Fig. 8
Depth of brittle–ductile transition (BDT) as a function of time. The BDT of the Martian lowlands (North Pole) and highlands (Solis Planum) under dry and wet conditions was obtained from the calculated strength profile models (Figs. 5, 6, 7). a BDT depth of the North Pole as a function of time under dry and wet conditions. The strain rates of 10−14 (solid line) and 10−16 s−1 (dashed line) are from Laskar et al. (2004), Phillips et al. (2008), and Tesauro et al. (2007). The BDT depth has increased with time. Under wet conditions, the depth of the BDT has shown a moderate increase. In contrast, the BDT depth has increased more rapidly under dry conditions compared with wet rheology. b Changes in BDT depth in the Martian highlands (Solis Planum) for strain rates of 10−16 s−1 (solid line) and 10−19 s−1 (dashed line) under dry (red lines) and wet (blue lines) conditions