Paper No. 6
Presentation Time: 8:00 AM-12:00 PM
THE MORPHOLOGIC RESPONSES OF PHILLIPS BEACH (MA) TO METEOROLOGICAL CONDITIONS, FALL 2010
Beaches are dynamic environments that experience cycles of erosion and accretion in response to changes in coastal conditions associated with meteorological events. Such morphologic changes have environmental and economical implications, and an understanding of a particular beach’s responses to storms can be beneficial to the local community. This study seeks to establish initial profile and volume data from Phillips Beach, Swampscott, MA in order to investigate the beach’s responses to meteorological events. The beach is a southeast facing, welded barrier beach with an approximate vertical relief of 6 meters, and a tidal range of ~3.7meters. A permanent stake has been placed in the back-barrier (42.47128°N x 070.88679°W), and beach profiling has been performed at a bearing of S70E from the stake using a modified Emory method. A baseline survey was conducted on 4/25/2010 and approximately bi-weekly surveys have been on-going since September 2010. The profile data yield cross-sectional profiles and volume data along the transect line which document morphological and volumetric changes that occurred on this beach. Data taken from buoy 44013, the Boston approach light buoy, documented a storm on 10/16/2010 that moved over this area with WNW winds that averaged speeds above 25 mph. The wave height at times was over 2 meters and the duration of the storm was approximately 40 hours. Surveys taken on 10/12/2010 and 10/28/2010 reveal a volume loss and a visible change to the profile. Data taken from the same buoy documented another storm on 11/9/2010 with NNE winds that reached speeds over 30 mph. This storm lasted approximately 48 hours and the wave height was over 3 meters for most of its duration. A survey taken on 11/11/2010 again shows a volume loss of sand. An off shore bar that was observed in the surf zone during this survey is likely the location of the removed sediment. Partial recovery of the beach was observed in the profile shape and associated volume gain from a survey taken on 12/12/2010.