Seismic Systems: Start of Line

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Frequently-anticipated questions:


What does this data set describe?

    Title: Seismic Systems: Start of Line
    Abstract:
    These data represent the first shot point for each line of data acquired with various seismic-reflection systems utilized during U.S. Geological Survey geophysical research cruises.

  1. How should this data set be cited?

    Denny, Jane F. , 2002, Seismic Systems: Start of Line: ESRI ArcView shapefile version 3.2, U.S. Geological Survey, Woods Hole, MA.

    This is part of the following larger work.

    Schwab, William C., Denny, Jane F., Foster, David S., Lotto, Linda L., Allison, Mead A., Uchupi, Elazar, Swift, B. Ann, Danforth, William W., Thieler, Robert E., and Butman, Bradford, 2002, High-Resolution Quaternary seismic stratigraphy of the New York Bight Continental Shelf: Open-File Report OFR02-152, U.S. Geological Survey, Woods Hole, MA.

     

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -74.06
    East_Bounding_Coordinate: -71.8000
    North_Bounding_Coordinate:
    41.2322 41.233
    South_Bounding_Coordinate: 40.15

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 07-May-1995
    Ending_Date: 01-Nov-1998
    Currentness_Reference: Publication Date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: digital vector 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):

      • point

    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 0.000089992. Longitudes are given to the nearest 0.000089992. Latitude and longitude values are specified in decimal degrees.

      The horizontal datum used is WGS84.
      The ellipsoid used is WGS84.
      The semi-major axis of the ellipsoid used is 6378137.0000000.
      The flattening of the ellipsoid used is 1/298.26.

      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: Assumed sea level
      Altitude_Resolution: 1
      Altitude_Distance_Units: Two-way travel time
      Altitude_Encoding_Method: Attribute values
      Depth_System_Definition:
      Depth_Datum_Name: Local surface
      Depth_Resolution: 1
      Depth_Distance_Units: Meters
      Depth_Encoding_Method: Attribute values

  7. How does the data set describe geographic features?

    Seismic Shot Point Navigation: Start of Line
    Shapefile Attribute Table (Source: ArcView 3.2)

    Shape
    internal ArcView 3.2 ID (Source: ArcView 3.2)

    ArcView 3.2

    Cruise
    USGS Cruise ID Number (Source: USGS Internal ID)

    Cruise ID Number

    Source
    Seismic data source (Source: none)

    Seismic data source

    Lon
    X Coordinate; Geographic Coodinate System (decimal degrees) (Source: data set)

    Range of values
    Minimum:-74.06
    Maximum:-71.8000

    Lat
    Y-Coordinate; Geographic Coordinate System (decimal degrees) (Source: data set)

    Range of values
    Minimum:40.15
    Maximum:41.2322

    Line
    Line Number (Source: data set)

    Line Number

    Shot
    Shot Point Number (Source: data set)

    Shot Point Number

    Utmx
    X-Coordinate UTM, Zone 18, WGS84 datum, meters (Source: data set)

    Range of values
    Minimum:57877.82
    Maximum:772576.56

    Utmy
    Y-Coordinate: UTM, zone 18, WGS84, meters (Source: data set)

    Range of values
    Minimum:4449316.76
    Maximum:4564959.94

    Year
    Year of Cruise (Source: data set)

    Calendar year

    Jd_hr_min
    Julian Day, hour, minute (Source: data set)

    Day and Time


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?

    Jane F. Denny
    US Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

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


Why was the data set created?

Beginning in 1995, the USGS, in cooperation with the U.S Army Corps of Engineers (USACE), New York District, began a program to generate reconnaissance maps of the sea floor offshore of the New York-New Jersey metropolitan area, one of the most populated coastal regions of the United States. The goal of this mapping program is to provide a regional synthesis of the sea-floor environment, including a description of sedimentary environments, sediment texture, seafloor morphology, and geologic history to aid in understanding the impacts of anthropogenic activities, such as ocean dumping. This mapping effort differs from previous studies of this area by obtaining digital, sidescan sonar images that cover 100 percent of the sea floor. This investigation was motivated by the need to develop an environmentally acceptable solution for the disposal of dredged material from the New York- New Jersey Port, by the need to identify potential sources of sand for nourishment of the southern shore of Long island, and by the opportunity to develop a better understanding of the transport and long-term fate of contaminants by investigations of the present distribution of materials discharged into the New York Bight over the last 100+ years (Schwab and others, 1997).


How was the data set created?

  1. From what previous works were the data drawn?

    OFR 01-97 (source 1 of 5)
    Hill, Jenna C. , Schwab, William C. , and Foster, David S. , 2001, Archive of Datasonics SIS-1000 Chirp Subbottom Data Collected During USGS Cruise SEAX 95007, New York Bight, 7-25 1995: Open-File Report 01-97, U.S. Geological Survey, Woods Hole, MA.

    Type_of_Source_Media: DVD-ROM
    Source_Contribution:
    This publication contains the raw SEG-Y CHIRP seismic-reflection data stored on DVD-ROM. The navigation used to generate the CHIRP trackline data were stripped from the raw SEG-Y header.

    CHIRP Archive (source 2 of 5)
    Hill, Jenna C., Schwab, W.C., and Foster, D.S., 2001, Archive of Chirp Subbottom Data Collected Druing USGS Cruise SEAX96004 New York Bight, 1 May - 9 June, 1996.: U.S. Geological Survey Open-File Report 01-96, U.S. Geological Survey, Woods Hole, MA.

    Type_of_Source_Media: DVD-ROM
    Source_Contribution:
    This publication contains the raw SEG-Y CHIRP seismic-reflection data stored on DVD-ROM. The navigation used to generate the CHIRP trackline data were stripped from the raw SEG-Y header.

    CHIRP Archive (source 3 of 5)
    Hill, Jenna C., Schwab, W.C., and Foster, D.S., 2001, Archive of Water Gun Subbottom Data Collected Druing USGS Cruise SEAX95007 New York Bight, 7-25 May, 1995: U.S. Geological Survey Open-File Report 01-157, U.S. Geological Survey, Woods Hole, MA.

    Type_of_Source_Media: DVD-ROM
    Source_Contribution:
    This publication contains the raw SEG-Y CHIRP seismic-reflection data stored on DVD-ROM. The navigation used to generate the CHIRP trackline data were stripped from the raw SEG-Y header.

    CHIRP Archive (source 4 of 5)
    Hill, Jenna C., Schwab, W.C., and Foster, D.S., 2001, Archive of Boomer Subbottom Data Collected Druing USGS Cruise SEAX96004 New York Bight, 1 May - 9 June, 1996.: U.S. Geological Survey Open-File Report 00-340, U.S. Geological Survey, Woods Hole, MA.

    Type_of_Source_Media: DVD-ROM
    Source_Contribution:
    This publication contains the raw SEG-Y CHIRP seismic-reflection data stored on DVD-ROM. The navigation used to generate the CHIRP trackline data were stripped from the raw SEG-Y header.

    CHIRP Archive (source 5 of 5)
    Hill, Jenna C., Schwab, W.C., and Foster, D.S., 2001, Archive of Water Gun Subbottom Data Collected Druing USGS Cruise SEAX96004 New York Bight, 1 May - 9 June, 1996.: U.S. Geological Survey Open-File Report 00-396, U.S. Geological Survey, Woods Hole, MA.

    Type_of_Source_Media: DVD-ROM
    Source_Contribution:
    This publication contains the raw SEG-Y CHIRP seismic-reflection data stored on DVD-ROM. The navigation used to generate the CHIRP trackline data were stripped from the raw SEG-Y header.

  2. How were the data generated, processed, and modified?

    Date: 2000 (process 1 of 1)
    The seismic shot navigation is received by the differential GPS system (DGPS), sent directly to the seismic acquisition system, and recorded in the SEG-Y header of each file. The navigation is later extracted from the SEG-Y header, the first shot point is extracted, converted from its native UTM projection (zone 18, units meters, WGS84 datum) to Geographic Coordinate System, and formatted into a comma-delimited ASCII file. This file is imported into ArcView 3.2 as a table. The table is then converted into a point shapefile.

    Person who carried out this activity:

    Jane F. Denny
    US Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

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

  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?

    DGPS is assumed to be accurate within 1-2 meters. Standard GPS is assumed accurate within 5-10 meters. 99% of the positional data is DGPS. Unless noted, all GPS/DGPS data is referenced to WGS84 (NAD83). Slant-range distance is recorded between the sidescan-sonar tow vehicle and a sidemount rigged with an acoustic transponder during acquisition of CHIRP sub-bottom data. Offset between thesidemount and GPS antennae is measured. Basic trigonomic calculations use the slant-range offset to calculate a 'fish'(tow-vehicle) navigation. An assumption in these calculations is that the tow-vehicle is traveling directly behind the vessel; movement to port or starboard is not accounted for within 'fish' navigation. Thus, the horizontal accuarcy of the CHIRP tow-vehicle is +/- 15 meters. The horizontal positioning for boomer, sparker, and water gun seismic systems did not account for source and receiver offsets and offset the GPS antennae and the source and streamer. It is estimated that these offsets could lead to inaccuracies of about 30 m.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    Complete

  5. How consistent are the relationships among the observations, including topology?

    These navigation data have been stripped from the header of seismic SEG-Y data. They have been quality checked by comparing these data to navigation data acquired during cruise operations.


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:
The U.S. Geological Survey must be referenced as the originator of the dataset in any future publications.

  1. Who distributes the data set? (Distributor 1 of 1)

    Jane F. Denny
    US Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543
    USA

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

  2. What's the catalog number I need to order this data set?

  3. What legal disclaimers am I supposed to read?

    This publication was prepared by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, expressed or implied, or assumes any legal liability or responsibility information, apparatus, product, or process disclosed in this report, or represents that its use would not infringe privately owned rights. Reference therein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. Any views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Although all data published on this DVD-ROM have been used by the USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and related materials and/or the functioning of the software. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of this data, software, or related materials.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 19-Jan-2002
Last Reviewed: 2002

Metadata author:
Jane F. Denny
US Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, MA 02543
USA

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

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)


Generated by mp version 2.7.17 on Mon Apr 15 12:54:03 2002