Networked configurations as an emergent property of transverse aeolian ridges on Mars

Abstract

Transverse aeolian ridges – enigmatic Martian features without a proven terrestrial analog – are increasingly important to our understanding of Martian surface processes. However, it is not well understood how the relationships between different ridges evolve. Here we present a hypothesis for the development of complex hexagonal networks from simple linear forms by analyzing HiRISE images from the Mars Reconnaissance Orbiter. We identify variable morphologies which show the presence of secondary ridges, feathered transverse aeolian ridges and both rectangular and hexagonal networks. We propose that the formation of secondary ridges and the reactivation of primary ridge crests produces sinuous networks which then progress from rectangular cells towards eventual hexagonal cells. This morphological progression may be explained by the ridges acting as roughness elements due to their increased spatial density which would drive a transition from two-dimensional bedforms under three-dimensional flow conditions, to three-dimensional bedforms under two-dimensional flow conditions.

A discrete time evolution model for fracture networks

“…Fragmentation is one of the most ubiquitous natural processes and the efforts to decode its geometry have been at the forefront of geological research (Adler and Thovert 1999;Domokos et al 2020;Goehring and Morris 2008;Goehring 2013;Steacy and Sammis 1991;Nagle-McNaughton 2021;Ma et al 2019;Aydin and DeGraff 1988;Garcia-Rodriguez 2015;Jagla and Rojo 2002;Turcotte 1986;Peacock et al 2018). While many aspects of fragmentation are inherently three dimensional, the 2D aspects of the phenomenon are interesting in their own right: the most visible fingerprints of fragmentation are surface fracture patterns (also called 2D fracture networks) on various scales (Goehring 2013;Turcotte 1986), ranging from mud cracks resulting from desiccation (Nagle-McNaughton 2021;Goehring 2013;Ma et al 2019) (see Fig. 1 for two examples) through basalt columns (Goehring and Morris 2008;Jagla and Rojo 2002) to the pattern defined by the tectonic plates (Domokos et al 2020;Bird 2003).…”