Fig. 2

Rheological model of the Martian lithosphere under wet conditions. A constant thermal gradient of 8 K/km and a strain-rate of 10⁻¹⁹ s⁻¹ were used in the calculations. Positive and negative differential stresses correspond to tension and compression, respectively. The bending moment is calculated via a balance between tensional and compressional forces within the flexed lithosphere (shaded area). Elastic thickness was calculated from the integrated bending moment following the procedure of McNutt (1984). Mechanical thickness is the rheological boundary at based of lithosphere, which is calculated from the depth where stress threshold is assumed to be 50 MPa (McNutt 1984)