Fig. 3
From: Rate-and-state friction explains glacier surge propagation
Stress is transferred from the base to the margins during the surge. The velocity at the base becomes approximately equal to the velocity at the surface behind the surge front. The main panel shows the fraction of spatiotemporal shear stress τb, supported by the base. \(\tilde \tau _{\mathrm{m}}\) is the shear stress from the margins calculated by Supplementary equation 16. The right panel shows the average basal shear stress 〈τb〉, margin stress \(\langle \tilde \tau _{\mathrm{m}}\rangle\) and the average driving stress 〈τtot〉 as a function of time. There is a gradual build-up of stress before the surge starts around t = 15.5 years. During the surge, stress is transferred from the base to the margins, and the driving stress decreases. The bottom panel shows the ratio of basal and surface velocity for different instances in time during the surge. The grayscale dots correspond to the grayscale dots in the main panel and are uniformly spaced in time with intervals of 30 days. Behind the surge front, the basal and surface velocities are more or less equal. The simulation in the figure used dc = 1.0 m, q = 1.5
