CRED Fagatele Bay National Marine Sanctuary Bathymetric Position Index Habitat Structures 2004

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Frequently-anticipated questions:

What does this data set describe?

Title:
CRED Fagatele Bay National Marine Sanctuary Bathymetric Position Index Habitat Structures 2004
Abstract:
Bathymetric Position Index (BPI) Structures are derived from derivatives of Simrad EM-3000 multibeam bathymetry (1 m and 3 m resolution). BPI structures are surficial characteristics of the seafloor based on a bathymetric position index value range at a combined fine scale and broad scale, slope values and depth. High-resolution multibeam bathymetry, derivatives of bathymetry (bathymetric position index, slope and rugosity), backscatter imagery and in situ visual survey data have been combined in a geographic information system (GIS). These data are supplemented by three-dimensional (3D) visualization. Within this study, methods were developed for benthic mapping and applied to three sites around American Samoa, a new classification scheme was developed for bathymetric position index (BPI) zones (depressions, slopes, flats, crests) and structures (finer features within zones) around the study sites, and visual survey information was associated with the results.
  1. How should this data set be cited?

    Emily Lundblad, Oregon State Univ., 20040607, CRED Fagatele Bay National Marine Sanctuary Bathymetric Position Index Habitat Structures 2004: Fagatele Bay National Marine Sanctuary Office, Tutuila, American Samoa.

    Online Links:

    This is part of the following larger work.

    NOAA National Ocean Service (NOS) Special Projects, 20040607, Fagatele Bay National Marine Sanctuary Bathymetric Position Index Structures: Fagatele Bay National Marine Sanctuary Office, Tutuila, American Samoa.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -170.775030
    East_Bounding_Coordinate: -170.757960
    North_Bounding_Coordinate: -14.358282
    South_Bounding_Coordinate: -14.375030

  3. What does it look like?

    <http://data.nodc.noaa.gov/coris/data/NOAA/nmfs/pifsc/cred/benthic_habitat/fagatelebay/habitatstructures/FB-struct2-layout-cite.jpg> (JPEG)
    Fagatele Bay BPI Structures map

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

    Beginning_Date: Mar-2001
    Ending_Date: 07-Jun-2004
    Currentness_Reference: publication date

  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?

      This is a Raster data set. It contains the following raster data types:

      • Dimensions 624 x 620 x 1, type Grid Cell

    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: -2
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -171.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 10000000.000000

      Planar coordinates are encoded using Row and Column
      Abscissae (x-coordinates) are specified to the nearest 2.965509
      Ordinates (y-coordinates) are specified to the nearest 2.965509
      Planar coordinates are specified in meters

      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?

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?

    Emily Lundblad
    NOAA's Pacific Islands Fisheries Science Center's Coral Reef Ecosystem Division
    GIS Specialist
    1680 East-West Road POST 833
    Honolulu, Hawaii 96822
    USA

    808-956-2698 (voice)
    808-956-6539 (FAX)
    Emily.Lundblad@noaa.gov

Why was the data set created?

Structures were derived as a baseline, or framework, for spatial analysis during future habitat studies around American Samoa.

How was the data set created?

  1. From what previous works were the data drawn?

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

    Date: 24-Jun-2003 (process 1 of 1)
    This study uses the extensive multibeam bathymetry coverage around American Samoa to analyze and classify Bathymetric Position Index (BPI) zones, structures and rugosity for depths that can not be efficiently reached by other surveying methods. The methods developed here and applied to American Samoa sites are the first to successfully create a benthic classification for multibeam bathymetry beyond 30 meters depth that extends existing shallow water benthic classifications (See The Development and Application of Benthic Classifications for Coral Reef Ecosystems Below 30M Depth using Multibeam Bathynmetry: Tutuila, American Samoa, 2004, Appendix A). Spatial analysis was used to derive slope and multiple scales of bathymetric position from the original bathymetry. The resulting derivative grids were combined with a new algorithm to develop final products: BPI zones, structures and rugosity classification maps for each study site. The maps make use of a new classification scheme that may be extended to other coral reef systems. The classification methods identify thirteen structure classes: narrow depression, local depression on flat, lateral midslope depression, depression on crest, broad depression with an open bottom, broad flat, shelf, open slopes, local crest in depression, local crest on flat, lateral midslope crest, narrow crest, and steep slope.

    if (nfb02_tpi20st <= -100 and nfb02_tpi250s <= -100) fb02_20x250 = 1 else if (nfb02_tpi20st <= -100 and nfb02_tpi250s > -100 and nfb02_tpi250s < 100 and nfb02_slp <= 5 ) fb02_20x250 = 2 else if (nfb02_tpi20st <= -100 and nfb02_tpi250s > -100 and nfb02_tpi250s < 100 and nfb02_slp > 5) fb02_20x250 = 3 else if (nfb02_tpi20st <= -100 and nfb02_tpi250s >= 100) fb02_20x250 = 4 else if (nfb02_tpi20st > -100 and nfb02_tpi20st < 100 and nfb02_tpi250s <= -100) fb02_20x250 = 5 else if (nfb02_tpi20st > -100 and nfb02_tpi20st < 100 and nfb02_tpi250s > -100 and nfb02_slp <= 5 and nfb02_1m_utm < -22) fb02_20x250 = 6 else if (nfb02_tpi20st > -100 and nfb02_tpi20st < 100 and nfb02_tpi250s > -100 and nfb02_slp <= 5 and nfb02_1m_utm >= -22) fb02_20x250 = 7 else if (nfb02_tpi20st > -100 and nfb02_tpi20st < 100 and nfb02_tpi250s > -100 and nfb02_slp > 5 and nfb02_slp <= 70) fb02_20x250 = 8 else if (nfb02_tpi20st >= 100 and nfb02_tpi250s <= -100) fb02_20x250 = 9 else if (nfb02_tpi20st >= 100 and nfb02_tpi250s > -100 and nfb02_tpi250s < 100 and nfb02_slp <= 5) fb02_20x250 = 10 else if (nfb02_tpi20st >= 100 and nfb02_tpi250s > -100 and nfb02_tpi250s < 100 and nfb02_slp > 5) fb02_20x250 = 11 else if (nfb02_tpi20st >= 100 and nfb02_tpi250s >= 100) fb02_20x250 = 12 else if (nfb02_tpi20st > -100 and nfb02_tpi20st < 100 and nfb02_tpi250s > -100 and nfb02_slp > 70) fb02_20x250 = 13 endif

    where (1) narrow depression, (2) local depression on flat, (3) lateral midslope depression, (4) depression on crest, (5) broad depression with an open bottom, (6) broad flat, (7) shelf, (8) open slopes, (9) local crest in depression, (10) local crest on flat, (11) lateral midslope crest, (12) narrow crest, and (13) steep slope.

    For additional information see <ftp://ftp.soest.hawaii.edu/pibhmc/web/docs/Lundblad_Thesis.pdf>

    Person who carried out this activity:

    Emily Lundblad
    NOAA's Pacific Islands Fisheries Science Center's Coral Reef Ecosystem Division
    GIS Specialist
    1680 East-West Road POST 833
    Honolulu, Hawaii 96822
    USA

    808-956-2698 (voice)
    808-956-6539 (FAX)
    Emily.Lundblad@noaa.gov

    Data sources used in this process:

  3. What similar or related data should the user be aware of?

    Emily Lundblad, Oregon State University, 20040607, The Development and Application of Benthic Classifications for Coral Reef Ecosystems Below 30 m Depth using Multibeam Bathymetry: Tutuila, American Samoa: Department of Geosciences, Oregon State University.

    Online Links:

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

    For the bathymetry this grid was derived from: Soundings have been "cleaned" with a 2nd standard deviation filter to flag outliers (i.e., points beyond the 2nd standard deviation in Simrad bin stat post processing were flagged or removed). Tidal corrections: NOAA, verified, downloaded tide data, preliminary pressure water level data (N1) data are in meters above MLLW datum from station 1770000, Pago Pago, AS. Data have not yet been corrected with differential GPS.

  2. How accurate are the geographic locations?

  3. How accurate are the heights or depths?

    Derived from bathymetry that was post-processed with tidal corrections: NOAA, verified, downloaded tide data, preliminary pressure water level data (N1) data are in meters above MLLW datum from station 1770000, Pago Pago, AS.

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

    All structures found were accounted for in the classsification scheme.

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

    These data are believed to be logically consistent, though no tests were performed.

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: NOT for navigational purposes!!!

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

    Emily Lundblad
    NOAA's Pacific Islands Fisheries Science Center's Coral Reef Ecosystem Division
    GIS Specialist
    1680 East-West Road POST 833
    Honolulu, Hawaii 96822
    USA

    808-956-2698 (voice)
    808-956-6539 (FAX)
    Emily.Lundblad@noaa.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?

    NOT for navigational purposes!!! NOAA makes no warranty regarding these data,expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA does not assume liability for any damages caused by any errors or omissions in these data, nor as a result of the failure of these data to function on a particular system.

  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 29-Aug-2008
Metadata author:
NOAA's Pacific Islands Fisheries Science Center's Coral Reef Ecosystem Division
c/o Emily Lundblad
GIS Specialist
1680 East-West Road POST 833
Honolulu, Hawaii 96822
USA

808-956-2698 (voice)
808-956-6539 (FAX)
Emily.Lundblad@noaa.gov

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

Generated by mp version 2.8.23 on Fri Sep 5 04:18:56 2008