Superstorm Sandy had a historic impact on the New York and New Jersey coastlines. This collaborative Rapid Response project will assess the effect of Superstorm Sandy in estuarine and shallow coastal environments, focusing on the Western Bays and Jamaica Bay. The project will leverage pre-existing geophysical and sedimentological data collected by the PIs prior to the storm, and will complement a related field program planned by investigators at the University of Texas Institute for Geophysics. Previously sampled sites will be reoccupied for sediment sampling (gravity and box cores, grab samples) and textural and geochemical tracer analyses. Multibeam bathymetry will be collected in previously surveyed areas and will cover a new ebb-tidal delta system and smaller estuarine channels. These data will be combined with transport indicator and debris field mapping to evaluate the pathways and mechanisms of sediment transport during Superstorm Sandy.
This work will lead to a better understanding of the response of the shallow seafloor to extreme storms and will help to constrain the regional sediment budget, a potentially important consideration in the rebuilding process. Graduate and undergraduate students will be involved in the research. The PIs plan to work with regional partners (South Shore Estuary Reserve, Operation Splash) and engage in public outreach.
As part of an NSF RAPID response grant, geophysical and sediment sampling surveys were conducted to document the changes resulting from Hurricane Sandy on the coastal systems offshore of southern Long Island, New York. Due to sea-level rise and global climate warming, storms like Sandy will likely affect heavily populated coasts more frequently and it is critical that we learn how to deal with these disasters. The major goals of the program are to create a base line to evaluate future change and to assess the impact of Sandy on sediment transport within the estuarine, barrier and shoreface settings. By measuring the concentrations of heavy metals in the sediments and tracking their path with short-lived radioisotopes we evaluated the extent of sediment transport generated during and after Sandy. The areas of study are West Bay, Middle Bay, East Bay, Reynolds Channel and Jones Inlet offshore of the heavily populated southern coast of Long Island, Nassau County, and Long Beach barrier island, New York. Meeting our objectives will permit to develop effective remediation procedures and contribute to risk management including re-assessment of coastal building codes. Two surveys were conducted from the R/V Pritchard by a team of scientists and students from Adelphi University, Queens College CUNY and Stony Brook SUNY on February 2013 and June 2014. This program was in collaboration with colleagues from the University of Texas Institute for Geophysics at Austin that surveyed offshore Long Island. The teams with expertise in marine geology, geochemistry and geophysics addressed the following questions: How were sediments eroded, transported and deposited by the high tidal surge and ebb generated by Hurricane Sandy? Have the navigation channels been affected? Was there an impact on the sediments and ecosystems from the discharge of sewage overflow and other anthropogenic pollutants that resulted from the storm? Were contaminated sediments deposited offshore? If so how far offshore? The short-lived radioisotope 7Be (half life 53 days) forms in the atmosphere through cosmogenic reactions. It is rapidly associated with aerosols and deposited either dry or by precipitation on terrestrial environments. During Sandy, streams flooded and their high discharge transported sediments with high 7Be and heavy metal concentrations to the estuary, bays, inlets and offshore. Immediately after the super storm, it was reported that the Bay Park Sewage Treatment Plant spilled over 2 billion gallons of raw sewage into adjacent coastal waters as a result of Sandy. We measured the highest heavy metal concentrations near the plant and along the Long Beach landward shore. When comparing pre-Sandy with measurements obtained a few months after Sandy within the bays and inlets, we found that finer-grained sediments were more abundant and heavy metal concentrations greater. For example Pb concentrations were measured at 250 ppm, up to 10 times higher than background.These fine grain-sediments and contaminant concentrations could be tracked for 10 km offshore. One year after Sandy, we found that the highest concentrations of Pb, up to 250 ppm, are now buried 10-20 cm below the sea floor. This information together with a moderate abundance of organisms near the top of the cores, suggests that the system is returning to "normal" conditions. Amphipod tubes are commonly abundant in the western bays. We did not find any in the grab sampling program following Hurricane Sandy (February 2013), indicating major reworking of sediments in the western bays. However, amphipod tubes were present in the Reynold's Channel area on June 2014, suggesting the ecosystem was returning to a more normal state. Unfortunately, Pb ppm concentrations continue to be high, up to 80 ppm, and above background levels of 20 ppm as measured in other studies. This study has provided many opportunities for education at Queens College and the City University of New York: it is part of the PhD thesis of Pariskeh Hosseini, Dhiman Mondal and undergraduate student Yolanda Chow. Results were presented at special session of the American Geophysical Union Fall meeting in 2013 by Pi's and students and are being written for publication. Our findings also form part of the teaching curriculum at the introductory, non-science major level and for Earth and Environmental Sciences undergraduate majors and graduate students. We anticipate continued education opportunities stemming from this work in the future. It has been documented that the landward storm surge caused severe erosion and collapse of dunes. Our results tracked the greatest damage seawards and linked it to ebb currents and seaward-directed storm surge. It is likely that streams flooded by Sandy facilitated the transported of metals offshore. But, initial results from post-Sandy in 2014 indicate that the highest concentrations of heavy metals are now buried under 20 cm of mud and ecosystems appear to be returning to "normal" conditions. But most importantly this freshly deposited surface mud also contains high concentrations of heavy metals.
