GEOLOGIC MAPPING USING GIS AND INSIGHTS INTO PLANETARY VOLCANISM

Geologic mapping using spacecraft images has proven to be a useful tool to unravel stratigraphic relationships and the geologic histories of planetary bodies on both regional and global scales. Beginning in 2009 the NASA/USGS Planetary Geologic Mapping Program is requiring planetary geologic mapping projects to use Geographic Information Systems (GIS) software to produce formal map publications (i.e., those published by the USGS). In this presentation we discuss how ArcGIS™ software is being used to investigate two high interest targets in planetary volcanism: the Martian shield volcano Olympus Mons (OM), and Jupiter’s volcanic moon, Io. Geologic mapping of OM takes advantage of the new, high-resolution data sets obtained from Mars orbiters over the last 12 years. Preliminary mapping of lava flow morphologies shows a change in late-stage effusive style from tube-fed to channel-fed flows, a style change typical of terrestrial Hawaiian shield volcanoes. Complete mapping across OM will verify if this and other relationships are volcano-wide phenomena. Global geologic mapping of Io, using combined Galileo-Voyager mosaics, has enabled the whole surface to be mapped into process-related material units and structures for the first time. Io’s surface consists of plains buried by flows and pyroclastic deposits (~67%), lava flow fields (~28%), tectonic mountains (~3%), and paterae (caldera-like depressions, ~2%). The bulk of Io’s heat flow comes from the paterae, which cover the least amount of the surface. Spatial analyses using ArcGIS™ are being studied to further identify and investigate Io’s volcanic and tectonic processes.