PVMBG reported that a phreatic eruption at Sirung was recorded at 1644 on 21 July. A white-and-gray ash plume rose 2 km above the summit and drifted N. The report noted that the event was preceded by an increase in tremor amplitude that lasted about 10 hours; no volcanic earthquakes indicating magma movement were recorded and tremor amplitude did not notably increase. The Alert Level was raised to 2 (on a scale of 1-4), with visitors and tourists prohibited within a 1.5 km radius of Sirung.
Source: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM)
Syndicated from Smithsonian / USGS Weekly Volcanic Activity Report