Joseph F. Terrano Kathryn E.L. Smith Amanda L. Muni-Morgan Noreen A. Buster Forrest Foxen 20220315 Vector Digital Data Set (Point) Joseph F. Terrano Kathryn E.L. Smith Amanda L. Muni-Morgan Noreen A. Buster Forrest Foxen 20210122 2.0 U.S. Geological Survey Data Release doi:10.5066/P9GRUK4B St. Petersburg, FL U.S. Geological Survey https://doi.org/10.5066/P9GRUK4B Hydrographic sheets (H-sheets) and nautical charts produced by the National Ocean Service (NOS) during the 1800s provide historic sounding (water depth) measurements of coastal areas. The data can be vectorized into a geographic information system (GIS), adjusted to a modern vertical datum, and converted into a digital elevation model to provide an interpretation of the historic seafloor elevation. These data were produced to provide an estimate of historical bathymetry for the Mississippi-Alabama coastal region to aid geologic and coastal hazards studies. This data release includes georeferenced H-sheets, depth soundings, and a bathymetric grid derived from the 1847 and 1895 soundings. The original NOS H-sheets and nautical charts were scanned by the National Oceanic and Atmospheric Administration (NOAA) and are available through the National Geophysical Data Center (NGDC) website (NOAA, 2021) as non-georeferenced digital raster files. U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS SPCMSC) staff performed the following procedures: H-sheets were georeferenced, georeferenced raster images were projected to a modern datum, and historical bathymetric sounding measurements were digitized to create a vector point shapefile. Sounding data were converted from feet (ft) and fathoms (fm) to meters (m), projected to modern mean low water (MLW), and converted to the North American Vertical Datum of 1988 (NAVD88) GEOID12A using NOAA's datum transformation software, VDatum. Please read the full metadata for details on data collection, digitized data, dataset variables, and data quality. The purpose of this dataset is to document the historic bathymetry for a region of the Mississippi-Alabama coastal zone and intercoastal waterway. Data can be used to examine bathymetric change, calculate sediment budgets, and hindcast hydrodynamic modeling studies. The H-sheets included in this data release are: H-00191 (1847); H-00192 (1847-48); H-00193A (1848); H-00215 (1849); H-00227 (1850); H-00261 (1851); H-00262 (1851); H-00328 and H-00328A (1853); H-00329 (1852); H-00365 (1853); H-00430A (1854); H-01310 (1875-76). The nautical charts included in this data release are: LC-00018 (1895); LC-00188 (1856,1877); LC-00189 (1856,1894); LC-00034 (1856). The sounding shapefile was converted to a comma separated value (.csv) file and is published with the shapefile, to also provide the data in a non-proprietary format. 18470101 18950101 ground condition Complete As needed -88.715659 -87.672267 30.789348 29.960964 USGS Metadata Identifier USGS:f7933b13-0064-40dd-8dda-41a0d3116e16 None H-sheet Coastal Shoreline data Shoreline map Georeferenced Hydrographic sheet Nautical chart USGS Thesaurus Digitization Geomorphology Bathymetry measurement Coastal processes Digital Elevation Models Geospatial datasets Geographic information systems Topographic maps ISO 19115 Topic Category Oceans Environment Boundaries GeoscientificInformation InlandWaters Geographic Names Information System Mississippi Alabama Gulf of Mexico Grand Bay Grande Batture Islands North Rigolets Island Point Aux Chenes Bay West Petit Bois Island Pascagoula Mobile Bay Horn Island Dauphin Island Mobile Point Bon Secours Bay Mississippi Sound None The U.S. Geological Survey requests to be acknowledged as originator of the data in future products or derivative research. Acknowledgment of the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center, as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices. Sharing of new data layers developed directly from these data would also be appreciated by the U.S. Geological Survey staff. Users should be aware that comparisons with other datasets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in photointerpretation, mapping conventions, and digital processes over time. These data are not legal documents and are not to be used as such. Environment as of Metadata Creation: Microsoft Windows 10 Enterprise Version 20H2 (Build 19042.1237); Esri ArcGIS Version 10.6.1.9270 Service Pack N/A (Build N/A); NOAA VDatum software version 4.0.1 National Oceanic and Atmospheric Administration (NOAA) 20191024 Version 4.0.1 Silver Springs, MD U.S. Department of Commerce NOAA VDatum software was used to convert sounding data from modern MLW to NAVD88 GEOID12A. https://vdatum.noaa.gov/ Noreen A. Buster and Robert A. Morton 20110404 Version 1.0 Reston, VA U.S. Geological Survey Methods in this paper were used to determine how to derive the gridded bathymetry within this data release. https://doi.org/10.3133/sim3154 National Oceanic and Atmospheric Administration (NOAA) 2021 Version 1.0 Silver Springs, MD U.S. Department of Commerce Historical scanned non-georeferenced digital raster hydrographic sheets and nautical charts available for download. https://www.ngdc.noaa.gov/mgg/bathymetry/hydro.html https://historicalcharts.noaa.gov/ No formal attribute accuracy tests were conducted. A point representing bathymetry sampling locations and associated depth values (shown, in feet or fathoms, on the H-sheets) was digitized for each handwritten sounding included within the designated study area. Digitized points were checked to ensure no points were missed and all depths were correct. Data are provided in the attribute table as feet, meters, modern MLW, and orthometric height (z; NAVD88). Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. A formal accuracy assessment of the horizontal positional information in the dataset has not been conducted. A formal accuracy assessment of the vertical positional information in the dataset has either not been conducted or is not applicable. VDatum has a vertical accuracy of 15.7369 centimeters (cm). Methods used in this data release are based on those presented in Buster and Morton (2011). Hydrographic sheets were created for the Mississippi-Alabama coastal region from 1847 to 1895 and were downloaded from NOAA's National Geophysical Data Center (NGDC) website (NOAA, 2021) as non-georeferenced raster files. Hydrographic sheets downloaded include: H-00191 (1847); H-00192 (1847-48); H-00193A (1848); H-00215 (1849); H-00227 (1850); H-00261 (1851); H-00262 (1851); H-00328 and H-00328A (1853); H-00329 (1852); H-00365 (1853); H-00430A (1854); H-01310 (1875-76). The nautical charts downloaded include: LC-00018 (1895); LC-00188 (1856,1877); LC-00189 (1856,1894); LC-00034 (1856). Within ArcGIS 10.6.1, the H-sheets were projected into the North American Datum of 1983 Universal Transverse Mercator Zone 16N (NAD83 UTM Zone 16N) using the "project raster" tool to match the projection of the topographic sheets. Using the ArcGIS "Georeferencing" toolbar, H-sheets were georeferenced to spatially referenced topographic sheets (T-sheets) or previously referenced H-sheets using at least four graticules, prominent shoreline features, and benchmarks. The rectified H-sheets and nautical charts were saved in the tagged image file format (.tif) and will be henceforth referred to collectively as "H-sheets". 2021 U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Joseph F. Terrano Researcher III Mailing and physical

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St. Petersburg FL 33701 U.S. 727-502-8047 jterrano@contractor.usgs.gov To digitize the soundings, the georeferenced H-sheets were added to ArcMap 10.6.1. Using the ArcMap editor toolbar, the soundings were digitized based on a visual assessment of sounding locations within the imagery and saved as vector digital data within an ArcGIS point shapefile. The written sounding (depth in feet or fathoms) displayed on the H-sheets were populated in the shapefile attribute table (Hsheet_f attribute) as each sounding was digitized. Soundings were written in fathoms for depths deeper than 18 ft but were converted back to feet before being written in the "Hsheet_f" attribute field. Data were checked to ensure written soundings matched the depth of the digitized point. All depths were written as positive values. Soundings on nautical charts were only digitized to fill in H-sheet data gaps, thus not all soundings on nautical charts were digitized. 2021 U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Joseph F. Terrano Researcher III Mailing and physical

600 4th Street South

St. Petersburg FL 33701 U.S. 727-502-8047 jterrano@contractor.usgs.gov The ArcGIS point shapefile described in the previous processing step was converted into a comma separated value (.csv) file so additional processing outside of the ArcGIS environment could be conducted. The digitized depths (Hsheet_f attribute) obtained from the H-sheets were converted to meters (Hsheet_m attribute) and those depths were then converted to modern MLW by adding 0.325 m to each depth (Depth_MLW attribute). The 0.325 m value was calculated based on an average sea level rise (SLR) rate of 2.31 millimeters per year (mm/yr; based on calculations derived for this study in 2016) using the Pensacola, Florida NOAA tidal station (https://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?id=8729840). The Pensacola tidal station was chosen based on previous historical bathymetry published in the region (Buster and Morton, 2011). The MLW depths were then run through the NOAA datum transformation (VDatum; version 4.0.1) program to convert the depths to NAVD88 orthometric height using the GEOID12A model. VDatum has a vertical accuracy of 15.7369 cm. Final depth values were converted from positive to negative depths (z_NAVD88 attribute). The final .csv file was then converted back into an ArcGIS shapefile. 2021 U.S. Geological Survey St. Petersburg Coastal and Marine Science Center Joseph F. Terrano Researcher III Mailing and physical

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St. Petersburg FL 33701 U.S. 727-502-8047 jterrano@contractor.usgs.gov Vector Point 48905 Universal Transverse Mercator 16 0.9996 -87.0 0.0 500000.0 0.0 coordinate pair 0.6096 0.6096 Meter D_North_American_1983 GRS_1980 6378137.0 298.257222101 MS_AL_Bathymetric_Soundings.shp Attribute Table Table containing attribute information associated with the dataset. USGS x X coordinate of the feature in the North American Datum of 1983 Universal Transverse Mercator Zone 16N. USGS -88.715659 -87.672267 decimal degrees y Y coordinate of the feature in the North American Datum of 1983 Universal Transverse Mercator Zone 16N. USGS 29.960964 30.789348 decimal degrees Hsheet Hydrographic sheet or nautical chart identification number USGS Hydrographic sheet identification number in the H###### format or nautical chart identification number in the LC##### format. Hsheet_f Sounding derived from the hydrographic sheet, in feet. All depths are represented as positive values. USGS 0 96 feet Hsheet_m Sounding derived from the hydrographic sheet, in meters. All depths are represented as positive values. USGS 0 29.2608 meters Depth_MLW H-sheet sounding converted to modern mean low water (MLW), in meters. All depths are represented as positive values. USGS 0.325 29.5858 meters z_NAVD88 Soundings converted to the North American Vertical Datum of 1988 (NAVD88) orthometric heights referenced to GEOID12A, in meters. NAVD88 values were corrected to display as negative values. USGS -29.65119 -0.38751 meters Grid_Area Soundings classified and based on which bathymetric grid they were used to create. USGS Total extent Soundings used to derive the full MS/AL grid USGS Grand Bay and total extent Soundings used to derive both the Grand Bay grid and the larger MS/AL grid USGS The entity and attribute information provided here describes the tabular data associated with the dataset. 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. U.S. Geological Survey Coastal and Marine Science Center Joseph F. Terrano Researcher III Mailing and Physical

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St. Petersburg FL 33701 USA 727-502-8047 727-502-8182 jterrano@contractor.usgs.gov This digital publication was prepared by an agency of the United States Government. Although these data have been 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. ArcGIS shapefile (Vector Digital Point Data) https://coastal.er.usgs.gov/data-release/doi-P9GRUK4B/Bathymetric_Soundings.zip None. No fees are applicable for obtaining the dataset. 20220315 Joseph F. Terrano U.S. Geological Survey Coastal and Marine Science Center Researcher III Mailing and Physical

600 4Th Street South

St. Petersburg FL 33701 USA 727-502-8047 727-502-8182 jterrano@contractor.usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998 Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset. None Unclassified None