Archive of Digitized Analog Boomer Seismic Reflection Data Collected from the Northern Gulf of Mexico: Intersea 1980

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Frequently anticipated questions:

What does this data set describe?

Title:
Archive of Digitized Analog Boomer Seismic Reflection Data Collected from the Northern Gulf of Mexico: Intersea 1980
Abstract:
The U.S. Geological Survey (USGS) Coastal and Marine Hazards and Resources Program (CMHRP) has actively collected geophysical and sedimentological data in the northern 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 (m) long. As part of the National Geological and Geophysical Data Preservation Program (NGGDPP, https://datapreservation.usgs.gov/), and in collaboration with the Bureau of Ocean Energy Management, Marine Minerals Program, scientists from the USGS St. Petersburg Coastal and Marine Science Center (USGS-SPCMSC) 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 as industry standard Society of Exploration Geophysicists data exchange (SEG-Y) formatted files. This data release serves as an archive of HRSP profiles annotated with header information, converted SEG-Y files, navigation data, and cruise trackline shapefiles. The HRSP data were collected using a sparker seismic system onboard the research vessel (R/V) Amarillo and R/V Sea Raider. The two vessels collected seismic data along the northern Gulf of Mexico ranging from west of Sabine Pass, Texas to south of Marsh Island, Louisiana. The survey occurred from July 9 to September 26, 1980. Data collection and processing methods are described in USGS Data Series 1047 (Bosse and others, 2017).
Supplemental_Information:
The USGS-SPCMSC currently holds 13 major geophysical surveys from the northern Gulf of Mexico 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 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) images that were created using Seismic Unix and/or ImageMagick software. The northern Gulf of Mexico 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 of Mexico 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). The seismic data were collected using a Teledyne 40-tip Mini-Sparker and Hydrophone towed parallel to each other behind the vessels. The sparker floats 5 feet (ft) beneath the surface, while the hydrophone floats between 5 and 8 ft. Sparkers create sound waves from a collapsing bubble, which is a result of vaporizing water between positive and negative leads (Trabant, 1984). The signal emitted from the sparker source is received by a 5 m-long hydrophone streamer. The received signal was amplified and filtered using a Del Norte 502 Seismic Amplifier before being displayed on an EPC recorder. The signal was also recorded on tape by a Hewlett-Packard HP-3968 FM/Direct Recorder. The seismic returns were printed onto paper rolls as two-dimensional profiles representing shots horizontally (time along track) and depth (two-way travel time). Geographic positioning of the system was collected using a long-range navigation (LORAN-C) system and annotated onto the paper copies.
  1. How might this data set be cited?
    Bosse, Stephen T., Flocks, James G., and Forde, Arnell S., 20201123, Archive of Digitized Analog Boomer Seismic Reflection Data Collected from the Northern Gulf of Mexico: Intersea 1980: U.S. Geological Survey Data Release doi:10.5066/P9EFUAN3, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -94.0523
    East_Bounding_Coordinate: -91.8722
    North_Bounding_Coordinate: 29.7316
    South_Bounding_Coordinate: 28.3649
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 09-Jul-1980
    Ending_Date: 26-Sep-1980
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Multimedia presentation
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Entity Point (8379)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.0197920992. Longitudes are given to the nearest 0.0225110386. Latitude and longitude values are specified in Decimal seconds. The horizontal datum used is North American Datum 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?
    Intersea_Cruisepoints.shp and Intersea_nav.xlsx
    ArcGIS shapefile and navigation file containing seismic profile data for the cruise. These attributes are all based on the point vector shapefile. (Source: USGS)
    FID
    Feature ID (Source: Esri) Sequential unique whole numbers that are automatically generated
    Shape
    Feature geometry (Source: Esri) Point
    Latitude
    Latitude (NAD83) (Source: USGS)
    Range of values
    Minimum:28.3649
    Maximum:29.8568
    Units:Decimal Degrees
    Longitude
    Longitude (NAD83) (Source: USGS)
    Range of values
    Minimum:-94.0523
    Maximum:-91.8722
    Units:Decimal Degrees
    Time
    Time at which shot was taken (Source: USGS)
    Range of values
    Minimum:00:00
    Maximum:23:59
    JD
    Julian Date (Source: USGS)
    Range of values
    Minimum:191
    Maximum:270
    Date
    Date associated with each shot (Source: USGS)
    Range of values
    Minimum:07/09/1980
    Maximum:09/26/1980
    Line
    Line number (Source: USGS) Alphanumeric character string representing unique line numbers ranging from 185 to 348 with sub letters designating different sections of the line. In cases where there are more sub letters associated with SEGY, PWH, and PWS files than the navigation, the lines need to be split further due to the tech issues and bad weather that left major time gaps in the record. Not having a continuous record results in poor conversions with the ImageToSEGY software.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Stephen T. Bosse
    • James G. Flocks
    • Arnell S. Forde
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Stephen T. Bosse
    Cherokee Nation System Solutions/U.S. Geological Survey
    GIS Specialist II
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    sbosse@contractor.usgs.gov

Why was the data set created?

To archive all digitized analog boomer seismic profile data and associated files collected along the northern Gulf of Mexico, during the R/V Amarillo and R/V Sea Raider geophysical cruises.

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: 2020 (process 1 of 6)
    Raw data scanning - The seismic data collected from this survey is housed in the USGS SPCMSC archive. The analog sparker 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 digitized navigation data were imported into Esri ArcGIS version 10.6 as point data. For mapping trackline positions the point shapefiles were converted to lines using the “make polylines from points” tool from the XTools Pro version 12.2 (build 2197) toolbar. Person who carried out this activity:
    Stephen T. Bosse
    Cherokee System Solutions/U.S. Geological Survey
    GIS Specialist II
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    sbosse@contractor.usgs.gov
    Data sources used in this process:
    • TIFF
    Date: 2020 (process 2 of 6)
    Cropping - The scanned TIFF images were imported into Adobe Photoshop (Ps) Creative Cloud 2019 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-DataAssociation_trackline#.tif (for example, Intersea-PWH_186.tif). It includes the cruise identification (Intersea), data association (PWH [profiles with headers] or SEGY), and trackline number (sometimes this also includes a subsection letter after the line number for tracklines split between multiple rolls). Person who carried out this activity:
    Stephen T. Bosse
    Cherokee Nation System Solutions/U.S. Geological Survey
    GIS Specialist II
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    sbosse@contractor.usgs.gov
    Data sources used in this process:
    • TIFF
    Date: 2020 (process 3 of 6)
    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. Person who carried out this activity:
    Stephen T. Bosse
    Cherokee Nation System Solutions/U.S. Geological Survey
    GIS Specialist II
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    sbosse@contractor.usgs.gov
    Data sources produced in this process:
    • CruiseID-PWH_trackline#.tif
    Date: 2020 (process 4 of 6)
    Correcting scan distortion - Distortion correction is necessary because it is difficult to ensure vellum/paper rolls are fed into the scanner straight. Distortion correction is obtained by placing a guideline over the 0 ms line (water level) on the scan. It is important that horizontal lines are 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 Photoshop 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. Person who carried out this activity:
    Stephen T. Bosse
    Cherokee Nation System Solutions/U.S. Geological Survey
    GIS Specialist II
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    sbosse@contractor.usgs.gov
    Data sources used in this process:
    • TIFF
    Date: 2020 (process 5 of 6)
    Image to SEG-Y - The scanned, distortion-corrected images were converted to digital SEG-Y (.seg, which has the same file extension 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 ms), maximum two-way travel 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). Person who carried out this activity:
    Stephen T. Bosse
    Cherokee Nation System Solutions/U.S. Geological Survey
    GIS Specialist II
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    sbosse@contractor.usgs.gov
    Data sources used in this process:
    • SEG
    Data sources produced in this process:
    • CruiseID-SEGY_trackline#.seg
    Date: 2020 (process 6 of 6)
    Process_Description: Seismic processing: The SEG-Y data were processed with Seismic Unix (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 (two-way travel 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 file. Person who carried out this activity:
    James G. Flocks
    U.S. Geological Survey
    Research Geologist
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    jflocks@usgs.gov
    Data sources used in this process:
    • SEG-Y
    Data sources produced in this process:
    • *_scale.pdf
  3. What similar or related data should the user be aware of?
    Anderson, J.B., Rodriguez, A., Abdulah, K.C., Fillon, R.H., Banfield, L.A., McKeown, H.A., and Wellner, J.S., 20040101, 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: Society for Sedimentary Geology 79.

    Online Links:

    Other_Citation_Details: pages 1-23
    Barry, K.M., Cavers, D.A., and Kneale, C.W., 197504, Recommended standards for digital tape formats: Geophysics v. 40, no. 2.

    Online Links:

    Other_Citation_Details: pages 344-352
    Bosse, S.T., Flocks, J.G., and Forde, A.S., 20170421, 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: U.S. Geological Survey Data Series 1047.

    Online Links:

    Flocks, J.G., Ferina, N.F., and Kindinger, J.L., 2009, 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: College Station, Texas, Texas A&M University Press 3.

    Online Links:

    Other_Citation_Details: pages 157-173
    Greene, D.L., Jr., Rodriquez, A.B., and Anderson, J.B., 20070201, 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.: Journal of Sedimentary Research 77.

    Online Links:

    Other_Citation_Details: pages 139-158
    Harrison, A.S., Dadisman, S.V., Kindinger, J.L., Morton, R.A., Blum, M.D., Wiese, D.S., and Subino, J.A., 2007, 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: U.S. Geological Survey Data Series 296.

    Online Links:

    Kindinger, J.L., Flocks, J.G., Kulp, M.A., Penland, P.S., and Britsch, L.D., 2001, Sand resources, regional geology, and coastal processes for the restoration of the Barataria barrier shoreline: U.S. Geological Survey Open-File Report 2001-384.

    Online Links:

    Other_Citation_Details: 69 pages
    Kulp, M.A., Howell, P.D., Adiau, S., Penland, P.S., Kindinger, J.L., and Williams, S.J., 2002, Latest Quaternary stratigraphic framework of the Mississippi River delta region: Gulf Coast Association of Geological Societies Transactions 52.

    Online Links:

    Other_Citation_Details: pages 573-582
    Roberts, H.H., Fillon, R.H., Kohl, B., Robalin, J.M., and Sydow, J.C., 2004, 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: Society for Sedimentary Geology 79.

    Online Links:

    Other_Citation_Details: pages 142-189
    Rogers, B.E., Kulp, M.A., and Miner, M.D., 20090916, Late Holocene chronology, origin, and evolution of the St. Bernard shoals, northern Gulf of Mexico, USA: Geo-Marine Letters 29.

    Online Links:

    Other_Citation_Details: pages 379-394
    Sanford, J.M., Harrison, A.S., Wiese, D.S., and Flocks, J.G., 2009, 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: U.S. Geological Survey Data Series 429.

    Online Links:

    Other_Citation_Details: 2009a
    Sanford, J.M., Harrison, A.S., Wiese, D.S., and Flocks, J.G., 2009, 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: U.S. Geological Survey Data Series 428.

    Online Links:

    Other_Citation_Details: 2009b
    Sanford, J.M., Harrison, A.S., Wiese, D.S., and Flocks, J.G., 2009, 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: U.S. Geological Survey Data Series 370.

    Online Links:

    Other_Citation_Details: 2009c
    Trabant, P.K., 1984, Applied High-Resolution Geophysical Methods: Springer Netherlands, Dordrecht, Netherlands.

    Online Links:

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

  1. How well have the observations been checked?
    The validity or accuracy of sparker 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.
  2. How accurate are the geographic locations?
    As the seismic reflection data were acquired, the position of the vessel was recorded using a LORAN-C system. The accuracy of the LORAN-C varied from 528 to 1,320 feet (ft), with repeatable accuracy between 60 and 300 ft. Positions were recorded in latitude and longitude coordinates at various intervals and appear on the seismic profiles as incremental, hand-annotated vertical event marks. Navigation data were digitized from a trackline map in Global Mapper (v.20.1.0) and exported as a comma separated values file. For this cruise, the time between starting and ending times were interpolated.
  3. How accurate are the heights or depths?
    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.
  4. Where are the gaps in the data? What is missing?
    This dataset is considered complete for the information presented. With the exception of lines 190a, 323a, and 344b, which were not found in the archives, all analog seismic profiles collected during the original survey 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.
  5. How consistent are the relationships among the observations, including topology?
    This dataset is from the USGS SPCMSC archive and has consistent instrument calibrations.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None. These data are held in the public domain.
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
  1. Who distributes the data set? (Distributor 1 of 1)
    Stephen T. Bosse
    Cherokee Nation System Solutions/U.S. Geological Survey
    GIS Specialist II
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    sbosse@contractor.usgs.gov
    Contact_Instructions:
    This report is available online. The SEG-Y files are downloadable from the USGS Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/.
  2. What's the catalog number I need to order this data set? Intersea-SEGY_*.seg, Intersea-PWH_*.tif, Intersea_nav.xlsx, Intersea_Cruisepoints.shp
  3. What legal disclaimers am I supposed to read?
    This 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: 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. in format SEG-Y Size: 9858
      Network links: https://coastal.er.usgs.gov/data-release/doi-P9EFUAN3/data/Intersea_SEGY.zip
    • Cost to order the data: None

  5. What hardware or software do I need in order to use the data set?
    Use of SEG-Y data requires specialized seismic processing software, such as public domain software Seismic Unix (https://wiki.seismic-unix.org/doku.php).

Who wrote the metadata?

Dates:
Last modified: 16-Nov-2020
Metadata author:
Stephen T. Bosse
Cherokee Nation System Solutions/U.S. Geological Survey
GIS Specialist II
600 4th Street South
St. Petersburg, FL
USA

(727) 502-8000 (voice)
sbosse@contractor.usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/Intersea_metadata.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:18:50 2021