Figure 3

(a–e) Elevation contours and slope maps of experimental fans. Contour line spacing represents 5 mm elevation changes. (a–c) shows results for runs of constant clay content performed for different discharge timescales: (a) one 5-min flow, (b) three successive 5-minute flows (a) one 15-min continuous flow. (c–e) results for runs of one 15-min flow and clay contents of (c) 4%, (d) 6%, and (e) 8%. (More in Supplementary Figs. 3, 4). (f) Boxplot for the slope distribution of the fan surface in 9 representative experiments and the 2 field cases we studied. The boxplot displays the dataset based on the 1st, 5th, 25th, 50th, 75th, 95th, and 99th percentiles (Supplementary Table 10).