Shot point navigation at even 500 shot intervals for EdgeTech SB-512i chirp seismic-reflection data collected in 2015 by the U.S. Geological Survey along the Delmarva Peninsula, MD and VA (Esri point shapefile, GCS WGS 84).

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Frequently anticipated questions:


What does this data set describe?

Title:
Shot point navigation at even 500 shot intervals for EdgeTech SB-512i chirp seismic-reflection data collected in 2015 by the U.S. Geological Survey along the Delmarva Peninsula, MD and VA (Esri point shapefile, GCS WGS 84).
Abstract:
The Delmarva Peninsula is a 220-kilometer-long headland, spit, and barrier island complex that was significantly affected by Hurricane Sandy in the fall of 2012. The U.S. Geological Survey conducted cruises during the summers of 2014 and 2015 to map the inner continental shelf of the Delmarva Peninsula using geophysical and sampling techniques to define the geologic framework that governs coastal system evolution at storm-event and longer timescales. Geophysical data collected during the cruises include swath bathymetric, sidescan sonar, chirp and boomer seismic reflection profiles, grab sample and bottom photograph data. More information about the USGS survey conducted as part of the Hurricane Sandy Response-- Geologic Framework and Coastal Vulnerability Study can be found at the project website or on the WHCMSC Field Activity Web pages: https://woodshole.er.usgs.gov/project-pages/delmarva/, https://cmgds.marine.usgs.gov/fan_info.php?fan=2014-002-FA and https://cmgds.marine.usgs.gov/fan_info.php?fan=2015-001-FA. Data collected during the 2014 survey can be obtained here: https://doi.org/10.5066/F7MW2F60
  1. How might this data set be cited?
    U.S. Geological Survey, 2016, Shot point navigation at even 500 shot intervals for EdgeTech SB-512i chirp seismic-reflection data collected in 2015 by the U.S. Geological Survey along the Delmarva Peninsula, MD and VA (Esri point shapefile, GCS WGS 84).: data release DOI:10.5066/F7P55KK3, 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.

    Sweeney, Edward M., Pendleton, Elizabeth A., Ackerman, Seth D., Andrews, Brian D., Baldwin, Wayne E., Danforth, William W., Foster, David S., Thieler, E. Robert, and Brothers, Laura L., 2016, High-resolution geophysical data collected along the Delmarva Peninsula 2015, U.S. Geological Survey Field Activity 2015-001-FA: data release DOI:10.5066/F7P55KK3, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -75.891075
    East_Bounding_Coordinate: -75.156914
    North_Bounding_Coordinate: 37.839169
    South_Bounding_Coordinate: 36.999886
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data/field-activity-data/2015-001-FA/data/seismics/tracklines/2015-001-FA_512i_500sht_browse.jpg (JPEG)
    Thumbnail image of chirp seismic-reflection shot points at 500-interval spacing for Delmarva Peninsula.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 10-Jun-2015
    Ending_Date: 14-Jul-2015Currentness_Reference:
    ground condition; data were not collected on 20150628 (transition between Legs 1 and 2 of the survey)
  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 (10057)
    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?
    2015-001-FA_512i_500sht
    512i 500-interval shot points for survey 2015-001-FA along the Delmarva Peninsula. (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:420749.82
    Maximum:486145.96
    Units:meters
    Resolution:1
    North
    Northing coordinate in UTM Zone 18 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:4095036.83
    Maximum:4188017.75
    Units:meters
    Resolution:1
    Lon
    Longitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:-75.891075
    Maximum:-75.156914
    Units:degrees
    Resolution:.00001
    Lat
    Latitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:36.999885
    Maximum:37.839168
    Units:degrees
    Resolution:.00001
    LineName
    Name of the trackline along which seismic-reflection data were collected in the format: line number (i.e. 'l1') + file number (i.e. 'f1'). (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
    Shot number (first, last, and every 500 shot between). (Source: U.S. Geological Survey)
    Range of values
    Minimum:1
    Maximum:41889
    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 first, last, and every 500 shot point between 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. "2015-001-FA" where 2015 is the survey year, 001 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
    Entity_and_Attribute_Overview:
    The PNG seismic reflection images can be hyperlinked to their trackline location in ArcGIS. The 500 shot point intervals correspond to the x-axis ticks on the PNG images. The unique shot CSV file has the following column headings: Easting, Northing, Longitude, Latitude, LineName, Image, Shot, Year, JulianDay_Time. The first 9 columns correspond to the first 9 attributes of the shapefile.
    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)
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Edward M. Sweeney
    U.S. Geological Survey
    Physical Scientist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2256 (voice)
    508-457-2310 (FAX)
    emsweeney@usgs.gov

Why was the data set created?

This dataset contains 500 shot point navigation and unique shot point navigation for approximately 5,500 km of chirp seismic-reflection data collected by the U.S. Geological Survey during cruise 2015-001-FA along the Delmarva Peninsula, MD and VA. 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 shot point 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 of Cape May, NJ. 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 2)
    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 and shot points 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 was used to minimize S-boom cross talk (when multi-channel streamer lines were recorded simultaneously: Julian day 161-168) with a two-trace median stack (trim 50 percent of the values furthest from the median amplitude) and improve water bottom picking. This script was used for all lines even after multi-channel streamer was turned off, due to the improvements made to water bottom picks.
    3. The script Read512i_mstk was used to read median filtered stacked and 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). 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. Read512i_mstk called a Python script 512itoSQL15001.py, written by Wayne Baldwin, which imported the CSV files to the SpatialLite (version 3.0.1) enabled SQLite (version 3.7.9) database. Esri shape polyline and shot point files were exported directly from the SQLite database. Person who carried out this activity:
    Dave Foster
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA

    (508) 548-8700 x2271 (voice)
    (508) 457-2310 (FAX)
    dfoster@usgs.gov
    Date: 19-Apr-2017 (process 2 of 2)
    The online links to the data were updated to reflect the new server hosting the data. Additionally, other small edits could be made to the metadata, such as modifying http to https where appropriate. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. 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?
    Pendleton, Elizabeth A., Ackerman, Seth D., Baldwin, Wayne E., Danforth, William W., Foster, David S., Thieler, E. Robert, and Brothers, Laura L., 2015, High-resolution geophysical data collected along the Delmarva Peninsula 2014, U.S. Geological Survey Field Activity 2014-002-FA: data release DOI:10.5066/F7MW2F60, 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?
  2. How accurate are the geographic locations?
    The EdgeTech SB-0512i subbottom profiler was mounted on a catamaran sled and towed at the sea surface approximately 43 m astern of the M/V Scarlett Isabella. The transducer depth below water line was 0.5 meters below catamaran floats. Navigation data for the 512i were collected using a Differential GPS (DGPS) and Wide Area Augmentation System (WAAS) GPS enabled Garmin receiver, which was located on the catamaran sled and connected to the acquisition computer via a serial cable. Positioning data were recorded in SonarWiz (versions 5.00.015 and 5.06.0058) acquisition software, which logged positioning coordinates to individual trace headers SEG-Y and JSF format. WAAS enabled GPS horizontal positional accuracy is assumed to be within 2 m.
  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 l155f1.
  5. How consistent are the relationships among the observations, including topology?
    These seismic reflection profile data were collected at roughly 3.2 kilometer line spacing during the multi-channel seismic reflection profile survey (Julian day 161-168) and at 200 meter line spacing during the sidescan sonar mapping survey (JD 168-195). The M/V Scarlet Isabella can only survey in water depths greater than 8 meters, so there are some gaps in the survey lines where the vessel had to avoid crossing shallow shoals. Most of the gaps were planned with breaks in tracklines or maneuvers around the shoals. Most of the data were acquired roughly parallel to the orientation of Assateague Island at an average speed of 5 knots. Crosslines lines were collected roughly perpendicular to the coast. Line numbering begins at line 1 and ends at line 178. Any spurious data points were removed during processing. There is a starting shot point (1) and ending shot point (x) with even 500-shot intervals in the shapefile for each seismic trackline. The CSV file contains unique shot point navigation. No duplicate navigation fixes exist for multiple shots.

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)
    Edward M. Sweeney
    U.S. Geological Survey
    Physical Scientist
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2256 (voice)
    508-457-2310 (FAX)
    emsweeney@usgs.gov
  2. What's the catalog number I need to order this data set? USGS data release 2015-001-FA 512i shot point data from the Delmarva Peninsula area (2015-001-FA_512i_500sht.zip). The zip file contains a folder with the following shapefile: 2015-001-FA_512i_500sht.shp, a browse graphic (2015-001-FA_512i_500sht_browse.jpg), a CSV file of unique shot point locations (2015-001-FA_512i_shot-nav.csv) and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata files (2015-001-FA_512i_500sht.xml) in four standard formats are also included in the zip 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 zip file contains data available in shapefile format. The user must have software capable of reading shapefile format to use these data. The CSV file can be read with a text editor.

Who wrote the metadata?

Dates:
Last modified: 19-Apr-2017
Metadata author:
Edward M. Sweeney
U.S. Geological Survey
Physical Scientist
384 Woods Hole Road
Woods Hole, Massachusetts
USA

508-548-8700 x2256 (voice)
508-457-2310 (FAX)
emsweeney@usgs.gov
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.9.36 on Wed Apr 19 15:34:59 2017