Report on Colo (Indonesia) — 24 June-30 June 2015
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 24 June-30 June 2015
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2015. Report on Colo (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 24 June-30 June 2015. Smithsonian Institution and US Geological Survey.
0.162°S, 121.601°E; summit elev. 404 m
All times are local (unless otherwise noted)
PVMBG reports that seismicity significantly increased on 8 June, particularly volcanic and shallow-volcanic earthquakes; 12 volcanic earthquakes were recorded on 22 June (previously, 1-5 events per day had been recorded), and there were 11 shallow volcanic earthquakes on 23 June (previously, 1-8 events per day had been recorded). On 24 June the Alert Level was raised to 2 (on a scale of 1-4). However, observers at the Colo Volcano Observation Post in the Wakai village did not see plumes during April-23 June. Residents and tourists were warned not to approach the volcano within a radius of 1.5 km.
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.