Field Investigations at Fire Island, New York, to Better Understand Hurricane Sandy’s Impacts and Support Studies of Coastal Resilience
In response to Hurricane Sandy, which struck the U.S. east coast in October 2012, the U.S. Geological Survey (USGS) is engaged in a research project that examines the coastal dynamics of Fire Island, a 50-kilometer (30 mile)-long barrier island south of Long Island, New York. The research will provide basic scientific information on coastal evolution and recovery, and will aid mitigation efforts and management planning.
From June 9 through June 25, 2014, Cheryl Hapke, a coastal geologist from the USGS St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida (SPCMSC), led a comprehensive field effort to map changes and collect baseline geologic data from the coastline affected by Hurricane Sandy. Hapke had been conducting research on Fire Island before Hurricane Sandy (see Fire Island Coastal Change) as part of the USGS Coastal Change Processes project, and she served as a subject-matter expert at the Federal Emergency Management Agency’s (FEMA) Hurricane Sandy Joint Field Office in New York during the post-storm response to Sandy. Hapke and USGS personnel also conducted immediate post-storm coastal-change assessments (see USGS Open-File Report 2013–1231 and “USGS Scientists Predict, Measure Sandy’s Impacts on the Coastal Landscape,” Sound Waves, November/December 2012).
Supplemental funds from the Department of the Interior are making possible numerous USGS studies to aid recovery from Hurricane Sandy and preparation for future storms (see “USGS Research to Support Hurricane Sandy Rebuilding Gets Boost from Supplemental Funds”). Among these studies is the work at Fire Island, where the main goal is to understand the factors that influence the vulnerability and the resiliency of the barrier island, including sediment availability and the response and behavior of the active beach system—the zone in which sand moves offshore during periods of heavy waves and back onshore during periods of fair weather. The June 2014 field survey was part of an effort to meet both the short-term needs of planning for recovery and mitigation, and the longer term needs of basic science.
One of the challenges of Fire Island fieldwork is that the island is a unique blend of National Seashore, federal wilderness tracts, state and county parks, and several private communities. Fieldwork within the National Park entailed extra levels of logistical complexity, especially during Piping Plover nesting and hatching season and the beginning of the crowded tourist season.
Critical to the success of the research was the collection of topographic data (ground elevations) on the beach and geophysical data—specifically, measurements of seafloor depths and imagery of sediment beneath the seafloor—in shallow-water areas less than 20 meters (65 feet) deep. The shallow nearshore zone is an area of high energy and breaking waves where geophysical data collection is logistically challenging and has only been accomplished on a limited basis to date. A specific field target of interest is the breach that was opened during Sandy in the National Seashore’s Otis Pike Federal Wilderness tract. Breaches outside the wilderness tract were manually closed shortly after landfall, but because it is in a wilderness area, the Old Inlet/Sandy breach has been left open, giving the USGS an opportunity to study in detail the response of the natural system.
Field Activities and Participants
The June 2014 field study at Fire Island was a multipronged effort that included five main field activities staffed by people from multiple USGS centers. Altogether 15 USGS staff members from four centers participated, along with four collaborators from the U.S. Army Corps of Engineers (USACE). The teams made diverse field measurements:
A mobile ground-based lidar (light detection and ranging) system was used to measure beach and dune topography by personnel from the USGS Alabama Water Science Center (ALWSC). The ALWSC staff mounted their mobile ground-based lidar system on a truck and collected data while driving on the lower part of the dry beach. To supplement this topographic data collection, personnel from the SPCMSC used global positioning system (GPS) instruments to re-measure elevations along 15 beach profiles that had been established as monitoring locations in the days before Sandy. The pre-Sandy elevation profiles and a series of post-Sandy monitoring profiles are all available online at “Storm Impact and Recovery: Hurricane Sandy - Beach Profiles”.
In-situ measurements were acquired by personnel from the USGS New York Water Science Center (NYWSC) using an Oceanscience remotely operated Q-Boat to measure bathymetry (seafloor depth), flow velocities, and water levels at the Old Inlet breach and in Great South Bay immediately north of the breach. (Read details at “Evaluation of a barrier-island breach created by Hurricane Sandy at Fire Island National Seashore, N.Y.”)
A chirp subbottom profiler towed by a Lighter Amphibious Resupply Cargo (LARC) was used to collect seismic-reflection profiles (cross-sectional views of sub-seafloor sediment layers) in water depths from 0 to 20 meters (65 feet), extending approximately 2 kilometers (a little more than a mile) offshore. The LARC vehicle, which was mobilized from the USACE Field Research Facility in Duck, North Carolina, can be driven from the beach into the water, allowing access to the high wave-energy environment of the surf zone.
Two single-beam acoustic systems mounted on personal watercraft and several GPS backpack systems carried on foot were used to collect nearshore data in shallow water to provide detailed bathymetry of the Old Inlet breach and the shoreface (the zone seaward of the low-tide line, over which sand oscillates with changing wave conditions). The personal-watercraft and GPS surveys were conducted by USGS personnel from SPCMSC and from the USGS Pacific Coastal and Marine Science Center in Santa Cruz, California (PCMSC).
In the ebb and flood shoals of the Old Inlet breach, staff from SPCMSC used GPS backpack systems to collect shallow-water bathymetric data on foot.
The June 2014 field campaign on Fire Island was highly successful, acquiring almost twice the amount of data that had originally been tasked.
Other Opportunities during the Field Excursion
In addition to handling logistical operations, Hapke had the opportunity to meet with local citizens’ groups during the field operations. On June 14, the Point O’ Woods neighborhood association invited her to give a science presentation. Hapke had been invited to speak by late author and association member Robert F. Sayre, who passed away untimely in the spring of 2014. The association wanted to honor that request. Hapke spoke to an audience of approximately 50 residents, who were interested and engaged in coastal issues on the island. A recent book by Sayre—Fire Island, Past, Present, and Future: The Environmental History of a Barrier Beach—went to press just before Hurricane Sandy’s landfall in 2012, and Sayre was able to add a coda about some of the storm’s impacts on Fire Island.
Summary and Acknowledgments
Although Hurricane Sandy caused suffering and loss in communities on Fire Island and in many other coastal areas in the Northeast United States, the natural disaster also presents an opportunity to gain valuable insights into natural coastal processes. The complex field campaign at Fire Island was one of many USGS efforts to achieve such insights, which will help us better prepare for future storms and further our understanding of the basic science behind such events.
We would like to thank the people who participated in the June 2014 field operation. From the USGS: Dustin Kimbrow and Katie Lee (ALWSC); Chris Schubert and Amy Simonson (NYWSC); Jackson Currie, Tim Elfers, and Andrew Stevens (PCMSC); Owen Brenner, Mark Hansen, Cheryl Hapke, Kyle Kelso, Jen Miselis, Tim Nelson, BJ Reynolds, and Dave Thompson (SPCMSC). From the USACE: Jessie McNinch, Jason Pipes, Mark Preisser, and Heidi Wadman (Field Research Facility, Duck, North Carolina).
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