(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20161221/0605Z)
(3) Volcano:	Bogoslof (VNUM #311300)
(4) Current Color Code:	ORANGE
(5) Previous Color Code:	RED
(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:	The explosive eruption of Bogoslof volcano that occurred today at about 00:35 UTC (3:35 pm AKST) was short-lived, lasting approximately 30 minutes, and produced a detached ash cloud that rose to 34,000 ft (10.3 km) above sea level as reported by several pilots. A subsequent pilot report from 01:50 UTC (4:30 pm AKST) indicated that activity had decreased and the cloud was dispersing. The ash cloud was carried southward over the Gulf of Alaska and no ash fell on inhabited areas. No further explosions have been detected in seismic and infrasound networks indicating that the activity has subsided. No activity is apparent in recent nighttime satellite images. On the basis of this information, the Aviation Color Code is lowered to ORANGE and the Volcano Alert Level to WATCH. AVO has no ground-based volcano monitoring equipment on Bogoslof volcano and 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. Some previous eruptions of Bogoslof have lasted for weeks to months, and further explosive activity could occur with little warning. Mariners in the area should use caution.
(12) Volcanic cloud height:	None currently observed
(13) Other volcanic cloud information:	Unknown
(14) Remarks:
(15) Contacts:	Michelle Coombs, Scientist-in-Charge, USGS mcoombs@usgs.gov (907) 786-7497 Janet Schaefer, Acting Coordinating Scientist, DGGS janet.schaefer@alaska.gov (907) 322-4085
(16) Next Notice:

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AVO/USGS Volcanic Activity Notice

Volcano: Bogoslof (VNUM #311300)

Current Volcano Alert Level: WATCH
Previous Volcano Alert Level: WARNING

Current Aviation Color Code: ORANGE
Previous Aviation Color Code: RED

Issued: Tuesday, December 20, 2016, 9:05 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: The explosive eruption of Bogoslof volcano that occurred today at about 00:35 UTC (3:35 pm AKST) was short-lived, lasting approximately 30 minutes, and produced a detached ash cloud that rose to 34,000 ft (10.3 km) above sea level as reported by several pilots. A subsequent pilot report from 01:50 UTC (4:30 pm AKST) indicated that activity had decreased and the cloud was dispersing. The ash cloud was carried southward over the Gulf of Alaska and no ash fell on inhabited areas. No further explosions have been detected in seismic and infrasound networks indicating that the activity has subsided. No activity is apparent in recent nighttime satellite images.

On the basis of this information, the Aviation Color Code is lowered to ORANGE and the Volcano Alert Level to WATCH. AVO has no ground-based volcano monitoring equipment on Bogoslof volcano and 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.

Some previous eruptions of Bogoslof have lasted for weeks to months, and further explosive activity could occur with little warning. Mariners in the area should use caution.

Recent Observations:
[Volcanic cloud height] None currently observed
[Other volcanic cloud information] Unknown

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

Janet Schaefer, Acting Coordinating Scientist, DGGS
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.

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