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Report on Minami-Hiyoshi (Japan) — March 1984


Scientific Event Alert Network Bulletin, vol. 9, no. 3 (March 1984)
Managing Editor: Lindsay McClelland.

Minami-Hiyoshi (Japan) No water discoloration seen since March 1978

Please cite this report as:

Global Volcanism Program, 1984. Report on Minami-Hiyoshi (Japan) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 9:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198403-284131



23.5°N, 141.935°E; summit elev. -107 m

All times are local (unless otherwise noted)

Frequent monitoring of several known submarine volcanoes has continued. . . . Minami-Hiyoshi produced discolored sea water January-March 1977 and January-March 1978 but no further activity has been observed.

Geological Summary. Periodic water discoloration and water-spouting have been reported over this submarine volcano since 1975, when detonations and an explosion were also reported. It lies near the SE end of a coalescing chain of youthful seamounts, and is the only historically active vent. The reported depth of the summit of the trachyandesitic volcano has varied between 274 and 30 m. The morphologically youthful seamounts Kita-Hiyoshi and Naka-Hiyoshi lie to the NW, and Ko-Hiyoshi to the SE.

Information Contacts: JMA, Tokyo.