Preliminary hard and soft bottom seafloor substrate map (40m grid) derived from an unsupervised classification of gridded backscatter and bathymetry derivatives at Rose Atoll, Territory of American Samoa, USA.

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Distribution_Information
• Metadata_Reference_Information
• CoRIS

Identification_Information:

Citation:

Citation_Information:

Originator:

Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)

Publication_Date: 20110729

Title:

Preliminary hard and soft bottom seafloor substrate map (40m grid) derived from an unsupervised classification of gridded backscatter and bathymetry derivatives at Rose Atoll, Territory of American Samoa, USA.

Geospatial_Data_Presentation_Form: digital data

Online_Linkage: http://www.soest.hawaii.edu/pibhmc/

Online_Linkage:

http://www.soest.hawaii.edu/pibhmc/pibhmc_amsamoa_rose_geomorph.htm#substrate

Description:

Abstract:

Preliminary hard and soft seafloor substrate map derived from an unsupervised classification of multibeam backscatter and bathymetry derivatives at Rose Atoll, Territory of American Samoa, USA. The dataset was created from gridded (40 m cell size) multibeam bathymetry derivatives collected aboard R/V AHI; 2 scales of bathymetric variance and bathymetric rugosity, and from multibeam backscatter. Backscatter data were from a 30 kHz Simrad EM300 sonar, gridded at 5 m. Very limited seafloor photographs for groundtruthing are available for Rose Atoll and therefore no supervised classification was performed and we are unable to visually or empirically evaluate the accuracy of the unsupervised classification seafloor substrate map. However, in locations such French Frigate Shoals, NWHI and Tutuila, American Samoa, where ground truth data are available, the unsupervised classification method is a robust predictor of substrate type in similar depth ranges and seafloor environments. Since groundtruthing was not used to validate the unsupervised classification at Rose Atoll extreme caution should be used when examining these data to locate habitat of biological significance. The map should be used in conjunction with bathymetric derivatives such as rugosity, slope, and Bathymetric Position Index (BPI).

Purpose:

The hard and soft seafloor map is being used to improve sampling techniques for long-term ecosystem monitoring, to guide future ground-truthing operations and to identify coral-rich and species specific environments. This is a preliminary product and the methods used to generate the map are currently being evaluated for their accuracy.

Supplemental_Information:

Gridded multibeam data were collected aboard the NOAA Ship Hi'ialakai, a 218 ft United States National Oceanographic and Atmospheric Administration research ship. The process for deriving the 40-m gridded multibeam bathymetry is described in Rose_40m.asc.txt, available on www.soest.hawaii.edu/pibhmc. The resulting grid (rose_40m.grd) was clipped using the ESRI ArcToolbox tool 'Extract by Mask' leaving only the multibeam data collected on the slopes surrounding the atoll and excluding the discontinuous data around the base of the slopes. Classification was carried out using this clipped dataset. Finer resolution data were available for within the lagoon, and these were classified separately (Rose_5m_hardsoft.jpg). and are also available on www.soest.hawaii.edu/pibhmc. The metadata for the lagoon hard-soft classification can be seen at Rose_5m_hardsoft.txt. The process for deriving the 5-m gridded multibeam backscatter is described in rose-em300-bs-5m.grd.txt. Prior to classification the backscatter data were re-gridded at 40-m using the resample tool in the Arc Toolbox. The 40-m rugosity and bathymetric variance grids were generated for use in the classification process and are not served separately. See the process description portion of this document for additional informaiton about how the variance and unsupervised layers were derived.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20060210

Ending_Date: 20060313

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -168.176635

East_Bounding_Coordinate: -168.131605

North_Bounding_Coordinate: -14.525078

South_Bounding_Coordinate: -14.563367

Keywords:

Theme:

Theme_Keyword_Thesaurus: NCEI Geoportal Filter

Theme_Keyword: CoRIS_Metadata

Theme:

Theme_Keyword_Thesaurus: CRCP Project

Theme_Keyword:

Benthic Habitat Mapping and Characterization - American Samoa and the U.S. Pacific Remote Island Area

Theme_Keyword: 1084

Theme:

Theme_Keyword_Thesaurus: CoRIS Theme Thesaurus

Theme_Keyword:

EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs > Coral Reef Ecology > Habitats

Theme_Keyword:

EARTH SCIENCE > Oceans > Coastal Processes > Coral Reefs > Coral Reef Ecology > Rugosity

Theme_Keyword:

EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Mapping

Theme_Keyword:

EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Mapping > geomorphology Mapping

Theme_Keyword:

EARTH SCIENCE > Biosphere > Zoology > Corals > Reef Monitoring and Assessment > Mapping > Habitat Mapping

Theme:

Theme_Keyword_Thesaurus: CoRIS Discovery Thesaurus

Theme_Keyword: Geographic Information > Habitats

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category

Theme_Keyword: imageryBaseMapsEarthCover

Theme_Keyword: 010

Place:

Place_Keyword_Thesaurus: CoRIS Place Thesaurus

Place_Keyword:

OCEAN BASIN > Pacific Ocean > American Samoa > Rose Atoll (14S168W0001)

Place_Keyword:

COUNTRY/TERRITORY > United States of America > American Samoa > American Samoa > Rose Atoll (14S168W0001)

Place:

Place_Keyword_Thesaurus: CoRIS Region

Place_Keyword: AmSam

Access_Constraints: None

Use_Constraints:

These data are not to be used for navigation purposes. Please acknowledge the NOAA Pacific Islands Fisheries Science Center (PIFSC) Coral Reef Ecosystem Division (CRED) and the Pacific Islands Benthic Habitat Mapping Center (PIBHMC), and the Joint Institute for Marine and Atmospheric Research (JIMAR) and School of Ocean and Earth Science and Technology (SOEST), University of Hawaii as the sources of this information.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)

Contact_Address:

Address_Type: mailing and physical address

Address: NOAA IRC

Address: NMFS/PIFSC/CRED

Address: 1845 WASP Blvd., Building 176

City: Honolulu

State_or_Province: HI

Postal_Code: 96818

Contact_Voice_Telephone: 808 725-5360

Contact_Facsimile_Telephone: 808 725-5429

Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov

Contact_Instructions: e-mail preferred

Browse_Graphic:

Browse_Graphic_File_Name:

http://www.soest.hawaii.edu/pibhmc/amsamoa_images/Rose_40m_hardsoft_440.jpg

Browse_Graphic_File_Description: Hard and Soft Seafloor Substrate

Browse_Graphic_File_Type: JPEG, PDF

Data_Set_Credit: PIBHMC, CRED, PIFSC, NOAA, and JIMAR

Security_Information:

Security_Classification_System: Not applicable

Security_Classification: Unclassified

Security_Handling_Description: Not applicable

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Data are collected for resource management and research purposes and are tested for internal consistency; however, no effort is made to compare these data to external references or to other published data.

Logical_Consistency_Report:

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

Completeness_Report: Complete

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

Horizontal positioning system: GPS (SPS) Horizontal position accuracy: 25 meters

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

1 m Range resolution of sonar ~1.25 cm Raw sounding resolution: Variable Vertical accuracy of gridded product: 1% of water depth

Lineage:

Process_Step:

Process_Description:

Processing steps used to generate the backscatter and bathymetry grids used in the unsupervised classification process are described in their own metadata that can be found at www.soest.hawaii.edu/pibhmc. Rugosity grid was derived from the 40m gridded multibeam bathymetry (clipped as described above) using the Benthic Terrain Modeler (BTM). The BTM may be downloaded from https://coast.noaa.gov/digitalcoast//tools/btm/index.html. The BTM, written for ArcGIS ArcGIS 8.x or 9.x, includes a component for deriving rugosity using methods by Jeff Jenness that he wrote for ArcView 3.x. Bathymetric variance was calculated from the 40 m multibeam bathymetry in a two-step process using ArcMap Version 9.2. The first step involved calculating the standard deviation of the bathymetry layer using the Neighborhood Statistic tool from the Spatial Analyst pull-down menu in ArcMap Version 9.2. Rectangular neighborhood settings were set to a height and width of 3 grid cells to create a small-scale variance layer. The standard deviation output was then squared using the ArcMap Raster Calculater tool. A large-scale variance layer was also generated using a rectangular neighborhood height and width of 5 grid cells. The fine-scale variance is useful for defining small features that may indicate the presence of sediment ripples or possible coral-rich areas whereas the large-scale variance is useful for defining seafloor ridges, pinnacles, and significant changes in slope. Bathymetric variance proved to be a useful tool in previous efforts to map seafloor habitats by Dartnell and Gardner (2004). Their publication can be downloaded from www.soest.hawaii.edu/pibhmc/pibhmc_documentation.htm. The layers were then opened as ESRI GRIDS in the image processing software package ENVI (Environment for Visualizing Images) Version 4.3. A multi-band image was then created with the backscatter, small- and large-scale variance, and rugosity. A mask was also created in ENVI for the dataset. Image classification was performed on the multi-band image using the K-Means unsupervised classification method, which calculates initial class means evenly distributed in the data space and then iteratively clusters the pixels into the nearest class using a minimum distance technique. More information about K-Means algorithm can be found in the ENVI documentation available at www.ittvis.com/envi/. The number of classes was set to two and all other options were set to default. Class color mapping was performed on the resulting classified images. The substrate types of hard and soft were assigned based on a visual interpretation of backscatter intensity and corresponding classes.

Process_Date: 20110221

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Grid Cell

Row_Count: 544

Column_Count: 469

Vertical_Count: 1

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Planar:

Grid_Coordinate_System:

Grid_Coordinate_System_Name: Universal Transverse Mercator

Universal_Transverse_Mercator:

UTM_Zone_Number: -2

Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.9996

Longitude_of_Central_Meridian: -171

Latitude_of_Projection_Origin: 0

False_Easting: 500000

False_Northing: 10000000

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: Row and Column

Coordinate_Representation:

Abscissa_Resolution: 40

Ordinate_Resolution: 40

Planar_Distance_Units: meters

Geodetic_Model:

Horizontal_Datum_Name: D_WGS_1984

Ellipsoid_Name: WGS_1984

Semi-major_Axis: 6378137.000000

Denominator_of_Flattening_Ratio: 298.257224

Vertical_Coordinate_System_Definition:

Depth_System_Definition:

Depth_Datum_Name: mean lower low water

Depth_Resolution: 0.01

Depth_Distance_Units: meters

Depth_Encoding_Method: Attribute Values

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview: none

Entity_and_Attribute_Detail_Citation: none

Distribution_Information:

Distributor:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)

Contact_Address:

Address_Type: mailing and physical address

Address: NOAA IRC

Address: NMFS/PIFSC/CRED

Address: 1845 WASP Blvd., Building 176

City: Honolulu

State_or_Province: HI

Postal_Code: 96818

Contact_Voice_Telephone: 808 725-5360

Contact_Facsimile_Telephone: 808 725-5429

Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov

Contact_Instructions: e-mail preferred

Resource_Description: Downloadable Data

Distribution_Liability:

These data are not to be used for navigational purposes. NOAA makes no warranty regarding these data, expressed or implied, nor does the fact of distribution constitute such a warranty. NOAA cannot 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.

Standard_Order_Process:

Digital_Form:

Digital_Transfer_Information:

Format_Name: Arc ASCII

Format_Information_Content:

Arc ASCII can be converted to Arc Raster using ArcToolbox Conversion Tools (ASCIItoRaster).

Digital_Transfer_Option:

Online_Option:

Computer_Contact_Information:

Network_Address:

Network_Resource_Name:

ftp://ftp.soest.hawaii.edu/pibhmc/website/data/amsamoa/benthichabitatlayers/Rose_40m_HardSoft.zip

Fees: None

Metadata_Reference_Information:

Metadata_Date: 20190526

Metadata_Review_Date: 20110830

Metadata_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization:

Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Coral Reef Ecosystem Division (CRED), Pacific Islands Fisheries Science Center (PIFSC), National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA)

Contact_Address:

Address_Type: mailing and physical address

Address: NOAA IRC

Address: NMFS/PIFSC/CRED

Address: 1845 WASP Blvd., Building 176

City: Honolulu

State_or_Province: HI

Postal_Code: 96818

Contact_Voice_Telephone: 808 725-5360

Contact_Facsimile_Telephone: 808 725-5429

Contact_Electronic_Mail_Address: nmfs.pic.credinfo@noaa.gov

Contact_Instructions: e-mail preferred

Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: Universal Time

Metadata_Access_Constraints: None

Metadata_Use_Constraints: None

CoRIS:

CoRIS_ID: 20110830064639

CoRIS_Children: None

CoRIS_Beginning_Date: 20060210

CoRIS_Ending_Date: 20060313

CoRIS_Metadata_Link:

https://www.coris.noaa.gov/metadata/records/html/rose_40m_hardsoft.html

CoRIS_Tracking_ID: 6350