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. The 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 terrestrial mountain mapping. Map design was another challenge. At issue: how to depict on a map a region on Earth that humans will never see. The Hawaiian map 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. Selecting depth tints and relief colors based on the idea of cartographic realism is discussed. The paper also addresses the names of seafloor features, many of which are unofficial and inconsistently identified.