Global Volcanism Program | Image GVP-02061
An ash plume rises from the Shinzan lava dome at the summit of Chokaisan on 1 March 1974 after a long repose of 140 years. Phreatic eruptions occurred at Chokai in March and April and were accompanied by small lahars. The eruptions took place from an E-W-trending series of vents extending from the eastern caldera wall across the 1801 Shinzan lava dome and the Kojinyama cone. This view from the NW shows the eastern caldera wall behind Shinzan.
Photo courtesy of Japan Meteorological Agency, 1974.