North American Overlay Mapping

Layer Notes - Colored Relief Map

The images used for the relief map background layer were generated as a color relief map with data extracted from the GTOPO30 dataset, and then combined with a black and white shaded relief image to provide a suitable level of depth.

GTOPO30 is a global digital elevation model (DEM) resulting from a collaborative effort led by the staff at the U.S. Geological Survey's EROS Data Center in Sioux Falls, South Dakota. Elevations in GTOPO30 have a horizontal grid spacing of 30 arc seconds (approximately 1 kilometer). GTOPO30 was developed from several raster and vector sources of topographic information to meet the needs of the geospatial data user community for regional and continental scale topographic data. The GTOPO30 dataset is divided into 33 tile datasets, available for download at the GTOPO website.

The colors chosen were designed to give a clear idea of elevation changes. A key to the colors used, and the elevation values that they represent, can be seen above. The degree of shading used also depends on elevation - these colors can also be seen above. All values are in metres.

I can generate similar relief or bathymetry maps for any area of the Earth's surface, in a variety of colors, resolutions, scales and image-types. If you would like a custom relief map for home or business, please Contact me.