Report on Soputan (Indonesia) — 13 October-19 October 2004
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 13 October-19 October 2004
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2004. Report on Soputan (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 13 October-19 October 2004. Smithsonian Institution and US Geological Survey.
1.112°N, 124.737°E; summit elev. 1785 m
All times are local (unless otherwise noted)
According to DVGHM, volcanic tremor at Soputan began to increase to levels above normal on 18 October at 0930. In response, officials raised the Alert Level to Orange or 2 (on a scale of 1-4). Soputan erupted on 18 October at 1041, producing an E-drifting ash cloud to a height of ~600 m above the volcano's crater. At 1815 incandescence was visible reflecting 25-30 m above the crater's rim. Later that day, a "lava avalanche" traveled towards the S.
According to a news report, "ash and smoke" covered several parts of the nearby Minahasa regency and damaged hundreds of plantations along the mountain's slopes. Also, clouds of ash disrupted activities of residents in W Langowan district, where visibility fell to between 10 and 30 m. An official in the district said local homes were covered by up to 4 cm of ash. In the town of Palu, visibility decreased to 7 km. No evacuations were ordered.
Geologic Background. The Soputan stratovolcano on the southern rim of the Quaternary Tondano caldera on the northern arm of Sulawesi Island is one of Sulawesi's most active volcanoes. The youthful, largely unvegetated volcano rises to 1784 m and is located SW of Riendengan-Sempu, which some workers have included with Soputan and Manimporok (3.5 km ESE) as a volcanic complex. It was constructed at the southern end of a SSW-NNE trending line of vents. During historical time the locus of eruptions has included both the summit crater and Aeseput, a prominent NE-flank vent that formed in 1906 and was the source of intermittent major lava flows until 1924.