(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20200107/2133Z)
(3) Volcano:	Shishaldin (VNUM #311360)
(4) Current Color Code:	RED
(5) Previous Color Code:	ORANGE
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:	2020/A7
(8) Volcano Location:	N 54 deg 45 min W 163 deg 58 min
(9) Area:	Aleutians
(10) Summit Elevation:	9373 ft (2857 m)
(11) Volcanic Activity Summary:	Ash eruption at Shishaldin continues and has intensified as shown in satellite and lightning data. Satellite data suggest the ash cloud is as high as 27,000 ft asl and drifting east-northeast. Aviation Color Code is RED and Alert Level is WARNING. The National Weather Service has issued a SIGMET for this activity (https://www.weather.gov/aawu/). It is possible for the current activity to intensify or decrease with little warning. AVO will issue further information as warranted. Shishaldin is monitored by local seismic and infrasound sensors, satellite data, a web camera, a telemetered geodetic network, and distant infrasound and lightning networks.
(12) Volcanic cloud height:	Up to 27,000 ft asl
(13) Other volcanic cloud information:	Drifting ENE
(14) Remarks:	Shishaldin volcano, located near the center of Unimak Island in the eastern Aleutian Islands, is a spectacular symmetric cone with a base diameter of approximately 16 km (10 mi). A 200-m-wide (660 ft) funnel-shaped summit crater typically emits a steam plume and occasional small amounts of ash. Shishaldin is one of the most active volcanoes in the Aleutian volcanic arc, with at least 54 episodes of unrest including over 24 confirmed eruptions since 1775. Most eruptions are relatively small, although the April-May 1999 event generated an ash column that reached 45,000 ft above sea level.
(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:	A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu

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AVO/USGS Volcanic Activity Notice

Volcano: Shishaldin (VNUM #311360)

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

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

Issued: Tuesday, January 7, 2020, 12:33 PM AKST
Source: Alaska Volcano Observatory
Notice Number: 2020/A7
Location: N 54 deg 45 min W 163 deg 58 min
Elevation: 9373 ft (2857 m)
Area: Aleutians

Volcanic Activity Summary: Ash eruption at Shishaldin continues and has intensified as shown in satellite and lightning data. Satellite data suggest the ash cloud is as high as 27,000 ft asl and drifting east-northeast. Aviation Color Code is RED and Alert Level is WARNING.

The National Weather Service has issued a SIGMET for this activity (https://www.weather.gov/aawu/).

It is possible for the current activity to intensify or decrease with little warning. AVO will issue further information as warranted.

Shishaldin is monitored by local seismic and infrasound sensors, satellite data, a web camera, a telemetered geodetic network, and distant infrasound and lightning networks.

Recent Observations:
[Volcanic cloud height] Up to 27,000 ft asl
[Other volcanic cloud information] Drifting ENE

Remarks: Shishaldin volcano, located near the center of Unimak Island in the eastern Aleutian Islands, is a spectacular symmetric cone with a base diameter of approximately 16 km (10 mi). A 200-m-wide (660 ft) funnel-shaped summit crater typically emits a steam plume and occasional small amounts of ash. Shishaldin is one of the most active volcanoes in the Aleutian volcanic arc, with at least 54 episodes of unrest including over 24 confirmed eruptions since 1775. Most eruptions are relatively small, although the April-May 1999 event generated an ash column that reached 45,000 ft above sea level.

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

David Fee, Coordinating Scientist, UAFGI
dfee1@alaska.edu (907) 322-4085

Next Notice: A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu

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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