Solid state convection models of the lunar internal temperature

Lunar temperature profiles and their dependences on the viscosity of the lunar interior are calculated numerically for models that include finite-amplitude solid-state convective cooling. Cooling by subsolidus creep and the rheological behavior of geologic material are taken into account. It is found that the deep lunar temperature is about 1500 to 1600 K with an effective viscosity of between 10 to the 21st and 10 to the 22nd power sq cm/sec. The results are compared with lunar heat-flux measurements, seismic observations, and electrical-conductivity determinations.