Martian lava tube would also reduce the landed payload mass for manned missions which would be economically advantageous. Martian lava tube Martian lava tubes are natural sub-surface lava tube caverns on Mars that are believed to form as a result of fast-moving, basaltic lava flows associated with shield volcanism. Lava tubes usually form when the external surface of the lava channels cools more quickly and forms a hardened crust over subsurface lava flows. The flow eventually ceases and drains out of the tube, leaving a conduit-shaped void space which is usually several meters below the surface. Lava tubes are typically associated with extremely
Volcanology of Io dozen of them. The limited area of Io's lava flows suggests that much of the resurfacing needed to erase Io's cratering record must come from plume deposits. The most common type of volcanic plume on Io are dust plumes, or Prometheus-type plumes, produced when encroaching lava flows vaporize underlying sulfur dioxide frost, sending the material skyward. Examples of Prometheus-type plumes include Prometheus, Amirani, Zamama, and Masubi. These plumes are usually less than tall with eruption velocities around . Prometheus-type plumes are dust-rich, with a dense inner core and upper canopy shock zone, giving them an umbrella-like appearance. These plumes often