Shikotsu Caldera and Tarumai

Japan - Hokkaido

SUMMARY:

Type: composite cone in caldera
Activity: active
Last Eruption: 1981 AD
Rock Type: ?
Eruptive Volume: ? cu km
Location Map from Xerox PARC
Latitude: 42.68 N
Longitude: 141.38 E

GEOLOGIC HISTORY

The 13 x 15 km Shikotsu caldera, largely filled by the waters of Lake Shikotsu, was formed during one of Hokkaido's largest Quaternary eruptions (Å30,000 years ago). The small Tarumai stratovolcano sites on the caldera's SE rim. The summit of Tarumai contains a small 1.5-km-wide caldera formed during two of Hokkaido's largest historical eruptions, in 1667 and 1739.

Historic Activity: At least 35 eruptions from 1667 to 1981.

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 seismic activity during June to August 1996.

Data Sources

  • Smithsonian's SEAN Bulletin (V. 13, No. 2)
  • Global Volcanism Network (V. 21, No. 7 to V. 21, No. 8).

ADDITIONAL INFORMATION

Last Update: 2/26/00