Kusatsu-Shirane volcano (Honshu, Japan): increasing activity

JMA reported that at 0959 on 23 January an eruption began at Kusatsu-Shiranesan coincident with the onset of volcanic tremor; there were no indications of an impending eruption. The Alert Level was raised to 3 (on a scale of 1-5). Skiers at the popular ski resort Kusatsu Kokusai took video showing a plume of tephra and ejected bombs rising from a vent on the Motoshiranesan edifice, about 2 km SSE of Yagama Crater on Shiranesan (where all previous historical activity has been). ... Read all

During 5-12 December JMA maintained Alert Level 2 for Kusatsu-Shiranesan due to continued unrest. GPS measurements indicated inflation, although thermal anomalies had been absent since July. Volcanic earthquakes continued at a low level and tremor was absent. ... Read all