SERENDIPITY IN LONG-TERM COASTLINE FIELD STUDIES: HURRICANE SANDY AND CAPE HENLOPEN (DE) SPIT PROGRADATION

Long-term field studies of temporally slow but spatially large geological processes can give students an increased sense of the variability of geologic rates and access the impacts of infrequent but more catastrophic events embedded in the long-term record. The growth of the spit at Cape Henlopen, Delaware is a good example of this overall process and the need for good data collection during each phase of the long-term data collection. Here we describe the process by which students have collected and archived past and more recent total spit areas using GPS and analyzed these data using ArcGis software. In particular, we document the changes to the spit taken from ground surveys, traditional aerial photography and Google Earth starting in 1845 and adding to that database student surveys in 2009, early October 2012, immediately after Hurricane Sandy and in October 2013 to determine the effects of long-term long-shore sand transport versus avulsive events such as Hurricane Sandy. At Cape Henlopen, the storm removed a significant amount of sand from the Delaware Bay side and a smaller area from the Atlantic beach side because the eye of Sandy was to the north of the Cape and thus the wind vectors were offshore. The one-year Post-Sandy spit survey shows that most of the sand removed from the Atlantic beach side has been returned to the spit suggesting that the sand was stored offshore. The course based student research field project approach teaches much more than could be learned from traditional lecture or in-house laboratory exercises. The use of GPS and GIS opens up new ways of quantifying the effects of extreme meteorological phenomena on coastline change and leads to greater student awareness of the implications for the future development of coastlines.