WEATHER-INDUCED EROSION AND ACCRETION AT SEAWALL BEACH, PHIPPSBURG, MAINE

An examination of Seawall Beach, a barrier beach in Phippsburg, Maine, and the collection of local weather data were used to determine patterns of erosion and accretion of sediment under summer and winter weather conditions. Methods included topographic profiling of five transects perpendicular to the shoreline, at different locations along the length of the beach. Activation rods were used to determine specific areas of erosion or accretion along the transects, and digital photographs were taken to support the profile data. The NOAA Portland Weather Buoy and a weather station installed at nearby Morse Mountain recorded weather conditions, including wind, waves, and local barometric pressure. The responses of the eastern, central, and western sections of Seawall Beach were studied to determine spatial variability in erosion and accretion.

Preliminary results indicate that the eastern sector of the beach is strongly influenced by the dynamics of the Morse River Inlet and has been in an erosive mode since the summer. The central sector of the beach was scarped in November but heavy erosion was limited due to the extensive presence of berm-colonizing plants on the backshore and possibly the presence of Morse Hill to the east, which may have blocked erosive winds. In contrast, recent storms have caused more removal of the berm in the western sector of the beach where there was little protection from easterly winds.