Report on Soputan (Indonesia) — May 1984
Scientific Event Alert Network Bulletin, vol. 9, no. 5 (May 1984)
Managing Editor: Lindsay McClelland
Soputan (Indonesia) Tephra eruption
Please cite this report as:
Global Volcanism Program, 1984. Report on Soputan (Indonesia). In: McClelland, L (ed.), Scientific Event Alert Network Bulletin, 9:5. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.SEAN198405-266030.
1.112°N, 124.737°E; summit elev. 1785 m
All times are local (unless otherwise noted)
Soputan erupted from 24 May at 2243 until 26 May at 0300. An ash column rose to 4 km and moved W. Ash and sand-sized tephra fell on the area W of the volcano, forming a deposit >10 cm thick over ~75 km and 1-10 cm thick over an additional 125 km. Although there were no people within the danger zone, ~3,000 were in the alert zone. About 350 spontaneously evacuated from the area, where the primary cultivation is of coconut palms. Manado and Gorontalo airports (~50 km NNE and ~200 km SW of Soputan) were closed 26 and 27 May.
As of 30 May, no volcanic earthquakes had been recorded, although two tectonic events were detected. No premonitory activity was observed.
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.
Information Contacts: A. Sudradjat, VSI.