Tokachi

Japan - Hokkaido

SUMMARY:

Type: composite
Activity: active
Last Eruption: 1989 AD
Rock Type: ?
Eruptive Volume: ? cu km
Location Map from Xerox PARC
Latitude: 43.42 N
Longitude: 142.68 E

GEOLOGIC HISTORY

Tokachi consists of a group of stratovolcanoes arranged on a NE-SW line above a plateau of welded Pleistocene tuffs. Numerous explosion craters and cinder cones are located on the upper flanks, with the youngest Holocene craters at the NW end of the chain.

Historic Activity: At least 12 eruptions from 1670 to 1962. Partial cone collapse during a 1926 eruption produced a disastrous avalanche and mudflow.

Recent Activity:

  • April to August 1985 there were ejections of hot muddy water. February to March 1987 ground temperatures increased and tremor and seismic swarms occurred. Increased seismicity in Nov. 1988 led to an eruption which began on Dec. 19th. and was continued to March 5, 1989. No activity from early March thru June 1989 except for continuous steam plume.
  • Weak volcanic tremor on June 1990.
  • Increased seismicity in July and August 1995. Again in Dec.
  • High seismicity during 18-22 May 1996.

Data Sources

  • Smithsonian's SEAN Bulletin (V. 10, No. 6 to V. 14, No. 6)
  • Global Volcanism Network (V. 15, No. 6 to V. 21, No. 5).

ADDITIONAL INFORMATION

Last Update: 2/26/00