|(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)|
|(3) Volcano:||Shishaldin (VNUM #311360)|
|(4) Current Color Code:||ORANGE|
|(5) Previous Color Code:||RED|
|(6) Source:||Alaska Volcano Observatory|
|(7) Notice Number:||2020/A63|
|(8) Volcano Location:||N 54 deg 45 min W 163 deg 58 min|
|(10) Summit Elevation:||9373 ft (2857 m)|
|(11) Volcanic Activity Summary:||Ash emissions declined greatly at about 8:30 PM AKST (5:30 UTC 20 January). Seismicity is currently low. The Aviation Color Code is lowered to ORANGE and Alert Level to WATCH.
Satellite images show the detached volcanic cloud drifting east-southeast over the Pacific Ocean. A sigmet from the National Weather Service is still in effect for the detached cloud: https://www.weather.gov/aawu/sigmets
Low-level steam and ash emissions may be ongoing from the summit vent. It is possible for more significant eruption to resume with little warning.
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:||na|
|(13) Other volcanic cloud information:||na|
|(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
firstname.lastname@example.org (907) 786-7497
David Fee, Coordinating Scientist, UAFGI
email@example.com (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|