Effects of Storms on Coastal Vulnerability Through Revisiting Sites Impacted by Super Storm Sandy Offshore Long Island, New York

Abstract:

Recent models indicate that due to climate change storm activity can intensify. Sea level rise as a result of climate change can lead to storm flooding and coastal damage in low-lying populated areas such as NE, USA. The New York metropolitan area experienced one of the highest storm surges in its history during Hurricane Sandy. The peak storm-tide elevation measured by USGS in Jamaica Bay was about 3.5 m, 1.4 m higher than historical measurements in the same area. As part of a National Science Foundation Rapid Response we surveyed from the R/V Pritchard and sampled the bays and inlets along the southern shore of Long Island after Super Storm Sandy in January 2013 and during June 2014 for assessing the impact of the storm.

Short-lived radioisotopes, heavy metals and grain size variability were used to track the path of the storm. In 2013 high concentrations of metals (Pb 184 ppm) were deposited on the landward side of barrier islands and were tracked offshore for10 km. In 2014, we revisited the 2013 locations. The offshore, metal enriched mud layer was seen as small inclusions in sand and not present at the surface suggestive that natural processes are cleansing the sea-floor. Inland the cores showed three facies. From the base upwards: 1) coarse sand with low Pb 99 ppm. Interpreted as either sand transported landwards by the storm or in situ; 2) fine-grained, organic rich sediment with the high Pb 443 ppm and interpreted as seaward transport by the storm; 3) organic rich mud with lower Pb 200 ppm was found in the core tops. Most importantly the sea-floor was colonized by tubeworms suggestive that the environment is returning to normal conditions. These results coupled to other regional studies indicate that the storm was catastrophic and resulted in significant sediment transport. The surge brought sand inland modifying channel and inlet depths but most damaging was the seaward surge that brought contaminants offshore. It appears that the bays and inlets are resilient and returning to pre-storm conditions.