Report on Soputan (Indonesia) — 1 July-7 July 2015
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
1 July-7 July 2015
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2015. Report on Soputan (Indonesia). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 1 July-7 July 2015. Smithsonian Institution and US Geological Survey.
1.112°N, 124.737°E; summit elev. 1785 m
All times are local (unless otherwise noted)
PVMBG reported that during June-3 July white plumes were observed rising as high as 750 m above Soputan even though inclement weather sometimes obscured crater views. Seismicity during the previous three months had declined (specifically shallow volcanic earthquakes, volcanic earthquakes, and signals indicating emissions and avalanches) but remained higher than levels recorded prior to the elevated activity which lead to the Alert Level increase on 26 December 2014. Low-frequency harmonic tremor was occasionally detected. The Alert Level was lowered to 2 (on a scale of 1-4). Residents and tourists were advised not to approach the craters within a radius of 4 km, or 6.5 km on the WSW flank.
Geological Summary. 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 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.