PNG Images of chirp sub-bottom profiler data collected by the U.S. Geological Survey offshore of Fire Island, NY in 2011 (PNG Image Format)

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Frequently anticipated questions:

What does this data set describe?

Title:
PNG Images of chirp sub-bottom profiler data collected by the U.S. Geological Survey offshore of Fire Island, NY in 2011 (PNG Image Format)
Abstract:
The U.S. Geological Survey (USGS) mapped approximately 336 square kilometers of the lower shoreface and inner-continental shelf offshore of Fire Island, New York in 2011 using interferometric sonar and high-resolution chirp seismic-reflection systems. These spatial data support research on the Quaternary evolution of the Fire Island coastal system and provide baseline information for research on coastal processes along southern Long Island. For more information about the WHCMSC Field Activity, see https://cmgds.marine.usgs.gov/fan_info.php?fan=2011-005-FA.
  1. How might this data set be cited?
    U.S. Geological Survey, 2015, PNG Images of chirp sub-bottom profiler data collected by the U.S. Geological Survey offshore of Fire Island, NY in 2011 (PNG Image Format): data release DOI:10.5066/F75X2704, 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., 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:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -73.278147
    East_Bounding_Coordinate: -72.745661
    North_Bounding_Coordinate: 40.749798
    South_Bounding_Coordinate: 40.544405
  3. What does it look like?
    https://cmgds.marine.usgs.gov/data/field-activity-data/2011-005-FA/data/seismics/2011-005-FA_chimages.png (PNG)
    Thumbnail image of chirp subbottom data collected by the U.S. Geological Survey on the inner-continental shelf offshore of Fire Island, NY, 2011.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 21-May-2011
    Ending_Date: 05-Jun-2011
    Currentness_Reference:
    ground condition during 20110521 - 20110605
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: raster 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?
  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?

PNG images of each seismic profile were generated in order to incorporate images of the seismic data into Geographic Information System (GIS) projects and data archives. These PNG images represent 2200 kilometers of chirp seismic data collected with an Edgetech Geo-Star FSSB sub-bottom profiling system and an SB-0512i towfish (0.5 - 12 kHz) during USGS field activity 2011-005-FA. The PNG format is universal and yields an easily viewable image of the seismic profiles. Corresponding trackline navigation is contained within a polyline shapefile (2011-005-FA_chirptrk.shp), shot-point locations are available in a point shapefile (2011-005-FA_chirp500sht.shp). (see: https://doi.org/10.5066/F75X2704)

How was the data set created?

  1. From what previous works were the data drawn?
    chirp images (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, Raw seismic data.

    Type_of_Source_Media: disk
    Source_Contribution:
    Shallow geologic framework and surficial geology were interpreted from approximately 2200 trackline kilometers of chirp seismic-reflection profiles that were collected during U.S. Geological Survey field activity 2011-005-FA ( https://cmgds.marine.usgs.gov/fan_info.php?fan=2011-005-FA). Final, post-processed profiles were used to make the interpretations. Survey: Survey lines were run at an average speed of 5 knots. Lines 14 through 27 were run at a 75-m line spacing to achieve full coverage of the seafloor with sonar systems in a priority area of interest in the nearshore, in water depths less than 15 meters. Lines 28 through 92 were run at a 150-m line spacing, with the exception of tie lines (lines 52 through 60, 65 through 67, 89 through 92), which were run at approximately a 2-km line spacing. Seismic Data: 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. Chesapeake Technologies' SonarWiz (v.5.03.0016) 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 record DGPS 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 0.25-s shot rate, a 5-ms pulse length, and a 0.5 to 8 kHz frequency sweep. Recorded trace lengths were approximately 200 ms (4340 samples/trace and .000046-s sample interval).
  2. How were the data generated, processed, and modified?
    Date: 2011 (process 1 of 6)
    Processing Seismic Data: 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. Wayne E. Baldwin performed this and all subsequent process steps. Person who carried out this activity:
    Wayne E. Baldwin
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 x2226 (voice)
    508-457-2310 (FAX)
    wbaldwin@usgs.gov
    Date: 2011 (process 2 of 6)
    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 (WGS84) using Proj (version 4.6.0). Header information from each SEG-Y file were 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. 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 PNG images.
    Date: 2011 (process 3 of 6)
    Seismic Unix (version 4.2) was used to read all processed SEG-Y files and plot the data as 8-bit gray scale Postscript files using the Seismic Unix 'psimage' algorithm. All images were created with a horizontal scale of 200 traces per inch. The profiles contain 60 milliseconds of Two-Way Travel Time within an 12-inch vertical window, yielding approximately 5 milliseconds per inch. Postscript images were converted to PNG format using ImageMagick (version 6.6.1) The x-axis units of the images are shot number while the y-axis is two-way travel time in seconds.
    Date: 18-Apr-2017 (process 4 of 6)
    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
    Date: 20-Jul-2018 (process 5 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: 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?
    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:

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 was mounted on a catamaran sled and towed at the sea surface 51.5 m (lines l14f1 - l74f1) and 43.2 m (lines l75f1 - l92f1) astern of the M/V Scarlett Isabella. Position data were provided by a Differential Global Positioning System (DGPS) navigation receiver (F180 (lines l14f1 - l74f1) and BR2G (lines l75f1 - l92f1)). Layback navigation was generated to account for towfish position. Positional accuracy is assumed to be ± 10 m.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Acquired chirp seismic data (Lines 14 - 92) were processed and PNG images produced. Only bathymetric data were collected for lines 1 -13, as outlined in the research plan.
  5. How consistent are the relationships among the observations, including topology?
    All subbottom data were collected during USGS cruise 2011-005-FA using an Edgetech SB-512i chirp subbottom profiler. Processed chirp seismic data (lines 14 - 92) 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 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)
    508-457-2311 (FAX)
    jdenny@usgs.gov
  2. What's the catalog number I need to order this data set? 2011-005-FA_chimages.zip - this zip file contains 303 PNG files representing seismic-reflection profiles collected during WHCMSC field activity 2011-005-FA.
  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 PNG image viewing software.

Who wrote the metadata?

Dates:
Last modified: 18-Mar-2024
Metadata author:
Jane F. Denny
U.S. Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, MA
USA

508-548-8700 x2311 (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/2011_005_fa/2011-005-FA_chimages.faq.html>
Generated by mp version 2.9.51 on Wed Apr 24 13:53:35 2024