Bathymetric Contours

ground condition

MarineCadastre.gov Data Registry

URL where the source data were originally accessed.

Individual .asc files

URL where the source data were originally accessed.

Digital Elevation Model (DEM) layer package

Merge the three contour data sets to make one Contours set for the America EEZ & dissolve based on the Contours interval. Utilize a shapefile of America & US Territories land areas only to erase sections of contours that might fall on land given the granularity of the Rasters. Call this contour set: USA_EEZContours_Clipped.

Utilized the Smooth Line (Cartography) Tool with the PAEK algorithm to calculate a smoothed line that will not pass through the input line vertices at a .1 Decimal Degree smoothing tolerance & preserving endpoints for closed lines to create an enhanced cartographic product for viewing.

Gather individual American Samoa .asc files, set proper projections for each file, merge American Samoa files to one Raster, project into Mercator. Utilize Raster to Polygon to create an exact area of the American Samoa Raster to cut out of EEZ_DEM contours. Utilize the contour tool (spatial analyst) & create three data sets, 1. zero to -100 creating a contour every 10 meters, 2. -101 to -500 with contours every 25meters, 3. -501+ with contours every 100m. Remove any contours that create that are not within the designated layer by using the select by attribute in the Attribute Table & selecting only the contours you want to keep, export the data as a new shapefile. Merge the three contour data sets to make one Contour set & dissolve based on the Contours interval, call layer American Samoa Contours.

Download GRMT DEM of all USA & Territory areas to the EEZ & mosaic together to form one EEZ_DEM. Utilize ArcGIS spatial analyst - contour tool & create three data sets, 1. zero to -100 creating a contour every 10 meters, 2. -101 to -500 with contours every 25meters, 3. -501+ with contours every 100m. Remove any contours that are created that are not within the designated layers by using the select by attribute in the Attribute Table & selecting only the contours you want to keep, export the data as a new shapefile.

From the USA_EEZContours_Clipped utilize the Erase tool using the American Samoa Raster Polygon. This will remove any of the contours that were created previously that are at a lower detail existing where the American Samoa Contours will exist. Merge the American Samoas Contours into the EEZ_DEM contours & Dissolve by Contour then name the resulting contour shapefile: Elevation_Bathymetry. Label all the features by contour with a mask for increased visibility, add scale range to not show when zoomed out past 1:15million (min scale).