AVO Semisopochnoi ORANGE/WATCH – Nothing noteworthy seen in cloudy satellite data or regional infrasound

Aug 22, 2019 20:18 – No eruptive activity was observed in cloudy satellite imagery or regional infrasound over the past day. Local seismic data is currently offline. It remains possible for unrest to escalate rapidly with little to no warning.

Semisopochnoi is monitored with an on-island seismic network and remotely by satellite and lightning sensors. An infrasound array on Adak Island may detect explosive emissions from Semisopochnoi with a slight delay (approximately 13 minutes) if atmospheric conditions permit.