Arnell S. Forde 20250312 1.0 Vector digital data (point and polyline) Arnell S. Forde Chelsea A. Stalk James G. Flocks 20250312 1.0 U.S. Geological Survey data release doi:10.5066/P13SMFT7 St. Petersburg, Florida U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center https://doi.org/10.5066/P13SMFT7 As part of the Breton Island Post Construction Monitoring project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted a nearshore geophysical survey in August 2024 to map the borrow site created during the Breton Island, Louisiana (LA) restoration effort that began in December 2020. The restoration effort was part of the Deepwater Horizon oil spill settlement to restore natural resources and services injured by the spill. Following restoration, monitoring efforts of the island and surrounding seafloor are necessary to evaluate the programmatic goals of the restoration. This survey, funded by the Louisiana Outer Coast Restoration project, reoccupies a subset of sub-bottom profile tracklines originally acquired in August 2022; refer to Forde and others (2023) for details. The data provided in this publication provide baseline information regarding the physical structure of the dredge pit and help researchers monitor morphologic evolution over time. The data release associated with this metadata record serves as an archive of high-resolution chirp sub-bottom trace data and navigation files. Shapefiles (.shp) provided in the data release represent point and polyline vector datasets of Field Activity Number (FAN) 2024-320-FA chirp sub-bottom profile trackline, start of line, and 1,000-shot-interval locations. The purpose of the data release described herein is to archive and disseminate digital chirp sub-bottom profile data and associated files collected during USGS FAN 2024-320-FA. Additional survey and data details are available from the USGS Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/services/activity.php?fan=2024-320-FA. 20240809 20240809 ground condition Complete None planned -89.12960 -89.09370 29.48070 29.45700 USGS Metadata Identifier USGS:021d19b1-461f-4686-935d-3ac8cee1c7ed ISO 19115 Topic Category geoscientificInformation oceans location USGS Thesaurus sub-bottom profiling marine geology geology coastal processes navigational data geospatial datasets None trackline locations start of line locations 1,000-shot-interval locations barrier island mapping seismic reflection chirp 2024-320-FA Common Geographic Areas Breton Islands Breton National Wildlife Refuge Breton Sound Breton Wilderness Louisiana No access constraints. Please see 'Distribution Information' for details. These data are marked with a Creative Common CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Arnell S. Forde U.S. Geological Survey Geologist Mailing and physical

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Saint Petersburg FL 33701 USA (727) 502-8000 aforde@usgs.gov Funding and (or) support for this study was provided by the USGS Coastal and Marine Hazards and Resources Program. The authors thank Captain Andrew Farmer of the SPCMSC for his assistance in data collection and piloting the Research Vessel (R/V) Sallenger. Field activity planning was performed by James Flocks; data collection conducted by Chelsea Stalk and James Flocks; and data processing performed by Arnell Forde. This document was improved by scientific/editorial and metadata reviews from Christopher Bemelmans and Tess Rivenbark-Terrano of the SPCMSC. Environment as of Metadata Creation: Microsoft Windows 11 Enterprise Version 23H2; Environmental Systems Research Institute (Esri) ArcGIS Pro 3.2.1; MacOS Sonoma 14.6.1; Seismic Unix (Release 44); PROJ.5.1.0. Cohen, J.K. Stockwell, J.W., Jr. 2010 Golden, Colorado Center for Wave Phenomena, Colorado School of Mines https://github.com/JohnWStockwellJr/SeisUnix Forde, A.S. Flocks, J.G. Farmer, A.S. 20231101 U.S. Geological Survey data release doi:10.5066/P9Q28MFD St. Petersburg, Florida U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center https://doi.org/10.5066/P9Q28MFD These datasets are from one field activity with consistent instrument calibrations. Seismic data were acquired during a single survey, 2024-320-FA, which occurred between August 2 and 12, 2024. A total of 28 seismic lines were collected during this field activity. Additional survey and data details are available from the Field Activity Collection System (FACS) logs and acquisition geometry figure, which are included as supplemental information in the download file, 2024-320-FA_logs.zip. As the sub-bottom profile data were acquired, the position of the vessel was continuously determined by an Applanix POS MV Wavemaster II inertial aided navigation system (IANS), which is accurate to within 0.5-2 meters (m). Positions from the POS MV IANS were recorded and written to the seismic trace headers approximately every 0.20 seconds, with unique navigation fixes being recorded every second. The approximate 4-m offset between the chirp and vessel's IANS reference point has not been accounted for in the comma-delimited American Standard Code for Information Interchange (ASCII) navigation or geospatial files. Navigation information was extracted from the seismic trace headers (seismic data available from the data release) using Seismic Unix release 44 software (Cohen and Stockwell, 2010), processed with PROJ.5.1.0 software (https://proj.org/) to generate Universal Transverse Mercator (UTM) Zone 16 North (N) coordinates from latitude and longitude coordinates (World Geodetic System of 1984, WGS84), and then saved as ASCII text files in comma-separated values (CSV) format. Navigation files for each sub-bottom line, saved by line number, were concatenated into comma-delimited text files so they could be represented geospatially using geographic information system (GIS) software. The final output files are as follows: (1) 2024-320-FA_nav.csv contains unique shotpoint positions (along each line) for the entire survey, (2) 2024-320-FA_1000sht.csv includes the 1,000-shot-interval locations that were generated to correlate shot locations along the trackline with evenly spaced 1,000-shot index markers along the top of the printable profile images, and (3) 2024-320-FA_sol.csv has the start-of-line locations for each trackline. These CSV files are available from the data release, see 2024-320-FA_nav.zip. *.txt 20240820 2024-320-FA_nav.csv 2024-320-FA_1000sht.csv 2024-320-FA_sol.csv Arnell S. Forde U.S. Geological Survey Geologist Mailing and physical

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St. Petersburg FL 33701 USA 727-502-8000 aforde@usgs.gov The reformatted text files referenced in the previous process step were then further processed using Esri ArcGIS Pro 3.2.1 software to generate shapefiles. The 1,000-shot navigation file, 2024-320-FA_1000sht.csv, provided in the data release was imported into ArcGIS Pro software to produce a geographic representation of the 1,000-shotpoint data collected within the survey area. The 1,000-shot-interval point shapefile (2024-320-FA_1000sht.shp) was generated to correlate shot locations with evenly spaced 1,000-shot index markers along the top of the printable profile images. Likewise, a point shapefile containing the start of line locations for all chirp tracklines, that are based on the reformatted text file, 2024-320-FA_sol.csv, was used to create 2024-320-FA_sol.shp. Finally, the 2024-320-FA_nav.csv file containing unique shotpoint positions was imported into ArcGIS Pro to produce a geographic representation of the sub-bottom profile tracklines collected within the survey area. The 'PointsToLine (Data Management)' geoprocessing tool was used to create a shapefile (2024-320-FA_trkln.shp) in which individual chirp shotpoints were connected to form tracklines. A non-proprietary version of the shapefiles was created with the 'Map To KML (Conversion)' geoprocessing tool that converted the map document layers to keyhole markup language (.kml) format prior to them being compressed (zipped) and saved as a .kmz file (2024-320-FA.kmz). All geospatial files can be found in 2024-320-FA_gis.zip. 2024-320-FA_1000sht.csv 2024-320-FA_sol.csv 2024-320-FA_nav.csv 20240826 2024-320-FA_1000sht.shp 2024-320-FA_sol.shp 2024-320-FA_trkln.shp 2024-320-FA.kmz Arnell S. Forde U.S. Geological Survey Geologist Mailing and physical

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St. Petersburg FL 33701 (727) 502-8000 aforde@usgs.gov Vector 0.0197905787 0.0226037719 Decimal Degrees WGS_1984 WGS_84 6378137.0 298.257223563 Geospatial files (2024-320-FA_gis.zip): The shapefiles created as part of this dataset are a derivative of the ASCII CSV navigation files provided in 2024-320-FA_nav.zip, which is available from the data release. The navigation and geospatial files mainly share the same attribute labels and definitions, aside from "FID" and "Shape", which are specific to the .shp files. Due to ArcGIS Pro character restrictions, the point shapefile attribute labels were changed to “DOY_HR_MIN” within the attribute tables. The detailed attribute descriptions for these files are provided in the data dictionary (DataDictionary_SBP.docx); the metadata are not complete without this file. The trackline file, 2024-320-FA_trkln.shp (28 data records), is a polyline geospatial dataset representing all the chirp sub-bottom profile tracklines; 2024-320-FA_1000sht.shp (91 data records) is a point geospatial dataset representing the 1,000th shot interval; and 2024-320-FA_sol.shp (28 data records) provides locations for the start of each seismic line as a point geospatial dataset. The entity and attribute information were generated by the individual or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information. SPCMSC Data Management Group U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Mailing and physical

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St. Petersburg FL 33701 USA (727) 502-8000 gs-g-spcmsc_data_inquiries@usgs.gov 2024-320-FA_1000sht.shp, 2024-320-FA_sol.shp, 2024-320-FA_trkln.shp, 2024-320-FA.kmz Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. KML 2024-320-FA_gis.zip contains the survey navigation data represented geospatially using a Google Earth Keyhole Markup Language Zipped (KMZ) file, which is a non-proprietary format, and support information. Winzip or 7zip 0.384 https://coastal.er.usgs.gov/data-release/doi-P13SMFT7/data/2024-320-FA_gis.zip shapefile 2024-320-FA_gis.zip contains the survey navigation data represented geospatially using point and polyline shapefiles, which can be read by most GIS software packages, and support information. Winzip or 7zip 0.384 https://coastal.er.usgs.gov/data-release/doi-P13SMFT7/data/2024-320-FA_gis.zip None The geospatial files were created for use with Esri ArcGIS Pro 3.2.1 software. They may also be viewed with QGIS (https://www.qgis.org/en/site/, 2024), Google Earth (https://earth.google.com/, 2024), or other GIS software capable of importing the data. 20250312 SPCMSC Data Management Group U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Mailing and physical

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St. Petersburg FL 33701 USA (727) 502-8000 gs-g-spcmsc_data_inquiries@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998