The Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) issued a special report for Awu, noting increased seismicity over a two-day period. On 18 June the seismic network recorded 55 shallow volcanic earthquakes and during 0000-1800 on 19 June the network recorded 81 shallow volcanic earthquakes, three deep volcanic earthquakes, and one low-frequency earthquake. The Alert Level remained at 2 (on a scale of 1-4) and PVMBG reminded the public to stay 3 km away from the crater’s center.

Geological Summary. The massive Gunung Awu stratovolcano occupies the northern end of Great Sangihe Island, the largest of the Sangihe arc. Deep valleys that form passageways for lahars dissect the flanks of the volcano, which was constructed within a 4.5-km-wide caldera. Powerful explosive eruptions in 1711, 1812, 1856, 1892, and 1966 produced devastating pyroclastic flows and lahars that caused more than 8000 cumulative fatalities. Awu contained a summit crater lake that was 1 km wide and 172 m deep in 1922, but was largely ejected during the 1966 eruption.

Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)