Based on information from PVMBG and weather models, the Darwin VAAC reported that on 7 March an eruption at Soputan generated ash plumes that rose to an altitude of 9.1 km (30,000 ft) a.s.l. and drifted 260 km SE and SW. A thermal anomaly was detected in satellite images. BNPB noted that the eruption occurred at 1709, and produced ash plumes that rose 4.5 km above the crater and drifted E. Pyroclastic flows traveled 2.5 km down the W flank. Minor ashfall was reported in the Silian Raya district, Touluaan, Tombatu, and party in the districts of Pasan and Rataha. The Alert Level remained at 3 (on a scale of 1-4). The next day the VAAC noted that an ash plume rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted almost 95 km SE.

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.

Sources: Badan Nacional Penanggulangan Bencana (BNPB), Darwin Volcanic Ash Advisory Centre (VAAC)