As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off the northern Chandeleur Islands, Louisiana, in June of 2011. The overall objectives of the study are to better understand barrier-island geomorphic evolution, particularly storm-related depositional and erosional processes that shape the islands over annual to interannual timescales (1-5 years). Collection of geophysical data will allow us to identify relationships between the geologic history of the island and its present day morphology and sediment distribution. This mapping effort was the first in a series of three planned surveys in this area. High resolution geophysical data collected in each of three consecutive years along this rapidly changing barrier-island system will provide a unique time-series dataset that will significantly further the analyses and geomorphological interpretations of this and other coastal systems, improving our understanding of coastal response and evolution over short time scales (1-5 years). This report serves as an archive of processed interferometric swath and single-beam bathymetry data that were collected during two cruises (USGS Field Activity Numbers 11BIM01 and 11BIM02) along the northern portion of the Chandeleur Islands, Breton National Wildlife Refuge, Louisiana, in June of 2011. Geographic information system data products include a 50 m-cell-size interpolated bathymetry grid surface, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee metadata.

As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off the northern Chandeleur Islands, Louisiana, in June of 2011. The overall objectives of the study are to better understand barrier-island geomorphic evolution, particularly storm-related depositional and erosional processes that shape the islands over annual to interannual timescales (1-5 years). Collection of geophysical data will allow us to identify relationships between the geologic history of the island and its present day morphology and sediment distribution. This mapping effort was the first in a series of three planned surveys in this area. High resolution geophysical data collected in each of three consecutive years along this rapidly changing barrier-island system will provide a unique time-series dataset that will significantly further the analyses and geomorphological interpretations of this and other coastal systems, improving our understanding of coastal response and evolution over short time scales (1-5 years). This report serves as an archive of processed interferometric swath and single-beam bathymetry data that were collected during two cruises (USGS Field Activity Numbers 11BIM01 and 11BIM02) along the northern portion of the Chandeleur Islands, Breton National Wildlife Refuge, Louisiana, in June of 2011. Geographic information system data products include a 50 m-cell-size interpolated bathymetry grid surface, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee metadata.

An Ellipsoidally Referenced Survey (ERS) using two Teledyne Reson SeaBat T50-P multibeam echosounders, in dual-head configuration, was conducted by the U.S Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) offshore of the Chandeleur Islands, Louisiana, August 16-21, 2018. This dataset, Chandeleur_ Islands_2018_MBES_xyz.zip, includes the processed elevation point data (x,y,z), as derived from a 1-meter (m) bathymetric grid.

An Ellipsoidally Referenced Survey (ERS) using two Teledyne Reson SeaBat T50-P multibeam echosounders, in dual-head configuration, was conducted by the U.S Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) offshore of the Chandeleur Islands, Louisiana, August 16-21, 2018. This dataset, Chandeleur_ Islands_2018_MBES_xyz.zip, includes the processed elevation point data (x,y,z), as derived from a 1-meter (m) bathymetric grid.

An Ellipsoidally Referenced Survey (ERS) using two Teledyne Reson SeaBat T50-P multibeam echosounders, in dual-head configuration, was conducted by the U.S Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) offshore of the Chandeleur Islands, Louisiana, August 9-12, 2017. This dataset, Chandeleur_Islands_2017_MBB_xyz.zip, includes the processed elevation point data (x,y,z), as derived from a 1-meter (m) bathymetric grid.

An Ellipsoidally Referenced Survey (ERS) using two Teledyne Reson SeaBat T50-P multibeam echosounders, in dual-head configuration, was conducted by the U.S Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) offshore of the Chandeleur Islands, Louisiana, August 9-12, 2017. This dataset, Chandeleur_Islands_2017_MBB_xyz.zip, includes the processed elevation point data (x,y,z), as derived from a 1-meter (m) bathymetric grid.

Scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted single-beam and multibeam bathymetry (Stalk and others, 2025) surveys around the northern Chandeleur Islands, Louisiana, from June 12 to 20 and from July 31 to August 9, 2023, as part of Field Activity Number (FAN) 2023-325-FA. The purpose of data collection was to measure submerged coastal elevations along the Chandeleur Islands, located in the Breton National Wildlife Refuge. Funded by the Extending Government Funding and Delivering Emergency Assistance Act (Public Law 117-43) enacted on September 30, 2021, these data, in combination with previous bathymetric data collected at the study area (Stalk and others, 2017; Stalk and others, 2020), can be used to quantify storm-related barrier island sediment redistribution following the 2020-2021 hurricane seasons. The survey encompassed approximately 760 square kilometers (km) of the gulf-side and sound-side nearshore environments around the northern Chandeleur Islands. The single-beam bathymetry was acquired using two 12-foot (ft) personal watercrafts and two boats (a 20-ft Twin Vee [TVEE] and a 17-ft Mako). All vessels were outfitted with high precision Global Navigation Satellite System receivers, motion reference units, and survey grade single-beam echosounders (SBES). Long Term Change (LTC) lines were collected by the TVEE as part of a comparative long term change analysis, but for this data release, LTC lines represent shore-perpendicular transects extending both offshore and soundward 3 km on either side of the island. Sub-bottom profile geophysical data were also collected during this FAN and are provided in Forde and others (2024).

Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS - SPCMSC) in St. Petersburg, Florida, conducted a single-beam bathymetric survey of Cedar Island, Virginia, August 9-15, 2019. During this study, bathymetry data were collected aboard a towed seismic sled outfitted with a single-beam echosounder.

Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS - SPCMSC) in St. Petersburg, Florida, conducted a single-beam bathymetric survey of Rockaway Peninsula, New York September 27 - October 6, 2019. During this study, bathymetry data were collected aboard two personal watercraft (PWC) outfitted with single-beam echosounders, as well as a towed seismic sled with similar instrumentation.

Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS - SPCMSC) in St. Petersburg, Florida, conducted a single-beam bathymetric survey of Rockaway Peninsula, New York September 27 - October 6, 2019. During this study, bathymetry data were collected aboard two personal watercraft (PWC) outfitted with single-beam echosounders, as well as a towed seismic sled with similar instrumentation.