QUANTIFYING MACRO-SCALE GEOMORPHOLOGICAL CHANGES POST-HURRICANE SANDY AT ASSATEAGUE ISLAND UTILIZING BATHYMETRIC MAPPING TECHNIQUES

Assateague Island is a barrier island complex that stretches 37 miles along the Atlantic coast of Maryland and Virginia. The island’s location along the eastern seaboard makes for a highly dynamic system that not only changes over long temporal scale through long shore transport and sea level transgression/ regression, but also over short seasonal scales due to strong currents and storm events such as Hurricane Sandy in late October 2012. Geologically speaking, Hurricane Sandy gave us a rare opportunity to quantify large spatial scale sea-floor changes over a short temporal scale because of the vast amount of energy that moved through the region in 2012. This coastal geomorphological study will aim to quantify the macro-scale changes that took place over time by utilizing data collected via bathymetric sea-floor mapping surveys that took place in 2011 and 2014. The first data set was collected in a study for the National Parks service pre-Hurricane Sandy (2011), using a single-beam echosounder. This will be compared to multi-beam data that was collected by the United States Geological Survey post-Hurricane Sandy (2014) using a SWATHplus interferometric sonar. Comparing these two data sets allows us to measure large-scale changes over a short temporal scale. In addition, the formative changes that were constructed via the strong wind, currents and swells from Hurricane Sandy that will be quantified between the 2011 and 2014 data sets, will also be compared to data from 2015 that was collected by the University of Delaware utilizing an Edgetech 6205 multi-beam echosounder. This will aim to quantify to what level (if any) recovery has been made to a pre-Hurricane Sandy condition in the time span of a couple years. This study will have implications for quantifying near shore sand resource movement during storm events.