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

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Frequently anticipated questions:

What does this data set describe?

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
Abstract:
In June of 1996, the U.S. Geological Survey conducted geophysical surveys from Nueces to Copano Bays, Texas. This report serves as an archive of unprocessed digital boomer seismic reflection data, trackline maps, navigation files, GIS information, cruise log, and formal FGDC metadata. Filtered and gained digital images of the seismic profiles and high resolution scanned TIFF images of the original paper printouts are also provided. The archived trace data are in standard Society of Exploration Geophysicists (SEG) SEG-Y format (Barry and others, 1975) and may be downloaded and processed with commercial or public domain software such as Seismic Unix (SU). Example SU processing scripts and USGS software for viewing the SEG-Y files (Zihlman, 1992) are also provided.
For more information on the seismic surveys see http://walrus.wr.usgs.gov/infobank/b/b0296tx/html/b-02-96-tx.meta.html
These data are also available via GeoMapApp (http://www.geomapapp.org/) and Virtual Ocean (http://www.virtualocean.org/) earth science exploration and visualization applications.
Supplemental_Information:
The USGS Florida Integrated Science Center (FISC) - St. Petersburg assigns a unique identifier to each cruise or field activity. For example, 96CCT02 tells us the data were collected in 1996 for the Coastal Change and Transport (CCT) study and the data were collected during the second field activity for that study in that calendar year. Refer to http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html for a detailed description of the method used to assign the cruise ID. The naming convention used for each seismic line is as follows: xxmdd_##a, where xx is an abbreviation of the geographic area where the data were collected and mdd is the month and day the trackline was collected, ## is a 2-digit number representing a specific track, and a is a letter representing the section of a line if recording was prematurely terminated or rerun for quality or acquisition problems. The boomer plate is an acoustic energy source that consists of capacitors charged to a high voltage and discharged through a transducer in the water. The transducer is towed on a sled at the sea surface and when discharged emits a short acoustic pulse, or shot, that propagates through the water and sediment column. The acoustic energy is reflected at density boundaries (such as the seafloor or sediment layers beneath the seafloor), detected by the receiver, and recorded by a PC-based seismic acquisition system. This process is repeated at timed intervals (for example, 0.5 s) and recorded for specific intervals of time (for example, 100 ms). In this way, a 2-D vertical image of the shallow geologic structure beneath the ship track is produced. An ORE GeoPulse power supply provided 105 Joules per shot. Reflected energy was received by an Innovative Transducers, Inc. (ITI) ST-5 streamer and recorded by Delph Seismic acquisition software. The streamer contains 10 hydrophones evenly spaced every 0.5 m. For lines tx710_1 through tx715_27, phones 5-8 were used, and for lines tx715_28 through tx716_44, phones 3, 4, 7, and 8 were used. The streamer had two configurations (either directly behind or beside the research vessel), both of which had it positioned parallel to the boomer sled and laterally separated from it by about 4 m. Refer to figure 1 included with this archive (Data Series 296) for a diagram of the acquisition geometries. The sample frequency of the data was 12 kHz, and record length was 100 - 150 ms. Based on survey speeds of 3.5 - 4 knots and a shot rate of every 0.25 - 0.5 s, shot spacing was about 0.5 - 1 m. The unprocessed seismic data are stored in SEG-Y, integer, Motorola format, which is a standard digital format that can be read and manipulated by most seismic processing software packages (Barry and others, 1975). The SEG-Y formatted trace files have .SEG and .TRA extensions. Additional recording parameters for each trace file can also be found in the .PAR file associated with each .TRA file. However, the .PAR files included here are needed only to process or display the data with Delph Seismic software. Also provided are example Seismic Unix scripts that allow the user to strip off navigation fixes from the SEG-Y headers, along with a fix for every 500 shots, and produce a filtered and gained GIF image of each profile.
  1. How might this data set be cited?
    Harrison, Arnell S., Dadisman, Shawn V., Kindinger, Jack L., Morton, Robert A., Blum, Mike D., Wiese, Dana S., and Subino, Janice 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, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -97.517841
    East_Bounding_Coordinate: -97.017841
    North_Bounding_Coordinate: 28.144507
    South_Bounding_Coordinate: 27.744507
  3. What does it look like?
    http://pubs.usgs.gov/ds/296/maps/cruisenav/96cct02_location.jpg (JPEG)
    Location map of all digital boomer seismic reflection data collected during USGS Cruise 96CCT02. This map was created at a scale of 1:30,000. Refer to the Lineage section below for the trackline map creation process.
    http://pubs.usgs.gov/ds/296/maps/cruisenav/96cct02_area1.jpg (JPEG)
    Trackline map of digital boomer seismic reflection data collected in Area 1 (refer to Area 1 of the Location map) during USGS Cruise 96CCT02. This map was created at a scale of 1:140,000. Refer to the Lineage section below for the trackline map creation process.
    http://pubs.usgs.gov/ds/296/maps/cruisenav/96cct02_area2.jpg (JPEG)
    Trackline map of digital boomer seismic reflection data collected in Area 2 (refer to Area 2 of the Location map) during USGS Cruise 96CCT02. This map was created at a scale of 1:40,000. Refer to the Lineage section below for the trackline map creation process.
    http://pubs.usgs.gov/ds/296/maps/cruisenav/96cct02_area3.jpg (JPEG)
    Trackline map of digital boomer seismic reflection data collected in Area 3 (refer to Area 3 of the Location map) during USGS Cruise 96CCT02. This map was created at a scale of 1:85,000. Refer to the Lineage section below for the trackline map creation process.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 10-Jul-1996
    Ending_Date: 16-Jul-1996
    Currentness_Reference:
    Data collection interval
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Seismic Reflection Profile Section
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      Indirect_Spatial_Reference:
      Horizontal X and Y locations (latitude and longitude and Zone 14 UTM coordinates) for each shot are provided as ASCII text files, along with the date and time (UTC) the shot was recorded. --------------------------------------------------------------------------------
      This is a Point data set.
    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 0.0000027. Longitudes are given to the nearest 0.0000027. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is WGS84.
      The ellipsoid used is WGS84.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298.257.
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    Binary data file: Trace data are available as binary files in SEG-Y format. These files have .SEG and .TRA extensions and range in size from 8 to 236 MB.
    Entity_and_Attribute_Overview:
    Graphic image file: Printable profiles are available as GIF images. Scanned images of the analog records are available as TIFF files. The line navigation maps and trackline maps are JPEG images. The trackline maps contain links to the printable seismic profiles.
    Entity_and_Attribute_Overview:
    Navigation file: Navigation files are available as ASCII text files. Provided are raw (unprocessed) shotpoint navigation files, processed shotpoint navigation files, and processed 500-shot-interval location files.
    Entity_and_Attribute_Overview:
    GIS file: The GIS project used to create the trackline maps is provided as a .zip file composed of ESRI map documents, shapefiles, and metadata. --------------------------------------------------------------------------------
    Entity_and_Attribute_Detail_Citation:
    Barry, K.M., Cavers, D.A., and Kneale, C.W., 1975, Recommended standards for digital tape formats: Geophysics, v. 40, no. 2, p. 344-352. Also available online at http://www.seg.org/publications/tech-stand.
    Entity_and_Attribute_Detail_Citation:
    Zihlman, F.N., 1992, DUMPSEGY V1.0: A program to examine the contents of SEG-Y disk-image seismic data: U.S. Geological Survey Open-File Report 92-590, 28 p.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Arnell S. Harrison
    • Shawn V. Dadisman
    • Jack L. Kindinger
    • Robert A. Morton
    • Mike D. Blum
    • Dana S. Wiese
    • Janice A. Subino
  2. Who also contributed to the data set?
    Funding and (or) support for this study was provided by the USGS Coastal and Marine Geology Program. This document was improved by the reviews of Charlene Sullivan (ETI) and Nick Ferina (USGS) of the FISC in St. Petersburg, Florida. --------------------------------------------------------------------------------
  3. To whom should users address questions about the data?
    Shawn Dadisman
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 803-8747, ext. 3029 (voice)
    sdadisman@usgs.gov

Why was the data set created?

The data archived here were collected as part of the USGS Coastal Change and Transport (CCT) study.

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: 2002 (process 1 of 6)
    Boomer processing: boomer data were collected in ELICS format and saved onto MO discs. The data were plotted daily at 200 dpi with an OYO Geospace GS-612 thermal plotter. Digital data for lines tx715_29 - tx715_38 were later converted from nonstandard ELICS format to standard SEG-Y format using Delph Seismic software. Digital data were not recoverable for lines tx710_1 - tx715_28 and tx716_39 - tx716_44. Analog data for these lines were scanned at 400 dpi using a Crystal Tx40 (1394) scanner and WIDEimage software, V. 2.8.1. The WIDEimage software was used to straighten the scanned images. Each line was saved as a separate TIFF file. Adobe Photoshop CS2 was then used to place an information header on each image. The original trace files for lines tx711_04, tx711_05, tx712_13, tx712_14, tx713_18, tx713_19, tx713_20, tx713_22, tx714_25, tx714_27, tx716_39, and tx716_42 were divided into two or more trace files each (for example, tx711_04 became tx711_04a and tx711_04b) because the original total number of traces exceeded the maximum allowed by the processing software. The scanned records were then converted to SEG-Y files (complete with time stamps, shotpoints and navigation) using Chesapeake Technology, Inc. (CTI) ImageToSEGY software, which produces an interpolated fix for every shot it creates from the scanned images. The SEG-Y data were finally processed with Seismic Unix to produce GIF images of the seismic profiles included in this report. A representative boomer processing sequence consisted of (1) running a bandpass filter of 300-500-2500-3000 Hz, (2) applying automatic gain control, (3) displaying PostScript, and (4) converting of PostScript image to a GIF image.
    Date: 2005 (process 2 of 6)
    Navigation processing: Shotpoint navigation files and 500-shot-interval location files were extracted from the trace headers of each line using Seismic Unix software. For those lines for which only analog records are available, ImageToSEGY software was used to match navigation fixes to known locations on the scans. Navigation which fell in between known locations was determined by linear interpolation. NOTE: Navigation fixes for the converted lines were available only at 5-minute intervals because the navigation is plotted on the paper record using this increment. ImageToSEGY, nevertheless, creates an interpolated point for every shot it created from the scanned image; therefore, the shot numbers printed on the converted records do not match the original shots printed out on the analog paper records. The navigation files were then processed with PROJ.4 software (http://www.remotesensing.org/proj) to generate UTM coordinates from latitude and longitude coordinates and reformatted for use with Environmental Systems Research Institute (ESRI) GIS software.
    Date: 2007 (process 3 of 6)
    Trackline map creation: The trackline maps provided in this archive were created using the Points to Lines ArcScript (D. Rathert, http://arcscripts.esri.com/details.asp?dbid=12702) along with ESRI ArcGIS 9.1 software and then exported to Adobe Illustrator for further editing. Due to file size limitations associated with the ArcScript, the initial .TXT files from the recovered trackline navigation had to be broken up into smaller files before the individual tracklines and associated shapefiles could be created. See the readme.txt file in the ARC folder for more details. The maps were later converted into JPEG format by Adobe GoLive. The USGS is the originator of all layers used.
    Date: 2007 (process 4 of 6)
    Data Series preparation: In addition to the process steps described above, the following steps were taken to produce this Data Series report: the handwritten log was scanned and saved as a PDF file, digital logs were created using the handwritten log and personal accounts of the crew members and saved as PDF files, and an HTML-based format was used to present the various parts of this archive.
    Date: 24-Jan-2017 (process 5 of 6)
    Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Alan O. Allwardt
    Contractor -- Information Specialist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7551 (voice)
    831-427-4748 (FAX)
    aallwardt@usgs.gov
    Date: 13-Oct-2020 (process 6 of 6)
    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?

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 marine seismic reflection profiles 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. All scanned images contain handwritten and plotter-generated annotations as well as handdrawn interpretations (tx712_6 - tx712_8 and tx712_10 - tx713_21).
  2. How accurate are the geographic locations?
    As the seismic reflection data were acquired, the position of the vessel was continuously determined by a Rockwell PLGR GPS receiver, which is accurate to within 15-m. Positions were recorded and written to the trace headers in latitude and longitude coordinates about every 60 s. The ASCII navigation files and trackline maps have not been corrected to reflect the approximately 10-m (lines tx710_1 and tx710_2) and 2-m offsets (all remaining lines) between the boomer and GPS antenna. Refer to figure 1 included with this archive (Data Series 296) for a diagram of the acquisition geometries, including the GPS offset measurements.
  3. How accurate are the heights or depths?
    Boomer data are relative to sea level. However, varying recorded static shifts of the data have been known to occur. Therefore, these data are not to be used for bathymetry.
  4. Where are the gaps in the data? What is missing?
    These data are collected along tracklines (2-D) and are therefore inherently incomplete. Geologic details between lines must be inferred. Examination of the data, after the cruise, showed that only 10 (tx715_29 - tx715_38) of the 44 lines of digital data could be recovered; however, analog records are available for these lines, with the exception of lines tx710_12 and tx713_24.
  5. How consistent are the relationships among the observations, including topology?
    This data set is from one cruise 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:
The U.S. Geological Survey requests to be acknowledged as originator of the data in future products or derivative research.
  1. Who distributes the data set? (Distributor 1 of 1)
    Shawn Dadisman
    U.S. Geological Survey
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 803-8747, ext. 3029 (voice)
    sdadisman@usgs.gov
    Contact_Instructions: All of this report except the SEG-Y files is available on-line.
  2. What's the catalog number I need to order this data set? U.S. Geological Survey Data Series 296
  3. What legal disclaimers am I supposed to read?
    This DVD 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, or for general or scientific purposes, 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 standard format (Barry and others, 1975) consists of the following: a 3,600-byte reel identification header, with the first 3,200 bytes consisting of an 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: 504
      Media you can order: DVD (format ISO 9660)
      Note: UNIX, Linux, DOS, Macintosh
      Data format: The GIS project used to create the trackline maps is composed of map documents, shapefiles, and metadata. Map documents were created with ESRI ArcGIS 9.1 software. The shapefiles provided may also be viewed using other versions of ArcView, ArcGIS, or public domain software ArcExplorer (http://www.esri.com/software/arcexplorer/index.html). in format map document, shapefile, metadata Size: 23.6
      Network links: https://pubs.usgs.gov/ds/296/software/arc/arc.zip
      Data format: The SEG-Y standard format (Barry and others, 1975) consists of the following: a 3,600-byte reel identification header, with the first 3,200 bytes consisting of an 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 SEGY data download Size: 504
      Network links: https://cmgds.marine.usgs.gov/data/96cct02/
    • Cost to order the data: Prices vary.

    • Special instructions:
      Publications are available from USGS Information Services, Box 25286, Federal Center, Denver, CO 80225-0046 (telephone: 1-888-ASK-USGS, e-mail: infoservices@usgs.gov).
  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:
Arnell Harrison
ETI, contracted by U.S. Geological Survey
Geologist
600 4th Street South
St. Petersburg, FL
USA

(727) 803-8747, ext. 3111 (voice)
aharrison@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998 --------------------------------------------------------------------------------)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/ds-296metadata.faq.html>
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