| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20210827/1724Z) |
| (3) Volcano: | Atka volcanic complex (VNUM #311160) |
| (4) Current Color Code: | GREEN |
| (5) Previous Color Code: | YELLOW |
| (6) Source: | Alaska Volcano Observatory |
| (7) Notice Number: | 2021/A710 |
| (8) Volcano Location: | N 52 deg 19 min W 174 deg 8 min |
| (9) Area: | Aleutians |
| (10) Summit Elevation: | 5030 ft (1533 m) |
| (11) Volcanic Activity Summary: | The Alaska Volcano Observatory is lowering the Aviation Color Code and Alert Level at the Atka volcanic complex to GREEN/NORMAL. On August 10, AVO detected an increase in small earthquakes, located between 6 and 2 km (4 and 1 miles) below sea level, about 5 km (3 miles) west of Kliuchef volcano within the Atka volcanic complex.. After several days of increased seismicity, the earthquake rate began to drop, and has subsequently returned to background levels. Previous alerts by the Alaska Volcano Observatory for unrest at the Atka volcanic complex have been for Korovin Volcano, the site of the most recent historical eruptions. The location of earthquakes, however, is not specific to Korovin and could be related to several other volcanic vents that are part of the Atka volcanic complex, including Mount Kliuchef. The Alaska Volcano Observatory will continue to monitor the Atka volcanic complex for signs of volcanic activity. The area is monitored by local seismic and infrasound sensors, satellite data, and regional lightning detection instruments. |
| (12) Volcanic cloud height: | n/a |
| (13) Other volcanic cloud information: | n/a |
| (14) Remarks: | |
| (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: | |