Lake Superior bathymetric shaded relief map contoured with interval 25 m (100 m with thicker lines). The deepest point, roughly off its southeastern shore, is marked with "×". For land, the vertical datum is sea level; for bathymetry, low water datum of the lake. According to NGDC information, Lake Superior data this map is based on are incomplete. The map was created using the Generic Mapping Tools, GMT, version 5.1.1.