Underestimation of Planetary Contraction due to Obscuration by Surface Roughness: The Case of Mercury
Abstract
Estimating Mercury’s radial contraction is key to understanding the planet’s geodynamic evolution. Contraction has been inferred from mapped shortening structures, whose heterogeneous distribution contradicts the isotropic contraction expected from global cooling. Here we investigate the possibility that the tectonic record is partly obscured by geologically recent resurfacing features like crater ejecta. Using topographic roughness as a proxy for surface freshness, we examine how roughness influences the mapped distribution of shortening structures. Our new global roughness map is compared to contractional strain maps derived from a shortening structures catalog. We find a lack of shortening structures in rough regions, suggesting that roughness-related processes obscure pre-existing structures,……
Read the original article on Geophysical Research Letters
Article inforamation
Nishiyama, G., Broquet, A., Tosi, N., Preusker, F., Stark, A., Hussmann, H., & Hauber, E. (2026). Underestimation of planetary contraction due to obscuration by surface roughness: The case of Mercury. Geophysical Research Letters, 53, e2026GL124067.
DOI: https://doi.org/10.1029/2026GL124067
