Seismic Reflection Results from the Gyre 1997 Cruise at the Bryant Canyon of the Louisiana Gulf Coast

Frequently anticipated questions:

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

What does this data set describe?

1. How might this data set be cited?
   Nealon, Jeffrey, 1999, Seismic Reflection Results from the Gyre 1997 Cruise at the Bryant Canyon of the Louisiana Gulf Coast: Open-File Report 99-449, U.S. Geological Survey, Woods Hole, MA.

   Online Links:

   • https://doi.org/10.3133/ofr99449

   This is part of the following larger work.
   Nealon, Jeffrey W., Dillon, William P., and Twichell, David, 2000, Seismic reflection results from the GYRE 1997 cruise of the Bryant Canyon on the Louisiana Gulf Coast: Open-File Report 99-449, U.S. Geological Survey, Reston, VA.

   Online Links:

   • https://doi.org/10.3133/ofr99449

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -92.833333
   East_Bounding_Coordinate: -91.916667
   North_Bounding_Coordinate: 27.5
   South_Bounding_Coordinate: 26.25
   

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

   Beginning_Date: 09-Apr-1997

   Beginning_Time: 045227
   

   Ending_Date: 13-Apr-1997

   Ending_Time: 131459
   

   Currentness_Reference:

   not available from original metadata - assumed to be the start and end of the data acquisition

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

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      

      Indirect_Spatial_Reference: Gulf of Mexico, Louisiana Continental Slope
      

   2. What coordinate system is used to represent geographic features?
      

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:

      UTM_Zone_Number: 15
      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: .9997
      Longitude_of_Central_Meridian: -93
      Latitude_of_Projection_Origin: 0
      False_Easting: 0
      False_Northing: 0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 5
      Ordinates (y-coordinates) are specified to the nearest 5
      Planar coordinates are specified in meters
      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.
      The flattening of the ellipsoid used is 1/298257.
      

      Vertical_Coordinate_System_Definition:

      Altitude_System_Definition:

      Altitude_Datum_Name: assumed sea level
      Altitude_Resolution: 1
      Altitude_Distance_Units: two-way travel time
      Altitude_Encoding_Method: Attribute values
      

      Depth_System_Definition:

      Depth_Datum_Name: fish depth below sea level (local surface)
      Depth_Resolution: 1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
      

7. How does the data set describe geographic features?

   Entity_and_Attribute_Overview:

   Direct_spatial_Reference_method: raster Raster_Object Information: Raster_Object_Type: Voxel Row_Count: > 10000 Column_Count: 1 Vertical Count: 4096

   Entity_and_Attribute_Detail_Citation:

   Based on the direct spatial reference method in the original metadata that didn't meet the standard formatting requirements.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Nealon, Jeffrey
2. Who also contributed to the data set?
   D. Twichell, D. Nichols, T. O'Brien, B. Irwin, V. Cross, M. Taylor D. Foster, B. Danforth, S. Harrison, J. Brand, C. Spagnuolo
3. To whom should users address questions about the data?
   Twichell, Dave

   U.S. Geological Survey

   Seafloor Mapping Project

   U.S. Geological Survey

   Woods Hole Field Center

   384 Woods Hole Road

   Quissett Campus

   Woods Hole, MA
   

   USA

   (508) 548-8700 (voice)

   (508) 457-2310 (FAX)

   dtwichell@usgs.gov

Why was the data set created?

How was the data set created?

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

   Date: unknown (process 1 of 3)

   The original SEG-Y files were acquired from David C. Twichell on CD-ROM.
   Flow 1 : load file and geometry
   2D Marine geometry spreadsheet
   Seg-Y Input
   File to input: Raw.seg-y
   Store Processing History:Yes
   Input Auxiliary Traces: Yes
   Get Channel Number from Trace Headers: Yes
   Input Trace Format: Get from Headers
   Display ensemble Formation: No
   Data Input Sample Rate: 0.5 msec
   Maximum Time to input: variable
   Is this Stacked Data: No
   Max Traces Per Ensemble: 120
   Primary Sort Header Word: SHOT
   Input Primary Selection Choice:Input all
   Input secondary selection Choice:None
   Input global XY coordinates: No
   Use coordinate Scalar: Yes
   Remap Seg-Y header Values: No
   Inline Geometry header Load
   water velocity: 1525
   Primary header to match database: FFID
   Secondary Header to match database: None
   Match by Valid trace Number: NO
   Drop traces with Null CDP headers: No
   Drop Traces with Null receiver Headers: No
   Verbose Diagnostics: YES
   Trace header Math
   select Mode:fixed equation Mode
   define header equation:FFID =CDP
   Disk Data Output
   output dataset file Name: geom
   New or existing file:New
   record length to output:0(default parameter means include all)
   Trace sample format:16 bit
   Skip primary disk storage:No
   Flow 2: Mute and Deconvolution
   Disk Data Input
   Read data from other lines/surveys:No
   Select input file: geom
   Trace read option: Get all
   Read data multiple times: No
   Input trace headers only: No
   Override input datas sample interval:No
   Trace Muting
   Reapply Previous mutes: no
   Mute time reference:Time 0
   Type of Mute: TOP
   Starting ramp:30
   Extrapolate mute times:No
   Get Mute Times from Database:Yes
   Select Database:Topmute(Horizon picked ~300 ms above seafloor)
   True Amplitude recovery
   Apply spherical divergence corrections: NO
   Apply inelastic attenuation correction: NO
   Apply db/sec corrections:YES
   DB per second constant:6
   Apply time raise to a power corrections:NO
   Time power constant:NO
   Apply effect to data or remove function:APPLY
   Maximum application Time: 3500-4000
   Spiking Predictive decon
   Type of deconvolution:MIN PHASE SPIKING
   Decon Operator length:80
   Operator white noise level:.1
   window rejection length:2
   Time gate reference:DATABASE FILE
   Select decon gate from Database: Yes Select database:DECON
   Output traces or filters:TRACES
   Apply a band pass filter after decon:NO
   Reapply mutes after decon:YES
   Disk Data Output
   Output dataset file Name:decon
   New or existing file:New
   record length to output:0(default parameter means include all)
   Trace sample format:16 bit
   Skip primary disk storage:No
   Flow 3 Stack
   Disk Data Input
   Read data from other lines/surveys: No
   Select input file:decon
   Trace read option:sort
   Primary Sort header word:CDP
   Secondary sort header word:NONE
   Sort order dataset:*/
   Presort in memory or disk:Memory
   Read data multiple times:No
   Input trace headers only: No
   Override input datas sample interval:No
   CDP Ensemble Stack
   sort order of input ensembles:CDP
   Method of trace summing:Mean
   root Power scalar for stack normalization:0.5
   Apply final datum statics after Stack:Yes
   Has NMO been applied:No
   Disk Data Output
   Output dataset file Name:stack
   New or existing file:New
   record length to output:0(default parameter means include all)
   Trace sample format:16 bit
   Skip primary disk storage:No
   Disk Data Input
   Read data from other lines/surveys:No
   Select input file:stack
   Trace read option:get all
   Read data multiple times:No
   Input trace headers only:No
   Override input data's sample interval:No
   Bandpass Filter
   Type of Filter:single filter
   Type of filter specification:ormsby bandpass
   Phase of filter:Zero
   domain of filter application:Frequency
   Percent zero padding for FFT:25
   Apply notch filter:no
   Ormbsby bandpass filter values:4-8-100-150
   Reapply trace mute after filter:yes
   Seg-Y Output
   type of seg-y:standard
   file name:line1pro.sgy
   Retrieve history form header:yes
   copy reel header:default
   job id for binary header:9999
   line number for binary header:9999
   desired trace format:4 bit integer
   maximum time to output:variable
   remap seg-y header values:no

   Date: 19-Jan-2022 (process 2 of 3)

   Add the larger work citation to incorporate all the authors. Fixed errors flagged by MP, which results in "information not available from original metadata" in some instances. Added the field activity to the supplemental information. Added USGS Thesaurus and ISO 19115 Topic Category theme keywords. Removed the source citation information - and moved the brief information to the first process step. Removed empty, non-required fields. Updated the distribution information. Modified the distribution information to include the data formats and links to the data. The metadata date (19970408), but not the contact (except email and contact instructions) was updated. The metadata available from a harvester may supersede metadata available from the publication. Compare the metadata dates to determine which metadata file is most recent. 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

   Date: 06-Aug-2024 (process 3 of 3)

   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?
   
2. How accurate are the geographic locations?
   The ship was navigated with differential GPS The GI air gun was towed 10 m aft of the ship The two-channel streamer was towed 100 m aft of the ship. Each channel consisted of a 25 m length of streamer. accurate within 5-10 meters
3. How accurate are the heights or depths?
   The air gun was towed at depth of 1 meter. The streamer was towed at a depth of 5 meters. Vertical resolution of the seismic data is about 1-2 meters. There was no correction to a datum such as mean sea level.
4. Where are the gaps in the data? What is missing?
   archive of SEG-Y format seismic data
5. How consistent are the relationships among the observations, including topology?
   information not available from original metadata

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   Soderberg, Nancy

   U.S. Geological Survey

   Data Library

   U.S. Geological Survey

   Woods Hole Field Center

   384 Woods Hole Road

   Quissett Campus

   Woods Hole, MA
   

   USA

   (508) 548-8700 (voice)

   (508) 457-2310 (FAX)

   nsoderberg@usgs.gov
2. What's the catalog number I need to order this data set? U.S. Geological Suvey Internal CD-ROM Data Archive
3. What legal disclaimers am I supposed to read?
   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.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	SEG-Y for both the raw and processed data. in format SEG-Y
     Network links:	https://pubs.usgs.gov/of/1999/of99-449/disc1/seg_y/ https://pubs.usgs.gov/of/1999/of99-449/disc2/seg_y/ https://pubs.usgs.gov/of/1999/of99-449/disc3/seg_y/ https://doi.org/10.3133/ofr99449
     Media you can order:	CD-ROM (Density 512 bytes) (format ISO 9660) Note: UNIX, DOS, MAC

     Data format:	JPEG images of the processed seismic data. in format JPEG
     Network links:	https://pubs.usgs.gov/of/1999/of99-449/disc1/html_docs/images.html https://doi.org/10.3133/ofr99449

     Data format:	Text files of the navigation data. Includes raw navigation files (*.raw), space-delimited formatted navigation files (*.txy), and tab-delimited shot point navigation (*.txt). in format TEXT
     Network links:	https://pubs.usgs.gov/of/1999/of99-449/disc1/html_docs/nav.html https://pubs.usgs.gov/of/1999/of99-449/disc1/nav/ https://doi.org/10.3133/ofr99449

   • Cost to order the data: none for the online data

Who wrote the metadata?

Dates:

Last modified: 06-Aug-2024

Metadata author:

Foster, David

U.S. Geological Survey

Geophysics Group

U.S. Geological Survey

Woods Hole Field Center

384 Woods Hole Road

Quissett Campus

Woods Hole, MA

USA

(508) 548-8700 (voice)

(508) 457-2310 (FAX)

whsc_data_contact@usgs.gov

Contact_Instructions:

The metadata contact email address is a generic address in the event the metadata contact is no longer with the USGS.

Metadata standard:

FGDC Content Standard (FGDC-STD-001-1998)