| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20210512/2113Z) |
| (3) Volcano: | Veniaminof (VNUM #312070) |
| (4) Current Color Code: | UNASSIGNED |
| (5) Previous Color Code: | YELLOW |
| (6) Source: | Alaska Volcano Observatory |
| (7) Notice Number: | 2021/A247 |
| (8) Volcano Location: | N 56 deg 11 min W 159 deg 23 min |
| (9) Area: | Alaska Peninsula |
| (10) Summit Elevation: | 8225 ft (2507 m) |
| (11) Volcanic Activity Summary: | No eruptive activity at Veniaminof has been observed in satellite or infrasound data since early April. The Alaska Volcano Observatory is downgrading the Aviation Color Code and Volcano Alert Level from YELLOW/ADVISORY to UNASSIGNED/UNASSIGNED. The UNASSIGNED status is a result of several seismic station outages impairing the ability of the AVO to assess seismic unrest at the volcano. These stations may come back online as snowpack decreases. Any eruptive activity or unrest may still be detected with the remaining seismic stations, in regional infrasound networks, through detection of lightning, and/or monitoring of satellite images. Eruptive activity at Veniaminof usually consists of minor ash emissions, lava fountaining and lava flows from the small cone in the summit caldera. Ash emissions are typically confined to the summit crater, but larger events can result in ash fall in nearby communities and drifting airborne ash. |
| (12) Volcanic cloud height: | n/a |
| (13) Other volcanic cloud information: | n/a |
| (14) Remarks: | Mount Veniaminof volcano is an andesitic stratovolcano with an ice-filled 10-km diameter summit caldera located on the Alaska Peninsula, 775 km (480 mi) southwest of Anchorage and 35 km (22 mi) north of Perryville. Veniaminof is one of the largest (~300 cubic km; 77 cubic mi) and most active volcanic centers in the Aleutian Arc and has erupted at least 14 times in the past 200 years. Recent eruptions in 1993-95, 2005, 2013, and 2018 all occurred at the intracaldera cone and lasted for several months. These eruptions produced lava spattering and fountaining, minor emissions of ash and gas, and small lava flows into intracaldera icefield. Minor ash-producing explosions occurred nearly annually between 2002 and 2010. Previous historical eruptions have produced ash plumes that reached 15,000 to 20,000 ft above sea level (1939, 1956, and 2018) and ash fallout that blanketed areas within about 40 km (25 mi) of the volcano (1939, 2018). |
| (15) Contacts: | Michelle Coombs, Scientist-in-Charge, USGS mcoombs@usgs.gov (907) 786-7497 David Fee, Coordinating Scientist, UAF dfee1@alaska.edu (907) 322-4085 |
| (16) Next Notice: | A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu |