Patterns occur in a variety of forms in our natural world, including living and non-living systems. These patterns are somewhat visible regularities or, put in another way, are the absence of randomness. They are observable on the ground surface of our planet and other planetary bodies as lines, circles, nets and polygons, collectively referred to as patterned grounds. Patterned grounds are widespread in high-alpine and arctic environments on Earth, but also on Mars, where their formation is linked to frozen water ice and oscillating freezing temperatures (e.g., freeze-thawing cycles & frost heave). However, we find those patterns, in particular, polygonal networks also in the Yungay area of the hyper-arid Atacama Desert, where water availability is extremely limited and freezing temperatures are almost absent. Hence, processes and/or environmental conditions must be distinct from those forming patterns in the cold environments.    

The goal of this project was to investigate the formation processes of polygonal networks in the hyper-arid Atacama Desert, to better understand the information they can provide, and their relevance as habitat including their implications for Mars. In order to identify the underlying formation processes, various soil characteristics (e.g., salt content, mineralogy, temperature profiles) and morphometric parameters (e.g., size, orientation, shape) of various patterned grounds were determined. This was realized through a multi-methodological approach including drone-based remote sensing followed by 3D-reconstruction of the patterned grounds, geochemical and sedimentological soil analyses, as well as long-term field and laboratory experiments. Patterned grounds occurring on Mars are expected to hold much information on long-term climatic conditions and the distribution of ground ice. However, thus far they have only been compared to those occurring in periglacial regions on Earth. Hence, we anticipate that a comparative study of all three study areas will advance our understanding of ongoing soil processes in the Atacama Desert and periglacial regions, and furthermore provide insights on potentially analogous processes occurring on Mars.

This project (Duration: May 2019 - April 2023) was conducted by Christof Sager as part of his dissertation.

For further contact, ideas, suggestions: Christof Sager (christof.sager[[at]]mfn.berlin)

Publications:

2023:

Doctoral Thesis:

Sager, Christof (2023), Formation and development of polygonal soils in the hyper-arid Atacama Desert and their relevance as a habitat on earth and beyond, https://doi.org/10.14279/depositonce-17841

Sager, C., Airo, A., Mangelsdorf, K., Arens, F. L., Karger, C., & Schulze-Makuch, D. (2023). Habitability of Polygonal Soils in the Hyper-arid Atacama Desert after a Simulated Rain Experiment. Journal of Geophysical Research: Biogeosciences, 128, e2022JG007328. https://doi.org/10.1029/2022JG007328

2022:

Sager, C., Airo, A., Arens, F.L., Schulze-Makuch, S. , Eolian erosion of polygons in the Atacama Desert as a proxy for hyper-arid environments on Earth and beyond. Scientific Reports 12, 12394 (July 2022). DOI: 10.1038/s41598-022-16404-y

2021

Sager, C., Airo, A., Arens, F.L., Schulze-Makuch, S, New types of sand wedge polygons in the salt cemented soils in the hyper-arid Atacama Desert (January 2021). Geomorphology, Volume 373
doi: 10.1016/j.geomorph.2020.107481

Figure 1: Patterned ground in the form of soil polygons located in the hyper-arid Atacama Desert. (Photo by Christof Sager)