2021 CSDMS meeting-102
Arctic soil patterns analogous to fluid instabilities
Rachel Glade, Los Alamos National Lab Los Alamos New Mexico, United States. firstname.lastname@example.org
Michael Fratkin, Los Alamos National Lab Los Alamos New Mexico, United States. Mulufratkin@gmail.com
Mehdi Pouragha, Carleton University Ontario , Canada. MehdiPouragha@cunet.carleton.ca
Ali Seiphoori, MIT Cambridge Massachusetts, United States. email@example.com
Joel Rowland, Los Alamos National Lab Los Alamos New Mexico, United States. jrowland@LANL.GOV
Slow-moving arctic soils commonly organize into striking large-scale spatial patterns called solifluction terraces and lobes. Though these features impact hillslope stability, carbon storage and release, and landscape response to climate change, no mechanistic explanation exists for their formation. Everyday fluids—such as paint dripping down walls—produce markedly similar fingering patterns resulting from competition between viscous and cohesive forces. Here we use a scaling analysis to show that soil cohesion and hydrostatic effects can lead to similar large-scale patterns in arctic soils. A large new dataset of high-resolution solifluction lobe spacing and morphology across Norway supports theoretical predictions and indicates a newly observed climatic control on solifluction dynamics and patterns. Our findings provide a quantitative explanation of a common pattern on Earth and other planets, illuminating the importance of cohesive forces in landscape dynamics. These patterns operate at length and time scales previously unrecognized, with implications toward understanding fluid-solid dynamics in particulate systems with complex rheology.