PNG formatted images of EdgeTech 424 seismic-reflection profiles collected by the U.S. Geological Survey in Barnegat Bay, NJ in 2011, 2012, and 2013

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Frequently anticipated questions:


What does this data set describe?

Title:
PNG formatted images of EdgeTech 424 seismic-reflection profiles collected by the U.S. Geological Survey in Barnegat Bay, NJ in 2011, 2012, and 2013
Abstract:
Water quality in the Barnegat Bay-Little Egg Harbor estuary along the New Jersey coast is the focus of a multidisciplinary research project begun in 2011 by the U.S. Geological Survey in partnership with the New Jersey Department of Environmental Protection. This narrow estuary is the drainage for the Barnegat Watershed and flushed by just three inlets connecting it to the Atlantic Ocean, is experiencing degraded water quality, algal blooms, loss of seagrass, and increases in oxygen-depletion events, seaweed, stinging nettles, and brown tide. The scale of the estuary and the scope of the problems within it necessitate a multidisciplinary approach that includes characterizing its physical characteristics (for example, depth, magnitude and direction of tidal currents, distribution of seafloor and subseafloor sediment) and modeling how the physical characteristics interact to affect the estuary's water quality. Scientists from USGS Coastal and Marine Geology Program offices in Woods Hole, Massachusetts, and St. Petersburg, Florida, began mapping the seafloor of the Barnegat Bay-Little Egg Harbor estuary in November 2011 and completed in September 2013. With funding from the New Jersey Department of Environmental Protection and logistical support from the USGS New Jersey Water Science Center, data were collected with a suite of geophysical tools, including swath bathymetric sonar for measuring seafloor depth, a sidescan sonar for collecting acoustic-backscatter data (which provides information about seafloor texture and sediment type), and a subbottom profiler for imaging sediment layers beneath the floor of the estuary. More information about the individual USGS surveys conducted as part of this study can be found on Woods Hole Coastal and Marine Science Center Field Activity webpages: >2011-041-FA: http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2011-041-FA >2012-003-FA: http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2012-003-FA >2013-014-FA: http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2013-014-FA >2013-030-FA: http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2013-030-FA
  1. How might this data set be cited?
    U.S. Geological Survey, 2015, PNG formatted images of EdgeTech 424 seismic-reflection profiles collected by the U.S. Geological Survey in Barnegat Bay, NJ in 2011, 2012, and 2013: Data Series 937, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Andrews, Brian D., Miselis, Jennifer L., Danforth, William W., Irwin, Barry J., Worley, Charles R., Bergeron, Emile M., and Blackwood, Dann S., 2015, Marine geophysical data collected in a shallow back-barrier estuary: Barnegat Bay, New Jersey: Data Series 937, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -74.318611
    East_Bounding_Coordinate: -74.049497
    North_Bounding_Coordinate: 40.090249
    South_Bounding_Coordinate: 39.468325
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 01-Nov-2011
    Ending_Date: 16-Sep-2013
    Currentness_Reference:
    ground condition of individual surveys during bathymetry collection: 20111101-20111107; 20120321-20120408; 20130313-20130326; 20130911-20130916.
  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?
  7. How does the data set describe geographic features?

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?
    Please recognize the U.S. Geological Survey (USGS) as the source of this information
  3. To whom should users address questions about the data?
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov

Why was the data set created?

Portable Network Graphics (PNG) images of each seismic profile line were produced for visually display of the shot traces and for use in GIS software along with the shapefile of the tracklines. The PNG files are not georeferenced, but can be "spatially linked" by using them with the seismic shots (BarnBaySeisShot100.shp) and tracklines (BarnBaySeisTrks.shp) published in this same report.

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, SEG-Y and JSF 512i data..

    Type_of_Source_Media: disc
    Source_Contribution:
    Seismic profile data were collected along approximately 2092 kilometers of survey lines using an EdgeTech 424 subbottom profiling system (frequency modulation swept frequency 4-24 kHz) which was towed from the starboard side of the R/V Rafael. SonarWiz seismic-acquisition software was used to control the EdgeTech 3100 portable topside unit, digitally log trace data in SEG-Y rev. 1 format (IEEE floating point), and record GPS navigation coordinates to the SEG-Y trace headers (in arcseconds of latitude and longitude, multiplied by a scalar of 100). Data were acquired using a 250 ms shot rate with a 5 ms transit pulse length, logging 100 ms of data per trace during the first day (Julian day 305) of survey 2011-014-FA. The shot rate was changed on Julian day 306 to a 500 ms but maintained a record length of 100 ms. This shot rate was maintained for all surveys. A swept frequency spectrum of 4-24 kHz was used for the entire survey, selectable via SonarWiz communicating with the EdgeTech 3100 topside controller. DGPS navigation was supplied by a Hemisphere receiver with the antenna located on the port side aft cabin. Cable layback is 4 meters, depth below water line 0.5 meters. GPS offset from sheave: x = 2.38, y = .62, z = 0. Entered these values into SonarWiz starting with line 1. Seismic-reflection data were processed using SIOSEIS (2011) and Seismic Unix (Stockwell and Cohen, 2008). All navigation data were extracted from trace headers, edited, and saved as ASCII text files.
  2. How were the data generated, processed, and modified?
    Date: 2013 (process 1 of 6)
    Step 1: SIOSEIS (version 2010.2.25) was used to read SEG-Y files, renumber shots starting from one, 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. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: 2013 (process 2 of 6)
    Step 2: Seismic Unix (version 4.2) was used to read renumbered 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). Geographic coordinates (WGS84) were converted to UTM zone 18 coordinates (WGS 84) using Proj (version 4.6.0). 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, and shots with unique navigation coordinates. End shots and shots at multiples of 100 may not have unique navigation coordinates. A 100 shot interval was chosen because it corresponds to the annotation interval provided along the top of the seismic-reflection profile PNG images. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: 2014 (process 3 of 6)
    Step 3: PRODUCE SIESMIC IMAGE An executable C-Shell script called on Seismic Unix (v. 4.1) to read the SEG-Y files and plot the data as 24-bit gray scale Postscript image files. All images were created with the horizontal scale at 100 traces per inch. The profiles contain between 20 and 50 milliseconds of Two-Way Travel Time within an 8-inch vertical window, yielding 4.2 milliseconds per inch. Postscript images were converted to PNG format using ImageMagick (version 6.8.9). Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Date: 20-Jul-2018 (process 4 of 6)
    USGS Thesaurus keywords added to the keyword section. 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: 15-Nov-2019 (process 5 of 6)
    Crossref DOI link was added as the first link in the metadata. 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 6 of 6)
    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?
    Stockwell, John, 2011, CWP/SU: Seismic Unix: Center for Wave Phenomena - Colorado School of Mines, Golden, CO.

    Online Links:

    Henkart, Paul, 2011, SIOSEIS: Scripps Institution of Oceanography, University of California - San Diego, LaJolla, CA.

    Online Links:

    Norris, Michael W., and Faichney, Alan K., 2002, SEGY Rev.1 Data Exchange Format1: Society of Exploration Geophysicists, Tulsa, OK.

    Online Links:


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

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Seismic lines that were shorter than 100 shots and did not record usable data were not included. Gaps in sequential line numbers may exist. One PNG image exists for each seismic (profile) trackline identified in the "image" attribute of the trackline shapefile "BarnBaySeisTrks.shp"<http://pubs.usgs.gov/ds/0937/downloads/shapefile/BarnBaySeisTrks.zip>
  5. How consistent are the relationships among the observations, including topology?
    Processed seismic data were converted to PNG format for ease of seismic trace display. Quality control was conducted during processing.

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: none
  1. Who distributes the data set? (Distributor 1 of 1)
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    bandrews@usgs.gov
  2. What's the catalog number I need to order this data set? 2011_041_FA.zip, 2012_003_FA.zip, 2013_014_FA.zip, and 2013_030_FA.zip contain the seismic profile images in PNG format collected during each survey and the associated metadata.
  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?
    These data can be viewed with any viewing software capable of viewing a Portable Network Graphics (PNG) file.

Who wrote the metadata?

Dates:
Last modified: 08-Sep-2020
Metadata author:
Brian Andrews
U.S. Geological Survey
Geographer
384 Woods Hole Rd.
Woods Hole, MA
USA

508-548-8700 x2348 (voice)
508-457-2310 (FAX)
bandrews@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/data_series/DS-937/seismic_profiles.faq.html>
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