Trackline navigation for EdgeTech SB-512i chirp seismic-reflection data collected in 2014 by the U.S. Geological Survey offshore of Fire Island, NY (Esri polyline shapefile, GCS WGS 84)

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Frequently anticipated questions:

What does this data set describe?

Title:
Trackline navigation for EdgeTech SB-512i chirp seismic-reflection data collected in 2014 by the U.S. Geological Survey offshore of Fire Island, NY (Esri polyline shapefile, GCS WGS 84)
Abstract:
The U.S. Geological Survey (USGS) conducted a geophysical and sampling survey in October 2014 that focused on a series of shoreface-attached ridges offshore of western Fire Island, NY. Seismic-reflection data, surficial grab samples and bottom photographs and video were collected along the lower shoreface and inner continental shelf. The purpose of this survey was to assess the impact of Hurricane Sandy on this coastal region. These data were compared to seismic-reflection and surficial sediment data collected by the USGS in the same area in 2011 to evaluate any post-storm changes in seabed morphology and modern sediment thickness on the inner continental shelf. For more information about the WHCMSC Field Activity, see: https://cmgds.marine.usgs.gov/fan_info.php?fan=2014-009-FA.
  1. How might this data set be cited?
    U.S. Geological Survey, 2017, Trackline navigation for EdgeTech SB-512i chirp seismic-reflection data collected in 2014 by the U.S. Geological Survey offshore of Fire Island, NY (Esri polyline shapefile, GCS WGS 84): data release DOI:10.5066/F7FF3QTQ, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Denny, Jane F., Schwab, William C., Ackerman, Seth D., Baldwin, Wayne E., Danforth, William W., Moore, Eric, Nichols, Alexander, and Worley, Charles, 2017, High-resolution geophysical and sample data collected offshore of Fire Island, NY in 2014, U.S. Geological Survey Field Activity 2014-009-FA: data release DOI:10.5066/F7FF3QTQ, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -73.313743
    East_Bounding_Coordinate: -72.976662
    North_Bounding_Coordinate: 40.679967
    South_Bounding_Coordinate: 40.593182
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data/field-activity-data/2014-009-FA/data/seismics/2014-009-FA_512i_Tracklines_browse.jpg (JPEG)
    Image showing chirp sub-bottom profiler tracklines collected by the U.S. Geological Survey on the inner-continental shelf offshore of Fire Island, NY, 2014.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 20-Oct-2014
    Ending_Date: 26-Oct-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):
      • String (94)
    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 D_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?
    2014-009-FA_512i_Tracklines
    512i tracklines for survey 2015-009-FA offshore of Fire Island, NY. (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.
    FileName
    Seismic-reflection survey trackline file name. (Source: U.S. Geological Survey) Character set
    Image
    PNG image name of seismic-reflection profile corresponding to survey line. The '_s' refers to the image file for data that has been through swell filter processing. (Source: U.S. Geological Survey) Character set
    Shot_ini
    Shot number at the start of the survey line. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1
    Maximum:1
    Units:shot
    Resolution:1
    Year
    Year at the end of the survey line. (Source: U.S. Geological Survey)
    Range of values
    Minimum:2014
    Maximum:2014
    Units:year
    Resolution:1
    JD_UTC_ini
    Julian day and UTC time at the start of the survey line 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
    Shot_end
    Shot number at the end of the survey line. (Source: U.S. Geological Survey)
    Range of values
    Minimum:1147
    Maximum:18543
    Units:shot
    Resolution:1
    JD_UTC_end
    Julian day and UTC time at the end of the survey line 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. "2014-009-FA" where 2014 is the survey year, 009 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
    Sonar 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). (Source: U.S. Geological Survey)
    Range of values
    Minimum:1.402069
    Maximum:21.554634
    Units:kilometers
    Resolution:0.000001

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?
    Jane F. Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x 2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov

Why was the data set created?

This dataset contains trackline navigation for approximately 745 km of chirp seismic-reflection data collected by the U.S. Geological Survey during cruise 2014-009-FA offshore of Fire Island, NY. This information can help spatially correlate the subbottom data with other data in the GIS.

How was the data set created?

  1. From what previous works were the data drawn?
    SEG-Y and JSF 512i data (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, 512i trackline data.

    Type_of_Source_Media: disc
    Source_Contribution:
    Chirp seismic data were collected using an EdgeTech Geo-Star FSSB sub-bottom profiling system and an SB-0512i towfish (0.5-12 kHz), which was mounted on a catamaran and towed astern of the M/V Scarlett Isabella offshore of Fire Island, NY. Chesapeake Technology's SonarWiz (versions 5.00.0015 and 5.06.0058) seismic acquisition software was used to control the Geo-Star topside unit, digitally log trace data in the SEG-Y Rev. 1 format (IEEE floating point) and JSF format, and record GPS navigation coordinates to the SEG-Y trace headers (in arc seconds of Latitude and Longitude, multiplied by a scalar of 100). Data were acquired using a 250 ms shot rate, a 5-ms pulse length, and a 0.5 to 8 kHz frequency sweep. Recorded trace lengths were approximately 180 ms.
  2. How were the data generated, processed, and modified?
    Date: 2015 (process 1 of 5)
    Scripts within SIOSEIS (version 2013.1.1) and Seismic Unix (version 4.2) were used to process SEG-Y data, create navigation files, and plot images. The processing flow and scripts used to produce navigation files including trackline shapefiles are summarized below and in the following processing steps.
    1. SIOSEIS (version 2013.1.1) was used to read SEG-Y files, renumber shots starting from one, extract the envelope-detected trace, and write out new SEG-Y files. The original shot numbers, which were assigned by SonarWiz sequentially over the duration of an acquisition session despite SEG-Y file changes, are preserved in the raw SEG-Y data.
    2. The SIOSEIS script Sio_medianstk applied a two-trace median stack (trim 50 percent of the values furthest from the median amplitude) to improve subsequent water bottom picking.
    3. The script Read512i_mstk was used to read renumbered and two-trace median filter stacked SEG-Y files, write a Seismic Unix file, and extract SEG-Y trace header information, including shot number, longitude, latitude, year, Julian day, and time of day (UTC). Header information from each SEG-Y file was saved to text files after an AWK (no version) filter was used to maintain the first and last shots, shots at multiples of 100, 500, and shots with unique navigation coordinates. Geographic coordinates (WGS 84) were converted to UTM zone 18 N coordinates (WGS 84) using Proj (version 4.6.0). End shots and shots at multiples of 100 may not have unique navigation coordinates. Separate text files containing the first and last shots and even 500 shot intervals were also saved. A 500 shot interval was chosen because it corresponds to the annotation interval provided along the top of the seismic-reflection profile images.
    Person who carried out this activity:
    Wayne Baldwin
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700 x2226 (voice)
    (508) 457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: 2015 (process 2 of 5)
    A Python (version 2.7) script was used to apply layback to seismic navigation acquired during the 2014-009-FA survey. Attributes oldEast and oldNorth in the table 2014-009-512i_lbunique.csv', which is included in the zip compressed version of the shapefile 2014-009-FA_512i_500sht.shp', document pre-layback shot/trace positions. Using Easting and Northing coordinates (UTM Zone 18 N, WGS84) produced in the previous step, the script calculated easting and northing differential values between consecutive trace positions. Headings between consecutive traces were calculated using the arctangent function (arctan2(dy,dx)), and reciprocal back bearings were determined using a lookup table. Back bearings were smoothed along track using a moving median function with a window length defined by the user (59 traces during 2014-009-FA). Layback easting and northing offsets were calculated by multiplying the linear distance between the catamaran and the shipboard DGPS receiver (43 m during 2014-009-FA) by the sine and cosine of the smoothed back bearing, respectively. Offset values were then added to the original coordinates to produce layback positions. ** The layback routine introduces a stair-step offset in the tie-line seismic shot point and trackline navigation. This is a by-product of the moving median function and appears in the north-south oriented tie-lines. ** Person who carried out this activity:
    Wayne Baldwin
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700 x2226 (voice)
    (508) 457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: 2015 (process 3 of 5)
    An awk script (do_nav_gisprep) was used to process unique, 100 shot, and 500 shot lay-back corrected navigation to a merged csv file that can be utilized by ArcGIS to create a trackline and shotpoint shapefile. Text files containing unique shot point positions for each seismic line with layback-adjusted navigation were concatenated into a comma-delimited text file. Then the layback-corrected position CSV file was imported into ArcMap (version 10.2.2) using 'Add XY data' and saved as points (Geographic, WGS84) in the Esri shapefile format. Person who carried out this activity:
    Wayne Baldwin
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700 x2226 (voice)
    (508) 457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: 2015 (process 4 of 5)
    The shapefile containing unique shot point positions, created in the previous step, was used as an input for VACExtras points to lines (version 2.1), a VB collection of tools developed by VeeAnn Cross (USGS-WHCMSC), which converts point data to a new polyline shapefile ('2014-009-FA_512i_Tracklines.shp'), based on record order. The 'FileName' field was used to define which points were used to generate each polyline feature. Additional fields for survey ID, vessel ID, and device ID were added to the attribute table and populated using "Add Field" and "Field Calculator". Using XTools Pro (version 7.1.0) for ArcGIS desktop, the length of each polyline segment was calculated and included in the attribute field 'Length_km', specifying UTM, Zone 18 N, WGS84, and kilometers. Person who carried out this activity:
    Wayne Baldwin
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700 x2226 (voice)
    (508) 457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: 12-Jul-2024 (process 5 of 5)
    Added keywords section with USGS persistent identifier as theme keyword (20200908). Fixed a USGS Thesaurus term (20240712). 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?
    Denny, Jane F., Schwab, William C., Baldwin, Wayne E., Bergeron, Emile, and Moore, Eric, 2015, High-resolution geophysical data collected offshore of Fire Island, New York in 2011, USGS Field Activity 2011-005-FA: data release DOI:10.5066/F75X2704, U.S. Geological Survey, Reston, VA.

    Online Links:

    Schwab, William C., Baldwin, Wayne E., Hapke, Cheryl J., Lentz, Erika E., Gayes, Paul T., Denny, Jane F., List, Jeffrey H., and Warner, John C., 2013, Geologic Evidence for Onshore Sediment Transport from the Inner Continental Shelf: Fire Island, New York: Journal of Coastal Research Volume 29, Issue 3, pp. 526-544., Coastal Education and Research Foundation, Inc., Florida, USA.

    Online Links:

    Foster, David S., Swift, Ann B., and Schwab, William C., 1999, Stratigraphic Framework Maps of the nearshore area of southern Long Island from Fire Island to Montauk Point, NY: Open-File Report 99-559, U.S. Geological Survey, Reston, VA.

    Online Links:

    Schwab, William C., Thieler, E. Robert, Denny, Jane F., Danforth, William W., and Hill, Jenna C., 2000, Seafloor sediment distribution off southern Long Island, New York: Open-File Report 00-243, U.S. Geological Survey, Reston, VA.

    Online Links:

    Schwab, W.C., Denny, J.F., and Baldwin, W.E., 2014, Maps Showing Bathymetry and Modern Sediment Thickness on the Inner Continental Shelf Offshore of Fire Island, New York, Pre-Hurricane Sandy: Open-File Report 2014-1203, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    This publication contains the backscatter image generated from data collected during WHCMSC field activity 2011-005-FA.
    Schwab, W.C., Baldwin, W.E., and Denny, J.F., 2014, Maps Showing the Change in Modern Sediment Thickness on the Inner Continental Shelf Offshore of Fire Island, New York, Between 1996-97 and 2011: Open-File Report 2014-1238, U.S. Geological Survey, Reston, VA.

    Online Links:

    Schwab, William C., Baldwin, Wayne E., Denny, Jane F., Hapke, Cheryl J., Gayes, Paul T., List, Jeffrey H., and Warner, John C., 2014, Modification of the Quaternary stratigraphic framework of the inner-continental shelf by Holocene marine transgression: An example offshore of Fire Island, New York: Marine Geology Volume 355, Elsevier B.V., Amsterdam, Netherlands.

    Online Links:

    Goff, J.A., Flood, R.D., Austin, J.A., Schwab, W.C., Christensen, B., Browne, C.M., Denny, J.F., and Baldwin, W.E., 2015, The impact of Hurricane Sandy on the shoreface and inner shelf of Fire Island, New York: Large bedform migration and limited erosion: Continental Shelf Research V. 98, pp. 13-25, Elsevier B.V., Amsterdam, Netherlands.

    Online Links:

    Denny, Jane F., Danforth, William W., Couch, Stephen, and Schwab, William C., 2015, Swath bathymetry collected offshore of Fire Island and western Long Island, New York in 2014, U.S. Geological Survey Field Activity 2014-072-FA: data release DOI:10.5066/F7C827BX, U.S. Geological Survey, Reston, VA.

    Online Links:

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    All attributes were evaluated during processing as standard quality control to ensure attributes contain accurate and relevant information and values.
  2. How accurate are the geographic locations?
    Differential Global Positioning System (DGPS) navigation data were acquired with an Ashtech BR2G receiver and recorded with HYPACK (www.hypack.com). The DGPS antenna was located on the aft, port-side of the acquisition van. The SB-0512i was mounted on a catamaran sled and towed at the sea surface approximately 43 m astern of the M/V Scarlett Isabella. Fish depth below water line was 0.5 meters below catamaran floats. The GPS offset from sheave was x = 8.75 m; y = -43 m; z = 0. Navigation data were sent to SonarWiz (version 5) acquisition application and offsets were recorded in the acquisitions software, which logged the coordinates to individual trace headers SEG-Y and JSF format. Layback navigation was generated to account for towfish position. Positional accuracy is assumed to be ± 10 m.** The layback routine introduces a stair-step offset in the tie-line seismic shot point and trackline navigation. This is a by-product of the moving median function and appears in the north-south oriented tie-lines. **
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Sections of tracklines where navigation was recorded but no seismic data were logged are not included such as some turns and transits. There is no line l67f1.
  5. How consistent are the relationships among the observations, including topology?
    All subbottom data were collected during USGS cruise 2014-009-FA using an Edgetech SB-512i chirp subbottom profiler. Seismic trackline navigation was generated from unique shot navigation for the seismic system. The unique shot navigation data were evaluated during processing for spurious points; all spurious points were removed prior to generating the trackline navigation.

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)
    Jane F. Denny
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x 2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov
  2. What's the catalog number I need to order this data set? USGS data release 2014-009-FA seismic-reflection data from offshore Fire Island, NY (2014-009-FA_512i_Tracklines.zip). The zip file contains the following: a shapefile (2014-009-FA_512i_Tracklines.shp and other files associated with a shapefile), a browse graphic (2014-009-FA_512i_Tracklines_browse.jpg) and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata files (2014-009-FA_512i_Tracklines_meta.xml) in four standard formats.
  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 zip file contains data available in shapefile format. The user must have software capable of reading shapefile format to use these data.

Who wrote the metadata?

Dates:
Last modified: 12-Jul-2024
Metadata author:
Jane F. Denny
U.S. Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, Massachusetts
USA

508-548-8700 x 2311 (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 USGS. (updated on 20240318)
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/field_activities/2014_009_fa/2014-009-FA_512i_Tracklines_meta.faq.html>
Generated by mp version 2.9.51 on Tue Jul 16 09:57:53 2024