Geothermal power is a power option that seems for inviting than solar or wind. Geothermal power is generated by using the high temperatures that exist deep underground to boil a fluid such as water, and then using the steam produced to turn a generator turbine. In addition to supplying the Mars base with energy, it can also provide an abundant supply of liquid water.

    Now that we have assessed that geothermal power has the potential to be extremely advantageous to Martian settler, the question now comes up, "do they exist?" The answer to this is most probably yes. First, if volcanoes such as the Tharsis, Elysium, and Aracadia are still active they would be a source. In fact, they don't even have to be presently active! The ground stays hot a long time after activity has subsided! In addition, Mars possesses large supplies of ice water in the northern ice caps; possibly containing large amounts of liquid water a kilometer beneath the surface.

    Obviously, once a efficient power source has been established by the nuclear reactor, the expansion to either solar, wind, or especially geothermal will be inevitable. Once these power sources have been established on Mars, the growth of the base will become exponential.