USGS Volcano Notice for Aviation - DOI-USGS-AVO-2023-08-17T07:56:06-08:00

(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20230817/1659Z)
(3) Volcano:	Aniakchak (VNUM #312090)
(4) Current Color Code:	GREEN
(5) Previous Color Code:	YELLOW
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:	2023/A1278
(8) Volcano Location:	N 56 deg 54 min W 158 deg 12 min
(9) Area:	Alaska Peninsula
(10) Summit Elevation:	4400 ft (1341 m)
(11) Volcanic Activity Summary:	The number of earthquakes beneath Aniakchak volcano and the measurable uplift of the ground surface in the caldera have declined to background levels. Due to these changes, the Alaska Volcano Observatory is lowering the Aviation Color Code to GREEN and the Volcano Alert Level to NORMAL. There have been no signs of unrest in other monitoring data. AVO monitors Aniakchak with a local network, which consists of six seismometers, a web camera, and a single infrasound sensor, as well as satellite remote sensing data and regional infrasound and lightning networks. To view current monitoring data, see https://avo.alaska.edu/activity/Aniakchak.php
(12) Volcanic cloud height:	none
(13) Other volcanic cloud information:	none
(14) Remarks:	Aniakchak volcano, located in the central portion of the Alaska Peninsula, consists of a stratovolcano edifice with a 10 km (6 mile) diameter summit caldera. The caldera-forming eruption occurred around 3,500 years ago. Postcaldera eruptions have produced lava domes, tuff cones, and larger spatter and scoria cone structures including Half-Cone and Vent Mountain all within the caldera. The most recent eruption occurred in 1931 and created a new vent and lava flows on the western caldera floor while spreading ash over much of southwestern Alaska. Aniakchak volcano is 25 km (15 miles) southeast of the nearest community, Port Heiden, and 670 km (416 miles) southwest of Anchorage, Alaska.
(15) Contacts:	Matt Haney, Scientist-in-Charge, USGS mhaney@usgs.gov (907) 786-7497 David Fee, Coordinating Scientist, UAFGI dfee1@alaska.edu (907) 378-5460
(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.