Sentinel-1 satellite radar interferogram spanning March 8–20, 2023, Tanaga Island. The color bands, or fringes, near the northwestern coast of the island show surface deformation suggestive of magma intrusion below Sajaka volcano and consistent with earthquake activity. Figure by Ronni Grapenthin, UAFGI/AVO.

Sentinel-1 satellite radar interferogram spanning March 8–20, 2023, Tanaga Island. The color bands, or fringes, near the northwestern coast of the island show surface deformation suggestive of magma intrusion below Sajaka volcano and consistent with earthquake activity. Figure by Ronni Grapenthin, UAFGI/AVO.

Date: Mar 20th, 2023
Volcano(es): Tanaga
Photographer: Grapenthin, Ronni
URL: avo.alaska.edu/image/view/194281

Tanaga unrest 2023

On Tuesday, March, 7, 2023, AVO elevated the Aviation Color Code and Volcano Alert Level at Tanaga to YELLOW/ADVISORY, stating "earthquake activity beneath Tanaga Volcano began to increase slowly starting at about 1:30 pm AKST today. At roughly 8:45 pm AKST this evening, the activity escalated with earthquakes occurring as often as 2 or 3 each minute. Initial locations of these earthquakes place them at shallow depths beneath the summit of Tanaga Volcano, and the largest of these earthquakes have magnitudes between 2 and 3."
On Thursday, March 9, 2023, AVO elevated Tanaga again to ORANGE/WATCH, stating "Over the past 24 hours, earthquake activity near Tanaga Volcano has been elevated and continues. This sustained activity indicates an increased potential for eruption at the volcano.*** Seismic activity is also elevated at Takawangha volcano, which is about 8 km (5 mi) east of Tanaga on Tanaga Island. If an eruption were to occur, it is uncertain at this stage if it would come from Tanaga or Takawangha."

Image courtesy of the AVO/UAF-GI.
Please cite the photographer and the Alaska Volcano Observatory / University of Alaska Fairbanks, Geophysical Institute when using this image.
Full Resolution.