Benthic Habitat Data

Bathymetry

Zipped data files contain 1) grid data file (GMT or ASCII), 2) high-res JPG of image, and 3) explanatory metadata text file (identical to linked file listed below).
* Ikonos imagery & USGS Digital Ortho Quarter Quads NOT included with download.

Saipan 5m grid data
Marpi 5m grid data
Merged Multibeam Bathymetry, IKONOS Derived Depths
5m grid data files

CNMI-Guam: Saipan Island (and Marpi Bank)

[ Bathymetry | Backscatter | Optical Validation | Geomorphology ]

Gridded Geomorphology

Download 5 meter grid:
Substrate, Slope, Rugosity, BPI Structures, BPI Zones

Click here for a Discussion of Geomorphological Layers

Please note that the current geomorphology products cover only Saipan Island, and do not include Marpi Bank.

Zipped data files contain 1) Arc ASCII file, 2) layer (.lyr) file for symbology, 3) high-res JPG of image, and 4) explanatory metadata text file (identical to linked file listed below).

Substrate, Hard bottom vs. Soft bottom - 5 meter grid

Substrate :This is a preliminary product derived from an unsupervised classification of multibeam bathymetric data derivatives and multibeam backscatter data. Cell values reflect whether the seafloor is hard or soft. Please see the metadata for additional information.

Image map of Saipan substrate.

This map includes both the Simrad em3002d and Reson 8101 substrate data sets.
Download this image as a high-res JPG or PDF

Hard vs. Soft substrate classification data files

GeoTIFFs derived separately from Simrad em3002d and Reson 8101 backscatter:

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Slope - 5 meter grid

Slope: Cell values reflect the maximum rate of change (in degrees) in elevation between neighboring cells. Slope was derived with the ArcGIS Spatial Analyst extension.

Image map of Saipan slope.

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Slope data files
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Rugosity - 5 meter grid

Rugosity: Cell values reflect the surface area and (surface area) / (planimetric area) ratio for the area contained within that cell’s boundaries. They provide indices of topographic roughness and convolutedness. (Jenness 2003)

Image map of Saipan rugosity.

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Rugosity data files
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BPI Structures - 5 meter grid

BPI Structures: Derived from two scales (20 & 250) of BPI; slope; and depth. Three ranges of slope defined flats, slopes and near vertical: x < 5; 5 < x < 70. Depth alone, in this case, is added only to separate flat structures into shelf (<30 m) and broad flat (>30 m) environments (depths based on SCUBA limits).

Figure giving visual description of BPI Structure classes.

A visual description of BPI Structure classes (Click image for larger view.)

Image map of guam BPI Structures.

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BPI Structures data files
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BPI Zones - 5 meter grid

BPI Zones: Derived from a broad scale (250) BPI grid and slope. Two ranges of slope defined flats and slopes: x < 5 and 5 < x < 70.

Image map of guam BPI Zones.

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BPI Zones data files
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