Fig. 3

Heat flow at the North Pole and Solis Planum on Mars. a Surface heat flow (solid line) and mantle heat flow (dashed line) as a function of time at the North Pole. The surface heat flow was calculated from the crustal and mantle heat flows (Eq. 5). The mantle heat flow was calculated by assuming that the total radiogenic heat from the Martian mantle is equal to the average value of the total radiogenic heat in the Martian crust (Eq. 6). b Surface heat flow (solid line) and mantle heat flow (dashed line) as functions of time at Solis Planum