Unique common mid-point (cmp) navigation for multi-channel seismic data collected by the U.S. Geological Survey on U.S. Atlantic Seaboard in 2014 (Geographic, WGS84, point shapefile 2014-011-FA_mcscmp.shp)

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Frequently anticipated questions:


What does this data set describe?

Title:
Unique common mid-point (cmp) navigation for multi-channel seismic data collected by the U.S. Geological Survey on U.S. Atlantic Seaboard in 2014 (Geographic, WGS84, point shapefile 2014-011-FA_mcscmp.shp)
Abstract:
In summer 2014, the U.S. Geological Survey conducted a 21-day geophysical program in deep water along the Atlantic continental margin by using R/V Marcus G. Langseth (Field Activity Number 2014-011-FA). The purpose of the seismic program was to collect multichannel seismic reflection and refraction data to determine sediment thickness. These data enable the United States to delineate its Extended Continental Shelf (ECS) along the Atlantic margin. The same data can also be used to understand large submarine landslides and therefore assess their potential tsunami hazard for infrastructure and communities living along the eastern seaboard. Supporting geophysical data were collected as marine magnetic data, gravity data, 3.5-kilohertz shallow seismic reflections, multibeam echo sounder bathymetry, and multibeam backscatter. 
The survey was conducted from water depths of approximately 1,500 meters to abyssal seafloor depths greater than 5,000 meters. Approximately 2,761 kilometers of multi-channel seismic data was collected along with 30 sonobuoy profiles.
This field program had two primary objectives: (1) to collect some of the data necessary to establish the outer limits of the U.S. Continental Shelf, or Extended Continental Shelf, as defined by Article 76 of the United Nations Convention of the Law of the Sea and (2) to study the sudden mass transport of sediments down the continental margin as submarine landslides that pose potential tsunamigenic hazards to the Atlantic and Caribbean coastal communities.
Supplemental_Information:
For more information on the field activity, see the field activity page https://cmgds.marine.usgs.gov/fan_info.php?fan=2014-011-FA
  1. How might this data set be cited?
    U.S. Geological Survey, 2017, Unique common mid-point (cmp) navigation for multi-channel seismic data collected by the U.S. Geological Survey on U.S. Atlantic Seaboard in 2014 (Geographic, WGS84, point shapefile 2014-011-FA_mcscmp.shp): data release DOI:F7V69HHS, U.S. Geological Survey, Coastal and Marine Science Center, Woods Hole, MA, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Arsenault, M.A., Miller, N.C., Hutchinson, D.R., Baldwin, W.E., Moore, E.M., Foster, D.S., O'Brien, T.F., and Fortin, W.F., 2017, Geophysical data collected along the Atlantic continental slope and rise 2014, U.S. Geological Survey Field Activity 2014-011-FA, cruise MGL1407: data release DOI:F7V69HHS, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested Citation:
    Arsenault, M.A., Miller, N.C., Hutchinson, D.R., Baldwin, W.E., Moore, E.M., Foster, D.S., O’Brien, T.F., and Fortin, W.F., 2017, Geophysical data collected along the Atlantic continental slope and rise 2014, U.S. Geological Survey Field Activity 2014-011-FA, cruise MGL1407: U.S. Geological Survey data release, https://doi.org/10.5066/F7V69HHS.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -76.0712509229095
    East_Bounding_Coordinate: -65.7862940327174
    North_Bounding_Coordinate: 39.2502207326285
    South_Bounding_Coordinate: 30.6754905941078
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data/field-activity-data/2014-011-FA/data/seismics/2014-011-FA_mcscmp.jpg (JPEG)
    Image showing common mid-point (cmp) navigation for seismic navigation data collected by the U.S. Geological Survey on the R/V Marcus G. Langseth, 2014
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 23-Aug-2014
    Ending_Date: 11-Sep-2014
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity point (447236)
    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 0.0000001. Longitudes are given to the nearest 0.0000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is GCS_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
  7. How does the data set describe geographic features?
    2014-011-FA_mcscmp
    Unique common mid-point (cmp) navigation for multi-channel seismic data collected by the U.S. Geological Survey in U.S. Atlantic Seaboard in 2014 (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
    CMP
    Number of unique seismic cmp (Source: U.S. Geological Survey)
    Range of values
    Minimum:1000
    Maximum:50000
    Resolution:1
    CMP_LON
    X-coordinate representing the longitude location of common mid-point (WGS84) (Source: U.S. Geological Survey)
    Range of values
    Minimum:-76.071251
    Maximum:-65.786293
    Units:decimal degrees
    Resolution:0.00001
    CMP_LAT
    Y-coordinate representing the latitude location of common mid-point (WGS84) (Source: U.S. Geological Survey)
    Range of values
    Minimum:30.675491
    Maximum:39.250221
    Units:decimal degrees
    Resolution:0.00001
    LINENAME
    Line and file number for corresponding seismic files. This information is used during data acquisition, processing and archival. Format: SHPCCCCMCSXX, where SHP = Ship name abbreviation; CCCC = Cruise number; MCS= Type of data; XX = Line number. An example would be MGL1407MCS01; MGL = The R/V Marcus G. Langseth, 1407 = the Cruise ID, MCS = multi-channel seismic, 01 = Line 01. (Source: U.S. Geological Survey) text defining line and file number for corresponding seismic files
    YEAR
    Calendar year of data collection (Source: U.S. Geological Survey)
    Range of values
    Minimum:2014
    Maximum:2014
    Units:calendar year
    Resolution:1
    MEAN_JDAY
    Average julian day representing the day of data collection, averaged across all shot points. Julian day is the integer number representing the interval of time in days since January 1 of the year of collection. (Source: U.S. Geological Survey)
    Range of values
    Minimum:236
    Maximum:254
    Units:24 hour day, represented as julian number
    Resolution:1
    MEAN_DATET
    Average calendar date and time for all traces combined for a cmp. Format is YYYY-MM-DDTHH:MM:SS.SSSSSSZ, where T indicates the end of the calendar notation, and Z indicates the time is UTC, or 'Z' time. (Source: U.S. Geological Survey) Text field representing the date and time
    LINE_START
    Julian day at the start of the line (Source: U.S. Geological Survey)
    Range of values
    Minimum:236
    Maximum:254
    Units:24 hour day, represented as julian number
    Resolution:1
    LINE_END_J
    Julian day at the end of the line collection (Source: U.S. Geological Survey)
    Range of values
    Minimum:236
    Maximum:254
    Units:24 hour day, represented as julian number
    Resolution:1

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • U.S. Geological Survey
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Nathan C. Miller
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x 2293 (voice)
    508-457-2310 (FAX)
    ncmiller@usgs.gov

Why was the data set created?

This shapefile contains common mid-point (cmp) navigation for approximately 2,761 kilometers of multi-channel seismic data collected by the U.S. Geological Survey during USGS survey 2014-04-FA. These data were collected off the U.S. Seaboard Atlantic as part of the U.S. Extended Continental Shelf project and investigations of tsunami hazards. The unique common mid-point (cmp) navigation is generally used to aid in interpretation. The common mid-point (cmp) navigation allows features in the seismic data to be correlated to features visible within coincident geophysical data.

How was the data set created?

  1. From what previous works were the data drawn?
    original raw data (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, Multi-channel Seismic Data.

    Type_of_Source_Media: online
    Source_Contribution:
    Multi-channel seismic data were acquired with a 36-element, 6600 cubic inch airgun source array, and 8-km-long solid state digital hydrophone streamer towed behind the R/V Marcus G. Langseth. The source air guns were configured in four parallel, 9-gun strings and towed at the rear of the ship at a depth of 9 meters. The Sentry Solid Streamer Sercel hydrophone cable consists of 12 hydrophones, which are summed in analog, and the spacing between the center of these groups is 12.5 m. Streamer depth was set to 9 m for all lines. Approximately 2,761 km of data were collected. Data were recorded at a 4-millisecond (ms) sample rate and in Society of Exploration Geophysicists D (SEG-D) format.
    Source and receiver positions were determined by LDEO staff using Concept Systems's Spectra multichannel seismic navigation software. Source positions were logged using differential GPS antennas on three of the four source sub arrays. Receiver positions were calculated using data from Digicourse Digirange acoustic pods on the source array and on the head, middle, and tail of the streamer; depth and heading data from Digicourse depth control birds located every 300 m along the streamer; and a differential GPS on the streamer tail buoy. All survey positions use the World Geodetic System 1984 datum (WGS84), and both global and local geodetic calculations utilized the WGS84 reference ellipsoid with a semi-major axis of 6378137.0 m and an inverse flattening of 298.257224.
  2. How were the data generated, processed, and modified?
    Date: 2016 (process 1 of 5)
    Navigation was acquired using the R/V Marcus G. Langseth's fully integrated multicomponent navigation system, consisting of echosounder, speedlog, Differential Global Positioning System (DGPS), gyrocompass, POS/MV Integrated Navigation System, Kongsberg Seapath 200 Inertial Navigation System and Lamont Data Systems (LDS) data logger. Source and receiver positions were determined by LDEO staff using Concept Systems's Spectra multichannel seismic navigation software. Source positions were logged using differential GPS antennas on three of the four source sub arrays. Receiver positions were calculated using data from Digicourse Digirange acoustic pods on the source array and on the head, middle, and tail of the streamer; depth and heading data from Digicourse depth control birds located every 300 m along the streamer; and a differential GPS on the streamer tail buoy. All survey positions use the World Geodetic System 1984 datum (WGS84), and both global and local geodetic calculations utilized the WGS84 reference ellipsoid with a semi-major axis of 6378137.0 m and an inverse flattening of 298.257224. Streamer geometry calculations were performed in Universal Transverse Mercator (UTM) northern hemisphere projection 19 North . Source-receiver midpoints were calculated using source and receiver positions from the processed P190 seismic navigation. All midpoint and bin calculations were made in UTM 19N coordinates using Shearwater’s OpenCPS (version 3.3.0) seismic processing software. To handle extreme streamer feathering, CMP bin assignments were made using 1000-m wide rectangular bins spaced every 6.25m along prescribed CMP lines. Midpoints that fall outside these 6.25x1000m bins were assigned CMP=0 and were excluded from processing. CMP lines were drawn to maximize the number of midpoints from source-receiver offsets of <1000m in each bin (i.e., fold). Person who carried out this activity:
    Nathan C. Miller
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2293 (voice)
    508-457-2310 (FAX)
    ncmiller@usgs.gov
    Date: 2016 (process 2 of 5)
    SEG-D format shot gathers were imported into OpenCPS (version 3.3.0) software, and processed through a standard sequence of trace editing, common-midpoint (CMP) sorting, bandpass filtering, deconvolution, velocity analysis, normal moveout correction, stretch muting, stacking, and post-stack time migration. True group and source locations were taken from the P190 navigation files provided by the crew of the R/V Marcus Langseth. Files were written to SEG-Y format using OpenCPS (version 3.3.0) seismic proicessing software. Processing step specifics are written into the SEG-Y text header for each line:
    Description Post-stack phase shift time migration to 200 Hz using auto-picked velocities guided by a 1D velocity function hung between picked water-bottom, basement, and Moho.
    This is an example from line MGL1407MCS03:
    Prestack gains: Spherical divergence Poststack gains: None Band: 6-200 Hz
    Cruise:MGL1407 Line:MGL1407MCS03 Coordinate projection:WGS84/UTM 19N ESPG:32619 WKT:"+proj=utm +zone=19 +datum=WGS84 +units=m +no_defs"
    Nathan C. Miller performed this and all subsequent process steps. Person who carried out this activity:
    Nathan C. Miller
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2293 (voice)
    508-457-2310 (FAX)
    ncmiller@usgs.gov
    Date: 2016 (process 3 of 5)
    Coordinates were converted to Universal Transverse Mercator (UTM) northern hemisphere projection 19 North for streamer geometry calculations (calculation of cmp position). While the data extends beyond the singular UTM Zone 19N, the selected UTM zone is central to the majority of the data. Projected coordinates are often used for binning, and CMP calculation as the units (meters) are easier to use than fractional degrees of latitude and longitude. CMP locations were converted back to geographic coordinates. CMP locations were written as geographic coordinates (WGS84) to a text file (*.csv) using a Python script within OpenCPS (version 3.3.0) , and then imported into Esri ArcMap 10.3 using ArcCatalog, Create Feature Class from XY Table, specifying geographic coordinates, WGS84 coordinate system (EPSG code 4326).
    Date: 29-Jan-2018 (process 4 of 5)
    An error was fixed in one of the originator names. Also fixed in the suggested citation. 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: 08-Sep-2020 (process 5 of 5)
    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?
    Observatory, Lamont-Doherty Earth, 2014, Rolling Deck to Repository (R2R): UNCLOS, UNCLOS.

    Online Links:

    Other_Citation_Details:
    Standard data products listed on the Rolling Deck to Repository website include cruise level metadata with an expedition summary including cruise id, vessel, operator, project titles and funding awards, science party, ports, dates, survey targets, and trackline geometry. There is also quality-controlled shiptrack navigation, and scientific sampling event logs. Some post-processed geophysical trackline profiles (underway gravity, magnetics, bathymetry, etc), for vessels equipped with these instrument types; and hydrographic profiles (depth, temperature, salinity, etc from CTD).

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?
    Navigation was acquired using the R/V Marcus G. Langseth's fully integrated multicomponent navigation system, consisting of echosounder, speedlog, Differential Global Positioning System (DGPS), gyrocompass, POS/MV Integrated Navigation System, Kongsberg Seapath 200 Inertial Navigation System and Lamont Data Systems (LDS) data logger. All survey positions use the World Geodetic System 1984 datum (WGS84), and both global and local geodetic calculations utilized the WGS84 reference ellipsoid with a semi-major axis of 6378137.0 m and an inverse flattening of 298.257224. Streamer geometry calculations were performed in Universal Transverse Mercator (UTM) northern hemisphere projection 19 North . Water bottom topography in stacked sections agrees well with multi beam bathymetry data gridded to 50 m, implying that these CMP locations are accurate to <50m.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    This shapefile contains common mid-point (cmp) navigation for all of the multi-channel seismic data collected during USGS field activity 2014-011-FA. 16 multi-channel seismic lines were collected in total, and the lines are not sequentially numbered, and some lines are partitioned into A and B sections.
  5. How consistent are the relationships among the observations, including topology?
    Field work is inherently unpredictable, and the original cruise plan was modified to accommodate a hurricane, a medical evacuation, and extreme feathering of the streamer due to the Gulf Stream. While the original cruise plan identified sequentially numbered cruise tracks, interruptions to data collection necessitated the renaming and renumbering of seismic lines to include A and B segments, and the exclusion of lower-priority lines (like 4 and 5). Regardless of name, seismic lines were collected in a consistent manner.
    Although data quality was in general excellent, there are several known problems with the data, including noisy channels (up to 71 channels out of 636 in the 8-km configuration, and 65 channels out of 480 in the 6-km configuration), extreme feathering of the streamer on lines which crossed the Gulf Stream, occasional reduced source size for maintenance on the airgun strings, and one 12-minute power down for a protected species. Rough weather also produced wave noise on the streamer. The events, and timing of these events are too numerous to list here, and the logs archived on the Rolling Deck to Repository Archive system (http://www.rvdata.us/catalog/MGL1407) should be referenced for the exact timing of events effecting the quality of the data presented here.

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 redistributable 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)
    Nathan C. Miller
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2293 (voice)
    508-457-2310 (FAX)
    ncmiller@usgs.gov
  2. What's the catalog number I need to order this data set? USGS data release 2014-011-FA multi-channel seismic data from the Atlantic Ocean (2014-011-FA_mcscmp.zip). The compressed file contains a comma delimited text file: 2014-011-FA_mcscmp.csv, an Esri formatted vector shapefile in geographic coordinates (2014-011-FA_mcscmp.shp), a mapview image of the data (2014-011-FA_mcscmp.jpg) and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata files (2014-011-FA_mcscmp.xml) in standard xml, txt and html formats are also included in the compressed file.
  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?
    This compressed file contains data available in Esri shapefile format anc CSV format. The compressed file also contains associated metadata. The user must have software capable of reading and processing the data file. The data are also available as text format. The data are also available in text format.

Who wrote the metadata?

Dates:
Last modified: 08-Sep-2020
Metadata author:
Matthew A. Arsenault
U.S. Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, Massachusetts
USA

508-548-8700 x2354 (voice)
508-457-2310 (FAX)
marsenault@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

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