Chirp seismic reflection data from the Edgetech 512i collected in Little Egg Inlet and offshore the southern end of Long Beach Island, NJ, during USGS field activity 2018-001-FA (shotpoints point shapefile, survey trackline shapefile, PNG profile images, and SEG-Y trace data).

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Frequently anticipated questions:

What does this data set describe?

Title:
Chirp seismic reflection data from the Edgetech 512i collected in Little Egg Inlet and offshore the southern end of Long Beach Island, NJ, during USGS field activity 2018-001-FA (shotpoints point shapefile, survey trackline shapefile, PNG profile images, and SEG-Y trace data).
Abstract:
The natural resiliency of the New Jersey barrier island system, and the efficacy of management efforts to reduce vulnerability, depends on the ability of the system to recover and maintain equilibrium in response to storms and persistent coastal change. This resiliency is largely dependent on the availability of sand in the beach system. In an effort to better understand the system's sand budget and processes in which this system evolves, high-resolution geophysical mapping of the sea floor in Little Egg Inlet and along the southern end of Long Beach Island near Beach Haven, New Jersey was conducted from May 31 to June 10, 2018, followed by a sea floor sampling survey conducted from October 22 to 23, 2018, as part of a collaborative effort between the U.S. Geological Survey and Stockton University. Multibeam echo sounder bathymetry and backscatter data were collected along 741 kilometers of tracklines (approximately 200 square kilometers) of the coastal sea floor to regionally define its depth and morphology, as well as the type and distribution of sea-floor sediments. Six hundred ninety-two kilometers of seismic-reflection profile data were also collected to define the thickness and structure of sediment deposits in the inlet and offshore. These new data will help inform future management decisions that affect the natural and recreational resources of the area around and offshore of Little Egg Inlet. These mapping surveys provide high-quality data needed to build scientific knowledge of the evolution and behavior of the New Jersey barrier island system.
Supplemental_Information:
Additional information on the field activities associated with this project are available at https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-001-FA and https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-049-FA.
  1. How might this data set be cited?
    U.S. Geological Survey, 20210422, Chirp seismic reflection data from the Edgetech 512i collected in Little Egg Inlet and offshore the southern end of Long Beach Island, NJ, during USGS field activity 2018-001-FA (shotpoints point shapefile, survey trackline shapefile, PNG profile images, and SEG-Y trace data).: data release DOI:10.5066/P9C3J33K, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Ackerman, Seth D., Barnhardt, Walter A., Worley, Charles R., Nichols, Alex R., Baldwin, Wayne E., and Evert, Steve, 2021, High-resolution geophysical and geological data collected in Little Egg Inlet and offshore the southern end of Long Beach Island, NJ, during USGS Field Activities 2018-001-FA and 2018-049-FA: data release DOI:10.5066/P9C3J33K, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Ackerman, S.D., Barnhardt, W.A., Worley, C.R., Nichols, A.R., Baldwin, W.E., and Evert, S., 2021, High-resolution geophysical and geological data collected in Little Egg Inlet and offshore the southern end of Long Beach Island, NJ, during USGS Field Activities 2018-001-FA and 2018-049-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P9C3J33K.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -74.472758
    East_Bounding_Coordinate: -74.197467
    North_Bounding_Coordinate: 39.566903
    South_Bounding_Coordinate: 39.378308
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/5f5f94ad82ce3550e3bff214/?name=2018-001-FA_SB512i_browse.jpg (JPEG)
    Location of seismic profile and shotpoint locations from USGS Field Activity 2018-001-FA.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 31-May-2018
    Ending_Date: 10-Jun-2018
    Currentness_Reference:
    ground condition during field activity 2018-001-FA: 20180531-20180610
  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 0.000005. Longitudes are given to the nearest 0.000005. 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?
    2018-001-FA_SB512iTracklines.shp
    SB-512i Trackline shapefile for survey 2018-001-FA (83 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: Line-FileNumber (i.e.'Line-0004'). (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
    Shot_init
    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
    Shot_end
    Shot number at the end of the survey line. (Source: U.S. Geological Survey)
    Range of values
    Minimum:260
    Maximum:12897
    Units:shot
    Resolution:1
    Year
    Calendar year the data were collected (Source: U.S. Geological Survey) Character set
    JDUTC_init
    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
    JDUTC_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. "2018-001-FA" where 2018 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
    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:0.310164
    Maximum:15.732960
    Units:kilometers
    Resolution:0.000001
    2018-001-FA_512i_Shot500.shp
    SB512i 500-interval shot point shapefile for survey 2018-001-FA (1107 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:545297.06
    Maximum:568972.11
    Units:meters
    Resolution:0.01
    North
    Northing coordinate in UTM Zone 18 N meters, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:4358968.75
    Maximum:4379960.50
    Units:meters
    Resolution:0.01
    Lon
    Longitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:-74.472758
    Maximum:-74.197467
    Units:degrees
    Resolution:1E-06
    Lat
    Latitude coordinate in decimal degrees, WGS 84 (Source: U.S. Geological Survey)
    Range of values
    Minimum:39.378308
    Maximum:39.566903
    Units:degrees
    Resolution:1E-06
    LineName
    Name of the trackline along which seismic-reflection data were collected in the format: Line-FileNumber (i.e.'Line-0004'). (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
    Shot
    Shot number (values are first, last, and every 500 shot between). (Source: U.S. Geological Survey)
    Range of values
    Minimum:1
    Maximum:12897
    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. "2018-001-FA" where 2018 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
    2018-001-FA_SB512i_ShotUnique.csv
    SB512i shot point comma separated values file for survey 2018-001-FA (250056 point features). (Source: U.S. Geological Survey)
    2018-001-FA_512i_Images
    Portable network graphic images of processed SB512i profiles for survey 2018-001-FA (83 PNG images). (Source: U.S. Geological Survey)
    2018-001-FA_512i_SegyData
    SEG-Y (REV. 1) format files of processed SB512i profiles for survey 2018-001-FA (83 SEG-Y files). (Source: U.S. Geological Survey)
    Entity_and_Attribute_Overview:
    The column headings and range domain values in '2018-001-FA_SB512i_ShotUnique.csv' match those in '2018-001-FA_SB512i_Shot500.shp'. The PNG seismic reflection images can be hyperlinked to their corresponding trackline or shotpoint locations in ArcGIS using the shapefiles '2018-001-FA_SB512i_Tracklines.shp' or '2018-001-FA_SB512i_Shot500.shp', respectively. The fist, last, and multiple of 500 shot features in '2018-001-FA_SB512i_Shot500.shp' correspond to the x-axis ticks on the PNG images, which show two-way travel time (seconds) on the y-axis and distance along profile (annotation at 500 shot intervals) on the x-axis.
    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)
    • U.S. Geological Survey
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    sackerman@usgs.gov

Why was the data set created?

This dataset contains shotpoint and trackline navigation, profile images, and raw SEG-Y trace data for 692 km of EdgeTech 512i chirp seismic-reflection data collected by the U.S. Geological Survey during USGS field activity 2018-001-FA off southern Long Beach Island, New Jersey. Images of each seismic profile were generated in order to provide portable and easily viewable alternatives to the SEG-Y versions of the data. Each profile image can be hotlinked to its corresponding trackline navigation contained within the Esri polyline shapefile '2018-001-FA_SB512i_Tracklines.shp'. Shotpoint index and tick marks along the top of the PNG images correlate to the positions of 500 shot intervals within the Esri point shapefile '2018-001-FA_SB512i_Shot500.shp'. This information allows for spatial correlation of chirp seismic-reflection profiles images with other geophysical and sample data for investigating sea-floor morphology and stratigraphy in the area.

How was the data set created?

  1. From what previous works were the data drawn?
    SEG-Y SB-512i data (source 1 of 1)
    U.S. Geological Survey, unpublished material, SB-512i SEG-Y trace 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 R/V Petrel. SonarWiz 6 (version 6.05.011) seismic acquisition software was used to control the Geo-Star FSSB topside unit, digitally log three trace data (envelope, real, and imaginary) in the SEG-Y Rev. 1 format (IEEE floating point), 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 250 ms shot rate, with a 5-ms pulse length and a 0.5 to 8 kHz or 0.7 to frequency sweep or a 20-ms pulse length and a 0.7 to 7 frequency sweep. Recorded trace lengths were approximately 200 ms.
  2. How were the data generated, processed, and modified?
    Date: Feb-2020 (process 1 of 2)
    PROCESS STEP 1: SIOSEIS (version 2016.3.1) and python were used to process SEG-Y data and extract navigation data. The processing flows and scripts used are summarized below and in the following processing steps.
    1) The SIOSEIS script sio_renum read the raw SEG-Y files, extracted the envelope-detected trace, renumbered shots starting from one, and wrote 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 system cross talk by performing a two-trace median stack (trim 50 percent of the values furthest from the median amplitude) which improves water bottom picking.
    3) The script read512i_s was used to read the swell filtered 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.
    4) The SIOSEIS script siothresh_pltwbt (which runs the sio_threshwbt script) was used to predict water-bottom times from the envelope SEG-Y traces in each file and write the predicted two-way travel times for the seafloor to a '*.wbt.csv' file. This created new swell filtered SEG-Y files (which are included in the archive '2018-001-FA_SB512i_SegyData.zip'). Note: there is a known bug in the swell filtering algorithm that removes the last trace that was recorded in the median stack filtered SEG-Y and duplicates time and position of the third-to-last trace as the new last trace of the SEG-Y file. This affects less than a second of time at the end of each seismic profile but does not otherwise affect the rest of the sub-bottom data.
    5) Seismic Unix (version 4.2) was used to read all the swell filtered SEG-Y files and plot the data as 8-bit gray-scale Postscript files using the Seismic Unix 'psimage' algorithm. The profiles contain 80 milliseconds of two-way travel time within a 14-inch vertical window, yielding approximately 5.7 milliseconds per inch. Postscript images were converted to PNG format using ImageMagick (version 6.9.9-40). The x-axis units of the images are shot number while the y-axis is two-way travel time in seconds (note: extremely short lines may not display a complete x-axis in these images).
    6) The python script 512intoSQL18001_py2.py imports the navigation, shot, year, day, and UTC time data from CSV files into a SpatiaLite (version 4.3.0a) enabled SQLite (version 3.27.1) database, creating two tables containing point geometries. The first contained records for all of the input shots with unique navigation coordinates, and the second maintained records for the first and last shots, and shots at multiples of 500. End shots and shots at multiples of 500 may not have unique navigation coordinates. The resulting database columns for each table consist of East, North (UTM18N m), Lon, Lat (WGS84 dd), LineName, ImageName, Shot, Year, JD_UTC (DDD:HH:MM:SS), SurveyID, VehicleID, DeviceID. A third table was created to contain trackline geometries generated from the unique navigation point geometries for each line (sorted by LineName and Shot), and the line length in kilometers was calculated. The resulting database columns of the line geometry table consist of LineName, ImageName, Shot_init, Shot_end, Year, JDUTC_init, JDUTC_end, SurveyID, VehicleID, DeviceID, and Length_km.
    This process step was conducted between June 2018 and February 2020. This step and all subsequent process steps were conducted by the same person - Seth Ackerman. Person who carried out this activity:
    Seth Ackerman
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    508-548-8700 x2315 (voice)
    508-457-2310 (FAX)
    sackerman@usgs.gov
    Date: 25-Feb-2020 (process 2 of 2)
    PROCESS STEP 2: The SB-512i 500 shot, trackline and unique shot features were exported from the SQLite database as Esri point shapefile, polyline shapefiles, and text CSV file respectively, using the following SpatiaLite and SQLite commands creating the files '2018-001-FA_SB512i_Shot500.shp', '2018-001-FA_SB512iTracklines.shp' and '2018-001-FA_SB512i_ShotUnique.csv'. 
    >> spatialite_tool -e -shp 2018-001-FA_SB512i_Tracklines -d ./2018-001-FA-SQLdb_NEW2.sqlite -t track_ln -g geom_t -c CP1252 -s 4326 --type LINESTRING
>> spatialite_tool -e -shp 2018-001-FA_SB512i_Shot500 -d ./2018-001-FA-SQLdb_NEW2.sqlite -t sht500_pt -g geom_500 -c CP1252 -s 4326 --type POINT
>>sqlite3 -header -csv ./2018-001-FA-SQLdb_NEW2.sqlite "select * from unique_pt;" > 2018-001-FA_SB512i_ShotUnique.csv
  3. What similar or related data should the user be aware of?

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-512i sub-bottom profiler was mounted on a catamaran and towed astern of the R/V Petrel. Navigation data for the 512i were collected using a Wide Area Augmentation System (WAAS) enabled Garmin GPS receiver, which was located on the catamaran sled and connected to the acquisition computer via a serial cable. Positioning data were recorded using SonarWiz 6 (version 6.05.001) acquisition software, which logged coordinates to individual trace headers in SEG-Y format. A conservative estimate of horizontal positional accuracy is within 2 m.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Data were collected on the following dates: 20180531-20180610 (Julian day 151-161); no surveying was done on 20180603 (Julian day 154). Sections of tracklines where navigation was recorded but no seismic data were logged are not included such as during testing, some turns, and very short files. There is no Line-0068 or Line-0077 in this dataset.
  5. How consistent are the relationships among the observations, including topology?
    Chirp seismic-reflection data were collected during the geophysical survey 2018-001-FA offshore of Long Beach Island, NJ. The shapefile '2018-001-FA_SB-512i_Shot500.shp' contains the first (1), last (x), and 500-interval shotpoints for each seismic trackline, and '2018-001-FA_SB-512i_shtnav.csv' contains all unique shot point navigation. The attribute fields 'LineName' and 'ImageName' for each polyline feature in '2018-001-FA_SB-512iTracklines.shp' correspond to the SEG-Y data files in '2018-001-FA_SB-512i_SegyData.zip' and the PNG profile images in "2018-001-FA_SB-512i_Images.zip", respectively. One SEG-Y file, and PNG image exists for each feature. 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:
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
    U.S. Geological Survey
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    United States

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? EdgeTech SB512i chirp seismic-reflection data collected along the southern end of Long Beach Island, NJ during USGS field activity 2018-001-FA: includes '2018-001-FA_SB512i_Shot500.shp' containing the first, last and 500-interval shotpoint locations, '2018-001-FA_SB512i_ShotUnique.csv' containing unique shot point locations, '2018-001-FA_SB512i_Tracklines.shp' containing trackline features, '2018-001-FA_SB512i_Images.zip' containing 83 PNG images named according to line convention, '2018-001-FA_SB512i_SegyData.zip' containing 83 SEG-Y (REV. 1) format files of the processed traces, the browse graphic 2018-001-FA_SB512i_browse.jpg, and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file '2018-001-FA_SB512i_meta.xml'. These datasets can be downloaded individually or packaged on-demand in a zip file (see the Digital Transfer Option section).
  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. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), and have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, firm, or product 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: 22-Apr-2021
Metadata author:
Seth Ackerman
U.S. Geological Survey
Geologist
384 Woods Hole Rd.
Woods Hole, MA
USA

508-548-8700 x2315 (voice)
508-457-2310 (FAX)
sackerman@usgs.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P9C3J33K/2018-001-FA_SB512i_meta.faq.html>
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