Mount Ontake

On 27^th September at 11:52 JST, Mount Ontakesan (also known as Ontake) erupted without warning. Mount Ontake is Japan’s second highest volcano (3067m). The first historical eruption occurred in 1979 measuring a VEI 2. Between 1999 and 2007 very minor phreatic activity occurred.

This year’s eruption was phreatic in nature and followed on from seismic tremor and uplift which were detected just 11 minutes before the eruption. The eruption measured a VEI 3. According the Global Vocalism Program, there was a temporary increase in seismic activity near the summit between 10^th and11^th September and on the 14^th September low frequency signals were detected.

 The eruption on the 27^th ejected an ash plume which reached heights 7 to 10km and ash fall affected the area in the vicinity, measuring 50cm in thickness around the crater. The deadly pyroclastic flow which was responsible for the fatalities travelled 3km down the south flank of the volcano.

57 fatalities occurred, 70 were injured and a further 6 are still missing. Search and rescue efforts to find the missing have been suspended due to winter and will resume in spring.

Since the event numerous photographs of the eruption taken by the victims in their last moments have been discovered.

The Alert Level has been raised to 3 (on a scale of 1 to 5) since the eruption and remains a 3.

 Izumi Noguchi took this photo moments before he was killed by the pyroclastic flow

 Izumi Noguchi took this photo moments before he was killed by the pyroclastic flow

 Izumi Noguchi was one of the 57 fatalities