Arnell S. Forde 20221018 Vector Digital Dataset (Point) Arnell S. Forde James G. Flocks Stanley D. Locker 20221018 U.S. Geological Survey data release doi:10.5066/P9YTIG6G St. Petersburg, Florida U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center https://doi.org/10.5066/P9YTIG6G From September 16 through 23, 2015, the U.S. Geological Survey (USGS) conducted geophysical surveys to investigate the geologic controls on barrier island evolution and sediment transport offshore of Dauphin Island, Alabama. Geophysical data were collected as part of the Alabama Barrier Island Restoration Feasibility Study. This shapefile represents a point dataset of field activity number (FAN) 2015-330-FA chirp subbottom profile 1,000-shot-interval locations. To aid in the registering of digital chirp subbottom profile data collected during USGS FAN 2015-330-FA. Additional survey and data details are available from the USGS Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/fan_info.php?fan=2015-330-FA and in the Field Activity Collection System (FACS) logs, which are included in the download file, 2015-330-FA_logs.zip (Forde and others, 2022). 20150916 20150923 ground condition Complete None planned -88.327469 -88.041133 30.247244 30.160775 USGS Metadata Identifier USGS:66e51acc-28cd-406d-97b7-d6d8418b33a8 ISO 19115 Topic Category geoscientificInformation oceans location USGS Thesaurus sub-bottom profiling marine geology geology coastal processes navigational data geospatial datasets None 1,000-shot-interval locations barrier island mapping seismic reflection 2015-330-FA chirp National Fish and Wildlife Foundation Restoration and Stewardship of Outdoor Resources and Environment Common Geographic Areas Little Dauphin Island Alabama Gulf of Mexico None The U.S. Geological Survey requests to be acknowledged as originator of the data in future products or derivative research. Arnell S. Forde U.S. Geological Survey Geologist Mailing and physical

600 4th Street South

St. Petersburg FL 33701 USA 727-502-8000 aforde@usgs.gov Data collection and processing were performed by Jim Flocks, Stan Locker (former employee), and Arnell Forde of the USGS St. Petersburg Coastal and Marine Science Center. Environment as of Metadata Creation: Microsoft Windows 10 Version 6.2 (Build 9200); Environmental Systems Research Institute (Esri) ArcMap 10.7.1.11595; Seismic Unix (Release 44). The validity or accuracy of marine subbottom profiles is highly qualitative and depends on equipment and operating condition variables. Visual inspection of the images rendered from the data did not show any major anomalies. This dataset is from one field activity with consistent instrument calibrations. A total of 118 seismic lines were collected during this field activity. Two test lines, 2015-330-FA.001 and 2015-330-FA.002, were collected in Mobile Bay on DOY 258. Lines 2015-330-FA, JD-260, and JD-264.003 were partial lines containing no usable data and line JD-264.010 was corrupted during acquisition; consequently, all of the preceding lines were excluded from this data release. As the subbottom 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 were recorded and written to seismic trace headers every second (s). The approximately 19-m offset between the chirp and GPS antenna has not been accounted for in the comma-delimited American Standard Code for Information Interchange (ASCII) navigation files and trackline map. Navigation files were extracted from the seismic trace headers using Seismic Unix release 44 software, processed with PROJ.5.1.0 software to generate Universal Transverse Mercator (UTM) 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. 20220311 Arnell S. Forde U.S. Geological Survey Geologist Mailing and physical

600 4th Street South

St. Petersburg FL 33701 USA 727-502-8000 aforde@usgs.gov The reformatted text files were imported into Esri ArcMap 10.7 software to produce a geographic representation of the shotpoint data collected within the survey area. A 1,000-shot-interval point shapefile (.shp) was generated to correlate shot locations on the trackline map with evenly spaced 1,000-shot index markers along the top of the printable profile images. 20220322 Arnell S. Forde U.S. Geological Survey Geologist Mailing and physical

600 4th Street South

St. Petersburg FL 33701 USA 727-502-8000 aforde@usgs.gov Vector Entity point 893 0.0197878862 0.0227705392 Decimal degrees WGS_1984 WGS_84 6378137.0 298.257223563 2015-330-FA_shots.shp Attribute Table Table containing attribute information associated with the dataset. U.S. Geological Survey FID Internal feature number. Esri Sequential unique whole numbers that are automatically generated. Shape Feature geometry. Esri Coordinates defining the features. UTMX UTM-X easting coordinate Universal Transverse Mercator (WGS 1984, Zone 16) 372230.629 399796.137 UTMY UTM-Y northing coordinate Universal Transverse Mercator (WGS 1984, Zone 16) 3337073.333 3346752.366 Line Trackline name U.S. Geological Survey The naming convention used for each subbottom line is as follows: xy_bp_mod, where 'x' is an alphanumeric identifier indicating a specific trackline (for example, JD-262 or JD-265b), 'y' is a number (such as, .001, .002, etc.) representing a new line if recording was prematurely terminated or reran for quality or acquisition problems, and 'env_bp' denotes that the seismic traces were output as an envelope and a bandpass filter was applied. Shot Shotpoint number U.S. Geological Survey 1000 33000 Lon Longitude World Geodetic System of 1984 Geographic Coordinate System -88.327469 -88.041133 Lat Latitude World Geodetic System of 1984 Geographic Coordinate System 30.160775 30.247244 YEAR Year of data acquisition U.S. Geological Survey 2015 2015 DOY_HR_MIN Day of year:hour:minute:second U.S. Geological Survey Day of year, hour, minute and second of data acquisition, in Coordinated Universal Time. Navigation files are available as ASCII delimited text files in CSV format. The final navigation files are provided in 2015-330-FA_nav.zip (Forde and others, 2022) and represent the reprojected survey shotpoint navigation, 1,000-shot-interval locations, and start of line files. The entity and attribute information provided here describes the tabular data associated with the shapefile, 2015-330-FA_shots.shp. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the dataset. The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information. Arnell S. Forde U.S. Geological Survey Geologist Mailing and physical

600 4th Street South

St. Petersburg FL 33701 USA (727) 502-8000 aforde@usgs.gov This publication was prepared by an agency of the United States Government. Although these data were processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Shapefile, MXD, KMZ, GIF 2015-330-FA_gis.zip contains the survey navigation data represented geospatially using a Google Earth keyhole markup language zipped (KMZ) file, Esri ArcMap document (MXD), shapefiles, and a folder of processed subbottom profile images (Graphics Interchange Format [GIF], accessible via hyperlinks included in the MXD). This metadata record describes the 1,000-shot-interval locations provided in, 2015-330-FA_shots.shp, which is one of the three Esri shapefiles included in the geographic information system (GIS) data ZIP file. Winzip or 7zip 113.1 https://coastal.er.usgs.gov/data-release/doi-P9YTIG6G/data/2015-330-FA_gis.zip None This shapefile was created for use with Esri ArcGIS software. It may also be viewed with Esri public domain software Explorer for ArcGIS, GeoMapApp 3.6.14 (http://www.geomapapp.org, 2021), or other GIS software capable of importing the data. 20220912 U.S. Geological Survey Arnell S. Forde Geologist Mailing and physical

600 Fourth Street South

St. Petersburg FL 33701 USA 727-502-8000 aforde@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998