Fig. 5: Displacement-length relations and radius change.
a Log-log plot of maximum fault displacement as a function of fault length for 31 lobate scarps (red circles) on Mercury. The ratio γ of the population of thrust faults was obtained by a linear fit to the D–L data with the intercept set to the origin. A value of γ ≅ 7.2 × 103 is obtained using estimates of Dmax based on fault plane dips θ = 30°. The error bars indicate the range in displacement for θ = 25°, 35°. b Plot of radius decrease ΔR and areal contractional strain ε as a function of fault plane dip θ. ΔR and ε are determined for four cases; (1) all mapped faults over the total surface area of Mercury (black dashed line), (2) the total surface area less the smooth plains volcanic units and mapped faults within (red dashed single-dot line), (3) the surface area of the southern hemisphere and mapped faults within (blue short-dashed line), and (4) the surface area of the northern hemisphere and mapped faults within (purple dashed double-dot line). Over the likely range of θ of typical thrust faults (25° to 35°, area shaded in gray), ΔR only reaches ~2 km in the southern hemisphere case.
