Morphometric analysis of large Martian shield volcanoes using MOLA data

GROSSE, P.; BYRNE, P.; KERVYN, M.; VAN WYK DE VRIES, B.

Noordwijk

Simposio; 48th ESLAB Symposium; 2014

We present a comprehensive characterization and analysis of the morphometry of large Martian shield volcanoes using the ~460 metre per pixel (m/px) spatial resolution Mars Orbiter Laser Altimeter (MOLA) digital elevation model (DEM) data set, expanding upon the findings of Plescia (2004). 16 edifices were analysed following the methodology and using the algorithms described in Grosse et al. (2012, 2014) and Euillades et al. (2013). Volcano edifice boundaries were defined applying the semi-automatic NETVOLC algorithm (Euillades et al., 2013), which calculates boundaries by minimizing a cost function based on breaks in slope between volcano flanks and the surrounding plains, with additional manual corrections where necessary. The MORVOLC algorithm (Grosse et al., 2012) was then used to compute a set of morphometric parameters for each edifice including size measurements (e.g., basal area and width, summit region area and width, height, and volume), profile shape ratios (e.g., height/basal width, summit width/basal width), planform shape descriptors (e.g., ellipticity and irregularity indexes), and edifice flank slope statistics. Ellipticity, irregularity, and slope as a function of elevation produce profiles that characterize each edifice. Furthermore, the studied edifices were classified into component landform elements (e.g., flanks, aprons, and calderas), which were then individually quantified in terms of size, slope, and roughness. High-resolution photogeological (High Resolution Stereo Camera [HRSC] and Context Imager [CTX]) data (~12 m/px and ~6 m/px, respectively) were used to refine the morphological boundaries, and to provide a geological context for our morphometric analysis. In this presentation, we show how the obtained morphometric data can be analysed in relation to edifice age, the formation of erosional features, the processes that control edifice structure, the migration of activity upon a given volcano, and the variations in eruptive activity. We also compare our results with the morphometry of terrestrial shield volcanoes, obtained through a similar analysis, to demonstrate the applicability of the methodology and algorithms to volcanic edifices throughout the Solar System.