What Every Print Is Made From

The map

Every mountain is drawn from OpenStreetMap data, © OpenStreetMap contributors, available under the Open Database License. Each print is a produced work and carries this credit in its margin. Searches go through Nominatim, run by the OpenStreetMap Foundation; surveys come from the Overpass API at overpass-api.de, with VK Maps' public instance as the fallback.

The ground

Heights, relief and contours come from the AWS Terrain Tiles on the Registry of Open Data on AWS, as their attribution document asks to be credited:

• ArcticDEM terrain data DEM(s) were created from DigitalGlobe, Inc., imagery and funded under National Science Foundation awards 1043681, 1559691, and 1542736;
• Australia terrain data © Commonwealth of Australia (Geoscience Australia) 2017;
• Austria terrain data © offene Daten Österreichs, Digitales Geländemodell (DGM) Österreich;
• Canada terrain data contains information licensed under the Open Government Licence, Canada;
• Europe terrain data produced using Copernicus data and information funded by the European Union, EU-DEM layers;
• Global ETOPO1 terrain data U.S. National Oceanic and Atmospheric Administration;
• Mexico terrain data source: INEGI, Continental relief, 2016;
• New Zealand terrain data Copyright 2011 Crown copyright (c) Land Information New Zealand and the New Zealand Government (All rights reserved);
• Norway terrain data © Kartverket;
• United Kingdom terrain data © Environment Agency copyright and/or database right 2015. All rights reserved;
• United States 3DEP (formerly NED) and global GMTED2010 and SRTM terrain data courtesy of the U.S. Geological Survey.

The published heights

Each summit's published height is read on a named page, quoted in its own words with the survey it credits, and dated. The prominence of each peak and both lists of the Seven Summits come from Wikipedia. All of it is kept in sources.json.

The faces

Big Shoulders Display, drawn for the City of Chicago; Public Sans, from the United States Web Design System; and IBM Plex Mono, from IBM. Each is under the SIL Open Font License and served from our own pages through Fontsource.

The measuring

Lengths on the ellipsoid follow Vincenty's method, checked in our tests against Charles Karney's geodesic test set to within a millimetre.