Gas-Pistoning at Drainhole Vent in Pu'u 'O'o Crater (June 3, 2006)
Gas-Pistoning at Drainhole Vent in Pu'u 'O'o Crater (June 3, 2006)Gas-pistoning is an interesting phenomenon seen at Kilauea and other volcanoes. It is caused by the accumulation of gas within, or the rise of a gas slug through, a column of lava. In either case, the gas pushes up the overlying lava (the "piston"). Eventually, the gas breaches the surface and escapes, sometimes as a forceful jet of fume and spatter.