Archive of digitized analog boomer seismic reflection data collected along the Louisiana Shelf, 1982–1984

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Frequently anticipated questions:

What does this data set describe?

Title:
Archive of digitized analog boomer seismic reflection data collected along the Louisiana Shelf, 1982–1984
Abstract:
The U.S. Geological Survey (USGS) Coastal and Marine Geology Program 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 long. As part of the National Geological and Geophysical Data Preservation Program (https://datapreservation.usgs.gov/), and in collaboration with the Bureau of Ocean Energy Management, Marine Minerals Program, scientists at the USGS St. Petersburg Coastal and Marine Science Center are converting the analog paper records to digital format using a large-format continuous scanner. The image files created by scanning were further processed to fix distortions and crop out blank spaces to create industry standard Society of Exploration Geophysicists date exchange (SEG-Y) format. This data release serves as an archive of HRSP profiles annotated with header information, converted Society of Exploration Geophysicists SEG-Y files, navigation data, and cruise trackline shapefiles. The HRSP data were collected using a Huntec boomer seismic system onboard the Research Vessels (R/V) R.J. Russell and Carancahua. While on the R/V R.J. Russel, geophysical surveys were conducted at various times between December 1982 and July 1984 with the data being acquired from waterbodies surrounding Isles Dernieres (Lacoss 82-2, 83-3 and 83-4), within Terrebonne and Caillou Bay (82-2), and offshore of Port Fourchon, Louisiana (84-5). While on the R/V Carancahua, geophysical surveys were collected between August and September 1982 off the coast of Holly Beach, Louisiana (82-3). Data collection and processing methods are described in USGS Data Series 1047.
Supplemental_Information:
The USGS Saint Petersburg Coastal and Marine Science Center (SPCMSC) currently holds 13 major geophysical surveys from the northern Gulf of Mexico in its paper repository. A conservative estimate of 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 system (GIS) and interpretative software. Conversion of these 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, http://datapreservation.usgs.gov) 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 seafloor 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 (for example, 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, 2011). The seismic data were collected using a single-channel Huntec boomer/benthos hydrophone system with an Ocean Research Equipment (ORE) Geopulse power supply. The system consists of an electromagnetic sound source mounted on a catamaran sled towed behind the vessel at the water surface. The signal emitted from the sound source is received by a 5 meter (m)-long hydrophone streamer towed alongside the sled. The received signal is processed into response amplitudes via a topside computer running the acquisition software; the settings varied by cruise. The seismic data were printed onto paper rolls as two-dimensional profiles representing track length and depth (time). Geographic positioning of the system was collected using a long-range navigation (LORAN) 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., 20180201, Archive of digitized analog boomer seismic reflection data collected along the Louisiana Shelf, 1982–1984: U.S. Geological Survey Data Release doi:10.5066/F7NP23H4, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

    Other_Citation_Details: 2018a
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -93.74829
    East_Bounding_Coordinate: -89.99125
    North_Bounding_Coordinate: 29.78429
    South_Bounding_Coordinate: 28.38948
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 28-Aug-1982
    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 (1921)
    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 0.0197919601. Longitudes are given to the nearest 0.0225194781. 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?
    Lacoss82-2_CruiseShapefiles.shp, Lacoss82-3_CruiseShapefiles.shp, Lacoss83-3_CruiseShapefiles.shp, Lacoss83-4_CruiseShapefiles.shp, Lacoss84-5_CruiseShapefiles.shp, Lacoss82-2_Navigation.xls, Lacoss82-3_Navigation.xls, Lacoss83-3_Navigation.xls, Lacoss83-4_Navigation.xls, Lacoss84-5_Navigation.xls
    Shapefile containing seismic profile data and navigation Excel files (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:28.38948
    Maximum:29.78429
    Units:Decimal Degrees
    Longitude
    Longitude (NAD83) (Source: USGS)
    Range of values
    Minimum:-93.74829
    Maximum:-89.99125
    Units:Decimal Degrees
    Time
    HH:MM (Z) (Source: USGS)
    Range of values
    Minimum:00:00
    Maximum:23:55
    Date
    Date associated with each shot (Source: USGS)
    Range of values
    Minimum:04/18/1981
    Maximum:07/27/1991
    Tape
    Tape number (Source: USGS)
    Range of values
    Minimum:1
    Maximum:7
    Line
    Line number (Source: USGS) Character string representing unique line numbers.

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?
    U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center (SPCMSC).
  3. To whom should users address questions about the data?
    Stephen T. Bosse
    Cherokee Nation Technologies/U.S. Geological Survey
    Researcher I
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    sbosse@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 Lacoss 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: 2017 (process 1 of 7)
    Raw Data Scanning - The analog seismic data collected during each survey are currently located in the SPCMSC archives and arranged in cruise-specific storage boxes. The analog boomer data are in the form of 50 centimeter (cm)-wide paper rolls, paper fan-folds, and vellum rolls. The various rolls can be up to 20 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 two-way travel time in milliseconds (ms), and vertical lines represent navigation fixes acquired and annotated as the survey was underway. The raw data was scanned on a Contex SD 3600 continuous-feed scanner. Using the NEXTimage 4 program (Contex), the scans were saved as 8-bit grey-scale TIFF files at 300 dots-per-inch (dpi) resolution. In order to minimize the final image file size for archiving, a batch conversion program was used to reduce the resolution to 210 dpi. The raw navigation data were imported into Esri ArcGIS version 10.3 as point data. For mapping trackline purposes, the point shapefiles were converted to lines using the “make polylines from points” tool from the XTools Pro toolbar. Person who carried out this activity:
    Stephen T. Bosse
    Cherokee Nation Technologies/U.S. Geological Survey
    Researcher I
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    sbosse@usgs.gov
    Data sources used in this process:
    • TIFF
    Date: 2017 (process 2 of 7)
    Cropping - The scanned TIFF images were imported into Adobe Photoshop (Ps) Creative Cloud 2017 and blank edge areas were cropped out to further reduce file sizes. 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, Lacoss82_2-SEGY_4.tif). It includes the cruise identification (Lacoss82-2), 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 Technologies/U.S. Geological Survey
    Researcher I
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    sbosse@usgs.gov
    Data sources used in this process:
    • TIFF
    Date: 2017 (process 3 of 7)
    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 2010, exported as PDF files, appended to the far left of the image frame in Adobe Photoshop, and then flattened onto the image to reduce file size. The final TIFF images with attached header files are available for download from Bosse and others (2018a). Person who carried out this activity:
    Stephen T. Bosse
    Cherokee Nation Technologies/U.S. Geological Survey
    Researcher I
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    sbosse@usgs.gov
    Data sources produced in this process:
    • CruiseID-PWH_trackline#.tif
    Date: 2017 (process 4 of 7)
    Correcting Scan Distortion - Distortion correction is necessary because it is difficult to ensure vellum rolls are fed into the scanner straight. Therefore, a reference line was placed 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 Technologies/U.S. Geological Survey
    Researcher I
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    sbosse@usgs.gov
    Data sources used in this process:
    • TIFF
    Date: 2017 (process 5 of 7)
    Image to SEG-Y - The scanned, distortion-corrected images were converted to digital SEG-Y (.seg) format (revision 0) (Barry and others, 1975) using the proprietary software ImageToSEGY 2.2 (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 s. Person who carried out this activity:
    Stephen T. Bosse
    Cherokee Nation Technologies/U.S. Geological Survey
    Researcher I
    600 4th Street South
    St. Petersburg, FL

    (727) 502-8000 (voice)
    sbosse@usgs.gov
    Data sources used in this process:
    • SEG
    Data sources produced in this process:
    • CruiseID-SEGY_trackline#.seg
    Date: 2017 (process 6 of 7)
    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 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
    Date: 13-Oct-2020 (process 7 of 7)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  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., 2004, Late Quaternary stratigraphic evolution of the northern Gulf of Mexico margin: 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., 1975, 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, U.S. Geological Survey, St. Petersburg, FL.

    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., 2007, 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 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 Society 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., 2009, 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 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

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 boomer 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 every five minutes and appear on the seismic profiles as incremental, hand-annotated vertical event marks. The datum in which these were recorded is unknown. Navigation data were obtained as .dat files and saved as tab-delimitated text files. For the Lacoss 82-3 cruise, there were no navigation records on file. Therefore, the navigation data were acquired by georectifying an accompanying analog trackline map using the WGS84 geographic coordinate system, which was then converted to NAD83.
  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?
    These data were collected along tracklines (2-D) and are therefore inherently incomplete.
  5. How consistent are the relationships among the observations, including topology?
    This dataset is from five field activities with 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
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    sbosse@usgs.gov
    Contact_Instructions:
    This report is available online. The SEG-Y files are downloadable from the Coastal and Marine Geoscience Data System.
  2. What's the catalog number I need to order this data set? Lacoss82-2_SEGY_*.seg, Lacoss82-3_SEGY_*.seg, Lacoss83-3_SEGY_*.seg, Lacoss83-4_SEGY_*.seg, Lacoss84-5_SEGY_*.seg, Lacoss82-2_PWH_*.tif, Lacoss82-3_PWH_*.tif, Lacoss83-3_PWH_*.tif, Lacoss83-4_PWH_*.tif, Lacoss84-5_PWH_*.tif, Lacoss82-2_Navigation.xls, Lacoss82-3_Navigation.xls, Lacoss83-3_Navigation.xls, Lacoss83-4_Navigation.xls, Lacoss84-5_Navigation.xls, Lacoss82-2_CruiseShapefiles.shp, Lacoss82-3_CruiseShapefiles.shp, Lacoss83-3_CruiseShapefiles.shp, Lacoss83-4_CruiseShapefiles.shp, Lacoss84-5_CruiseShapefiles.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?
  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 (http://www.cwp.mines.edu/cwpcodes/index.html).

Who wrote the metadata?

Dates:
Last modified: 13-Oct-2020
Metadata author:
Stephen T. Bosse
Cherokee Nation Technologies/U.S. Geological Survey
Researcher I
600 4th Street South
St. Petersburg, FL
USA

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