The heat flow of Venus from global lithosphere strength

Despite their similar size and mass, Earth and Venus have very different internal dynamics that reflect contrasting modes of heat loss. On Earth, plate tectonics drive heat loss through lithosphere recycling, with a substantial contribution from hydrothermal circulation through oceanic plates, and a minor contribution from mantle plume (i.e. hot spot) activity. In comparison, the surface of Venus is more homogeneous, has lower relief, and shows abundant evidence of effusive volcanism, and its global dynamics is not well understood. Here, we present the first global heat flow map for Venus, as well as estimates of the total heat loss, obtained from an inversion of geophysical data, including lithospheric effective elastic thickness, crustal thickness, and radioactive heat production. The obtained heat flow is lower and less geographically structured for Venus than for Earth, but with maximum values reaching those typical of magmatically active terrestrial areas. Some previous works obtained widespread heat flow similar to those of active terrestrial regions were affected by the use of excessively high values for the thermal conductivity of lithospheric rocks. The obtained total heat loss is 11-15 TW, similar to estimates of the total radioactive heat production of the planet. Therefore, at present, Venus proportionally dissipates much less heat than Earth.