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Report on Minami-Hiyoshi (Japan) — July 1979


Minami-Hiyoshi

Scientific Event Alert Network Bulletin, vol. 4, no. 7 (July 1979)
Managing Editor: David Squires.

Minami-Hiyoshi (Japan) Discolored water seen during January-March 1978

Please cite this report as:

Global Volcanism Program, 1979. Report on Minami-Hiyoshi (Japan) (Squires, D., ed.). Scientific Event Alert Network Bulletin, 4:7. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN197907-284131



Minami-Hiyoshi

Japan

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

All times are local (unless otherwise noted)


Minami-hiyoshi, formerly named Hiyoshi-oki-no-ba, was active January-March 1977 and January-March 1978. [Discolored water was specifically noted, in an included table of observations during January 1978-July 1979, on 26 January, 23 February, and 24 March 1978.]

Geological Summary. Periodic water discoloration and water-spouting have been reported over the Minami-Hiyoshi submarine volcano since 1975, when detonation sounds and an explosion were also reported. It lies near the SE end of a coalescing chain of youthful seamounts, and is the only vent with recorded activity. 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.