(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20161221/0220Z)
(3) Volcano:	Bogoslof (VNUM #311300)
(4) Current Color Code:	RED
(5) Previous Color Code:
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:
(8) Volcano Location:	N 53 deg 55 min W 168 deg 2 min
(9) Area:	Aleutians
(10) Summit Elevation:	492 ft (150 m)
(11) Volcanic Activity Summary:	A short-lived explosive eruption of Bogoslof volcano was reported by several pilots around 0100 UTC (4:00 pm AST). They reported a volcanic ash cloud rising to an estimated altitude of 34,000 ft (10.3 km). Satellite data show a discrete, short-lived explosion just prior to 0100 UTC that detached and drifted to the south by 0115 UTC. A subsequent pilot report from 0150 UTC indicated that activity had decreased. On the basis of this information, the Aviation Color Code is increased to Red and the Volcano Alert Level to Warning. There is no ground-based volcano monitoring equipment on Bogoslof volcano so AVO is unable to provide a forecast of future eruptive activity. We will monitor satellite images and data from distant seismic and infrasound instruments for indications of significant explosive activity.
(12) Volcanic cloud height:	34,000 ft
(13) Other volcanic cloud information:	Height based on pilot report.
(14) Remarks:
(15) Contacts:	Michelle Coombs, Scientist-in-Charge, USGS mcoombs@usgs.gov (907) 786-7497 Janet Schaefer, Acting Coordinating Scientist, UAFGI janet.schaefer@alaska.gov (907) 322-4085
(16) Next Notice:

---

AVO/USGS Volcanic Activity Notice

Volcano: Bogoslof (VNUM #311300)

Current Volcano Alert Level: WARNING

Current Aviation Color Code: RED

Issued: Tuesday, December 20, 2016, 5:20 PM AKST
Source: Alaska Volcano Observatory
Notice Number:
Location: N 53 deg 55 min W 168 deg 2 min
Elevation: 492 ft (150 m)
Area: Aleutians

Volcanic Activity Summary: A short-lived explosive eruption of Bogoslof volcano was reported by several pilots around 0100 UTC (4:00 pm AST). They reported a volcanic ash cloud rising to an estimated altitude of 34,000 ft (10.3 km). Satellite data show a discrete, short-lived explosion just prior to 0100 UTC that detached and drifted to the south by 0115 UTC. A subsequent pilot report from 0150 UTC indicated that activity had decreased.

On the basis of this information, the Aviation Color Code is increased to Red and the Volcano Alert Level to Warning. There is no ground-based volcano monitoring equipment on Bogoslof volcano so AVO is unable to provide a forecast of future eruptive activity. We will monitor satellite images and data from distant seismic and infrasound instruments for indications of significant explosive activity.

Recent Observations:
[Volcanic cloud height] 34,000 ft
[Other volcanic cloud information] Height based on pilot report.

Hazard Analysis:
[Ash cloud] Ash cloud observed moving towards the south in satellite data through 0115 UTC.
[Ashfall] None expected in populated areas.

Contacts: Michelle Coombs, Scientist-in-Charge, USGS
mcoombs@usgs.gov (907) 786-7497

Janet Schaefer, Acting Coordinating Scientist, UAFGI
janet.schaefer@alaska.gov (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.

---