Report on Takawangha (United States) — 1 March-7 March 2023
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 1 March-7 March 2023
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2023. Report on Takawangha (United States) (Sennert, S, ed.). Weekly Volcanic Activity Report, 1 March-7 March 2023. Smithsonian Institution and US Geological Survey.
51.873°N, 178.006°W; summit elev. 1449 m
All times are local (unless otherwise noted)
AVO reported that the earthquake swarm at Takawangha that began in November 2022 was ongoing with 120 earthquakes located during 25 February-3 March. The number of events per day was highest on 28 February and 1 March, with over 50 earthquakes located on each of those days. Three earthquakes had magnitudes greater than 3, occurred at shallow depths of less than 6 km, and were located about 6 km E of the volcano. During 3-7 March small daily earthquakes with magnitudes less than M2 occurred in the vicinity of the volcano. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale).
Geological Summary. Takawangha is a youthful volcano with an ice-filled caldera on northern Tanaga Island, near the western end of the Andreanof Islands. It lies across a saddle from historically active Tanaga volcano to the west; older, deeply eroded volcanoes lie adjacent to the east. The summit of the dominantly basaltic to basaltic-andesite volcano is largely ice covered, with the exception of five Holocene craters that during the last few thousand years produced explosive eruptions and lava flows that reached the lower flanks. No historical eruptions are known, although radiocarbon dating indicates explosive eruptions have occurred within the past several hundred years.