(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued: (20210420/0022Z)
(3) Volcano: Tanaga (VNUM #311080)
(4) Current Color Code: GREEN
(5) Previous Color Code: UNASSIGNED
(6) Source: Alaska Volcano Observatory
(7) Notice Number: 2021/A175
(8) Volcano Location: N 51 deg 53 min W 178 deg 8 min
(9) Area: Aleutians
(10) Summit Elevation: 5925 ft (1806 m)
(11) Volcanic Activity Summary: Communication with two seismic stations has been reestablished. With four local seismic stations active, the Alaska Volcano Observatory can resume locating earthquakes and detect unrest at Tanaga. The Aviation Color Code is now GREEN and the Volcano Alert Level is now designated as NORMAL.

Any eruptive activity or unrest may also still be detected in regional infrasound networks, through detection of lightning, and/or monitoring of satellite images.
(12) Volcanic cloud height: Unknown
(13) Other volcanic cloud information: Unknown
(14) Remarks:
(15) Contacts: Aaron Wech, Acting Scientist-in-Charge, USGS
awech@usgs.gov (907) 786-7497

Jessica Larsen, Acting Coordinating Scientist, UAF
jflarsen@alaska.edu (907) 322-4085
(16) Next Notice:

AVO/USGS Volcanic Activity Notice

Volcano: Tanaga (VNUM #311080)

Current Volcano Alert Level: NORMAL
Previous Volcano Alert Level: UNASSIGNED

Current Aviation Color Code: GREEN
Previous Aviation Color Code: UNASSIGNED

Issued: Monday, April 19, 2021, 4:22 PM AKDT
Source: Alaska Volcano Observatory
Notice Number: 2021/A175
Location: N 51 deg 53 min W 178 deg 8 min
Elevation: 5925 ft (1806 m)
Area: Aleutians

Volcanic Activity Summary: Communication with two seismic stations has been reestablished. With four local seismic stations active, the Alaska Volcano Observatory can resume locating earthquakes and detect unrest at Tanaga. The Aviation Color Code is now GREEN and the Volcano Alert Level is now designated as NORMAL.

Any eruptive activity or unrest may also still be detected in regional infrasound networks, through detection of lightning, and/or monitoring of satellite images.


Recent Observations:
[Volcanic cloud height] Unknown
[Other volcanic cloud information] Unknown

Contacts: Aaron Wech, Acting Scientist-in-Charge, USGS
awech@usgs.gov (907) 786-7497

Jessica Larsen, Acting Coordinating Scientist, UAF
jflarsen@alaska.edu (907) 322-4085

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.