Novarupta Lava Dome, Alaska -- The enormously explosive Katmai eruption at the Novarupta volcano in 1912 released about 15 km3 of magma, most of which accumulated in a large ignimbrite. The eruption ended with the extrusion of degassed lava through the Novarupta vent to form the lava dome shown here. The dome is ~275 m in diameter and ~75m high. Courtesy of T.P. Miller, USGS.