As the Pacific Ring Of Fire and the world enters its 24th day without a major quake volcano activity is having no such problems with the Kilauea volcano, State of Hawaii, USA, Mt Merapi Volcano Central Java, Indonesia and the Fuego Volcano Guatemala all causing havoc this month, the Great Sitkin Volcano, Alaska has joined in on the act.
Earthquake activity at Great Sitkin Volcano has been elevated over the past five days, and earlier today at 11:39 AKDT (19:39 UTC), a signal that may represent a short-lived steam explosion was detected by seismic data.
AVO is thus raising the Aviation Color Code and Alert Level to YELLOW/ADVISORY.
Great Sitkin Volcano is monitored by a five-station seismic network on Great Sitkin Island and with additional seismic stations on the nearby islands of Igitkin, Adak, Kagalaska, and Kanaga.
A six-element infrasound array to detect explosions (atmospheric pressure waves) was installed on Adak Island in June 2017, although it is currently (June 2018) only partly operational.
AVO also uses satellite imagery to monitor Great Sitkin Volcano.