GeoNodeFeatureCatalogue Generic Feature Catalogue Generic Feature Catalogue 1.0 2016-01-11 Organization Name pointOfContact geonode:Shelf The shelf base layer represents the spatial extent of the shelf areas of the worlds oceans based on interpretation of the SRTM30 plus v7 global bathymetry model. The layer is one of the 25 layers that make up the global seafloor geomorphic features map (Harris et.al. 2014). The continental shelf is defined by IHO (2008)as “a zone adjacent to a continent (or around an island) and extending from the low water line to a depth at which there is usually a marked increase of slope towards oceanic depths”. The low-water mark is taken in this study as the 0 m depth contour. The shelf break (i.e. the line along which there is marked increase of slope at the seaward margin of a shelf) was digitised manually at a nominal spatial scale of 1:500,000 in ArcGIS based on 10 m, 50 m and 100 m contours, depending on the slope and bathymetric profile of the region. In most cases 100 m contours were sufficient at the selected scale of 1:500,000 to identify the shelf break. However, where there was a gradual break in slope over a broad area, more closely spaced contours were used. Floating ice shelves cover large sections of the Antarctic continental shelf and these areas were simply left blank. false Shelf base layer fid 1 1 xsd:int the_geom 1 1 gml:MultiPolygonPropertyType Geomorphic 1 1 xsd:string area_km2 1 1 xsd:double