MULTI-DATASET CHARACTERIZATION OF UNUSUAL LANDFORMS AND SURFACE COVER UNITS ON THE NORTHERN PLAINS OF MARS

The northern plains of Mars have proven to be unique in several important ways. Dark regions in the northern plains are compositionally distinct in the thermal infrared from southern dark regions. The topography is generally flat and topographic analysis of putative shorelines suggest they are consistent with the presence of a past northern ocean. The role of glacial and periglacial processes are also suspected in many regions. The northern plains also host a number of unique surface units and landforms which will be described in this paper in the context of a study that has been undertaken to use multiple orbital datasets to characterize and better understand the nature of these surface cover units and landforms. Distinct surface cover units include: flow-like surface units, mottled terrains, terrains with differing apparent thermal inertias (“patchwork terrains”) and terrains with unusual morphology (“blebby terrains”). Unique landforms in the northern plains include: pitted cones, terraced mesas, sinuous troughs with medial ridges, and domes. Mars Odyssey Thermal Emission Imaging System (THEMIS) Mid-wave Infrared (MWIR) and Visible and Near Infrared (VNIR) data have been placed in a Geographic Information System (GIS). We are also working to extract thermal inertia and emissivity data from the THEMIS data. For large scale surface cover units, higher spectral resolution MWIR Thermal Emission Spectrometer (TES) spectra are being extracted. Initial results indicate thermal inertia differences between pitted cones and the background plains and between some of the dome structures and the background plains although these units do not display substantive multispectral MWIR differences with the surrounding plains. Further characterization of the other surface cover units and landforms is on-going.