Shapefile of Historical Bathymetric Soundings for Mississippi and Alabama Derived from National Ocean Service (NOS) Hydrographic Sheets

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Terrano, Joseph F., Smith, Kathryn E.L., Muni-Morgan, Amanda L., Buster, Noreen A., and Foxen, Forrest, 20220315, Shapefile of Historical Bathymetric Soundings for Mississippi and Alabama Derived from National Ocean Service (NOS) Hydrographic Sheets:.

   This is part of the following larger work.
   Terrano, Joseph F., Smith, Kathryn E.L., Muni-Morgan, Amanda L., Buster, Noreen A., and Foxen, Forrest, 20210122, Historical Bathymetry in the Mississippi-Alabama Coastal Region: Bathymetric Soundings, Gridded Digital Elevation Model, and Hydrographic Sheets: U.S. Geological Survey Data Release doi:10.5066/P9GRUK4B, U.S. Geological Survey, St. Petersburg, FL.

   Online Links:

   • https://doi.org/10.5066/P9GRUK4B

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -88.715659
   East_Bounding_Coordinate: -87.672267
   North_Bounding_Coordinate: 30.789348
   South_Bounding_Coordinate: 29.960964
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date:

   Ending_Date:

   Currentness_Reference:

   ground condition

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: Vector Digital Data Set (Point)
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Point (48905)
   2. What coordinate system is used to represent geographic features?
      

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:

      UTM_Zone_Number: 16
      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -87.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in Meter
      The horizontal datum used is D_North_American_1983.
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
      
7. How does the data set describe geographic features?

   MS_AL_Bathymetric_Soundings.shp Attribute Table

   Table containing attribute information associated with the dataset. (Source: USGS)

   x

   X coordinate of the feature in the North American Datum of 1983 Universal Transverse Mercator Zone 16N. (Source: USGS)

   Range of values
   Minimum:	-88.715659
   Maximum:	-87.672267
   Units:	decimal degrees

   y

   Y coordinate of the feature in the North American Datum of 1983 Universal Transverse Mercator Zone 16N. (Source: USGS)

   Range of values
   Minimum:	29.960964
   Maximum:	30.789348
   Units:	decimal degrees

   Hsheet

   Hydrographic sheet or nautical chart identification number (Source: 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. (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	96
   Units:	feet

   Hsheet_m

   Sounding derived from the hydrographic sheet, in meters. All depths are represented as positive values. (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	29.2608
   Units:	meters

   Depth_MLW

   H-sheet sounding converted to modern mean low water (MLW), in meters. All depths are represented as positive values. (Source: USGS)

   Range of values
   Minimum:	0.325
   Maximum:	29.5858
   Units:	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. (Source: USGS)

   Range of values
   Minimum:	-29.65119
   Maximum:	-0.38751
   Units:	meters

   Grid_Area

   Soundings classified and based on which bathymetric grid they were used to create. (Source: USGS)

   Value	Definition
   Total extent	Soundings used to derive the full MS/AL grid
   Grand Bay and total extent	Soundings used to derive both the Grand Bay grid and the larger MS/AL grid

   Entity_and_Attribute_Overview:

   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.

   Entity_and_Attribute_Detail_Citation:

   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.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Joseph F. Terrano
   • Kathryn E.L. Smith
   • Amanda L. Muni-Morgan
   • Noreen A. Buster
   • Forrest Foxen
2. Who also contributed to the data set?
   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.
3. To whom should users address questions about the data?

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: 2021 (process 1 of 3)

   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". Person who carried out this activity:
   

   U.S. Geological Survey St. Petersburg Coastal and Marine Science Center

   Attn: Joseph F. Terrano

   Researcher III

   600 4th Street South

   St. Petersburg, FL
   

   U.S.

   727-502-8047 (voice)

   jterrano@contractor.usgs.gov

   Date: 2021 (process 2 of 3)

   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. Person who carried out this activity:
   

   U.S. Geological Survey St. Petersburg Coastal and Marine Science Center

   Attn: Joseph F. Terrano

   Researcher III

   600 4th Street South

   St. Petersburg, FL
   

   U.S.

   727-502-8047 (voice)

   jterrano@contractor.usgs.gov

   Date: 2021 (process 3 of 3)

   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. Person who carried out this activity:
   

   U.S. Geological Survey St. Petersburg Coastal and Marine Science Center

   Attn: Joseph F. Terrano

   Researcher III

   600 4th Street South

   St. Petersburg, FL
   

   U.S.

   727-502-8047 (voice)

   jterrano@contractor.usgs.gov

3. What similar or related data should the user be aware of?
   National Oceanic and Atmospheric Administration (NOAA), 20191024, Vertical Datum Transformation (VDatum) Software: U.S. Department of Commerce, Silver Springs, MD.

   Online Links:

   • https://vdatum.noaa.gov/

   Other_Citation_Details:

   NOAA VDatum software was used to convert sounding data from modern MLW to NAVD88 GEOID12A.

   Noreen A. Buster and Robert A. Morton, 20110404, Historical Bathymetry and Bathymetric Change in the Mississippi-Alabama Coastal Region: U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.3133/sim3154

   Other_Citation_Details:

   Methods in this paper were used to determine how to derive the gridded bathymetry within this data release.

   National Oceanic and Atmospheric Administration (NOAA), 2021, Scanned non-georeferenced digital raster hydrographic sheets and nautical charts: U.S. Department of Commerce, Silver Springs, MD.

   Online Links:

   • https://www.ngdc.noaa.gov/mgg/bathymetry/hydro.html
   • https://historicalcharts.noaa.gov/

   Other_Citation_Details:

   Historical scanned non-georeferenced digital raster hydrographic sheets and nautical charts available for download.

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?
   No formal attribute accuracy tests were conducted.
2. How accurate are the geographic locations?
   A formal accuracy assessment of the horizontal positional information in the dataset has not been conducted.
3. How accurate are the heights or depths?
   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).
4. Where are the gaps in the data? What is missing?
   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.
5. How consistent are the relationships among the observations, including topology?
   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).

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey Coastal and Marine Science Center

   Attn: Joseph F. Terrano

   Researcher III

   600 4Th Street South

   St. Petersburg, FL
   

   USA

   727-502-8047 (voice)

   727-502-8182 (FAX)

   jterrano@contractor.usgs.gov
2. What's the catalog number I need to order this data set?
3. What legal disclaimers am I supposed to read?
   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.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	ArcGIS shapefile (Vector Digital Point Data)
     Network links:	https://coastal.er.usgs.gov/data-release/doi-P9GRUK4B/Bathymetric_Soundings.zip

   • Cost to order the data: None. No fees are applicable for obtaining the dataset.

Who wrote the metadata?

Dates:

Last modified: 15-Mar-2022

Metadata author:

Joseph F. Terrano

U.S. Geological Survey Coastal and Marine Science Center

Researcher III

600 4Th Street South

St. Petersburg, FL

USA

727-502-8047 (voice)

727-502-8182 (FAX)

jterrano@contractor.usgs.gov

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)