Exploring Potential Mechanisms for the Initiation of Solifluction Patterns

Hillslopes in arctic regions commonly display large-scale features—known as solifluction patterns—that form due to the exceedingly slow downhill movement of frost-heaved soil. Here we use a combination of remote sensing data, linear stability analysis, numerical modeling, and review of a wide range of literature to evaluate several working hypotheses for the necessary and sufficient conditions needed to form solifluction patterns. We find that despite striking visual similarity, fluid buckling, wrinkling, dripping, and roll wave patterns are not directly analogous to solifluction patterns. However, broadly inspired by non-inertial instabilities observed in shear-thickening oobleck, we propose a conceptual framework for the formation of solifluction instabilities that relies on spatial heterogeneity of soil velocities in the presence of random topographic bumps. More broadly, this study illustrates both caveats and the potential for success in drawing inspiration from diverse fields to understand pattern formation in the complex granular/fluid materials on Earth’s surface.