A Topographic Survey of Mars
The following survey of the entire surface of Mars is divided into four regions of equal area which cover both northern and southern hemispheres in 90° wide longitudinal sections, progressing west from the Martian prime meridian. These regions are the Acidalia-Marineris-Argyre Region (0–90°), the Arcadia-Tharsis-Sirenum Region (90–180°W), the Utopia-Elysium-Cimmeria Region (180–270°W) and the Vastitas-Sabaea-Hellas Region (270–360°W). The polar areas are discussed in more detail above. The survey is largely topographically descriptive, but additional information has been included in terms of setting some features against a geological perspective.