Mountains unseen: Developing a relief map of the hawaiian seafloor

Abstract

The Seafloor Map of Hawai‘i, a medium-scale relief map intended for lay audiences, posed production and design challenges typical of ocean-bottom mapping in general. Te biggest problem was incomplete bathymetry data marred by artifacts. Fixing these bad data—filling voids and removing background noise—involved techniques similar to those used by cartographers for terrain mapping. Map design posed another challenge: how to depict a region on Earth that humans will never see. The Seafloor Map of Hawai‘i uses plan oblique relief, which reveals the seafloor features with three-dimensional offset, a technique borrowed from National Geographic maps painted by Heinrich Berann and Tibor Tóth. Other challenges included selecting depth tints and relief colors based on the idea of cartographic realism and determining the names of seafloor features, many of which are unofficial and inconsistently identified.