Event Name : Semisopochnoi 2018/09
|Start:||September 16, 2018 ||Observed|Description:
AVO raised the Aviation Color Code and Volcano Alert Level at Semisopochnoi to YELLOW/ADVISORY on September 16, 2018, citing an increase in seismicity, beginnnig at 16:31 UTC (08:31 AKDT). On September 17, 2018, strong tremor increased at 20:49 UTC (12:49 AKDT), suggesting ash emissions may be occurring or imminent. AVO raised the Aviation Color Code and Volcano Alert Level to ORANGE/WATCH at 21:33 UTC (13:33 AKDT).