Monday, June 18, 2012

Who's Who: Stephanie Nebel

Steph is in her third year as a PhD candidate of Geology at the University of Delaware. She is at the tail end of her project, currently writing the analyses and eventual conclusions of her dissertation.


Steph's dissertation is a continuation of her masters thesis, which was also conducted through UD. As a graduate student, she investigated the retreat rates and shoreline movement of Cedar Island, a barrier island in Virginia near the Delmarva Peninsula. By means of varying sediment supply, sea level rise, and storms, Cedar Island is retreating landward at rates much higher than other barrier islands on the eastern coast. Steph determined how quickly the island is retreating and the variation of this rate over time using topographic maps, satellite images, GPS data, and other sources. Recently (1994-2007), Cedar Island has retreated at a rate of -12 m/yr! She was also able to compare the historical retreat rates with the Atlantic hurricane record and find that an increase in storm frequency correlated with an increase in island erosion.  


Now, her dissertation work looks at a different, less historical aspect of Cedar Island's trend of retreat. Instead of focusing only on the surficial features of the barrier island, she took a closer look at the features on and beneath the ocean floor to determine the preservation potential of its associated inlets. The instrumentation used took data that extended to as much as 60 meters below the seafloor. As Cedar Island migrates, its inlets should as well, in theory. Using seismic profiling and sidescan sonar, two surveys were completed in 2009 and 2010. The data was analyzed and visualized in SonarWiz. Steph is currently looking within the seismic records for an upwards "U", channel-like features that indicate old, previously filled inlets. If the inlets were not preserved, they would have eroded away and not appear in the seismic profiles at all. Once she finishes evaluating the seismic material, she will move on to the data taken with the sidescan sonar.


Steph enjoys studying Cedar Island and the surrounding areas in Virginia because they remain mostly uninhabited by people. Therefore, the trends observed are virtually free of human influence- a breath of fresh air on a coastline where beach tourism is prevalent.

Additionally, Steph had the opportunity to spend two and a half weeks on the Ocean Exploration Trust's E/V Nautilus in 2010. As a data logger, her role was to monitor data as it came in. She will be returning to the Nautilus this August to train as a data manager.

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