Overview of the seismic unrest in early March 2023 at Tanaga Island, which includes Takawangha and Tanaga volcanoes. The seismic data highlights the timing and amplitude of the largest earthquakes in the sequence. Thousands of earthquakes occurred during the time shown in the figure, but most were small and are not visible at the scale of the figure. Elevated earthquake activity under the volcanoes began in the fall of 2022 but increased dramatically on 8 March 2023. Earthquake locations during the swarm migrated from beneath Takawangha to beneath Tanaga and shallowed, increasing the likelihood that the activity could lead to an eruption and prompting AVO to increase the Aviation Color Code/Alert Level to ORANGE/WATCH. Earthquake rate and magnitude remained elevated through 12 March 2023 and then began to decline slowly. No signs of unrest were detected in other data streams. The decline in earthquake activity and lack of additional signs of unrest decreased the potential for an eruption so AVO lowered the Aviation Color Code/Alert Level to YELLOW/ADVISORY on 16 March.

Date:	March 16, 2023 10:00 AM AKDT
Volcano(es):	Takawangha, Tanaga
Photographer/Creator:	Lyons, John
URL:	http://www.avo.alaska.edu/images/image.php?id=194165