Ontake-san volcano today (image: Kaidakogen webcam)
The Japan Meteorological Agency (JMA) detected an elevated seismic activity over the past month.
On 23 February, earthquakes and tremor picked up in numbers located beneath the Crater 79-7.
4 minutes later, a volcanic tremor signal was detected associated with a ground uplift on the S flank.
Therefore, the alert level for the volcano was raised to Level 2.
Source: Japan Meteorological Agency volcano activity update 21 March 2022
Satellite image of Ontake-san volcano on 11 March (image: Sentinel 2)