Regional morphometric and geomorphologic mapping of Martian landforms

Abstract

Initial mapping of the Martian surface, based on stratigraphic markers identified from Viking imagery, resulted in the demarcation of broad planetary scale geological zones. Recent advances in image resolution have established the presence of many smaller surface elements superposed on the older geological zones, thereby indicating younger surface morphologies that are in contradiction with the older mapping. Moreover, the stratigraphic mapping technique is subjective and relatively cumbersome because of its reliance on visual interpretation of images.In this paper a new analytical technique is developed which uses morphometric analysis of the Martian elevation map (MOLA data) to automate delineation and mapping of landforms at the regional scale. The analysis relies on altitude, local relief and local watershed clustering to delineate the landforms, and applies statistical clustering to identify structures with similar properties.As a case study, the technique is applied to Atlantis and Gorgonum basins. Comparison of the delineated features with landforms visible on high-resolution THEMIS images illustrates the accuracy of the morphometric technique in delineating and classifying surface structures, and also permits interpretation of the origin and evolution of the landforms. Our results also show that morphometric data and morphologic evaluation can be combined into a single interpretation of the distribution of surface patterns. A new geomorphological map of the study area is produced and contrasted with the existing stratigraphic map.