| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20200908/2152Z) |
| (3) Volcano: | Makushin (VNUM #311310) |
| (4) Current Color Code: | GREEN |
| (5) Previous Color Code: | YELLOW |
| (6) Source: | Alaska Volcano Observatory |
| (7) Notice Number: | |
| (8) Volcano Location: | N 53 deg 53 min W 166 deg 55 min |
| (9) Area: | Aleutians |
| (10) Summit Elevation: | 5906 ft (1800 m) |
| (11) Volcanic Activity Summary: | Seismicity at Makushin Volcano has been steadily declining for months, following an earthquake sequence that began on June 15, 2020. This earthquake sequence was focused within an area about 6 miles (10 km) east of the summit at a depth of about 5 miles (8 km). Current observations indicate seismic activity has returned to background levels, and thus the Aviation Color Code and the Volcano Alert Level are being decreased to GREEN/NORMAL. Other data streams showed no signs of surface changes during the seismic sequence that started in June. The volcano is monitored with a network of seismic instruments, web camera, GPS, satellite data, and regional infrasound and lightning detection instruments. |
| (12) Volcanic cloud height: | n/a |
| (13) Other volcanic cloud information: | n/a |
| (14) Remarks: | Makushin volcano is located on northern Unalaska Island in the eastern Aleutian Islands. Makushin is a broad, ice-capped stratovolcano which rises to an elevation of 6680 feet. The summit caldera, 3 km diameter, is the site of frequent steam and minor ash eruptions; however, no large eruptions have occurred in this century. The community of Unalaska and port of Dutch Harbor are located 25 km (16 miles) east of Makushin volcano. |
| (15) Contacts: | Michelle Coombs, Scientist-in-Charge, USGS mcoombs@usgs.gov (907) 786-7497 David Fee, Coordinating Scientist, UAFGI dfee1@alaska.edu (907) 322-4085 |
| (16) Next Notice: | |