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Report on Colo (Indonesia) — September 1983

Scientific Event Alert Network Bulletin, vol. 8, no. 9 (September 1983)
Managing Editor: Lindsay McClelland.

Colo (Indonesia) Satellite observations of July-August eruption clouds

Please cite this report as:

Global Volcanism Program, 1983. Report on Colo (Indonesia). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 8:9. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198309-266010.

Volcano Profile |  Complete Bulletin


Colo

Indonesia

0.162°S, 121.601°E; summit elev. 404 m

All times are local (unless otherwise noted)


Since late August, no explosions have been reported by ground observers or seen on satellite imagery. Yosihiro Sawada searched all July and August images from the GMS satellite and provided table 1.

Table 1. Una Una eruption cloud data extracted from GMS satellite images. Data are tentative; some apparent plumes may have been weather clouds. Times are the beginnings of image scans, which are completed in about 25 minutes. Images are returned 14 times/day at intervals ranging from 30 minutes to 3 hours. New explosions are indicated in the remarks column. Data shown in parentheses are for plumes that are detached from the volcano because explosive activity had (apparently) stopped. A new plume was sometimes ejected before remnants of the previous explosive pulse had dissipated; dimensions of the old plume are then listed in parentheses below data on the new activity. Coldest temperatures at the tops of plumes are shown. Courtesy of Yosihiro Sawada.

Date Time Length (km) Width (km) Temp (°C) Comment
23 Jul 1983 1631 100 90 -74 --
23 Jul 1983 1801 -- -- -76 --
23 Jul 1983 1831 320 200 -- --
23 Jul 1983 1931 560 180 -- --
25 Jul 1983 2331 30 30 -70 New explosion
26 Jul 1983 0131 210 160 -- --
26 Jul 1983 0431 (520) (160) -- --
27 Jul 1983 1931 60 20 -- New explosion
28 Jul 1983 0131 160 20 -- --
28 Jul 1983 0431 170 50 -- --
28 Jul 1983 0631 290 70 -- --
28 Jul 1983 0731 260 40 -- --
28 Jul 1983 1031 500 70 -- --
28 Jul 1983 1331 550 60 -- --
28 Jul 1983 1631 710 80 -- --
28 Jul 1983 1831 650 70 -- --
28 Jul 1983 1931 500 30 -- --
28 Jul 1983 2331 (340) (20) -- --
30 Jul 1983 1631 80 40 -73 New explosion
30 Jul 1983 1801 -- -- -80 --
30 Jul 1983 1831 260 110 -- --
30 Jul 1983 1931 370 120 -- --
30 Jul 1983 2331 190 (340) 50 (320) -- New explosion
31 Jul 1983 0131 250 130 -- --
31 Jul 1983 0431 (260) (100) -- --
31 Jul 1983 1801 -- -- -70 New explosion
31 Jul 1983 1831 60 30 -71 --
31 Jul 1983 1901 -- -- -71 --
31 Jul 1983 1931 160 50 -71 --
31 Jul 1983 2331 (150) (80) -- --
01 Aug 1983 0131 (160) (110) -- --
01 Aug 1983 0431 (130) (50) -- --
02 Aug 1983 0431 70 50 -72 --
02 Aug 1983 0601 -- -- -65 --
02 Aug 1983 0631 160 70 -63 --
02 Aug 1983 0701 -- -- -72 --
02 Aug 1983 0731 240 80 -75 --
02 Aug 1983 1031 420 100 -79 --
02 Aug 1983 1331 50 (340) 15 (240) -60 New explosion
02 Aug 1983 1631 60 (420) 20 (320) -56 --
02 Aug 1983 1831 (130) (20) -- --
02 Aug 1983 1931 (450) (320) -- --
02 Aug 1983 2331 80 30 -71 --
03 Aug 1983 0131 (120) (60) -- --
03 Aug 1983 0431 (110) (20) -- --
03 Aug 1983 0631 (130) (15) -- --
04 Aug 1983 1031 80 40 -73 --
04 Aug 1983 1331 150 110 -73 --
04 Aug 1983 1631 190 120 -63 --
04 Aug 1983 1831 (190) (160) -- --
04 Aug 1983 1931 (210) (130) -- --
04 Aug 1983 2331 90 100 -79 New explosion
05 Aug 1983 0131 170 100 -81 --
05 Aug 1983 0431 280 200 -73 --
05 Aug 1983 0601 -- -- -61 --
05 Aug 1983 0631 170 170 -60 --
05 Aug 1983 0701 -- -- -64 --
05 Aug 1983 0731 30 30 -70 New explosion
05 Aug 1983 1031 60 60 -61 --
05 Aug 1983 1331 100 90 -63 --
05 Aug 1983 0131 30 20 -64 --
06 Aug 1983 0131 30 20 -64 New explosion
06 Aug 1983 0431 110 60 -- --
06 Aug 1983 0631 190 90 -- --
06 Aug 1983 0731 200 130 -- --
06 Aug 1983 1631 60 50 -73 New explosion
06 Aug 1983 1801 -- -- -69 --
06 Aug 1983 1831 110 70 -- --
06 Aug 1983 1931 (130) (80) -- --
07 Aug 1983 1331 190 80 -75 New explosion
07 Aug 1983 1631 320 110 -79 --
07 Aug 1983 1801 -- -- -77 --
07 Aug 1983 1831 190 150 -75 --
07 Aug 1983 1931 240 160 -- --
07 Aug 1983 2331 150 70 -- --
08 Aug 1983 0131 (190) (60) -- --
08 Aug 1983 0431 30 15 -- New explosion
08 Aug 1983 0631 60 15 -- --
08 Aug 1983 0731 (70) (20) -- --
10 Aug 1983 0131 30 20 -- (obscure)
10 Aug 1983 0431 30 10 -- (obscure)
10 Aug 1983 0631 50 15 -- (obscure)
11 Aug 1983 1331 290 80 -69 --
11 Aug 1983 1631 (510) (110) -- --
11 Aug 1983 1831 (680) (160) -- --
12 Aug 1983 0131 140 60 -73 New explosion
12 Aug 1983 0431 460 100 -- --
22 Aug 1983 1331 20 15 -- (obscure)
22 Aug 1983 1631 150 110 -- (obscure)
22 Aug 1983 1831 (260) (110) -- --
22 Aug 1983 1931 (300) (140) -- --
26 Aug 1983 1331 -- -- -- New explosion; almost circular plume
26 Aug 1983 1631 -- -- -- Cloud detected

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: Y. Sawada, MRI, Tsukuba.