Volcano Thought of the Month

        It is becoming increasingly clear that the magma reservoirs underlying the world’s active volcanoes are, for the most part, in a delicate state of gravitational equilibrium with enclosing rocks, and that many factors can contribute to their destabilization and to subsequent eruptive activity.  Eruption “triggers” are mostly related to processes that increase the buoyancy and mobility of magma bodies underlying volcanoes, and in many cases where long inactive volcanoes erupt, the renewed activity has been shown to be related to the ascent of new basaltic magma from below (as at Mt. Pinatubo in 1991).