The number of volcanic earthquakes at Azumayama increased on 5 May and data from a tiltmeter about 1 km SE of Ohana Crater showed inflation on 9 May, prompting JMA to raise the Alert Level to 2 (on a 5-level scale).
Field observations on 7 and 10 May indicated no changes in the fumarolic and thermal areas around Ohana.
Seismicity began to decrease on 10 May, though continued to fluctuate through 20 May.
Deformation continued but at a slower rate.
Source: Japan Meteorological Agency (JMA)