USGS Volcano Notice for Aviation - DOI-USGS-AVO-2024-01-02T10:41:08-09:00

(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20240102/2033Z)
(3) Volcano:	Shishaldin (VNUM #311360)
(4) Current Color Code:	YELLOW
(5) Previous Color Code:	ORANGE
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:	2024/A5
(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:	Volcanic activity at Shishaldin Volcano has gradually declined over the past two months since the last significant explosive event on November 3, 2023. Small explosions within the summit crater continue to be detected in infrasound data during periods of quiet (low wind) conditions but new deposits have not recently been seen inside or outside the crater. Satellite-observed surface temperatures remain low, suggesting lava is not present in the crater. The current activity is consistent with continued volcanic unrest but not an active eruption. Thus, the Aviation Color Code and the Volcano Alert Level are being decreased to YELLOW/ADVISORY. Shishaldin Volcano is monitored by local seismic and infrasound sensors, web cameras, and a telemetered geodetic network. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lighting data, and satellite images to detect eruptions.
(12) Volcanic cloud height:	none observed
(13) Other volcanic cloud information:	intermittent steaming continues
(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 660 ft. (200 m) wide 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 26 confirmed eruptions since 1824. Most eruptions are relatively small, although the April-May 1999 event generated an ash column that reached 45,000 ft. (14 km) above sea level.
(15) Contacts:	Dave Schneider, Acting Scientist-in-Charge, USGS djschneider@usgs.gov (907) 786-7497 David Fee, Coordinating Scientist, UAFGI dfee1@alaska.edu (907) 378-5460
(16) Next Notice: