An ash plume rises above Usu on the afternoon of 7 August 1977, on the first day of an eruption that lasted until 1982. Nine major explosive eruptions during 7-14 August 1977 were followed by slow growth of the Usu-Shinzan cryptodome. A crypotodome is a lava dome that uplifts the ground without breaking through to the surface.

Photo by T. Kobayashi, 1977 (courtesy Tokiko Tiba).

Keywords: ash plume | ash | plume | tephra | eruption

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