Quantifying overwash flux in barrier systems : an example from Martha’s Vineyard, Massachusetts, USA
Carruthers, Emily A.
MetadataShow full item record
LocationMartha's Vineyard, MA
Coastal barriers are particularly susceptible to the predicted effects of accelerated of sea-level rise and the potential for increased impacts of intense storms. Over centennial scales, barriers are maintained via overtopping during storms, causing deposition of washover fans on their landward sides. This study examines three washover fans on the south shore of Martha’s Vineyard using a suite of data including vibracores, ground penetrating radar, high resolution dGPS, and LiDAR data. From these data, the volumes of the deposits were determined and range from 2.1—2.4 x 104 m3. Two overwashes occurred during Hurricane Bob in 1991. The water levels produced by this storm have a return interval of ~28 years, resulting in an onshore sediment flux of 2.4—3.4 m3/m/yr. The third washover was deposited by a nor’easter in January 1997, which has a water level return interval of ~6 years, resulting in a flux of 8.5 m3/m/yr. These fluxes are smaller than the flux of sediment needed to maintain a geometrically stable barrier estimated from shoreline retreat rates, suggesting that the barrier is not in long-term equilibrium, a result supported by the thinning of the barrier over this time interval.
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2011
Showing items related by title, author, creator and subject.
Bennett, Sara L. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1988-09)The highly energetic Agulhas Retroflection region south of the African continent lies at the junction of the South Indian, South Atlantic, and Circumpolar Oceans. A new survey of the Agulhas Retroflection taken in March ...
Kading, Tristan (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2013-02)Thiol substances can form stable complexes with metals (especially copper and mercury) in the surface ocean that can impact cycling and bioavailability of those elements. In this study, I present seven concentration ...
Sanford, Lawrence P. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1984-08)Intermittent, shoreward propagating packets of high frequency first mode internal waves are common on the continental shelf when the water column is stratified and may induce large fluctuations in near bottom velocity. ...