Report on Soputan (Indonesia) — 30 July-5 August 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
30 July-5 August 2003
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2003. Report on Soputan (Indonesia). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 30 July-5 August 2003. Smithsonian Institution and US Geological Survey.
1.112°N, 124.737°E; summit elev. 1785 m
All times are local (unless otherwise noted)
Activity decreased at Soputan after an eruption occurred on 18 July. During 21-25 July, incandescent lava on the volcano's W slope gradually cooled and on 22 July volcanic tremor stopped. Ash explosions sporadically occurred, but their density and maximum height decreased. Small-amplitude tremor was continuously recorded. As of 25 July the Alert Level at Soputan was at 2 (on a scale of 1-4).
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 the only active cone in the Sempu-Soputan volcanic complex, which includes the Soputan caldera, Rindengan, and Manimporok (3.5 km ESE). Kawah Masem maar was formed in the W part of the caldera and contains a crater lake; sulfur has been extracted from fumarolic areas in the maar since 1938. Recent eruptions have originated at 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.