a Volcano Mask

From the suffocation of Pompeii to the air traffic gridlock suffered in Iceland in 2010, the tephra that is expelled during volcanic eruptions has long posed grave threats to civilization. Since volcanic eruptions cannot be controlled, the designers of the VolcanElectric Mask I propose constructing an industrial structure over a volcano that can collect tephra during an eruption, keeping it out of the skies and away from cities and villages below, and also harness the power from the volcano’s heat in calm periods to provide clean electric power to surrounding areas.
http://www.evolo.us/featured/volcano-skyscraper-harnesses-clean-energy-from-active-volcanoes/