(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20090212/0111Z)
(3) Volcano:	Shishaldin (VNUM #311360)
(4) Current Color Code:	GREEN
(5) Previous Color Code:	YELLOW
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:	2009/A4
(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:	The Alaska Volcano Observatory is lowering the Aviation Color Code to GREEN and the Alert Code to NORMAL at Shishaldin volcano. Seismic levels at Shishaldin volcano have decreased to background levels and have been at this level since late December 2008. A very weak thermal anomaly was last detected on February 3, 2009. Reports of steam issuing from the summit crater continue to be received although this is not anomalous activity at this volcano; steaming is typical.
(12) Volcanic cloud height:
(13) Other volcanic cloud information:
(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 10 miles (16 km). A small summit crater typically emits a noticeable steam plume with occasional small amounts of ash. Shishaldin is one of the most active volcanoes in the Aleutian volcanic arc, erupting atleast 28 times since 1775. Most of Shishaldin's eruptions have consisted of small ash and steam plumes, although the most recent eruption in April-May 1999 produced an ash column that reached a height of 45,000 ft above sea level.
(15) Contacts:	Tom Murray, Scientist-in-Charge, USGS tlmurray@usgs.gov (907) 786-7497 Steve McNutt, Coordinating Scientist, UAF steve@giseis.alaska.edu (907) 474-7131
(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: NORMAL
Previous Volcano Alert Level: ADVISORY

Current Aviation Color Code: GREEN
Previous Aviation Color Code: YELLOW

Issued: Wednesday, February 11, 2009, 4:11 PM AKST
Source: Alaska Volcano Observatory
Notice Number: 2009/A4
Location: N 54 deg 45 min W 163 deg 58 min
Elevation: 9373 ft (2857 m)
Area: Aleutians

Volcanic Activity Summary:
The Alaska Volcano Observatory is lowering the Aviation Color Code to GREEN and the Alert Code to NORMAL at Shishaldin volcano.

Seismic levels at Shishaldin volcano have decreased to background levels and have been at this level since late December 2008. A very weak thermal anomaly was last detected on February 3, 2009. Reports of steam issuing from the summit crater continue to be received although this is not anomalous activity at this volcano; steaming is typical.



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 10 miles (16 km). A small summit crater typically emits a noticeable steam plume with occasional small amounts of ash. Shishaldin is one of the most active volcanoes in the Aleutian volcanic arc, erupting atleast 28 times since 1775. Most of Shishaldin's eruptions have consisted of small ash and steam plumes, although the most recent eruption in April-May 1999 produced an ash column that reached a height of 45,000 ft above sea level.

Contacts:
Tom Murray, Scientist-in-Charge, USGS
tlmurray@usgs.gov (907) 786-7497

Steve McNutt, Coordinating Scientist, UAF
steve@giseis.alaska.edu (907) 474-7131

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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