Report on Colo (Indonesia) — October 1983
Scientific Event Alert Network Bulletin, vol. 8, no. 10 (October 1983)
Managing Editor: Lindsay McClelland.
Colo (Indonesia) July- August explosion times, plume heights, and photos
Please cite this report as:
Global Volcanism Program, 1983. Report on Colo (Indonesia). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 8:10. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198310-266010.
0.162°S, 121.601°E; summit elev. 404 m
All times are local (unless otherwise noted)
A VSI team monitored the eruption from near the island [beginning 23 July, and observed 22 distinct explosions (table 2). Many, but not all of these explosions were detected by satellite (table 1).]
|Date||Time||Plume height (km)|
|23 Jul 1983||1623||10|
|25-26 Jul 1983||2325-0021||7.5|
|27 Jul 1983||0400-0605||7.5|
|27 Jul 1983||1500-2010||7|
|28 Jul 1983||0002-0045||8|
|28 Jul 1983||1630-1730||8|
|30 Jul 1983||1615-?||6|
|01 Aug 1983||1834-2000||7|
|01-02 Aug 1983||2130-0230||6|
|02 Aug 1983||0314-0600||8|
|02 Aug 1983||0800-0900||8|
|02-03 Aug 1983||1905-0200||5|
|04 Aug 1983||0915-1100||6|
|06 Aug 1983||1520-?||6|
|07 Aug 1983||1100-1900||10|
|11 Aug 1983||1115-1135||8|
|12 Aug 1983||0047-0147||9|
|18 Aug 1983||1013-1240||12|
|22 Aug 1983||1203-?||8|
|24 Aug 1983||2148-2220||4|
|25 Aug 1983||1847-2000||5.5|
|26 Aug 1983||1023-1139||10|
Maurice Krafft visited Una Una in mid-Aug. He observed and photographed the 22 Aug explosion (table 2 and figure 3) and pyroclastic flow deposits from previous explosions (figure 4). The entire island had been devastated except for a narrow strip of undamaged vegetation and villages along the E coast.
|Figure 3. Explosion photographed from the S on 22 August 1983. Pyroclastic flows from this explosion continued 500 m beyond the SSW coast of the island and 1 km beyond the NNW coast. Courtesy of Maurice Krafft.|
Further Reference. Katili, J.A., and Sudradjat, A., 1984, The devastating 1983 eruption of Colo volcano, Una Una Island, central Sulawesi, Indonesia: Geologisches Jahrbuch, v. A75, p. 27-47.
Geologic Background. 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. Only three eruptions have been recorded in historical time, but two of those caused widespread damage over much of the island. The last eruption, in 1983, produced pyroclastic flows that swept over most of the island shortly after all residents had been evacuated.
Information Contacts: A. Sudradjat, VSI; M. Krafft, Cernay.