Una Una

Sulawesi

SUMMARY:

Type: composite with caldera
Activity: active
Last Eruption: 1983 AD
Rock Type: ?
Eruptive Volume: ? cu km
Location Map from Xerox PARC
Latitude: 0.17 S
Longitude: 121.61 E

GEOLOGIC HISTORY

Colo volcano forms the isolated small island of Una-Una in the middle of the Gulf of Tomini in northern Sulawesi. The broad, low volcano contains a 2-km-wide caldera with a small central cone. The 40-m-high summit cone is called "Colo" (originally "Tjolo") and the name is locally applied to the volcano itself.

Historic Activity:

  • One historic eruption in 1898.

Recent Activity:

  • Eruption began on July 18, 1983, and a paroxysmal eruption occurred on July 23, when pyroclastic flows devastated most of the island. Intermittent large explosions continued until the end of August, and minor activity was observed through December.
  • A plume was observed on a satellite image on July 14, 1987 but no comfirmation could be obtained and it was later dismissed as a weather related cloud.

Data Sources

  • Smithsonian's SEAN Bulletin (V. 8, No. 7 to V. 12, No. 10).

ADDITIONAL INFORMATION

Last Update: 2/29/00