High-resolution multichannel seismic reflection data collected along the New England outer continental shelf, slope, and rise south of Martha's Vineyard and Nantucket, Massachusetts, U.S. Geological Survey Field Activity 2016-018-FA

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Frequently anticipated questions:

What does this data set describe?

Title:
High-resolution multichannel seismic reflection data collected along the New England outer continental shelf, slope, and rise south of Martha's Vineyard and Nantucket, Massachusetts, U.S. Geological Survey Field Activity 2016-018-FA
Abstract:
High resolution multichannel seismic-reflection data were collected along the New England outer continental shelf, slope, and rise south of Martha's Vineyard and Nantucket, Massachusetts, aboard the Woods Hole Oceanographic Institute (WHOI) research vessel Neil Armstrong on June 11 - 12, 2016 in order to characterize the stratigraphy of a portion of the New England continental margin incised by submarine canyons and showing evidence of mass transport processes. The activity was conducted as a part of the Science Verification Leg 5 (AR5) for the new vessel.
Supplemental_Information:
Additional information on the field activity associated with this project is available from https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-018-FA and http://www.rvdata.us/catalog/AR5.
  1. How might this data set be cited?
    Baldwin, Wayne E., and Miller, Nathaniel C., 20230721, High-resolution multichannel seismic reflection data collected along the New England outer continental shelf, slope, and rise south of Martha's Vineyard and Nantucket, Massachusetts, U.S. Geological Survey Field Activity 2016-018-FA: data release DOI:10.5066/P9R3VW5H, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Baldwin, W.E. and Miller, N.C., 2023, High-resolution multichannel seismic reflection data collected along the New England outer continental shelf, slope, and rise south of Martha's Vineyard and Nantucket, Massachusetts, U.S. Geological Survey Field Activity 2016-018-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P9R3VW5H.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.760014
    East_Bounding_Coordinate: -69.510661
    North_Bounding_Coordinate: 40.270350
    South_Bounding_Coordinate: 39.617493
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data-releases/media/2023/10.5066-P9R3VW5H/34a09e579dc04ef88769d302156d1bbb/2016-018-FA_MCS_cmpTracklines_browse.jpg (JPEG)
    Thumbnail image showing the extent of multichannel seismic-reflection profile data collected along the New England outer continental shelf, slope, and rise south of Martha's Vineyard and Nantucket, during USGS Field Activity 2016-018-FA.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 11-Jun-2016
    Ending_Date: 12-Jun-2016
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Shapefile, CSV, PNG Image, SEG-Y
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the 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 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is WGS 1984.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257224.
  7. How does the data set describe geographic features?
    2016-018-FA_MCS_cmpTracklines.shp
    MCS CMP Trackline shapefile for survey 2016-018-FA (4 polyline features). (Source: U.S. Geological Survey)
    FID
    Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: Esri) Coordinates defining the features.
    LineName
    Name of the trackline along which seismic-reflection data were collected in the format: SurveyID_LineName (e.g., '2016-018-FA_Line-01'). (Source: U.S. Geological Survey) Character set
    ImageName
    PNG image name of seismic-reflection profile corresponding to survey line. (Source: U.S. Geological Survey) Character set
    CMP_init
    CMP number at the start of the survey line. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1005
    Maximum:1006
    Units:CMP
    Resolution:1
    CMP_end
    CMP number at the end of the survey line. (Source: U.S. Geological Survey)
    Range of values
    Minimum:3919
    Maximum:14459
    Units:CMP
    Resolution:1
    SurveyID
    WHCMSC field activity identifier (e.g., "2016-018-FA" where 2016 is the survey year, 018 is survey number of that year, and FA is Field Activity). (Source: U.S. Geological Survey) Character set
    VehicleID
    Survey vessel name. (Source: U.S. Geological Survey) Character set
    DeviceID
    Device used to collect seismic-reflection data. (Source: U.S. Geological Survey) Character set
    Length_km
    Length of CMP seismic-reflection data line in kilometers (UTM Zone 19N, WGS 84) calculated in the SQLite database. (Source: U.S. Geological Survey)
    Range of values
    Minimum:18.218
    Maximum:84.099
    Units:kilometers
    Resolution:0.01
    2016-018-FA_MCS_cmp500.shp
    MCS 500-interval CMP point shapefile for survey 2016-018-FA (73 point features). (Source: U.S. Geological Survey)
    FID
    Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: Esri) Coordinates defining the features.
    East
    Easting coordinate in UTM Zone 19 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:349682.43
    Maximum:456142.34
    Units:meters
    Resolution:.01
    North
    Northing coordinate in UTM Zone 19 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:4385506.78
    Maximum:4458106.70
    Units:meters
    Resolution:.01
    Lon
    Longitude coordinate in decimal degrees, WGS 84 (negative indicates west longitude) (Source: U.S. Geological Survey)
    Range of values
    Minimum:-70.759629
    Maximum:-69.510963
    Units:degrees
    Resolution:1E-06
    Lat
    Latitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:39.618196
    Maximum:40.269466
    Units:degrees
    Resolution:1E-06
    LineName
    Name of the trackline along which seismic-reflection data were collected in the format: SurveyID_LineName (e.g., '2016-018-FA_Line-01'). (Source: U.S. Geological Survey) Character set
    ImageName
    PNG image name of seismic-reflection profile corresponding to survey line. (Source: U.S. Geological Survey) Character set
    CMP
    CMP number. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1005
    Maximum:14459
    Units:CMP
    Resolution:1
    SurveyID
    WHCMSC field activity identifier (e.g., "2016-018-FA" where 2016 is the survey year, 018 is survey number of that year, and FA is Field Activity). (Source: U.S. Geological Survey) Character set
    VehicleID
    Survey vessel name. (Source: U.S. Geological Survey) Character set
    DeviceID
    Device used to collect seismic-reflection data. (Source: U.S. Geological Survey) Character set
    2016-018-FA_MCS_cmpnav.csv
    MCS CMP comma separated values file for survey 2016-018-FA (33844 point features). (Source: U.S. Geological Survey)
    East
    Easting coordinate in UTM Zone 19 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:349682.43
    Maximum:456142.34
    Units:meters
    Resolution:.01
    North
    Northing coordinate in UTM Zone 19 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:4385506.78
    Maximum:4458201.5
    Units:meters
    Resolution:.01
    Lon
    Longitude coordinate in decimal degrees, WGS 84 (negative indicates west longitude) (Source: U.S. Geological Survey)
    Range of values
    Minimum:-70.759629
    Maximum:-69.510963
    Units:degrees
    Resolution:1E-06
    Lat
    Latitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:39.618196
    Maximum:40.27035
    Units:degrees
    Resolution:1E-06
    LineName
    Name of the trackline along which seismic-reflection data were collected in the format: SurveyID_LineName (e.g., '2016-018-FA_Line-01'). (Source: U.S. Geological Survey) Character set
    ImageName
    PNG image name of seismic-reflection profile corresponding to survey line. (Source: U.S. Geological Survey) Character set
    CMP
    CMP number. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1005
    Maximum:14459
    Units:CMP
    Resolution:1
    SurveyID
    WHCMSC field activity identifier (e.g., "2016-018-FA" where 2016 is the survey year, 018 is survey number of that year, and FA is Field Activity). (Source: U.S. Geological Survey) Character set
    VehicleID
    Survey vessel name. (Source: U.S. Geological Survey) Character set
    DeviceID
    Device used to collect seismic-reflection data. (Source: U.S. Geological Survey) Character set
    2016-018-FA_MCS_shotnav.csv
    MCS shot point comma separated values file for survey 2016-018-FA (16972 point features). (Source: U.S. Geological Survey)
    East
    Easting coordinate in UTM Zone 19 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:349649.57
    Maximum:456167.74
    Units:meters
    Resolution:.01
    North
    Northing coordinate in UTM Zone 19 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:4385428.61
    Maximum:4458201.5
    Units:meters
    Resolution:.01
    Lon
    Longitude coordinate in decimal degrees, WGS 84 (negative indicates west longitude) (Source: U.S. Geological Survey)
    Range of values
    Minimum:-70.760014
    Maximum:-69.510661
    Units:degrees
    Resolution:1E-06
    Lat
    Latitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:39.617493
    Maximum:40.27035
    Units:degrees
    Resolution:1E-06
    LineName
    Name of the trackline along which seismic-reflection data were collected in the format: SurveyID_LineName (e.g., '2016-018-FA_Line-01'). (Source: U.S. Geological Survey) Character set
    FFID
    Shot number. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1
    Maximum:6744
    Units:shot
    Resolution:1
    Date
    Calendar date the data were collected in the format MM/DD/YYYY. (Source: U.S. Geological Survey) Character set
    UTC_DT
    Year, Julian day, and UTC time of the navigation fix in the format: YYYY:JD:HH:MM:SS; Julian day is the integer number (although recorded here in text string format) representing the interval of time in days since January 1 of the year of collection. (Source: U.S. Geological Survey) Character set
    SurveyID
    WHCMSC field activity identifier (e.g., "2016-018-FA" where 2016 is the survey year, 018 is survey number of that year, and FA is Field Activity). (Source: U.S. Geological Survey) Character set
    VehicleID
    Survey vessel name. (Source: U.S. Geological Survey) Character set
    DeviceID
    Device used to collect seismic-reflection data. (Source: U.S. Geological Survey) Character set
    2016-018-FA_MCS_Images.zip
    Portable network graphic images of MCS profiles processed through trace noise reduction and stack for survey 2016-018-FA (4 PNG images). (Source: U.S. Geological Survey)
    2016-018-FA_MCS_StackSegyData.zip
    Binary SEG-Y format files of MCS profiles processed through trace noise reduction and stack for survey 2016-018-FA (4 SEG-Y files). (Source: U.S. Geological Survey)
    2016-018-FA_Line-*.sht-raw_geom.sgy.zip
    Binary SEG-Y format files of MCS profiles processed through application of trace header geometry for survey 2016-018-FA (4 SEG-Y files). (Source: U.S. Geological Survey)
    Entity_and_Attribute_Overview:
    The PNG seismic reflection images can be hyperlinked to their corresponding trackline or CMP locations in a GIS using the shapefiles '2016-018-FA_MCS_cmpTracklines.shp' or '2016-018-FA_MCS_cmp500.shp', respectively. The images illustrate distance along the profile on the x-axis (annotation at 500 shot intervals) and two-way travel time (seconds) on the y-axis. The CMP point features (including first, last, and multiples of 500) in '2016-018-FA_MCS_cmp500.shp' correspond to the x-axis tick marks. Two binary SEG-Y files (Norris and Faichney, 2002) are provided for each survey line, one containing pre-stack shot gathers and the other CMP traces processed through stack. A SEG-Y file consists of 1) a 3200-byte textural file header containing general information (see examples following processing steps); 2) a 400-byte binary record with information such as sample rate and record length specific to the data set; and 3) multiple records, with one (stack) or more (shot gathers) seismic reflection traces per record. Each trace record is preceded by a 240-byte "trace header" containing information such as trace number and acquisition day and time specific to each trace. The trace data are represented as a time series of unitless 32-bit real numbers proportional to the pressure recorded at each hydrophone. The SEG-Y file is useful only if you have access to specialized software designed to process and display seismic reflection data.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Wayne E. Baldwin
    • Nathaniel C. Miller
  2. Who also contributed to the data set?
    The authors acknowledge our fellow participants of the multichannel seismic acquisition portion of field activity 2016-018-FA (AR5) Emile Bergeron, Tommy O'Brien, and Charles Worley of the U.S. Geological Survey and the crew of the R/V Neil Armstrong.
  3. To whom should users address questions about the data?
    Wayne Baldwin
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    US

    508-548-8700 x2226 (voice)
    508-457-2310 (FAX)
    wbaldwin@usgs.gov

Why was the data set created?

This dataset contains shot coordinate navigation, common mid-point (CMP) coordinate and trackline navigation, profile images, and processed stack and raw SEG-Y trace data for approximately 212 km of multichannel seismic-reflection data collected by the U.S. Geological Survey during USGS field activity 2016-018-FA along the New England outer continental shelf, slope, and rise south of Martha's Vineyard and Nantucket, Massachusetts. Images of each seismic profile were generated in order to provide portable and easily viewable alternatives to the SEG-Y versions of the data. Each profile image can be hyperlinked to its corresponding trackline navigation contained within the Esri polyline shapefile '2016-008-FA_MCS_cmpTracklines.shp'. CMP tick marks along the top of the PNG images correlate to the positions of 500 CMP intervals within the Esri point shapefile '2016-018-FA_MCS_cmp500.shp'. This information allows for spatial correlation of MCS seismic-reflection profiles images with other geophysical data for investigating sea-floor morphology and stratigraphy in the area.

How was the data set created?

  1. From what previous works were the data drawn?
    MCS data (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, Raw MCS data.

    Type_of_Source_Media: disc
    Source_Contribution:
    Multichannel seismic-reflection data were shot using an Applied Acoustics Delta sparker powered by an Applied Acoustics CSP-D 2400 power supply that was set to a total power output of 2400 Joules. The Delta sparker has six sparker tips mounted to a surface floated sled that was towed 50.96 m astern of the NRP from the port quarter of the R/V Neil Armstrong. The source was triggered every 6 seconds (~ 11 to 14 m depending on ship speed) using the Geometrics CNT-1 software. Shots were recorded using a Geometrics GeoEel digital streamer composed of nine 50 m liquid filled active sections (a total of 72 channel groups with 6.25-m spacing) connected to a Geometrics Streamer Power Supply Unit (SPSU). The first and last active groups trailed the NRP by 111.2 m and 557.3 m, respectively. Geometrics CNT-1 seismic acquisition software (version 5.64) running on a Windows PC was used to control the multichannel system, digitally log traces in the Geometrics SEG-D format, and record shot NRP GPS navigation coordinates to the SEG-D external headers. Raw records were recorded over trace lengths of 5.5 seconds, with sample intervals of 0.5 milliseconds
  2. How were the data generated, processed, and modified?
    Date: 2023 (process 1 of 3)
    PROCESS STEP 1:
    Shearwater Reveal (version 2021) seismic processing software was used to execute the following processing flows to produce SEG-Y files containing raw shot gathers with header geometry and CMP stack files processed through trace noise reduction.
    (1.) Import SEG-D sequences: SegDRead read raw Geometrics SEG-D shot MCS files, extracted navigation fixes from the external headers, and wrote them to new header words, and converted the source lat/lon positions from seconds of arc to decimal degrees (NRP_LAT, NRP_LON). UTMLatLong projected the geographic navigation to UTM Zone 19N WGS 84 meters (NRP_X, and NRP_Y). Output wrote the trace sequence to Reveal formatted .seis files.
    (2.) Layback geometry assignment: Input read trace files sorted by FFID/CHANNEL. The Python module ShotlineLayback (developed by Nathan Miller of USGS-WHCMSC) defined the source and streamer geometry based on measured horizontal offsets from the navigation reference point (NRP) to the center of the source (COS) and the centers of the first and last 6.25 m spaced channel groups. The following lists the linear offsets from the NRP to COS and index channels (IC) used to define layback geometry. NRP to COS, NRP to IC offset(IC#): for 72 channel streamer -50.962(0),-111.2(1)/-557.3(72). The module interpolated a sail line from the shot NRP positions (NRP_X and NRP_Y), then computed layback positions for the source and channel groups (values were interpolated for all channels in between the defined index channels) for each FFID by translating them back along the sail line by their respective offsets. Layback mid-point positions along the sail line were computed for each shot/receiver pair, CMP bin spacing was set to 6.25 m, the first CMP to 1000, and CMP coordinates (BIN_X and BIN_Y) were computed. HeaderMath computed and populated a new header word for trace offset using OFFSET = ABS(NRP2CHAN) - ABS(NRP2COS). Output wrote the trace sequence with defined geometry (offset and CMP) to new files. DBWrite wrote the layback geometry source positions (in UTM 19N WGS84 meters and geographic decimal degrees), FFID number, year, day number, and UTC times for the shots in each merged line to ASCII CSV files. Output wrote the lines to new seis files as well as SEG-Y Rev. 1 format (32-Bit IEEE floating point). Each output SEG-Y file contains a textural file header similar to the example from 2016-018-FA_Line-01.sgy included below.
    Example shot gather SEG-Y Textural File Header:
    U.S. Geological Survey Coastal and Marine Hazards and Resources Program Field Activity 2016-018-FA - Southern New England Shelf Edge - R/V Neil Armstrong
    Shot gathers with header geometry of 2016-018-FA_Line-01
    Acquisition: Applied Acoustics Delta Sparker source (2.4 kilojoules), 6 second shot interval, 72 channel GeoEel hydrophone streamer (6.25 meter groups), 0.5 millisecond sample interval, 5.5 second record lengths, recorded in SEG-D format.
    Processing: SEG-D import, assign SRC/REC/Midpoint layback geometry relative to NRP navigation, assign CMPs, top mute (above 5 ms, with 60 ms taper), apply Butterworth highpass filter (60 Hz minimum frequency).
    Output: 32-bit IEEE floating point SEG-Y, 5.5 second record length.
    SRC/GRP/CMP coordinate are stored in geographic arcseconds (scaled by 100). Divide by 360000 for decimal degrees. Coordinate scalar in bytes 71-72. SRC-X and SRC-Y in bytes 73-76 AND 77-80. GRP-X and GRP-Y in bytes 81-84 AND 85-88. CMP-X and CMP-Y in bytes 181-184 AND 185-188. CMP number stored in bytes 21-24.
    For additional information on this dataset refer to the associated USGS data release at: https://doi.org/10.5056/P9R3VW5H
    (3.) Trace Noise Reduction: Input read trace files with assigned geometry sorted to FFID/CHANNEL. Detrend removed any mean amplitude trend detected from each trace. A Butterworth bandpass filter (80 - 600 Hz) was applied to the traces. SphericalDivergence scaled traces using an offset dependent correction. A polygonal FKFilter rejected noise energy identified in shot gather f-k spectra. Output wrote preprocessed, noise-reduced traces to new files.
    (4.) Constant velocity CMP stack and SEG-Y output: Input read the geometry corrected and noise-reduced trace files sorted to CMP / OFFSET. NormalMoveout converted traces to zero offset using a constant velocity of 1500 m/s, and Stack produced a single trace per CMP bin. Output wrote the stacked traces to new seis files. HeaderMath converted the geographic coordinates from decimal degrees to seconds of arc multiplied by a scaler of 100, and set the coordinate unit header to 2 accordingly. DBWrite wrote the CMP positions (in UTM 19N WGS84 meters and geographic decimal degrees), CMP number and year to ASCII CSV text files by line. Output wrote the stacked traces to SEG-Y Rev. 1 format (32-Bit IEEE floating point). Each output SEG-Y file contains a textural file header similar to the example from 2016-018-FA_Line-01.sgy included below.
    Example stack SEG-Y Textural File Header:
    U.S. Geological Survey Coastal and Marine Hazards and Resources Program Field Activity 2016-018-FA - Southern New England Shelf Edge - R/V Neil Armstrong
    Preliminary CMP stack of 2016-018-FA_Line-01 through noise reduction processing.
    Acquisition: Applied Acoustics Delta Sparker source (2.4 kilojoules), 6 second shot interval, 72 channel GeoEel hydrophone streamer (6.25 meter groups), 0.5 millisecond sample interval, 5.5 second record lengths, recorded in SEG-D format.
    Processing: SEG-D import, assign SRC/REC/Midpoint layback geometry relative NRP navigation, assign CMPs, apply Butterworth bandpass filter (80-600 Hz), trace edits, SphericalDivergence scaled traces using an offset dependent correction, FK filtering, normal moveout correction (constant 1500 m/s velocity) ,stack.
    Output: 32-bit IEEE floating point SEG-Y, 5.5 second record length.
    CMP coordinates are stored in geographic arcseconds (scaled by 100). Divide by 360000 for decimal degrees. Coordinate scalar in bytes 71-72.
    CMP-X and CMP-Y in bytes 181-184 and 185-188. CMP number stored in bytes 21-24.
    For additional information on this dataset refer to the associated USGS data release at: https://doi.org/10.5056/P9R3VW5H
    These process steps and all subsequent process steps were conducted by Wayne Baldwin. Person who carried out this activity:
    Wayne Baldwin
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    US

    508-548-8700 x2226 (voice)
    508-457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: 2023 (process 2 of 3)
    PROCESS STEP 2:
    NAVIGATION PROCESSING AND FEATURE CLASS GENERATION:
    A python Jupyter notebook utilized the python modules pandas (version 1.5.2), geopandas (version 0.12.1), pyproj (version 3.4.0), numpy (version 1.23.5), shapely (version 1.8.5.post1), and sqlite3 (version 3.40.0) to process the layback source and CMP navigation data for each profile line in the following steps.
    (1.) Layback source csv navigation files were imported to a pandas dataframe. UTM Zone 19 North (WGS84) coordinates were converted to Geographic coordinates (WGS84) using PyProj Transformer and written to new dataframe columns. A subset of the dataframe consisting of values for easting and northing, latitude and longitude, profile line name, shot, UTC date/time, as well as new fields populated for profile image name, survey ID, vehicle ID, and device ID was generated. Geopandas and shapely were used to create a point geometry column from the geographic coordinates. SQL queries were used to load the layback source navigation dataframe into a table in a geospatial SQLite database using the pyspatialite interface.
    (2.) CMP bin csv navigation files were also imported to a pandas dataframe. UTM Zone 19 North (WGS84) coordinates were converted to Geographic coordinates (WGS84) using PyProj Transformer and written to new dataframe columns. A subset of the dataframe consisting of values for easting and northing, latitude and longitude, profile line name, CMP, UTC date/time, as well as new fields populated for profile image name, survey ID, vehicle ID, and device ID was generated. Geopandas and shapely were used to create a point geometry column from the geographic coordinates. SQL queries were used to load the shot navigation dataframe into three separate tables in the geospatial SQLite database using the pyspatialite interface. The first containing all CMP navigation, the second maintaining the first and last shots and even 500 shot intervals (which correspond to the annotation interval provided along the top of the seismic-reflection profile images), and the third containing trackline features created from the navigation point geometries.
    (2.) The 500 CMP and CMP trackline tables were imported into QGIS (version 3.28.2) from the SQLite database, then exported (Right click on database feature class > Data > Save Features As) to the new Esri point and polyline shapefiles '2016-018-FA_MCS_cmp500.shp' and '2016-018-FA_MCS_Tracklines.shp', respectively. The tables containing all csv and layback source navigation were also imported into QGIS, then exported as the csv files '2016-018-FA_MCS_cmpnav.csv' and '2016-018-FA_MCS_shtnav.csv', respectively.
    Date: 2023 (process 3 of 3)
    PROCESS STEP 4:
    PROFILE BROWSE IMAGE PRODUCTION
    The Seismic Unix (version 4.4) script 'plot_geomet' was used to read the stacked SEG-Y files and create variable density greyscale Postscript plots (using the Seismic Unix 'psimage' module) showing two-way travel time (seconds) along the y-axis (left margin) and CMP along profile (labeled at 500 CMP intervals) on the x-axis (along top of profile). The Postscript images were then converted to 150 dpi PNG formatted images using ImageMagick convert (version 6.9.11-60). The output PNG files were named according to filename convention.
  3. What similar or related data should the user be aware of?
    Norris, M.W., and Faichney, A.K., 2002, SEG-Y rev. 1 Data Exchange Format - SEG Technical Standards Committee: Society of Exploration Geophysicists, Tulsa, OK.

    Online Links:

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?
    Multichannel seismic-reflection shots were primarily navigated using the R/V Neil Armstrong primary CNAV DGPS antenna as the navigational reference point (NRP). The NRP was 35.96 meters forward of the stern. The Delta sparker source was towed from the port quarter 50.96 m astern of the NRP, and the GeoEel streamer (452 m active section) was towed with the center of the first (channel 1) and last (channel 72) active groups trailing the NRP by 111.2 m and 557.3 m, respectively. The Geometrics CNT-1 seismic acquisition software (version 5.64) logged the shot navigation coordinates to the SEG-D external header. Processing descriptions provided below outline the procedures for calculating layback distances between the NRP, acoustic source, and receivers and the Common Midpoint (CMP) binning process. Although horizontal accuracy of WAAS enabled DGPS is estimated to be within 2-3 m, we assume the accuracy of the shot positions to be +/- 10 m due to layback offset between the NRP and far offsets of the receivers (there was no tail buoy with GPS) and movement of the source astern of the ship. Accuracy of CMP bin location is assumed to be coarser due to the additional uncertainty added from calculation of source/receiver layback and common mid-point positions.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    The shot navigation file '2016-018-FA_MCS_shotnav.csv' contains navigation coordinates for all shot records acquired during the survey. Every shot record may not contain active reflection data if the source was not being fired.
  5. How consistent are the relationships among the observations, including topology?
    Quality control was conducted during processing to ensure consistency of stacked CMP SEG-Y data files with corresponding navigation ASCII CSV files, shapefiles and, seismic profile images. CMP numbers and navigation are consistent between corresponding survey lines in '2016-018-FA_MCS_StackSegyData.zip', 2016-018-FA_MCS_Images.zip', 2016-018-FA_MCS_cmp500.shp', '2016-018-FA_MCS_cmpnav.csv', and '2016-018-FA_MCS_cmpTracklines.shp'. The attribute fields 'LineName' and 'ImageName' for each polyline feature in '2016-018-FA_MCS_cmpTracklines.shp' correspond to the SEG-Y data files in '2016-018-FA_MCS_SegyData.zip' and the PNG profile images in '2016-018-FA_MCS_Images.zip', respectively.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints none
Use_Constraints Public domain data from the U.S. Government are freely distributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset.
  1. Who distributes the data set? (Distributor 1 of 1)
    Wayne Baldwin
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2226 (voice)
    508-457-2310 (FAX)
    wbaldwin@usgs.gov
  2. What's the catalog number I need to order this data set? USGS data release of multichannel seismic-reflection data collected using a Delta sparker source and Geometrics GeoEel digital streamer during USGS field activity 2016-018-FA includes: the zip archive '2016-018-FA_MCS_Shapefiles.zip' which includes '2016-018-FA_MCS_cmp500.shp' containing the first, last and 500-interval CMP locations, '2016-018-FA_MCS_cmpTracklines.shp' containing trackline features, and the browse graphic '2016-018-FA_MCS_cmpTracklines_browse.jpg'; the zip archive '2016-018-FA_MCS_cmpnav.csv.zip' containing all CMP locations; the zip archive '2016-018-FA_MCS_shotnav.csv.zip' containing all shot point locations; the zip archives '2016-018-FA_Line-01.sht-raw_geom.sgy.zip', '2016-018-FA_Line-02.sht-raw_geom.sgy.zip', '2016-018-FA_Line-03.sht-raw_geom.sgy.zip', and '2016-018-FA_Line-04.sht-raw_geom.sgy.zip' containing pre-stack shot gather traces in 4 binary SEG-Y files ('*.sgy'); the zip archive '2016-018-FA_MCS_StackSegyData.zip containing stacked CMP traces in 4 binary SEG-Y files ('*.sgy'); '2016-018-FA_MCS_Images.zip' containing 4 CMP stack profile PNG images; and the Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file 2016-018-FA_MCS_meta.xml.
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), and have been processed successfully on a computer system at the 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. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    To utilize these data, the user must have software capable of reading shapefiles, CSV files, PNG images, and/or SEG-Y seismic trace files.

Who wrote the metadata?

Dates:
Last modified: 21-Jul-2023
Metadata author:
U.S. Geological Survey
Attn: Wayne Baldwin
Geologist
384 Woods Hole Rd.
Woods Hole, MA

(508) 548-8700 x2226 (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 person is no longer with the USGS.
Metadata standard:
Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/DRB_data_release/DRB_P9R3VW5H/2016-018-FA_MCS_meta.faq.html>
Generated by mp version 2.9.51 on Wed Jul 26 11:09:59 2023