An ash cloud to 4.5 km altitude was reported in an aviation notice on 15 March. Imagery from the GMS-5 satellite confirmed the presence of an eruption plume during 0425-0632 GMT. A small plume can be seen on the 0425 image, but there was a definite plume with arms extending W and SW by 0532. The plume was still connected to the volcano at 0632, although it was starting to dissipate. On the 0732 image the plume was still visible, but appeared to have been disconnected from the volcano for some time.

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.

Information Contacts: Bureau of Meteorology, P.O. Box 735, Darwin NT 0801, Australia; Ian Sprod, Code 921, NASA Goddard Space Flight Center, Greenbelt MD 20771, USA.