Identification_Information:
  Citation:
    Citation_Information:
      Originator: Blake F. Smullen
      Originator: Arnell S. Forde
      Originator: James G. Flocks
      Publication_Date: 20260610
      Title: Archive of Digitized Analog Boomer Seismic-Reflection Data Collected in 1990 and 1991 during the ERDA90-2 and MB91-1 Surveys in Mobile Bay, Alabama
      Geospatial_Data_Presentation_Form: SEG-Y, tabular, and raster digital data
      Larger_Work_Citation:
        Citation_Information:
          Originator: Blake F. Smullen
          Originator: Arnell S. Forde
          Originator: James G. Flocks
          Publication_Date: 20260610
          Title: Archive of Digitized Analog Boomer Seismic-Reflection Data Collected in 1990 and 1991 During the ERDA90-2 and MB91-1 Surveys in Mobile Bay, Alabama
          Series_Information:
            Series_Name: U.S. Geological Survey data release
            Issue_Identification: doi:10.5066/P1V6EDD5
          Publication_Information:
            Publication_Place: St. Petersburg, Florida
            Publisher: U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
          Online_Linkage: https://doi.org/10.5066/P1V6EDD5
  Description:
    Abstract:
      The U.S. Geological Survey (USGS) Coastal and Marine Hazards and Resources Program has actively collected geophysical and sedimentological data in the northern Gulf of America (Gulf of Mexico) for several decades, including shallow subsurface data in the form of high-resolution seismic reflection profiles (HRSP). Prior to the mid-1990s most HRSP data were collected in analog format as paper rolls of continuous profiles up to 25 meters long. As part of the National Geological and Geophysical Data Preservation Program (NGGDPP,  https://www.usgs.gov/programs/national-geological-and-geophysical-data-preservation-program) scientists from the USGS St. Petersburg Coastal and Marine Science Center converted analog paper records to digital format using a large-format continuous scanner. The scanned image files were subsequently processed to fix distortions and crop out blank spaces prior to exporting them as industry standard Society of Exploration Geophysicists (SEG-Y) data exchange formatted files.
      This data release serves as an archive of HRSP profiles annotated with header information, converted SEG-Y files, navigation data, profile trackline files, and survey logbook. The HRSP data were collected between August 12 and August 19, 1990, for ERDA90-2, and May 15 and May 18, 1991, for MB91-1, using an EG&G Uniboom acoustic (boomer) system, onboard research vessel (R/V) ERDA 1 in Mobile Bay and into the Gulf of America. Data conversion methods are described in USGS Data Series 1047 (Bosse and others, 2017).
    Purpose: The data release associated with this metadata record serves as an archive of ERDA90-2 and MB91-1 geophysical, navigational, and support data collected between August 12 and August 19, 1990, and May 15 and May 18, 1991, respectively. This data release is part of an ongoing USGS data rescue effort to preserve geologic data that facilitates easier access to legacy datasets by scientists and the public.
    Supplemental_Information:
      The USGS-St. Petersburg Coastal and Marine Science Center (SPCMSC) currently holds 13 major geophysical surveys from the northern Gulf of America in its paper repository. Over 2,000 line-kilometers (km) of data are available. Paper copies of data are difficult and expensive to duplicate and share with other facilities and cannot be analyzed using standard geographic information systems (GIS) and interpretative software. Conversion of this data into a usable digital format is necessary to archive the geologic information that otherwise might be lost, requiring additional redundant and expensive marine geophysical surveys. The USGS National Geological and Geophysical Data Preservation Program (NGGDPP) addresses the need to preserve, catalog, and provide access to geological and geophysical data for scientific research and economic development. In addition to the current efforts under the NGGDPP, four geophysical investigations from the 1980s and 1990s were previously archived through a preservation project in collaboration with the Bureau of Ocean Energy Management (Harrison and others, 2007; Sanford and others, 2009a, b, c). The USGS-SPCMSC scans its analog HRSP holdings using a large-format continuous scanner. The analog to digital conversion process used for this dataset is similar to the processes used previously in Harrison and others (2007) and Sanford and others (2009a, b, c). The digital files were converted into Tagged Image File Format (TIFF) for standard accessibility by raster image processors. The TIFF images of the seismic profiles were also converted into SEG-Y format. This standard non-proprietary format is the accepted industry standard for seismic data and can be accessed by all major seismic data processing and interpretation systems. Accompanying the HRSP are navigation and metadata files, which are generated for use in GIS, database and Internet Message Access Protocol (IMAP) services. Processed seismic profile images are also provided. The processed profiles provided in this data release are Portable Document Format (.pdf) and Portable Network Graphics (.png) images that were created using Seismic Unix and/or ImageMagick software.
      The northern Gulf of America is a passive continental margin, where minimal structural change to the shallow stratigraphy has occurred during the last few thousand years (Anderson and others, 2004). Therefore, subsurface data collected from this environment for the purposes of geologic assessment can be considered useful in perpetuity. The geologic information collected by the USGS in the northern Gulf remains a valuable resource for sea floor and stratigraphic investigations and is continuously revisited by researchers interested in Holocene and recent earth processes. For example, decades-old geologic data are commonly used in sediment resource studies in coastal Louisiana (Kindinger and others, 2001; Kulp and others, 2002; Rogers and others, 2009) and previously collected datasets across the Mississippi-Alabama shelf have been used in recent geologic-framework assessments (Roberts and others, 2004; Greene and others, 2007; Flocks and others, 2009).
      Geophysical data were acquired using an EG&G Uniboom profiler. The transducer was mounted on a towed sled, with a power supply of 300 Joule. Data were recorded using an EPC 4100 recorder, with a bandpass of 0.4- 1.6 kilohertz (kHz).
      Navigation events, or shots, were recorded using mark events corresponding to approximately 18.75 meter (m) intervals along the preplotted line. Positioning was provided by long-range navigation (LORAN). A hyperbolic radio navigation system was used with an estimated accuracy of +/-0.02 to 0.08 km.
      Following SPCMSC data management protocols, these surveys were assigned a USGS field activity number (FAN), 1990-306-FA. Additional survey and data detail are available on the Coastal and Marine Geoscience Data System (CMGDS) at https://cmgds.marine.usgs.gov/services/activity.php?fan=1990-306-FA. 
  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 19900814
        Ending_Date: 19910518
    Currentness_Reference: ground condition
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: None planned
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -88.1244
      East_Bounding_Coordinate: -87.7883
      North_Bounding_Coordinate: 30.6487
      South_Bounding_Coordinate: 30.2636
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: USGS Metadata Identifier
      Theme_Keyword: USGS:0374c5a3-8854-48dc-ba0b-78f7d707fef2
    Theme:
      Theme_Keyword_Thesaurus: ISO 19115 Topic Category
      Theme_Keyword: geoscientificInformation
      Theme_Keyword: oceans
    Theme:
      Theme_Keyword_Thesaurus: USGS Thesaurus
      Theme_Keyword: marine geology
      Theme_Keyword: geology
      Theme_Keyword: sediment transport
      Theme_Keyword: ocean processes
      Theme_Keyword: coastal processes
      Theme_Keyword: seismic reflection methods
    Theme:
      Theme_Keyword_Thesaurus: None
      Theme_Keyword: Marine
      Theme_Keyword: Society of Exploration Geophysicists
      Theme_Keyword: SEG-Y
      Theme_Keyword: R/V ERDA
    Place:
      Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
      Place_Keyword: Gulf of America
      Place_Keyword: Mobile
      Place_Keyword: Alabama
      Place_Keyword: Mobile Bay
  Access_Constraints: No access constraints. Please see 'Distribution Information' for details.
  Use_Constraints: These data are marked with a Creative Commons 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.
  Point_of_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: James G. Flocks
        Contact_Organization: U.S. Geological Survey
      Contact_Position: Emeritus
      Contact_Address:
        Address_Type: mailing and physical
        Address: 600 4th Street South
        City: St. Petersburg
        State_or_Province: FL
        Postal_Code: 33701
      Contact_Voice_Telephone: (727) 502-8000
      Contact_Electronic_Mail_Address:
        jflocks@usgs.gov
        Native_Data_Set_Enviroment: Environment as of Metadata Creation: Microsoft Windows 11 Enterprise Version 23H2; Environmental Systems Research Institute (Esri) ArcGIS Pro 3.4.3; Seismic Unix (Relase 44); Adobe Photoshop Creative Cloud 2024; Microsoft Word for Office 365 version 16.
  Cross_Reference:
    Citation_Information:
      Originator: Anderson, J.B., Rodriguez, A., Abdulah, K.C., Fillon, R.H., Banfield, L.A., McKeown, H.A., and Wellner, J.S.
      Publication_Date: 20040101
      Title: Late Quaternary stratigraphic evolution of the northern Gulf of Mexico margins—A synthesis, in Anderson, J., and Fillon, R., eds., Late Quaternary stratigraphic evolution of the Northern Gulf of Mexico
      Series_Information:
        Series_Name: Society for Sedimentary Geology
        Issue_Identification: 79
      Other_Citation_Details: pages 1-23
      Online_Linkage: https://doi.org/10.2110/pec.04.79.0001
  Cross_Reference:
    Citation_Information:
      Originator: Barry, K.M., Cavers, D.A., and Kneale, C.W.
      Publication_Date: 197504
      Title: Recommended standards for digital tape formats
      Series_Information:
        Series_Name: Geophysics
        Issue_Identification: v. 40, no. 2
      Other_Citation_Details: pages 344-352
      Online_Linkage: https://library.seg.org/doi/pdf/10.1190/1.1440530
  Cross_Reference:
    Citation_Information:
      Originator: Bosse, S.T., Flocks, J.G., and Forde, A.S.
      Publication_Date: 20170421
      Title: Digitized analog boomer seismic-reflection data collected during U.S. Geological Survey cruises Erda 90-1_HC, Erda 90-1_PBP, and Erda 91-3 in Mississippi Sound, June 1990 and September 1991
      Series_Information:
        Series_Name: U.S. Geological Survey Data Series
        Issue_Identification: 1047
      Online_Linkage: https://doi.org/10.3133/ds1047
  Cross_Reference:
    Citation_Information:
      Originator: Flocks, J.G., Ferina, N.F., and Kindinger, J.L.
      Publication_Date: 2009
      Title: Recent geologic framework and geomorphology of the Mississippi-Alabama shelf, northern Gulf of Mexico, in, Buster, N.A., and Holmes, C.W., eds., Gulf of Mexico origin, waters, and biota: Volume III, Geology
      Series_Information:
        Series_Name: College Station, Texas, Texas A&M University Press
        Issue_Identification: 3
      Other_Citation_Details: pages 157-173
      Online_Linkage: https://muse.jhu.edu/book/1783
  Cross_Reference:
    Citation_Information:
      Originator: Greene, D.L., Jr., Rodriquez, A.B., and Anderson, J.B.
      Publication_Date: 20070201
      Title: Seaward-branching coastal-plain and piedmont incised-valley systems through multiple sea-level cycles: Late Quaternary examples from Mobile Bay and Mississippi Sound, U.S.A.
      Series_Information:
        Series_Name: Journal of Sedimentary Research
        Issue_Identification: 77
      Other_Citation_Details: pages 139-158
      Online_Linkage: https://doi.org/10.2110/jsr.2007.016
  Cross_Reference:
    Citation_Information:
      Originator: Harrison, A.S., Dadisman, S.V., Kindinger, J.L., Morton, R.A., Blum, M.D., Wiese, D.S., and Subino, J.A.
      Publication_Date: 2007
      Title: Archive of digital and digitized analog boomer seismic reflection data collected during USGS cruise 96CCT02 in Copano, Corpus Christi, and Nueces Bays and Corpus Christi Bayou, Texas, July 1996
      Series_Information:
        Series_Name: U.S. Geological Survey Data Series
        Issue_Identification: 296
      Online_Linkage: https://doi.org/10.3133/ds296
  Cross_Reference:
    Citation_Information:
      Originator: Kindinger, J.L., Flocks, J.G., Kulp, M.A., Penland, P.S., and Britsch, L.D.
      Publication_Date: 2001
      Title: Sand resources, regional geology, and coastal processes for the restoration of the Barataria barrier shoreline
      Series_Information:
        Series_Name: U.S. Geological Survey Open-File Report
        Issue_Identification: 2001-384
      Other_Citation_Details: 69 pages
      Online_Linkage: https://doi.org/10.3133/ofr01384
  Cross_Reference:
    Citation_Information:
      Originator: Kulp, M.A., Howell, P.D., Adiau, S., Penland, P.S., Kindinger, J.L., and Williams, S.J.
      Publication_Date: 2002
      Title: Latest Quaternary stratigraphic framework of the Mississippi River delta region
      Series_Information:
        Series_Name: Gulf Coast Association of Geological Societies Transactions
        Issue_Identification: 52
      Other_Citation_Details: pages 573-582
      Online_Linkage: https://archives.datapages.com/data/gcags/data/052/052001/0573.htm
  Cross_Reference:
    Citation_Information:
      Originator: Roberts, H.H., Fillon, R.H., Kohl, B., Robalin, J.M., and Sydow, J.C.
      Publication_Date: 2004
      Title: Depositional architecture of the Lagniappe Delta: Sediment characteristics, timing of depositional events, and temporal relationship with adjacent shelf-edge deltas, in Anderson, J.B., and Fillon, R., eds., Late Quaternary stratigraphic evolution of the northern Gulf of Mexico
      Series_Information:
        Series_Name: Society for Sedimentary Geology
        Issue_Identification: 79
      Other_Citation_Details: pages 142-189
      Online_Linkage: https://archives.datapages.com/data/sepm_sp/SP79/Depositional_Architecture_of_the_Lagniappe_Delta.pdf
  Cross_Reference:
    Citation_Information:
      Originator: Rogers, B.E., Kulp, M.A., and Miner, M.D.
      Publication_Date: 20090916
      Title: Late Holocene chronology, origin, and evolution of the St. Bernard shoals, northern Gulf of Mexico, USA
      Series_Information:
        Series_Name: Geo-Marine Letters
        Issue_Identification: 29
      Other_Citation_Details: pages 379-394
      Online_Linkage: https://doi.org/10.1007/s00367-009-0162-6
  Cross_Reference:
    Citation_Information:
      Originator: Sanford, J.M., Harrison, A.S., Wiese, D.S., and Flocks, J.G.
      Publication_Date: 2009
      Title: Archive of digitized analog boomer seismic reflection data collected from the Mississippi-Alabama-Florida shelf during cruises onboard the R/V Kit Jones, June 1990 and July 1991
      Series_Information:
        Series_Name: U.S. Geological Survey Data Series
        Issue_Identification: 429
      Other_Citation_Details: 2009a
      Online_Linkage: https://doi.org/10.3133/ds429
  Cross_Reference:
    Citation_Information:
      Originator: Sanford, J.M., Harrison, A.S., Wiese, D.S., and Flocks, J.G.
      Publication_Date: 2009
      Title: Archive of digitized analog boomer and minisparker seismic reflection data collected from the Alabama-Mississippi-Louisiana shelf during cruises onboard the R/V Carancahua and R/V Gyre, April and July, 1981
      Series_Information:
        Series_Name: U.S. Geological Survey Data Series
        Issue_Identification: 428
      Other_Citation_Details: 2009b
      Online_Linkage: https://doi.org/10.3133/ds428
  Cross_Reference:
    Citation_Information:
      Originator: Sanford, J.M., Harrison, A.S., Wiese, D.S., and Flocks, J.G.
      Publication_Date: 2009
      Title: Archive of digitized analog boomer seismic reflection data collected from Lake Pontchartrain, Louisiana, to Mobile Bay, Alabama, during cruises onboard the R/V ERDA-1, June and August 1992
      Series_Information:
        Series_Name: U.S. Geological Survey Data Series
        Issue_Identification: 370
      Other_Citation_Details: 2009c
      Online_Linkage: https://doi.org/10.3133/ds370
  Cross_Reference:
    Citation_Information:
      Originator: Trabant, P.K.
      Publication_Date: 1984
      Title: Applied High-Resolution Geophysical Methods
      Publication_Information:
        Publication_Place: Dordrecht, Netherlands
        Publisher: Springer Netherlands
      Online_Linkage: https://doi.org/10.1007/978-94-009-6493-8
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report: The validity or accuracy of boomer seismic profiling data 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. For the ERDA90-2 and MB91-1 navigation data files (.csv), the time stamps were 4 hours off the time stamps written on the profiles. Times in the navigation data files were adjusted to match the times written on the profiles. 
  Logical_Consistency_Report: This dataset is from the USGS SPCMSC archive and has consistent instrument calibrations.
  Completeness_Report: This dataset is considered complete for the information presented. All analog seismic profiles collected during the original survey, except line 16 in MB91-1, were successfully scanned and converted to digital format. The seismic profiles provide a two-dimensional (2D) representation of the subsurface along the acquisition tracklines. Users are advised to read the rest of the metadata record carefully for additional details.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report:
        As the seismic reflection data were acquired, the position of the vessel was recorded using a LORAN-A navigation system. The accuracy of the LORAN-A varied from 0.2 to 0.8 kilometer (km). Positions were recorded in latitude and longitude coordinates (in the World Geodetic System of 1984 [WGS84] coordinate system) at various intervals and appear on the seismic profiles as incremental, hand-annotated vertical event marks. Each vertical line represents a 305-meter (m) or 1000-foot (ft) interval.
        For this cruise, the time between starting and ending times were interpolated.
    Vertical_Positional_Accuracy:
      Vertical_Positional_Accuracy_Report: These data are not to be used for bathymetry. Two-way travel (TWT) times shown on the printable profile images are relative to local sea level at the time of data acquisition.
  Lineage:
    Process_Step:
      Process_Description: Raw data scanning - The seismic data collected from this survey is housed in the USGS SPCMSC archive. The analog boomer data are in the form of 30 centimeter (cm)-wide paper and vellum rolls. The various rolls can be up to 6 m long and contain multiple seismic tracklines. The rolls contain the seismic profile image with pertinent collection characteristics annotated during acquisition, such as shot number and time and may also include environmental conditions and equipment details. Horizontal lines across the profiles represent TWT time in milliseconds (ms), and vertical lines represent navigation fixes acquired and annotated as the survey was underway. The vellum rolls were scanned using NextImage. The lines were then saved at 200 dots per inch (dpi), grey scaled, in TIFF files.
      Source_Used_Citation_Abbreviation: Paper and vellum rolls
      Process_Date: 2025
      Source_Produced_Citation_Abbreviation: TIFF
      Process_Contact:
        Contact_Information:
          Contact_Person_Primary:
            Contact_Person: Blake F. Smullen
            Contact_Organization: U.S. Geological Survey
          Contact_Position: Student Services Contractor
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: FL
            Postal_Code: 33701
          Contact_Voice_Telephone: (727) 502-8000
          Contact_Electronic_Mail_Address: bsmullen@contractor.usgs.gov
    Process_Step:
      Process_Description: Image cropping - The scanned TIFF images were imported into Adobe Photoshop (Ps) Creative Cloud 2024 and blank edge areas were cropped out to further reduce file size. For rolls that included more than one line of seismic data, the file was separated into individual lines. Separation was completed by cropping everything except for the line of interest, determined by the raw navigation information, from the original scan and saving it as a new file with its associated line name. The file naming convention is as follows: CruiseID_trackline#_an.tif (for example, ERDA90-2_15_an.tif). It includes the cruise identification (ERDA90-2), and trackline number (sometimes this also includes a subsection letter after the line number for tracklines split between multiple rolls).
      Source_Used_Citation_Abbreviation: TIFF
      Process_Date: 2025
      Process_Contact:
        Contact_Information:
          Contact_Person_Primary:
            Contact_Person: Blake F. Smullen
            Contact_Organization: U.S. Geological Survey
          Contact_Position: Student Services Contractor
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: FL
            Postal_Code: 33701
          Contact_Voice_Telephone: (727) 502-8000
          Contact_Electronic_Mail_Address: bsmullen@contractor.usgs.gov
    Process_Step:
      Process_Description: Image headers - Each image of the scanned seismic profiles also includes a header with associated information including cruise- and line-specific information and processing details. The header files were created in Microsoft Word for Office 365 version 16, exported as PDF files, appended to the far left of the image frame in Adobe Ps, and then flattened onto the image to reduce file size.
      Process_Date: 2025
      Source_Produced_Citation_Abbreviation: CruiseID_*_an.tif
      Process_Contact:
        Contact_Information:
          Contact_Person_Primary:
            Contact_Person: James G. Flocks
            Contact_Organization: U.S. Geological Survey
          Contact_Position: Emeritus
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: FL
            Postal_Code: 33701
          Contact_Voice_Telephone: (727) 502-8000
          Contact_Electronic_Mail_Address: jflocks@usgs.gov
    Process_Step:
      Process_Description: Correcting scan distortion - Distortion correction was necessary because it was difficult to ensure vellum/paper rolls were fed into the scanner straight. Distortion correction practices occur in Ps and was obtained by placing a guideline over the 0 ms line (water level) on the scan. It was important that horizontal lines were perpendicular to the vertical lines on the scans or the image to SEG-Y conversion will not be accurate. The distortion was corrected by using the Rectangular Marquee Tool in Adobe Ps to select and create a new layer of the distorted area of the scan. A skewed transform was performed, and the corrected images were saved into a new folder without layers (flattened) to reduce file size (Bosse and others, 2017 and Barry and others, 1975).
      Source_Used_Citation_Abbreviation: CruiseID_*_an.tif
      Process_Date: 2025
      Process_Contact:
        Contact_Information:
          Contact_Person_Primary:
            Contact_Person: Blake F. Smullen
            Contact_Organization: U.S. Geological Survey
          Contact_Position: Student Services Contractor
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: FL
            Postal_Code: 33701
          Contact_Voice_Telephone: (727) 502-8000
          Contact_Electronic_Mail_Address: bsmullen@contractor.usgs.gov
    Process_Step: 
      Process_Description: Creation of .csv files - Each cruise has an associated comma-separated values (.csv) file with the date, time (hour, minute, second), latitude, longitude, shot number, associated line, and fix. The .csv files were needed for the creation of the shapefile (.shp). Data for the .csv files were generated using the logbooks and the LORAN-A navigation system. Each shot was logged as a fixed point in Excel then saved and exported as a .csv file. 
      Process_Date: 2025
      Source_Produced_Citation_Abbreviation: CruiseID_nav.csv
      Process_Contact:
        Contact_Information:
          Contact_Person_Primary:
            Contact_Person: Jim G. Flocks
            Contact_Organization: U.S. Geological Survey
          Contact_Position: Emeritus
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: FL
            Postal_Code: 33701
          Contact_Voice_Telephone: (727) 502-8000
          Contact_Electronic_Mail_Address: jflocks@usgs.gov
    Process_Step: 
      Process_Description: Creation of .shp file - The shapefiles (.shp) were created in ArcGIS Pro using the associated .csv for each cruise. The .csv files were imported into ArcGIS Pro as data tables. The tables were then converted into a point feature class using the "XY Table to Point" geoprocessing tool. Then, the "Points to Line" geoprocessing tool was used to create tracklines for each cruise. Each line was merged into a single feature class. The feature class was then exported to shapefiles using the "Feature Class to Shapefile" tool. 
      Process_Date: 2025
      Source_Produced_Citation_Abbreviation: CruiseID_Tracklines.shp 
      Process_Contact:
        Contact_Information:
          Contact_Person_Primary:
            Contact_Person: Blake F. Smullen
            Contact_Organization: U.S. Geological Survey
          Contact_Position: Student Services Contractor
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: FL
            Postal_Code: 33701
          Contact_Voice_Telephone: (727) 502-8000
          Contact_Electronic_Mail_Address: bsmullen@contractor.usgs.gov
    Process_Step:
      Process_Description: Image to SEG-Y - The scanned, distortion-corrected images were converted to digital SEG-Y (the .seg file extension was used, which has the same properties as .sgy) format revision 0 (Barry and others, 1975) using the proprietary software ImageToSEGY 2.2 from Chesapeake Technology. The scanned images were opened in ImageToSEGY and the export area was defined by assigning values to the top, bottom, left, and right pixel locations using the imaged water surface (0 milliseconds (ms)), maximum TWT time (for example, 112.5 ms) and raw navigation data for each line. Trace amplitudes in the scanned profiles are represented by pixels, so each pixel becomes a trace sample and the sample rate of the converted SEG-Y version is the record length divided by the number of vertical pixels in the profile. For example, if the profile is 4,435 pixels vertically and the two-way travel time is 112.5 ms, then the sample rate for the SEG-Y file version is 0.000025 seconds (s). The file naming convention is as follows: CruiseID_Trackline#.seg (for example, ERDA_90-2_5.seg). It includes the cruise identification (ERDA90-2) and trackline number (sometimes this also includes a subsection letter after the line number for tracklines split between multiple rolls). A text (.txt file) copy of the data is also published alongside the .seg data using the same file naming convention.
      Source_Used_Citation_Abbreviation: CruiseID_*_an.tif
      Process_Date: 2025
      Source_Produced_Citation_Abbreviation: CruiseID_*.seg
      Source_Produced_Citation_Abbreviation: CruiseID_*.txt
      Process_Contact:
        Contact_Information:
          Contact_Person_Primary:
            Contact_Person: Blake F. Smullen
            Contact_Organization: U.S. Geological Survey
          Contact_Position: Student Services Contractor
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: FL
            Postal_Code: 33701
          Contact_Voice_Telephone: (727) 502-8000
          Contact_Electronic_Mail_Address: bsmullen@contractor.usgs.gov
    Process_Step:
      Process_Description: Seismic processing: The SEG-Y data were processed with Seismic Unix (SU, Release 44) software to produce PDF images of the seismic profiles included in this data release. A representative data processing sequence consisted of (1) converting the SEG-Y file to SU format, (2) applying horizontal (number of traces) and vertical (TWT time) scales and generating a PostScript image of the traces, (3) converting the header file to a PostScript image then merging with the seismic profile image, and (4) converting the merged PostScript image to a .pdf. The file naming convention is as follows: CruiseID_Trackline#_PWS.pdf (for example, MB91-1_5_PWS.pdf). It includes the cruise identification (ERDA90-2), trackline number, and data type (profile with scale [PWS]). A .png copy of the data is also published alongside the .seg data using the same naming convention.
      Source_Used_Citation_Abbreviation: CruiseID_*.seg
      Process_Date: 2025
      Source_Produced_Citation_Abbreviation: CruiseID_*_PWS.pdf
      Source_Produced_Citation_Abbreviation: CruiseID_*_PWS.png
      Process_Contact:
        Contact_Information:
          Contact_Person_Primary:
            Contact_Person: James G. Flocks
            Contact_Organization: U.S. Geological Survey
          Contact_Position: Research Geologist
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: FL
            Postal_Code: 33701
          Contact_Voice_Telephone: (727) 502-8000
          Contact_Electronic_Mail_Address: jflocks@usgs.gov
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: Point
  Point_and_Vector_Object_Information:
    SDTS_Terms_Description:
      SDTS_Point_and_Vector_Object_Type: String
      Point_and_Vector_Object_Count: 384
Spatial_Reference_Information: 
    Horizontal_Coordinate_System_Definition: 
      Geographic: 
        Latitude_Resolution: 0.0197864699 
        Longitude_Resolution: 0.0228595953 
        Geographic_Coordinate_Units: Decimal degrees 
      Geodetic_Model: 
        Horizontal_Datum_Name: D_WGS_1984  
        Ellipsoid_Name: WGS_1984 
        Semi-major_Axis: 6378137.0
        Denominator_of_Flattening_Ratio: 298.257223563 
Entity_and_Attribute_Information:
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: erda_90-2-nav.csv
      Entity_Type_Definition: Navigation file (.csv) containing seismic profile data for cruise ERDA90-2. Time stamps in the data file were 4 hours off the time stamps written on the profiles. Times in the data file were adjusted to match the times written on the profiles. 
      Entity_Type_Definition_Source: USGS
    Attribute: 
      Attribute_Label: j.d. 
      Attribute_Definition: Julian date associated with each shot 
      Attribute_Definition_Source: USGS 
      Attribute_Domain_Values: 
        Range_Domain: 
          Range_Domain_Minimum: 226
          Range_Domain_Maximum: 231 
    Attribute: 
      Attribute_Label: date 
      Attribute_Definition: Date associated with each shot 
      Attribute_Definition_Source: USGS 
      Attribute_Domain_Values: 
        Range_Domain: 
          Range_Domain_Minimum: 8/14/1990
          Range_Domain_Maximum: 8/19/1990  
    Attribute: 
      Attribute_Label: hour 
      Attribute_Definition: Hour value of time that shot was recorded, in 24-hour time format 
      Attribute_Definition_Source: USGS 
      Attribute_Domain_Values: 
        Range_Domain: 
          Range_Domain_Minimum: 12 
          Range_Domain_Maximum: 21 
    Attribute: 
      Attribute_Label: min
      Attribute_Definition: Minute value of time that shot was recorded 
      Attribute_Definition_Source: USGS 
      Attribute_Domain_Values: 
        Range_Domain: 
          Range_Domain_Minimum: 00 
          Range_Domain_Maximum: 57 
    Attribute: 
      Attribute_Label: long 
      Attribute_Definition: Longitude degree value of position of vessel when shot was recorded 
      Attribute_Definition_Source: USGS 
      Attribute_Domain_Values: 
        Range_Domain: 
          Range_Domain_Minimum: -88.1244 
          Range_Domain_Maximum: -87.7883
    Attribute: 
      Attribute_Label: lat 
      Attribute_Definition: Latitude degree value of location of position of vessel when shot was recorded 
      Attribute_Definition_Source: USGS 
      Attribute_Domain_Values: 
        Range_Domain: 
          Range_Domain_Minimum: 30.2636 
          Range_Domain_Maximum: 30.6487
    Attribute: 
      Attribute_Label: shot 
      Attribute_Definition: Shot number 
      Attribute_Definition_Source: USGS 
      Attribute_Domain_Values: 
        Unrepresentable_Domain: Numbers from 1 to 24 followed by a letter (A,B, or C) when the line was interrupted due to a turn, course change, a pause in operations to fix equipment, the end of the tape or paper, or the changing of the event numbers. Lines with shots followed by a letter have the specific causes noted in the logbook.
    Attribute: 
      Attribute_Label: line 
      Attribute_Definition: Line number 
      Attribute_Definition_Source: USGS 
      Attribute_Domain_Values: 
        Unrepresentable_Domain: Numbers from 1 to 24 followed by a letter (A,B, or C) when the line was split into multiple segments
  Detailed_Description: 
    Entity_Type: 
      Entity_Type_Label: mb91-1_nav.csv 
      Entity_Type_Definition: Navigation file (.csv) containing seismic profile data for cruise MB91-1. Time stamps in the data file were 4 hours off the time stamps written on the profiles. Times in the data file were adjusted to match the times written on the profiles.
      Entity_Type_Definition_Source: USGS 
    Attribute:  
      Attribute_Label: J.D.  
      Attribute_Definition: Julian date associated with each shot  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: 135 
          Range_Domain_Maximum: 140  
    Attribute:  
      Attribute_Label: Hour  
      Attribute_Definition: Hour value of time that shot was recorded, in 24-hour time format  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: 12  
          Range_Domain_Maximum: 21  
    Attribute:  
      Attribute_Label: Min 
      Attribute_Definition: Minute value of time that shot was recorded  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: 8  
          Range_Domain_Maximum: 17  
    Attribute:  
      Attribute_Label: Sec  
      Attribute_Definition: Second value of time that shot was recorded  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: 0  
          Range_Domain_Maximum: 55  
    Attribute:  
      Attribute_Label: Lat  
      Attribute_Definition: Latitude degree value of location of position of vessel when shot was recorded  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: 30.2210  
          Range_Domain_Maximum: 30.3732 
    Attribute:  
      Attribute_Label: Long 
      Attribute_Definition: Longitude degree value of position of vessel when shot was recorded  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: -88.3284  
          Range_Domain_Maximum: -87.8200 
    Attribute:  
      Attribute_Label: Line  
      Attribute_Definition: Line number  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Unrepresentable_Domain: Numbers from 1 to 16 followed by a letter (A) when the line was split into multiple segments 
    Attribute:  
      Attribute_Label: Shot  
      Attribute_Definition: Shot number  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: 0  
          Range_Domain_Maximum: 43 
  Detailed_Description:   
    Entity_Type: 
      Entity_Type_Label: ERDA90-2_Tracklines.shp
      Entity_Type_Definition: GIS polyline shapefile (.shp) for cruise ERDA90-2. 
      Entity_Type_Definition_Source: USGS 
    Attribute:  
      Attribute_Label: FID  
      Attribute_Definition: Internal feature number  
      Attribute_Definition_Source: Esri  
      Attribute_Domain_Values:  
        Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated. 
    Attribute:  
      Attribute_Label: Shape
      Attribute_Definition: Shape type of feature   
      Attribute_Definition_Source: Esri  
      Attribute_Domain_Values:  
        Enumerated_Domain: 
          Enumerated_Domain_Value: Polyline 
          Enumerated_Domain_Value_Definition: A line represented by an array of points 
          Enumerated_Domain_Value_Definition_Source: Esri 
    Attribute:  
      Attribute_Label: Shape_Leng  
      Attribute_Definition: Length of line segment in degrees 
      Attribute_Definition_Source: Esri  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: 0.001342 
          Range_Domain_Maximum: 0.157396  
    Attribute:  
      Attribute_Label: line  
      Attribute_Definition: Line number  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Unrepresentable_Domain: Numbers from 1 to 24. Some line numbers are also followed by a letter (A, B, or C), when the line was split into multiple segments.
  Detailed_Description:   
    Entity_Type: 
      Entity_Type_Label: MB91-1_Tracklines.shp 
      Entity_Type_Definition: GIS polyline shapefile (.shp) for cruise MB91-1. 
      Entity_Type_Definition_Source: USGS 
    Attribute:  
      Attribute_Label: FID  
      Attribute_Definition: Internal feature number  
      Attribute_Definition_Source: Esri  
      Attribute_Domain_Values:  
        Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated. 
    Attribute:  
      Attribute_Label: Shape
      Attribute_Definition: Shape type of feature   
      Attribute_Definition_Source: Esri  
      Attribute_Domain_Values:  
        Enumerated_Domain: 
          Enumerated_Domain_Value: Polyline 
          Enumerated_Domain_Value_Definition: A line represented by an array of points 
          Enumerated_Domain_Value_Definition_Source: Esri 
    Attribute:  
      Attribute_Label: Shape_Leng  
      Attribute_Definition: Length of line segment in degrees 
      Attribute_Definition_Source: Esri  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: 0.001342 
          Range_Domain_Maximum: 0.157396  
    Attribute:  
      Attribute_Label: Line  
      Attribute_Definition: Line number  
      Attribute_Definition_Source: USGS  
      Attribute_Domain_Values:  
        Range_Domain:  
          Range_Domain_Minimum: 1
          Range_Domain_Maximum: 16  
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
        Contact_Person: USGS SPCMSC Data Management
      Contact_Address:
        Address_Type: mailing and physical
        Address: 600 4th Street South
        City: Saint Petersburg
        State_or_Province: FL
        Postal_Code: 33701
        Country: United States
      Contact_Voice_Telephone: 727-502-8000
      Contact_Electronic_Mail_Address: gs-g-spcmsc_data_inquiries@usgs.gov
  Resource_Description: ERDA90-2_Tracklines.shp, erda_90-2_nav.csv, ERDA90-2_#_PWS.pdf, EDRA90-2_#.png, ERDA90-2_#.seg, ERDA90-2_#.txt, MB91-1_Tracklines.shp, mb91-1_nav.csv, MB91-1_*_an.tif, MB91-1_#_PWS.png, MB91-1_#.seg, MB91-1_#.txt
  Distribution_Liability: 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.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: SEG-Y
        Format_Information_Content: The SEG-Y rev. 0 format (Barry and others, 1975) presented here consists of the following: a 3,600-byte reel identification header, with the first 3,200 bytes consisting of an American Standard Code for Information Interchange (ASCII) header block followed by a 400-byte binary header block, both of which include information specific to line and reel number; a trace data block that follows the reel identification header, with the first 240 bytes of each trace block consisting of the binary trace identification header; and seismic data samples that follow the trace identification header.
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users.
        Transfer_Size: 3080
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/ERDA90-2_SEGY.zip
    Fees: None
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: Portable Document Format, PNG
        Format_Information_Content: Processed seismic profile images with axis scales and headers for cruise ERDA90-2 (.pdf).
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users.
        Transfer_Size: 2550
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/ERDA90-2_ProfilesWithScales.zip
    Fees: None
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: TIFF
        Format_Information_Content: Printable seismic profiles with headers containing cruise, line, and scanning information for cruise ERDA90-2 (.tif).
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users.
        Transfer_Size: 2470
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/ERDA90-2_ProfilesWithHeaders.zip
    Fees: None
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: comma-delimited text
        Format_Information_Content: ERDA90-2 cruise navigation data (.csv).
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users.
        Transfer_Size: 0.024
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/ERDA90-2_Navigation.zip
    Fees: None
  Standard_Order_Process: 
    Digital_Form: 
      Digital_Transfer_Information: 
        Format_Name: shapefile 
        Format_Information_Content: Trackline shapefile of ERDA90-2 cruise (.shp). 
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users. 
        Transfer_Size: 0.040 
      Digital_Transfer_Option: 
        Online_Option: 
          Computer_Contact_Information: 
            Network_Address: 
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/ERDA90-2_Tracklines.zip 
    Fees: None 
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: SEG-Y
        Format_Information_Content: The SEG-Y rev. 0 format (Barry and others, 1975) presented here consists of the following: a 3,600-byte reel identification header, with the first 3,200 bytes consisting of an American Standard Code for Information Interchange (ASCII) header block followed by a 400-byte binary header block, both of which include information specific to line and reel number; a trace data block that follows the reel identification header, with the first 240 bytes of each trace block consisting of the binary trace identification header; and seismic data samples that follow the trace identification header.
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users.
        Transfer_Size: 745
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/MB91-1_SEGY.zip
    Fees: None
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: Portable Document Formant, PNG
        Format_Information_Content: Processed seismic profile images with axis scales and headers for cruise MB91-1 (.pdf).
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users.
        Transfer_Size: 1050
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/MB91-1_ProfilesWithScales.zip
    Fees: None
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: TIFF
        Format_Information_Content: Printable seismic profiles with headers containing cruise, line, and scanning information for cruise MB91-1 (.tif).
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users.
        Transfer_Size: 564
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/MB91-1_ProfilesWithHeaders.zip
    Fees: None
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: comma-delimited text
        Format_Information_Content: MB91-1 cruise navigation data (.csv).
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users.
        Transfer_Size: 0.024
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/MB91-1_Navigation.zip
    Fees: None
  Standard_Order_Process: 
    Digital_Form: 
      Digital_Transfer_Information: 
        Format_Name: sahpefile 
        Format_Information_Content: Trackline shapefile of MB91-1 cruise (.shp). 
        File_Decompression_Technique: Unzip using 7zip for PC users and BetterZip for Mac users. 
        Transfer_Size: 0.084 
      Digital_Transfer_Option: 
        Online_Option: 
          Computer_Contact_Information: 
            Network_Address: 
              Network_Resource_Name: https://coastal.er.usgs.gov/data-release/doi-P1V6EDD5/data/ERDA90-2_Tracklines.zip 
    Fees: None 
  Technical_Prerequisites: 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. Use of SEG-Y data requires specialized seismic processing software, such as public domain software Seismic Unix (https://github.com/JohnWStockwellJr/SeisUnix).
Metadata_Reference_Information:
  Metadata_Date: 20260610
  Metadata_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center
        Contact_Person: USGS SPCMSC Data Management
      Contact_Address:
        Address_Type: mailing and physical
        Address: 600 4th Street South
        City: Saint Petersburg
        State_or_Province: FL
        Postal_Code: 33701
        Country: United States
      Contact_Voice_Telephone: 727-502-8000
      Contact_Electronic_Mail_Address: gs-g-spcmsc_data_inquiries@usgs.gov
  Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
