Title:
Hurricane Sandy washover deposit data from southern Long Beach Island, New Jersey: Sample locations
Abstract:
Sedimentologic and topographic data from Hurricane Sandy (HS) washover deposits were collected from Southern Long Beach Island, New Jersey, in order to document changes to the barrier-island beaches, dunes, and coastal wetlands due to HS and subsequent storm events. These data will provide a baseline dataset for use in future coastal change descriptive and predictive studies and assessments. The data presented here were collected as part of the U.S. Geological Survey’s Barrier Island and Estuarine Wetland Physical Change Assessment Project (
http://coastal.er.usgs.gov/sandy-wetland-assessment/), which aims to assess ecological and societal vulnerability that results from long- and short-term physical changes to barrier islands and coastal wetlands. This metadata record describes data that were collected in April 2015, approximately two and a half years after HS’s landfall on 29 October 2012. During the field campaign, washover deposits were photographed and described. In addition, sediment samples, cores, and surface elevations were collected. Data products provided in the associated USGS Data Release (available at
https://doi.org/10.5066/F7PK0D7S) include, sample locations and elevations, core photographs, computed tomography (CT) scans, descriptive core logs, sediment grain-size data, and accompanying Federal Geographic Data Committee (FGDC) metadata.
Scientists from the U.S. Geological Survey Pacific Coastal and Marine Science Center (PCMSC), St. Petersburg Coastal and Marine Science Center (SPCMSC), and students from the University of Hawaii conducted field work from April 7th – 14th, 2015, during which time 49 trenches were dug, documented, and photographed. In addition, 33 sediment cores, 12 sediment source grab samples, and Differential Global Positioning System (DGPS) elevations were collected.
Trenches were dug such that the walls were roughly parallel to the long axis of the washover fan (parallel to the inferred overwash flow direction). Each trench was photographed and described with special attention paid to identifying the depth of the pre-Hurricane Sandy surfaces, where possible. At some locations, the pre-Hurricane Sandy surface, identified using pre-Sandy aerial imagery, was a brown, rooted, peat or soil that has been overlain by a light-colored sand. In these cases, identification of the pre-HS surface in the field was obvious. In other locations, a shallow water table resulted in collapse of the trench walls before reaching the pre-HS surface.
Cores were collected using either a 7.62 cm (3 inch) diameter push-core device or a 5.2 cm diameter, 50 cm long Russian peat auger. In general, push cores sampled shallow sediment that occurred above the groundwater table while the Russian cores were able to sample sediment within ponds or below the water table. In total 13 push cores and 20 Russian cores were collected. At six of the sites, multiple Russian cores were collected, each penetrating to different depths. Push cores were capped and sealed upon extraction and the location and core ID were recorded. A north arrow was marked on the push cores in order to orient them for CT scanning and laboratory analysis. Russian cores were transferred to PVC tubes that had been split lengthwise, then wrapped in plastic and taped. Location and core IDs were recorded but due to the nature of Russian core extraction, orientation was uncertain and not recorded. Bulk sediment grab samples weighing between 5 and 30 grams were collected from potential sediment sources and analyzed for grain size.
