Report on Tokachidake (Japan) — June 1990
Bulletin of the Global Volcanism Network, vol. 15, no. 6 (June 1990)
Managing Editor: Lindsay McClelland.
Tokachidake (Japan) Tremor episode
Please cite this report as:
Global Volcanism Program, 1990. Report on Tokachidake (Japan) (McClelland, L., ed.). Bulletin of the Global Volcanism Network, 15:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199006-285050
Tokachidake
Japan
43.418°N, 142.686°E; summit elev. 2077 m
All times are local (unless otherwise noted)
Weak volcanic tremor was recorded 19 June.... The tremor episode was the fifth and strongest recorded since April 1989 (table 2).... The number of earthquakes has remained fairly constant since August 1989.
Table 2. Amplitude of volcanic tremor episodes at Tokachi, May 1989-June 1990.
| Date | Amplitude |
| 24 Jul 1989 | 0.01µ |
| 24 Dec 1989 | 0.04µ |
| 18 Jan 1990 | 0.01µ |
| 22 Feb 1990 | 0.02µ |
| 19 Jun 1990 | 0.05µ |
Geological Summary. Tokachidake volcano consists of a group of dominantly andesitic stratovolcanoes and lava domes arranged on a NE-SW line above a plateau of welded Pleistocene tuffs in central Hokkaido. Numerous explosion craters and cinder cones are located on the upper flanks of the small stratovolcanoes, with the youngest Holocene centers located at the NW end of the chain. Frequent historical eruptions, consisting mostly of mild-to-moderate phreatic explosions, have been recorded since the mid-19th century. Two larger eruptions occurred in 1926 and 1962. Partial cone collapse of the western flank during the 1926 eruption produced a disastrous debris avalanche and mudflow.
Information Contacts: JMA.
