Multichannel Seismic-Reflection and Navigation Data Collected Using Sercel GI Guns and Geometrics GeoEel Digital Streamers During the Mid-Atlantic Resource Imaging Experiment (MATRIX), USGS Field Activity 2018-002-FA

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Frequently anticipated questions:

What does this data set describe?

Title:
Multichannel Seismic-Reflection and Navigation Data Collected Using Sercel GI Guns and Geometrics GeoEel Digital Streamers During the Mid-Atlantic Resource Imaging Experiment (MATRIX), USGS Field Activity 2018-002-FA
Abstract:
In summer 2018, the U.S. Geological Survey partnered with the U.S Department of Energy and the Bureau of Ocean Energy Management to conduct the Mid-Atlantic Resources Imaging Experiment (MATRIX) as part of the U.S. Geological Survey Gas Hydrates Project. The field program objectives were to acquire high-resolution 2-dimensional multichannel seismic-reflection and split-beam echosounder data along the U.S Atlantic margin between North Carolina and New Jersey to determine the distribution of methane gas hydrates in below-sea floor sediments and investigate potential connections between gas hydrate dynamics and sea floor methane seepage. MATRIX field work was carried out between August 8 and August 28, 2018 on the research vessel Hugh R. Sharp and resulted in acquisition of more than 2,000 track-line kilometers of multichannel seismic-reflection and colocated split-beam echosounder data, along with wide-angle seismic reflection and refraction data from 63 expendable sonobuoy deployments.
Supplemental_Information:
This research was supported by USGS Coastal and Marine Hazards and Resources Program, USGS-DOE interagency agreement DE-FE0023495, and USGS-BOEM interagency agreement M17PG00041. Additional information on the field activity is available from https://www.usgs.gov/centers/whcmsc/science/mid-atlantic-resource-imaging-experiment-matrix?qt-science_center_objects=0#qt-science_center_objects and https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-002-FA.
  1. How might this data set be cited?
    Baldwin, Wayne, Foster, David, Bergeron, Emile, Ferro, Peter Dal, McKee, Jennifer, Moore, Eric, Nichols, Alex, O'Brien, Thomas, Powers, Dan, Miller, Nathaniel, and Ruppel, Carolyn, 20200831, Multichannel Seismic-Reflection and Navigation Data Collected Using Sercel GI Guns and Geometrics GeoEel Digital Streamers During the Mid-Atlantic Resource Imaging Experiment (MATRIX), USGS Field Activity 2018-002-FA: data release DOI:10.5066/P91WP1RZ, 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., Foster, D.S., Bergeron, E.M., Dal Ferro, P., McKee, J.A., Moore, E.M., Nichols, A.R., O'Brien, T.F., Powers, D., Miller, N.C., and Ruppel, C.D., 2020, Multichannel seismic-reflection and navigation data collected using Sercel GI guns and Geometrics GeoEel digital streamers during the Mid-Atlantic Resource Imaging Experiment (MATRIX), USGS field activity 2018-002-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P91WP1RZ
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -74.827038
    East_Bounding_Coordinate: -70.913255
    North_Bounding_Coordinate: 39.025519
    South_Bounding_Coordinate: 34.848566
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/5f0e234e82ce21d4c4053f45/?name=2018-002-FA_MCSBrowseImage.jpg (JPEG)
    Multichannel seismic reflection browse image.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 10-Aug-2018
    Ending_Date: 28-Aug-2018
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: digital data
  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?
    2018-002-FA_MCS_cmpTracklines.shp
    MCS CMP Trackline shapefile for survey 2018-002-FA (19 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: FieldActivity#-FileNumber (i.e.'2018-002-FA_MX01'). (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:1
    Maximum:1462
    Units:CMP
    Resolution:1
    CMP_end
    CMP number at the end of the survey line. (Source: U.S. Geological Survey)
    Range of values
    Minimum:7501
    Maximum:77547
    Units:CMP
    Resolution:1
    Year
    Calendar year the data were collected (Source: U.S. Geological Survey) Character set
    SurveyID
    WHCMSC field activity identifier (e.g. "2018-002-FA" where 2018 is the survey year, 002 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 seismic-reflection data line in kilometers (UTM Zone 18N, WGS 84) calculated in the SQLite database. (Source: U.S. Geological Survey)
    Range of values
    Minimum:23.40
    Maximum:242.37
    Units:kilometers
    Resolution:0.01
    2018-002-FA_MCS_cmp200.shp
    MCS 200-interval CMP point shapefile for survey 2018-002-FA (3337 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 18 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:515638.55
    Maximum:860651.49
    Units:meters
    Resolution:.01
    North
    Northing coordinate in UTM Zone 18 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:3856535.15
    Maximum:4321254.56
    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:-74.826615
    Maximum:-70.913255
    Units:degrees
    Resolution:1E-06
    Lat
    Latitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:34.849127
    Maximum:39.018539
    Units:degrees
    Resolution:1E-06
    LineName
    Name of the trackline along which seismic-reflection data were collected in the format: FieldActivity#-FileNumber (i.e.'2018-002-FA_MX01'). (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:1
    Maximum:77547
    Units:CMP
    Resolution:1
    Year
    Year the data were collected YYYY. (Source: U.S. Geological Survey) Character set
    SurveyID
    WHCMSC field activity identifier (e.g. "2018-002-FA" where 2018 is the survey year, 002 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
    2018-002-FA_MCS_cmpnav.csv
    MCS CMP comma separated values file for survey 2018-002-FA (661359 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 18 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:515633.54
    Maximum:860651.49
    Units:meters
    Resolution:.01
    North
    Northing coordinate in UTM Zone 18 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:3856535.15
    Maximum:4321254.56
    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:-74.826669
    Maximum:-70.913255
    Units:degrees
    Resolution:1E-06
    Lat
    Latitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:34.849127
    Maximum:39.018539
    Units:degrees
    Resolution:1E-06
    LineName
    Name of the trackline along which seismic-reflection data were collected in the format: FieldActivity#-FileNumber (i.e.'2018-002-FA_MX01'). (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:1
    Maximum:77547
    Units:CMP
    Resolution:1
    Year
    Year the data were collected YYYY. (Source: U.S. Geological Survey) Character set
    SurveyID
    WHCMSC field activity identifier (e.g. "2018-002-FA" where 2018 is the survey year, 002 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
    2018-002-FA_MCS_shtnav.csv
    MCS shot point comma separated values file for survey 2018-002-FA (68669 point features). (Source: U.S. Geological Survey)
    East
    Easting coordinate in UTM Zone 18 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:515600.42
    Maximum:860135.27
    Units:meters
    Resolution:.01
    North
    Northing coordinate in UTM Zone 18 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:3856472.78
    Maximum:4322015.33
    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:-74.827038
    Maximum:-70.919027
    Units:degrees
    Resolution:1E-06
    Lat
    Latitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:34.848566
    Maximum:39.025519
    Units:degrees
    Resolution:1E-06
    LineName
    Name of the trackline along which seismic-reflection data were collected in the format: FieldActivity#-FileNumber (i.e.'2018-002-FA_MX01'). (Source: U.S. Geological Survey) Character set
    FFID
    Shot number. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1
    Maximum:10997
    Units:shot
    Resolution:1
    Year
    Year the data were collected YYYY. (Source: U.S. Geological Survey) Character set
    JD_UTC
    Julian day and UTC time for of the navigation fix in the format: 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. "2018-002-FA" where 2018 is the survey year, 002 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
    2018-002-FA_MCS_Images
    Portable network graphic images of MCS profiles processed through post-stack migration for survey 2018-002-FA (19 PNG images). (Source: U.S. Geological Survey)
    2018-002-FA_MCS_PSTM_SegyData
    Binary SEG-Y format files of MCS profiles processed through post-stack migration for survey 2018-002-FA (19 SEG-Y files). (Source: U.S. Geological Survey)
    2018-002-FA_MCS_ShotSegyData
    Binary SEG-Y format files of MCS shots with header geometry and navigation for survey 2018-002-FA (19 SEG-Y files). (Source: U.S. Geological Survey)
    2018-002-FA_StreamerConfig_InfoLogs.pdf
    PDF format document contaning streamer configuration diagrams and observer logs (12 pdf pages). (Source: U.S. Geological Survey)
    Entity_and_Attribute_Overview:
    The PNG seismic reflection images can be hyperlinked to their corresponding trackline or shotpoint locations in ArcGIS using the shapefiles '2018-002-FA_MCS_cmpTracklines.shp' or '2018-002-FA_MCS_cmp200.shp', respectively. The images illustrate distance along the profile on the x-axis (annotation at 1000 shot intervals) and two-way travel time (seconds) on the y-axis. The first, last, and multiple of 200 CMP features in '2018-002-FA_MCS_sht200.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 with header geometry and navigation, and the other containing CMP traces processed through post-stack migration. 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, one seismic reflection trace 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 16-bit integer or 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.
    '2018-002-FA_StreamerConfig_InfoLogs.pdf' contains four images illustrating streamer configurations used during the survey, a 3-page spreadsheet compiling information for each survey line (ie., streamer configuration, active section length, number of channels, shot spacing, recorded and processed sample intervals, raw and processed record lengths and delays, and environmental notes made by observers), and a 5-page log that documents changes in the number of guns firing in the source array over the course of the survey (columns note the date in the format MMDDYY, Julian Day, UTC time, number of active guns, and observer notes).
    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 Baldwin
    • David Foster
    • Emile Bergeron
    • Peter Dal Ferro
    • Jennifer McKee
    • Eric Moore
    • Alex Nichols
    • Thomas O'Brien
    • Dan Powers
    • Nathaniel Miller
    • Carolyn Ruppel
  2. Who also contributed to the data set?
    Colby Pedrie and E. Lee Ellett of Scripps Institution of Oceanography provided access to critical seismic equipment and expertise. Jess Stark and and Ray Hatton of Stark Industries assisted with compressor logistics. Timothy Elfers and Patrick Hart of the USGS - Pacific Coastal and Marine Science Center contributed to project scoping, compressor contracting, and machining. The marine office of the University of Delaware, along with the crew of the R/V Hugh R. Sharp, accommodated numerous requests and changes to ensure the success of the program. Protected species visual observers were provided by RPS, Inc.
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Wayne E. Baldwin
    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 and common midpoint (CMP) navigation, processed post-stack profile images, pre-stack and processed post-stack SEG-Y trace data, streamer configuration diagrams, and information logs for 2072 trackline kilometers of multichannel seismic-reflection data collected by the U.S. Geological Survey during the Mid-Atlantic Resource Imaging Experiment (MATRIX; field activity 2018-002-FA). The data were acquired along portions of the U.S. Atlantic margin between North Carolina and New Jersey to support mapping of sedimentary and structural features of the sea floor and subsurface and evaluation of geologic hazards and the distribution of methane gas hydrates in below-seafloor sediments.

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 up to four Sercel 105/105 cubic inch generator-injector (GI) airguns powered by four portable Stark Industries diesel compressors. The sources were configured in two strings of two guns that were towed 47.8 m astern of the NRP off the port and starboard quarters of the R/V Hugh R. Sharp. The sources were typically triggered on distance (25 - 35 m intervals) using the USGS developed RasperryPi and Python based TriggerPi controller, but also occasionally on time (equating to similar shot distances) using the Geometric CNT-1 software. Shots were recorded using a Geometrics GeoEel digital streamer composed of both solid state and oil-filled active sections of 50 and 100 m lengths (6.25 or 12.5 m groups, respectively) connected to a Geometrics Streamer Power Supply Unit (SPSU). Four configurations were utilized, resulting in active sections between 700 and 1200 m long and 112 to 160 channels (See '2018-002-FA_StreamerConfig_InfoLogs.pdf' for diagrams of the configurations, and processing step 1.3 for a table of streamer geometry by line). Depending on the configuration, the first and last active groups trailed the NRP between 174.6 and 176.6 m and 874.38 and 1373.12 m respectively. Vibration and isolation sections totaling 100 m and 25 - 50 m were positioned before and after the active sections to reduce the impacts of ship and tailbuoy tug, respectively. A Geospace Technologies streamer depth control system with up to six navigator birds spaced along the streamer length were used for depth control and up to six RBR Ltd. RBRsolo D depth loggers were also spaced along steamer to record depth data. Geometrics CNT-1 seismic acquisition software (version 5.361) 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 between 4 and 10 seconds, with sample intervals of 0.5 or 1 milliseconds. The airgun strings were controlled and synchronized by two Teledyne Marine Hotshot units.
  2. How were the data generated, processed, and modified?
    Date: Jun-2020 (process 1 of 6)
    PROCESS STEP 1:
    Shearwater Reveal (version 4.1) seismic processing software was used to execute the following processing flows to produce the raw shot SEG-Y files.
    1. Import SEG-D sequences: SegDRead read raw Geometrics SEG-D shot sequence files, extracted navigation fixes from the external headers, and wrote them to new header words. HeaderMath wrote a delay time header word when necessary (2 seconds for sequence B01A of MX01 and A01A of MX12), a raw trace length header word, 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 18N WGS 84 meters (NRP_X, and NRP_Y). Output wrote the trace sequence to Reveal formatted ".seis" files.
    2. Resample: RES resampled traces in the first two sequences of MX01 from 0.5 to 1 ms.
    3. Layback geometry assignment: Input read sequence 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 NRP to the center of the sources (cos) and the centers of the first and last 6.25 m spaced channel groups, and when necessary, the first and last 12.5 m spaced channel groups on the active streamer section. The following table lists the linear offsets from the NRP to center of source (COS) and index channels (IC) used to define layback geometry by line.
    NRP to COS offset,NRP to IC offset(IC#) - Linelist -47.8,-174.6(1)/-922.69(120)/-932.38(121)/-1320.81(152) - Line MX01 -47.8,-176.6(1)/-924.69(120)/-934.38(121)/-1322.81(152) - Lines MX02 and MX03 -47.8,-176.6(1)/-874.38(112) - Lines MX04 - MX10 -47.8,-176.6(1)/-975(128)/-984.69(129)/-1373.12(160) - Lines MX11 - MX17 -47.8,-176.6(1)/-975(128)/-984.69(129)/-1272.56(152) - Lines MX18 and MX19
    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 midpoint positions along the sail line were also computed for each shot/receiver pair. 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 to new files.
    4. Merge sequence files, remove delay, and set trace length: These processes were only necessary for a subset of the lines. Lines MX01, MX02, MX03, and MX12 were each compiled from multiple sequences that were acquired with variable trace lengths and delays. DissimilarInput allowed the sequences to be merged by line despite the differences, then TraceLength set a common trace length encompassing all inputs and ApplyStatic shifted traces with deep water delays to the appropriate origin times (a recording delay of 2 s was used for one sequence in lines MX01 and MX12). DBWrite wrote the layback geometry source positions (in UTM 18N 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 merged lines to new files.
    5. Define CMP bins: Survey lines were created in the Reveal project grid using a subset of NRP northing and easting coordinates to define crooked line binning geometries. Rectangular bins were defined along the survey tracks with along-track lengths of 3.125 m and crossline widths of 1000 m (centered on the survey track). Because lead in bins were included prior to shot locations for some lines, several stacked lines start with CMP numbers greater than one.
    6. Geometry modification for tailbuoy navigation: Tailbuoy GPS navigation acquired during lines MX01 to MX07 and MX11 to MX19 were used to adjust the streamer geometry to incorporate trigonometrically estimated streamer feather into the CMP binning process. Input read the layback geometry files. Text files containing tailbuoy positions and UTC times extracted from HYPACK raw files were used as inputs for DBmerge, which matched times in the trace headers to times in the tailbuoy navigation file (through interpolation) and inserted tailbuoy positions into the trace headers (TB_LON and TB_LAT). UTMLatLong projected the geographic tailbuoy positions to WGS84 UTM Zone 18N meters (TB_X and TB_Y). HeaderMath estimated the streamer feather azimuth relative to the NRP using CABLE_AZ_RAD = atan2(NRP_Y - TB_Y, NRP_X - TB_X), then calculated new layback and feather adjusted source and receiver positions using SRC_X = NRP_X + NRP2COS * cos(CABLE_AZ_RAD), SRC_Y = NRP_Y + NRP2COS * sin(CABLE_AZ_RAD), REC_X = NRP_X + NRP2CHAN * cos(CABLE_AZ_RAD), REC_Y = NRP_Y + NRP2CHAN * sin(CABLE_AZ_RAD). DBWrite wrote the feather adjusted source positions (in UTM 18N WGS84 meters and geographic decimal degrees), FFID number, year, day number, and UTC times for the shots in each line to ASCII CSV files. Output wrote the lines with streamer feather adjusted geometry to new files.
    7. Assign Common Midpoints: Input read files with (MX01 - MX07 and MX11 - MX19) or without (MX08 - MX10) streamer feather adjusted geometry. HeaderSetup computed new source/receiver pair midpoint positions for lines with streamer feather adjusted geometry, and also assigned traces to CMP bins and computed CMP bin positions (BIN_X and BIN_Y) for all lines using the project grid binning geometries defined in step 5. Output wrote the lines with assigned CMPs to new files.
    8. Assign static corrections: FFID's 1306 - 3311 of line MX03 required a static shift of -102 milliseconds (ms) due to unintentional application of a delay time while temporarily triggering on distance through the Geometrics controller. Additionally, readings from RBRSolo-D pressure depth recorders spaced along the streamer were inserted into the trace headers for all lines. Input read the geometry corrected trace files. Text files prepared to contain UTC time, offset location of the pressure depth probe along the streamer, and pressure depth values in meters were used as inputs for DBMerge, which matched times and trace offsets in the trace headers with those in the input text files (through interpolation) and populated a new receiver depth header word with pressure depth values for each channel of the active section. HeaderMath also populated a new header word containing a constant source depth value of 3 m (dictated by the rigging of the airgun strings), then converted both static values from meters to milliseconds (dividing by an assumed water column sound speed velocity of 1.514 m/ms) and wrote them to new header words. The source/receiver static values have not been applied to the traces. For line MX03, HeaderMath inserted the -102 ms value into the appropriate trace headers and ApplyStatic shifted the traces to match the remainder of the file. Output wrote the traces including static corrections to new files.
    9. SEG-Y output: Input read the files including static corrections. ButterworthPy applied a highpass butterworth filter (> 20 Hz with 4 corners). Mute applied top and bottom mutes at 60 ms beyond the trace start time (10 ms taper) and 20 ms less that the trace end time (30 ms taper), respectively. UTMLatLong projected source, receiver, and CMP bin positions from UTM Zone 18N WGS 84 meters to geographic and wrote them to new header words. HeaderMath converted the geographic coordinates from decimal degrees to seconds of arc multiplied by 100 and set the coordinate unit header to 2 accordingly, also scaled the source, receiver, and applied static header values (in meters) by 100, and finally set the time basis code to 2 for UTC. Output wrote the raw shot traces with defined geometry and static corrections to SEG-Y Rev. 1 format (32-Bit IBM floating point). Each output SEG-Y file contains a textural file header similar to the example from line MX01 included below.
    Though Wayne Baldwin is listed as the primary contact, shipboard and post-cruise processing were also conducted by Nathan Miller and David Foster.
    Example raw shot file SEG-Y Textural Header:
    C 1 U. S. GEOLOGICAL SURVEY COASTAL AND MARINE HAZARDS AND RESOURCES PROGRAM
    C 2 SURVEY_ID: 2018-002-FA AREA: US ATLANTIC MARGIN VESSEL: R/V HUGH R. SHARP
    C 3 YEAR: 2018 LINENAME: MX01
    C 4
    C 5 ACQUISITION: UP TO 4 x 105 CU IN AIR GUNS, 30 METER SHOT INTERVAL,
    C 6 1.156-KM, 152 CHANNEL GEOEEL HYDROPHONE STREAMER (6.25 AND 12.5 M GROUPS),
    C 7 0.5 OR 1 MS RECORDING SAMPLE INTERVAL, 6 OR 10 SEC RECORD LENGTHS,
    C 8 RECORDING DELAY OF 2 SEC FOR FFIDS 1583-2090 (PROBLEM WITH 1583-1586),
    C 9 RECORDED IN SEG-D FORMAT. SOURCE CHANGES THROUGHOUT WHILE TROUBLESHOOTING.
    C10
    C11 PROCESSING: IMPORT SEG-D SEQUENCE FILES, RESAMPLE TO 1.0 MS, DEFINE CROOKED
    C12 LINE CMP BINS (1-KM WIDE AND SPACED 3.125-M) USING NRP NAVIGATION, MERGE
    C13 SEQUENCE FILES, REMOVE DELAY AND SET TRACE LENGTH, ASSIGN SRC/REC/MIDPOINT
    C14 GEOMETRY USING TAIL BUOY GPS NAVIGATION, ASSIGN CMPS, ASSIGN SRC/REC STATIC
    C15 CORRECTIONS, BUTTERWORTH FREQUENCY DOMAIN HIGHPASS FILTER (> 20 HZ), TOP
    C16 MUTE (TRACE START + 60 MS, 10 MS TAPER), BOTTOM MUTE (TRACE END - 20 MS,
    C17 30 MS TAPER).
    C18
    C19 OUTPUT: 32-BIT IBM FLOATING POINT SEG-Y
    C20 RECORD LENGTH: 5.9 SEC (DATA LENGTH 3.9 SEC FOR FFIDS 1583-2090)
    C21
    C22 SRC/GRP/CDP COORDINATES ARE STORED IN GEOGRAPHIC ARCSECONDS (SCALED BY 100)
    C23 DIVIDE BY 360000 FOR DECIMAL DEGREES.
    C24 COORDINATE SCALAR IN BYTES 71-72
    C25 SRC-X AND SRC-Y IN BYTES 73-76 AND 77-80
    C26 GRP-X AND GRP-Y IN BYTES 81-84 AND 85-88
    C27 CDP-X AND CDP-Y IN BYTES 181-184 AND 185-188
    C28 CDP NUMBER STORED IN BYTES 21-24
    C29
    C30 SRC STATIC CONSTANT FROM RIGGING, GRP STATICS MEASURED BY 6 PRESSURE DEPTH
    C31 LOGGERS EVENLY SPACED ALONG STREAMER WITH VALUES INTERPOLATED LINEARLY
    C32 TO ALL CHANNELS.
    C33 SRC AND GRP STATIC CORRECTIONS (SCALED BY 100 AND NOT APPLIED)
    C34 SRC-STATIC IN BYTES 99-100
    C35 GRP-STATIC IN BYTES 101-102
    C36
    C37 FOR ADDITIONAL INFORMATION CONCERNING THIS DATASET REFER TO THE ASSOCIATED
    C38 USGS SCIENCEBASE DATA RELEASE ONLINE AT:
    C39 HTTPS://DOI.ORG/10.5066/P91WP1RZ
    C40 Person who carried out this activity:
    U.S. Geological Survey
    Attn: Wayne E. Baldwin
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700 x2226 (voice)
    (508) 457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: Jun-2020 (process 2 of 6)
    PROCESS STEP 2:
    Shearwater Reveal (version 4.1) seismic processing software was used to execute the following processing flows to produce SEG-Y files of profiles processed through post-stack time migration.
    1. Trace preprocessing and noise reduction: Import read files with geometry and static corrections. HeaderMath converted the cumulative source/receiver statics in meters to milliseconds by SRC_REC_STAT = (SRC_DEPTH + REC_DEPTH)/1.514 (assumed water column sound speed velocity in m/ms) and wrote them to new header words, and ApplyStatic shifted traces by the computed times. Despike estimated local median values within 600 ms windows then used the median values to replace samples that exceeded them by 10 times. SphericalDivergence scaled traces using an offset dependent correction. TraceLength set new trace start times and lengths for profiles in which the entire raw trace length was not used for processing (lines MX01, MX11 - MX19). FXSwell and FXDecon targeted low frequency noise (below 30 Hz) and random noise, respectively, using FX filtering. A polygonal FKFilter rejected noise energy identified in shot gather f-k spectra. Output wrote preprocessed, noise-reduced traces to new files.
    2. Constant velocity stack, sea floor picking, and 1D velocity model creation: To produce a quality control stack, Input read the preprocessed, noise-reduced traces, Bandpass filtered the data to 20-450 Hz, NormalMoveout converted traces to zero offset assuming a constant 1514 m/s sound speed through water, Stack produced a single trace per CMP bin, and Output wrote the stacked traces to new files. Sea floor reflection times were predicted for each line and saved to new database files. 1D velocity models hung from the sea floor reflection were created using subsurface velocity gradient information for this portion of the U.S. Atlantic margin derived from semblance analysis of 2D seismic data shot during R/V Marcus Langseth cruise MGL1407 (Arsenault and others, 2017). Input read the quality control stack traces, VelocityLayer created four subsurface layers of variable velocity gradient per trace initiated at set subsurface two-way travel times (0 ms and 0.12755 1/ms, 196 ms and 0.07462687 1/ms, 230 ms and 0.2089 1/ms, and 320 ms and 0.347222 1/ms) that combined to equal the input trace length, ApplyStatic shifted the velocity gradient traces by the predicted sea floor time, TraceMath calculated the velocities by trace sample using sample = sample (increasing by gradients) + 1514 (resulting in a water column sound speed velocity of 1514 m/s that then increased by the defined gradients extending into the subsurface), and Trace2Table wrote the 1D velocity models to new database tables for use in subsequent NormalMoveout and PostStackMigration operations.
    3. Source wavelet extraction: Input read the preprocessed, noise-reduced files. In preparation for source wavelet extraction, Deghost2D was used to estimate and attenuate source and receiver side ghost reflections from the input traces. ExtractWavelet extracted a minimum-phase wavelet from the input traces, and Output wrote the source wavelet to a new file.
    4. Source wavelet designature: Input read the preprocessed, noise-reduced files. Designature utilized the extracted source wavelet to estimate a zero-phase, whitened and bandpass filtered (20-30-400-450 Hz) inverse filter that was used to designature the input traces. Deghost2D was used to estimate and attenuate source and receiver side ghost reflections. Output wrote the designatured and deghosted traces to new files.
    5. 2D velocity model from semblance and surface related multiple extraction (SRME): These processes were limited to near-shelf, along-strike profiles (lines MX06, MX10, MX11, and MX19) where topographic variability associated with shelf-edge canyon traverses made the approach of hanging a layered 1D velocity model from the sea floor less appropriate, and shallow-section multiple energy particularly distracted from primary stratigraphy.
    A. 2D velocities were picked using an interactive Reveal semblance picking flow. Input read the designatured and deghosted files. Velocities were picked from Semblance generated on CMP gathers and evaluated by their effects on in line NormalMoveout and VelocityStack results. Picks were made from approximately 500 CMP intervals or less in sections where sea floor topography changed significantly. Picks shallower than the sea floor were set to a water column sound speed of 1514 m/s. Final picks were saved to Reveal database tables by line.
    B. In preparation for SRME, Input read the designatured and deghosted trace files limited to the 6.25 m group spaced portions of the active section (ie. the first 112 or 128 channels), SRMEPrepOffsets inserted place-holder traces for missing or dead traces in the shot domain, SphericalDivergence removed the previously applied offset dependent correction, SRMENearExtrap filled near offset traces using tau-p in the CMP domain, Mute applied a top mute to all traces just prior to the sea floor time, SRMEShotInterp interpolated shots in order to fill any missing shots and produce as consistent shot/receiver spacing as possible, SRMEPredict created traces containing predictions of multiple energy for each input shot record, and Output wrote the results to new multiple prediction files. SRME multiple reduction involved a multiport process in which Input read the designatured and deghosted and predicted multiple files in two parallel branches, static application and top mutes were applied to the designatured and deghosted traces the same as during preparation, SRMESubtract performed shot by shot comparison of the designatured and deghosted and predicted multiple traces to produce refined filtered multiple operators that were passed along to a second SRMESubtract process which subtracted the refined predicted multiple energy from the designatured and deghosted data. Finally, the offset dependant SphericalDivergence correction was reapplied and Output wrote the designatured, deghosted, and multiple-reduced data to new files.
    6. Processed stack: Input read either the designatured and deghosted or designatured, deghosted, and multiple-reduced files sorted to CMP, NormalMoveout converted traces to zero offset using either the 1D or 2D velocity model created for each file, Stack produced a single trace per CMP bin, and Output wrote the stacked traces to new files.
    7. Post-stack time migration: Input read the stacked files, PostStackMigration performed a phase-shift time migration using the 1D or 2D velocity model created for each file (450 Hz maximum frequency and 3.125 m bin spacing), and Output wrote the migrated stacked traces to new files. Subsequent to migration, the predicted sea floor picks were overlaid on the migrated trace display, manually adjusted to more closely approximate the migrated sea floor, and saved to new files.
    8. SEG-Y output: Input read the migrated stacked files. Table2Header wrote the modified sea floor picks to a water bottom time header word. Mute applied a top mute at the water bottom time. UTMLatLong projected the CMP bin positions from UTM Zone 18N WGS 84 meters to geographic and wrote them to new header words. HeaderMath inserted dead traces for empty CMPs and set their trace type to 3 accordingly, 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 18N WGS84 meters and geogpraphic decimal degrees), CMP number, year, and fold header words to ASCII CSV text files by line. Output wrote the migrated, stacked traces to SEG-Y Rev. 1 format (32-Bit IBM floating point). Each output SEG-Y file contains a textural file header similar to the example from line MX01 included below.
    Example migrated stacked file SEG-Y Textural File Header:
    C 1 U.S. GEOLOGICAL SURVEY COASTAL AND MARINE HAZARDS AND RESOURCES PROGRAM
    C 2 SURVEY_ID: 2018-002-FA AREA: US ATLANTIC MARGIN VESSEL: R/V HUGH R. SHARP
    C 3 YEAR: 2018 LINENAME: MX01
    C 4
    C 5 ACQUISITION: UP TO 4 x 105 CU IN AIR GUNS, 30 METER SHOT INTERVAL,
    C 6 1.156-KM, 152 CHANNEL GEOEEL HYDROPHONE STREAMER (6.25 AND 12.5 M GROUPS),
    C 7 0.5 OR 1 MS RECORDING SAMPLE INTERVAL, 6 OR 10 SEC RECORD LENGTHS,
    C 8 RECORDING DELAY OF 2 SEC FOR FFIDS 1583-2090 (PROBLEM WITH 1583-1586),
    C 9 RECORDED IN SEG-D FORMAT. SOURCE CHANGES THROUGHOUT WHILE TROUBLESHOOTING.
    C10
    C11 PROCESSING: IMPORT SEG-D SEQUENCE FILES, RESAMPLE TO 1.0 MS, DEFINE CROOKED
    C12 LINE CMP BINS (1-KM WIDE AND SPACED 3.125-M) USING NRP NAVIGATION, REMOVE
    C13 DELAY (2 S) AND SET TRACE LENGTH (10 S), MERGE SEQUENCE FILES, ASSIGN
    C14 SRC/REC/MIDPOINT GEOMETRY USING TAIL BUOY GPS NAVIGATION, ASSIGN CMPS,
    C15 ASSIGN SRC/REC STATIC CORRECTIONS, BUTTERWORTH HIGHPASS FILTER (> 20 HZ),
    C16 TRACE EDIT, DESPIKE, SPHERICAL DIVERGENCE CORRECTION, SET TRACE START TIME
    C17 (3.5 S) AND LENGTH (2.4 S), NOISE REDUCTION (FX AND FK FILTERING), SRC
    C18 WAVELET EXTRACTION, SRC DESIGNATURE TO ZERO PHASE (20-450 HZ BAND PASS),
    C19 SRC/REC DEGHOST, NMO CORRECTION (1D VELOCITY MODEL), STACK, PHASE SHIFT
    C20 TIME MIGRATION, TOP MUTE (WATER BOTTOM TIME - 10 MS), BOTTOM MUTE (TRACE
    C21 END, 30 MS TAPER). INSERT DEAD TRACES FOR EMPTY CMPS (3-7 and 12511-12598).
    C22
    C23
    C24 OUTPUT: 32-BIT IBM FLOATING POINT SEG-Y
    C25 RECORD LENGTH: 2.4 SEC
    C26 DELAY RECORDING TIME (3.5 S) IN BYTES 109-110
    C27
    C28 CDP COORDINATES ARE STORED IN GEOGRAPHIC ARCSECONDS (SCALED BY 100)
    C29 DIVIDE BY 360000 FOR DECIMAL DEGREES.
    C30 COORDINATE SCALAR IN BYTES 71-72
    C31
    C32 CDP-X AND CDP-Y IN BYTES 181-184 AND 185-188
    C33 CDP NUMBER STORED IN BYTES 21-24
    C34 TRACE ID IN BYTES 29-30 SET TO 2 FOR DEAD TRACES
    C35
    C36 FOR ADDITIONAL INFORMATION CONCERNING THIS DATASET REFER TO THE ASSOCIATED
    C37 USGS SCIENCEBASE DATA RELEASE ONLINE AT:
    C38 HTTPS://DOI.ORG/10.5066/P91WP1RZ
    C39
    C40
    Date: Jun-2020 (process 3 of 6)
    PROCESS STEP 3:
    A python script (GEnavtoSQL.py) imported shot and CMP navigation from ASCII CSV files (produced in earlier processing steps) into a SpatiaLite (version 4.3.0) enabled SQLite (version 3.3.0) database, creating three tables containing point geometries. The first contained records for all shots by line, the second contained records of all CMPs by line, and the third maintained records for the first and last CMPs, and CMPs at multiples of 200 by line. A 200-CMP interval was chosen because it corresponds to the annotation and tick interval provided along the top of the migrated, stacked profile images. The resulting database columns for the shot table consists of East, North (WGS84 UTM18N m), Lon, Lat (WGS84 dd), LineName, FFID, Year, JD_UTC (DDD:HH:MM:SS), SurveyID, VehicleID, and DeviceID. The resulting database columns for the CMP tables consist of East, North (WGS84 UTM18N m), Lon, Lat (WGS84 dd), LineName, ImageName, CMP, Year, Fold, SurveyID, VehicleID, and DeviceID. A third table was created to contain trackline geometries generated from the CMP point geometries for each line (sorted by LineName and CMP), and the line length in kilometers was calculated. The resulting database columns of the line geometry table consist of LineName, ImageName, CMP_init, CMP_end, SurveyID, VehicleID, DeviceID, and Length_km.
    Date: Jun-2020 (process 4 of 6)
    PROCESS STEP 4:
    The shot, CMP, and 200 CMP points, and CMP trackline features were added (Add Data) into ArcGIS Pro (version 2.3.3) from the SQLite database, then exported (using the Feature Class to Feature Class geoprocessing tool) to the new Esri point and polyline shapefiles '2018-002-FA_MCS_shtnav.shp', '2018-002-FA_MCS_cmpnav.shp', '2018-002-FA_MCS_cmp200.shp', and '2018-002-FA_MCS_cmpTracklines.shp', respectively. The Export Feature Attribute to ASCII geoprocessing tool was used to produce ASCII CSV files from the attribute tables of '2018-002-FA_MCS_shtnav.shp' and '2018-002-FA_MCS_cmpnav.shp'.
    Date: Jun-2020 (process 5 of 6)
    The Seismic Unix (version 4.3) script 'plot_geomet' was used to read the migrated, 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 shots along profile (labeled at 1000 shot intervals) on the x-axis (along top of profile). The Postscript images were then converted to 300 dpi PNG formatted images using ImageMagick convert (version 6.9.10-78). The output PNF files were named according to filename convention with either '.v1d.pspstm.png' or '.v2d.srme.pspstm.png' appended to note the type of processing conducted.
    Date: 26-Jan-2021 (process 6 of 6)
    Repaired some issues that the ScienceBase turn live process introduced - removed empty element (attribute accuracy report), in the distributions section added the additional links, access instructions, and additional distribution formats that had been deleted. Additionally, a typo in the abstract was fixed. Two distribution links were also updated to reflect the landing pages of the SEG-Y data. 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?
    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:

    Arsenault, Matthew, Miller, Nathaniel, Hutchinson, Deborah, Baldwin, Wayne, Moore, Eric, Foster, David, O'Brien, Thomas, and Fortin, Will, 2017, Geophysical data collected along the Atlantic continental slope and rise 2014, U.S. Geological Survey Field Activity 2014-011-FA, cruise MGL1407: field activity data release DOI:10.5066/F7V69HHS, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    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 navigated using a Wide Area Augmentation System (WAAS) enabled Hemisphere Differential GPS (DGPS) receiver, with the navigational reference point (NRP) antenna mounted on the 01 deck rail, approximately along the vessel centerline and 16.15 m from the stern of the R/V Hugh R. Sharp. The seismic sources were towed 47.8 m astern of the NRP off the port and starboard quarters and the GeoEel streamer (between 700 and 1200 m active section for various configurations) was towed dead astern with the center of the first and last active groups trailing the NRP between 170.83 and 172.83 m and 873.22 and 1373.4 m respectively. The Geometrics CNT-1 seismic acquisition software (version 5.361) logged the shot navigation coordinates to the SEG-D external header. The tailbuoy trailing the streamer was also navigated using an Adafruit Ultimate GPS FeatherWing (WASS/DGPS) with data transmitted to the ship via a Feather M0 RFM95 LoRa Radio and logged using HYPACK (version 2018, 18.1.11.0). Processing descriptions provided below outline the procedures for calculating layback distances between the NRP, acoustic sources, and receivers and the protocol that used NRP and tailbuoy positions to incorporate streamer feather estimates into 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 +/- 20 m due to layback offset between the NRP and sources and movement of the sources 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 midpoint positions.
  3. How accurate are the heights or depths?
    RBR Solo-D depths are estimated by the RBR Ltd. Ruskin utility (v2.9.5.202001201830) via the simplified derivation, where depth in meters = (measured presure in dbar - atmospheric pressure (set to default 10.1325 dbar)) / (density (set to default 1.0281 g/mL) * 0.980665). The RBR Solo-D units used are rated to 20 meters and RBR Ltd. state that they are accurate to +/- 0.05 percent of full scale (about 1 cm water depth).
  4. Where are the gaps in the data? What is missing?
    The shot navigation file '2018-002-FA_MCS_shtnav.csv' contains navigation coordinates for all shot records acquired during the survey, but every shot record may not contain active reflection data if the sources were not being fired simultaneously. Data were collected over two continuous legs that extended August 8-18 and August 19-28, 2018. No seismic data were recorded during transits to and from ports and seismic acquisition did not start until Aug. 10 (JD222). Hiatus in source operation and shot recording and variability in source level (number of guns firing in the array) occurred periodically throughout the survey due to complications arising from source and acquisition instrumentation issues (including triggering, bird communications, and airgun, compressor, or streamer troubleshooting, maintenance or repair), impacts from locally deployed fishing gear, mitigation of marine mammal encounters (power-downs, shut-downs, and ramp-ups), periods of inclement weather and sea state, and vessel equipment problems. Survey was halted due to inclement weather between Aug. 21 (JD233) 12:06 UTC and Aug 23 (JD235) 11:54 UTC. In '2018-002-FA_StreamerConfig_InfoLogs.pdf', the "Notes" column of the "MATRIX Line Note Log" outlines significant issues encountered during each line and the "MATRIX Number of Guns Log" documents changes in the source array throughout the survey. Communication problems in the navigator bird system resulted in the inability to effectively monitor and control the streamer depth periodically throughout the cruise. As a result, RBR depth logger data were primarily relied upon for streamer static information during post-processing.
  5. How consistent are the relationships among the observations, including topology?
    Quality control was conducted during processing to ensure consistency of prestack shot gather or CMP SEG-Y data files with corresponding navigation ASCII CSV and shapefiles and seismic profile images. UTC times, FFID numbers, and navigation are consistent between corresonding survey lines in 'MX**.sht-raw-tbnav-rbr.segy.zip' or 'MX**.sht-raw-rbr.segy.zip' files and '2018-002-FA_MCS_shtnav.csv'. Similarly, CMP numbers and navigation are consitent between 'MX**.v1d-pspstm.segy.zip' or 'MX**.v2d-srme-pspstm.segy.zip' files, 'MX**.v1d.pspstm.png' or 'MX**.v2d.srme.pspstm.png' images, '2018-002-FA_MCS_cmp200.shp', '2018-002-FA_MCS_cmpnav.csv', and '2018-002-FA_MCS_cmpTracklines.shp'. The attribute fields 'LineName' and 'ImageName' for each polyline feature in '2018-002-FA_MCS_cmpTracklines.shp' correspond to the SEG-Y data files in 'MX**.v1d-pspstm.segy.zip' or 'MX**.v2d-srme-pspstm.segy.zip' and the PNG profile images in '2018-002-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)
    U.S. Geological Survey - ScienceBase
    Federal Center
    Denver, CO

    1-888-275-8747 (voice)
  2. What's the catalog number I need to order this data set? USGS data release of multichannel seismic-reflection data collected using Sercel GI guns and Geometrics GeoEel digital streamers during the Mid-Atlantic Resource Imaging Experiment (MATRIX), USGS field activity 2018-002-FA: includes '2018-002-FA_MCS_cmp200.shp' containing the first, last and 200-interval CMP locations, '2018-002-FA_MCS_cmpnav.csv' containing all CMP locations, '2018-002-FA_MCS_cmpTracklines.shp' containing trackline features, '2018-002-FA_MCS_shtnav.csv' containing shot point locations, the zip archive '2018-002-FA_MCS_Images.zip' containing 19 PNG images named according to filename convention with either '.v1d.pspstm.png' or '.v2d.srme.pspstm.png' appended, 19 zip archive files containing the post-stack migration CMP traces in binary SEG-Y files ('MX**.v1d-pspstm.SEG-Y.zip' or 'MX**.v2d-srme-pspstm.SEG-Y.zip'), 19 zip archive files containing shot gathers with header geometry and navigation in binary SEG-Y files ('MX**.sht-raw-tbnav-rbr.SEG-Y.zip' or 'MX**.sht-raw-rbr.SEG-Y.zip', the PDF document '2018-002-FA_StreamerConfig_InfoLogs.pdf' containing streamer configuration illustrations and acquisition log material, the browse graphic '2018-002-FA_MCSBrowseImage.jpg', and the Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file 2018-002-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. Any use of trade, product, or firm 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: 27-Jan-2021
Metadata author:
U.S. Geological Survey
Attn: Wayne E. Baldwin
Geologist
384 Woods Hole Rd.
Woods Hole, MA

(508) 548-8700 x2226 (voice)
(508) 457-2310 (FAX)
wbaldwin@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P91WP1RZ/2018-002-FA_MCS_meta.faq.html>
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