Global Volcanism Program | Image GVP-01394
This closeup view on 20 May 1991 shows the first lava extrusion of the 1990-95 dome of Unzen volcano in Japan. The dome was extruded in the Jigokuato crater, which was formed by an explosion on the first day of the eruption, 17 November 1990. By 23 May the dome had reached a height of 44 m with a diameter of 110 m. It proceeded to grow over the east crater rim (upper right). Periodic collapse of the steep front of the dome produced pyroclastic flows that traveled progressively farther down the Mizunashi valley.
Photo courtesy Shimbara Earthquake and Volcano Observatory, 1991.