Preliminary hard and soft bottom seafloor substrate map derived from gridded sidescan and bathymetry derivatives at Apra Harbor, Guam U.S. Territory.

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: 20101122
Title:

Preliminary hard and soft bottom seafloor substrate map derived from gridded sidescan and bathymetry derivatives at Apra Harbor, Guam U.S. Territory.

Geospatial_Data_Presentation_Form: digital data
Online_Linkage: http://www.soest.hawaii.edu/pibhmc/
Online_Linkage:

http://www.soest.hawaii.edu/pibhmc/pibhmc_cnmi_apra_geomorph.htm

Description:

Abstract:

Preliminary hard and soft seafloor substrate map classified from sidescan data and bathymetric derivatives at Apra Harbor, Guam U.S. Territory. The dataset was created using Bathymetric Position Index (bpi) zones derived from Reson SeaBat 8125 multibeam data at a 1 m grid cell size, and Klein 3000 sidescan sonar data. The sonar frequency is 455 kHz for the Reson Seabat 8125 multibeam echosounder. Additional information on multibeam and sidescan datasets can be found in the Data Acquisition and Processing Report (DAPR) that can be accessed at: www.soest.hawaii.edu/pibhmc. Classification of the bathymetry and sidescan data into hard and soft seafloor substrates were validated using groundtruth data collected for the US Navy in Appendix J of the Final EIS Statement: Guam and CNMI Military Relocation accessed at: http://www.guambuildupeis.us/final_documents. Survey site images can be found at http://guamreeflife.com/htm/reeftour/cvn_survey_sites.htm. Although hard and soft classes from the substrate map are highly correlated with those from the optical validation data, the substrate map should be used with caution as groundtruth data were mostly collected at areas of known hard bottom in less than 60 ft of water depth.

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:

Survey data were acquired by the United States Navy (USN) Fleet Survey Team (FST) with Survey Vessel Swamp Fox. A Reson 8125 multibeam echosounder was mounted from an arm on the port side of the vessel. The Klein 3000 Side Scan Sonar was operated in the stern-towed configuration. Additional detailed information on data acquisition, equipment configuration, and corrections can be found in the Data Acquisition and Processing Report (DAPR), SWAMPFOX_DAPR_2008.pdf, that can be accessed at: www.soest.hawaii.edu/pibhmc and is included in the ZIP file containing the bathymetry grids. See the process description portion of this document for additional information about how the classes were derived.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 20080329
Ending_Date: 20080504

Currentness_Reference: ground condition

Status:

Progress: Complete
Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: 144.614
East_Bounding_Coordinate: 144.676
North_Bounding_Coordinate: 13.464
South_Bounding_Coordinate: 13.418

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 - Commonwealth of the Northern Mariana Islands and Guam

Theme_Keyword: 1398

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: imageryBaseMapsEarthCover
Theme_Keyword: 010

Theme:

Theme_Keyword_Thesaurus: CoRIS Theme Thesaurus
Theme_Keyword:

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

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

Theme:

Theme_Keyword_Thesaurus: CoRIS Discovery Thesaurus
Theme_Keyword: Geographic Information > Habitats

Place:

Place_Keyword_Thesaurus: CoRIS Place Thesaurus
Place_Keyword:

OCEAN BASIN > Pacific Ocean > Western Pacific Ocean > Guam > Apra Harbour (13N144E0051)

Place_Keyword:

COUNTRY/TERRITORY > United States of America > Guam > Apra Harbour (13N144E0051)

Place:

Place_Keyword_Thesaurus: CoRIS Region
Place_Keyword: Guam

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:

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:

https://www.soest.hawaii.edu/pibhmc/CNMI_images/apra_5m_hardsoft_445.jpg

Browse_Graphic_File_Description: Hard and Soft Seafloor Substrate
Browse_Graphic_File_Type: JPEG

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: see DAPR Horizontal position accuracy: see DAPR

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

see DAPR Raw sounding resolution: Variable

Lineage:

Process_Step:

Process_Description:

Processing steps used to generate the sidescan and bathymetry are described in their own metadata that can be found at www.soest.hawaii.edu/pibhmc. Initial efforts to create a hard and soft substrate map using traditional methods at PIBHMC were unsuccessful due to shadowing effects in the sidescan imagery. Instead, Bathymetric Position Index Zones were derived from the gridded multibeam bathymetry (apra_bty_1m) using the Benthic Terrain Modeler (BTM). The BTM (written for ArcGIS 8.x or 9.x) may be downloaded from http://dusk2.geo.orst.edu/djl/samoa/tools.html. BPI Zones are derived from a focal mean analysis on bathymetry and slope wherein bathymetric highs and lows are designated as crests and depressions respectively. After testing 5 experimental scales, the bpi with scalefactor 10 was chosen based on the diameter of reef structures seen in the bathymetry (also after Lundblad et al. 2006; see Supplemental_Information). Two ranges of slope defined flats and slopes: x < 5 and 5 < x < 70. The BPI Zones map was reclassified using the Spatial Analyst>Reclassify tool in ArcMap version 9.3.1 wherein classes equal to crests and slopes were considered hard and classes equal to flats were considered soft. These features were selected to correspond to hard features following visual assessment of the BPI map against the sidescan data. Depressions were validated by the sidescan imagery and called hard when corresponding to a sidescan value < 90 and soft when corresponding to a sidescan value > 90. Some additional areas corresponding to hard sidescan values (< 90) which did not correspond to features identified in the BPI map were also classified as hard. These were manually delineated in the raster using tools in ArcGIS version 9.3.1.

Process_Date: 20101115

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:

Raster_Object_Type: Grid Cell
Row_Count: 1021
Column_Count: 1333
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: 55
Transverse_Mercator:

Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: 147
Latitude_of_Projection_Origin: 0
False_Easting: 500000
False_Northing: 0

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: Row and Column
Coordinate_Representation:

Abscissa_Resolution: 5
Ordinate_Resolution: 5

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:

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/cnmi-guam/benthichabitatlayers/Apra_5m_Hardsoft.zip

Fees: None

Preliminary hard and soft bottom seafloor substrate map derived from gridded sidescan and bathymetry derivatives at Apra Harbor, Guam U.S. Territory.

Metadata: