Earthquake activity near Takawangha Volcano has decreased in both rate and magnitude from the peak of the swarm on March 9–11 when over 150 earthquakes per day were located on Tanaga Island to less than 3 earthquakes per day in the last few weeks. Recent satellite images do not indicate any ongoing deformation on the island. No other signs of volcanic unrest have been detected. The Alaska Volcano Observatory is therefore lowering the Aviation Color Code to GREEN and the Volcano Alert Level to NORMAL.
The Alaska Volcano Observatory will continue to closely monitor seismic activity on Tanaga Island.
Takawangha is monitored with a local seismic network, a single local infrasound sensor, regional infrasound and lightning sensors, and satellite imagery.
For current monitoring data: https://avo.alaska.edu/activity/Takawangha.php
Takawangha is a remote, 1,449 m (4,754 ft)-high stratovolcano located on the northeast portion of Tanaga Island, roughly 95 km (59 miles) west of Adak in the Andreanof Islands. Takawangha's summit is mostly ice-covered, except for four young craters that have erupted ash and lava flows in the last few thousand years. Parts of Takawangha's edifice are hydrothermally altered and may be unstable, possibly leading to localized debris avalanches from its flanks. Takawangha lies across a saddle from historically active Tanaga volcano to the west. No historical eruptions are known from Takawangha; however, field work shows that recent eruptions have occurred, and it is possible that historic eruptions attributed to Tanaga may instead have come from Takawangha.
Kristi Wallace, Acting Scientist-in-Charge, USGS kwallace@usgs.gov (907) 786-7497
Pavel Izbekov, Acting Coordinating Scientist, UAFGI peizbekov@alaska.edu (907) 378-5460
The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.
| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20230719/0028Z) |
| (3) Volcano: | Takawangha (VNUM #311090) |
| (4) Current Color Code: | GREEN |
| (5) Previous Color Code: | YELLOW |
| (6) Source: | Alaska Volcano Observatory |
| (7) Notice Number: | 2023/A1093 |
| (8) Volcano Location: | N 51 deg 52 min W 178 deg 1 min |
| (9) Area: | Aleutians |
| (10) Summit Elevation: | 4754 ft (1449 m) |
| (11) Volcanic Activity Summary: |
Earthquake activity near Takawangha Volcano has decreased in both rate and magnitude from the peak of the swarm on March 9–11 when over 150 earthquakes per day were located on Tanaga Island to less than 3 earthquakes per day in the last few weeks. Recent satellite images do not indicate any ongoing deformation on the island. No other signs of volcanic unrest have been detected. The Alaska Volcano Observatory is therefore lowering the Aviation Color Code to GREEN and the Volcano Alert Level to NORMAL. The Alaska Volcano Observatory will continue to closely monitor seismic activity on Tanaga Island. Takawangha is monitored with a local seismic network, a single local infrasound sensor, regional infrasound and lightning sensors, and satellite imagery. For current monitoring data: https://avo.alaska.edu/activity/Takawangha.php |
| (12) Volcanic cloud height: | None observed |
| (13) Other volcanic cloud information: | None observed |
| (14) Remarks: | Takawangha is a remote, 1,449 m (4,754 ft)-high stratovolcano located on the northeast portion of Tanaga Island, roughly 95 km (59 miles) west of Adak in the Andreanof Islands. Takawangha's summit is mostly ice-covered, except for four young craters that have erupted ash and lava flows in the last few thousand years. Parts of Takawangha's edifice are hydrothermally altered and may be unstable, possibly leading to localized debris avalanches from its flanks. Takawangha lies across a saddle from historically active Tanaga volcano to the west. No historical eruptions are known from Takawangha; however, field work shows that recent eruptions have occurred, and it is possible that historic eruptions attributed to Tanaga may instead have come from Takawangha. |
| (15) Contacts: | Kristi Wallace, Acting Scientist-in-Charge, USGS kwallace@usgs.gov (907) 786-7497 Pavel Izbekov, Acting Coordinating Scientist, UAFGI peizbekov@alaska.edu (907) 378-5460 |
| (16) Next Notice: | |