(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20170112/2235Z)
(3) Volcano:	Bogoslof (VNUM #311300)
(4) Current Color Code:	ORANGE
(5) Previous Color Code:	ORANGE
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:	2017/A18
(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 second explosive event has been detected at Bogoslof volcano. An abrupt increase in seismicity began at about 21:35 UTC (12:35 AKST). Both events have been observed by pilots. The first event at 20:23 UTC produced an eruption cloud to 18,000 ft asl. The estimated height of the second event from 21:35 UTC was 14,500 ft asl. Neither eruption cloud has been visible yet in subsequent satellite data. The altitude of the meteorological cloud deck is variable from about 10,000 ft to 12,000 ft. Additional ash-producing eruptions may occur at any time with limited precursory unrest and little warning. AVO is monitoring the volcano closely and will provide additional information if and when it becomes available.
(12) Volcanic cloud height:	Two events: First 18,000 ft. Second 14,500 ft asl
(13) Other volcanic cloud information:	Height from pilot reports.
(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

Current Aviation Color Code: ORANGE

Issued: Thursday, January 12, 2017, 1:35 PM AKST
Source: Alaska Volcano Observatory
Notice Number: 2017/A18
Location: N 53 deg 55 min W 168 deg 2 min
Elevation: 492 ft (150 m)
Area: Aleutians

Volcanic Activity Summary: A second explosive event has been detected at Bogoslof volcano. An abrupt increase in seismicity began at about 21:35 UTC (12:35 AKST). Both events have been observed by pilots. The first event at 20:23 UTC produced an eruption cloud to 18,000 ft asl. The estimated height of the second event from 21:35 UTC was 14,500 ft asl. Neither eruption cloud has been visible yet in subsequent satellite data. The altitude of the meteorological cloud deck is variable from about 10,000 ft to 12,000 ft. Additional ash-producing eruptions may occur at any time with limited precursory unrest and little warning. AVO is monitoring the volcano closely and will provide additional information if and when it becomes available.

Recent Observations:
[Volcanic cloud height] Two events: First 18,000 ft. Second 14,500 ft asl
[Other volcanic cloud information] Height from pilot reports.

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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