cusps. Multiple regression techniques were used to formulate an equation relating cusp width to the measured parameters. The life cycle of cusps was studied in order to gain insight into the factors affecting the groirth and decay of oosps. It was determined tiiat cusps are depositional in nature and develop sequentially from preferential areas of accretion on the beach. Cusp spacing was found to be a function primarily of wave height (energy) and wave period. Regularity of the wave regime during formation was found to result in uniform cusp spacing. Little migration was observed in mature cusps, and large changes in tlie wave regime or beach conditions were required to alter the cusp profiles. The action of large wind waves, storm surges, and breakers, was observed to destroy beach cusps.