Composite 2-m ASCII Bathymetric grid from National Oceanic and Atmospheric Administration (NOAA) Surveys H11252 and h11361 of the Sea Floor in Eastern Long Island Sound (SMR_COMP_2MUTM_XYZ.TXT, UTM Zone18)

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Frequently anticipated questions:

What does this data set describe?

Title:
Composite 2-m ASCII Bathymetric grid from National Oceanic and Atmospheric Administration (NOAA) Surveys H11252 and h11361 of the Sea Floor in Eastern Long Island Sound (SMR_COMP_2MUTM_XYZ.TXT, UTM Zone18)
Abstract:
The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology.
Anthropogenic wastes, toxic chemicals, and changes in land-use patterns resulting from residential, commercial, and recreational development have stressed the environment of the Sound, causing degradation and potential loss of benthic habitats (Koppelman and others, 1976; Long Island Sound Study, 1994). Detailed maps of the sea floor are needed to help evaluate the extent of adverse impacts and to help manage resources wisely in the future. Therefore, in a continuing effort to better understand Long Island Sound, we have constructed and interpreted multibeam bathymetric data within specific areas of special interest. This bathymetric data layer presented herein covers a roughly 156 km square area of the sea floor in the vicinity of Six Mile Reef, eastern Long Island Sound. The original multibeam bathymetric data were collected during 2004 as part of charting applications (surveys H11252 and h11361) aboard the NOAA Survey Vessel Thomas Jefferson. A Simrad EM1002 multibeam system mounted on the hull of this vessel was used to acquire data along survey lines from the deeper water (>20 m) parts of the survey areas. Two 29-foot launches with hull-mounted Reson systems were deployed from the ship and were used to acquire data along survey lines from the shallower areas.
Detailed bathymetric data and their interpretations serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The bathymetric data models also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretation of point measurements.
  1. How might this data set be cited?
    U.S. Geological Survey, 2007, Composite 2-m ASCII Bathymetric grid from National Oceanic and Atmospheric Administration (NOAA) Surveys H11252 and h11361 of the Sea Floor in Eastern Long Island Sound (SMR_COMP_2MUTM_XYZ.TXT, UTM Zone18): Open-File Report 2007-1191, 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.

    Poppe, L.J., Denny, J.F., Williams, S.J., Moser, M.S., Forfinski, N.A., Stewart, H.F., and Doran, E.F., 2007, The Geology of Six Mile Reef, Eastern Long Island Sound: Open-File Report 2007-1191, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -72.650332
    East_Bounding_Coordinate: -72.396231
    North_Bounding_Coordinate: 41.221784
    South_Bounding_Coordinate: 41.144777
  3. What does it look like?
    https://pubs.usgs.gov/of/2007/1191/data/composite/bathy/grids/utm/asciigrid/smr_comp_2mutm_xyz.gif (GIF)
    Thumbnail image showing the extent of soundings collected during NOAA surveys H11252 and H11361
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2004
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set.
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 18
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: .999600
      Longitude_of_Central_Meridian: -75.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 2.000359
      Ordinates (y-coordinates) are specified to the nearest 2.000000
      Planar coordinates are specified in meters
      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Mean lower low water
      Depth_Resolution: 9999
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    Three space separated values per record. Value one is the eastings coordinate in meters of the ship coordinate; value 2 is the northings coordinate in meters the ship's coordinate; value three is the acquired depth value. The depth value is recorded in meters as a positive value.
    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?
    Source data were acquired during National Oceanic and Atmospheric Administration (NOAA) surveys H11252 and H11361 aboard the survey vessel Thomas Jefferson. Please acknowledge NOAA as the originator of the datasets from which this dataset was derived.
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Lawrence Poppe
    Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    (508) 548-8700 x2314 (voice)
    (508) 457-2310 (FAX)
    lpoppe@usgs.gov

Why was the data set created?

To release an ASCII XYZ (Easting, Northing, and Depth) file containing the composite 2-m bathymetry generated from NOAA surveys H11252 and H11361 in Long Island Sound.

How was the data set created?

  1. From what previous works were the data drawn?
    Information unavailable from original metadata. (source 1 of 1)
    (assumed), NOAA, unknown, Information unavailable from original metadata..

    Type_of_Source_Media: DVD-ROM
    Source_Contribution:
    The original multibeam bathymetric data acquired with Simrad EM1002, Reson 8101, and 8125 echosounder systems during NOAA surveys H11252 and H11361 aboard the NOAA ship Thomas Jefferson. A Simrad EM1002 multibeam system mounted on the hull of this vessel was used to acquire data along survey lines from the deeper water (>20 m) parts of the study area. Two 29-foot launches with hull-mounted Reson systems were deployed from the ship and were used to acquire data along survey lines from the shallower areas.
  2. How were the data generated, processed, and modified?
    Date: Unknown (process 1 of 6)
    The multibeam data were acquired in XTF (extended Triton data format), recorded digitally through an ISIS data acquisition system, and processed using CARIS HIPS (Hydrographic Image Processing System) software for quality control, to incorporate sound velocity and tidal corrections, and to produce base surfaces averaging 2-m resolution over the study area. The data were exported in text (.txt) format in UTM Zone 18. Person who carried out this activity:
    Marc Moser
    National Oceanic and Atmospheric Administration
    Field Operations Officer
    439 West York Street
    Norfolk, VA
    USA

    (757) 441-6746 (voice)
    marc.s.moser@noaa.gov
    Data sources used in this process:
    • raw bathymetric data
    Data sources produced in this process:
    • h11252_2mutm18.xyz.txt
    • h11361_2mutm18.xyz.txt
    Date: 2007 (process 2 of 6)
    The xyz (easting, northing, and depth) data were combined using the University of New Brunswick SwathEd weigh_grid command and saved in .txt format. Person who carried out this activity:
    Jane Denny
    U.S. Geological Survey
    GIS Specialist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    508-548-8700 x2311 (voice)
    508-457-2310 (FAX)
    jdenny@usgs.gov
    Data sources used in this process:
    • h11252_2mutm18.xyz.txt
    • h11361_2mutm18.xyz.txt
    Data sources produced in this process:
    • smr_comp_2mutm_xyz.txt
    Date: 10-Feb-2017 (process 3 of 6)
    Edits to the metadata were made to fix any errors that MP v 2.9.36 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Attempted to modify http to https where appropriate. The source information was incomplete and had to be modified to meet the standard. In the case of the depth resolution, the value of 9999 was entered to indicate that the original metadata did not contain the required information. The geodetic model parameters for semi-major axis and denominator of flattening ratio were added to match the datum name. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. 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 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: 18-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?
    Poppe, L.J., Williams, S.J., Moser, M.S., Forfinski, N.A., Stewart, H.F., and Doran, E.F., 2007, Quaternary geology and sedimentary processes in the vicinity of Six Mile Reef, eastern Long Island Sound: Journal of Coastal Research v. 23, no. 6.

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?
    Navigation was by differential GPS. Horizontal resolution of the data varies with water depth, but averages 2 m.
  3. How accurate are the heights or depths?
    Vertical resolution is about 0.5% of the water depth.
  4. Where are the gaps in the data? What is missing?
    All collected bathymetric data from NOAA surveys H11252 and H11361 were processed and used to produce this dataset.
  5. How consistent are the relationships among the observations, including topology?
    Information unavailable from original metadata.

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:
Data are not to be used for navigation purposes.
Public domain data are freely redistributable with proper metadata and source attribution. Please recognize the National Oceanic and Atmospheric Administration (NOAA) as the originator of this information.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    Attn: Larry Poppe
    Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    (508) 548-8700 x2314 (voice)
    (508) 457-2310 (FAX)
    lpoppe@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    Although this data set has been used by the U.S. Geological Survey (USGS, no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or related materials. 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?
    The user must have a program capable of reading and processing ASCII formatted XYZ data files.

Who wrote the metadata?

Dates:
Last modified: 16-Nov-2021
Metadata author:
Larry Poppe
U.S. Geological Survey
Geologist
384 Woods Hole Road
Woods Hole, MA
USA

(508) 548-8700 x2314 (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 metadata contact is no longer with the USGS or the email is otherwise invalid.
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2007-1191/smr_comp_2mutm_xyz_mdata.faq.html>
Generated by mp version 2.9.50 on Tue Nov 16 10:06:35 2021