Field crews from the Alaska Volcano Observatory are performing seasonal maintenance on seismic monitoring equipment at Aniakchak Volcano. Enough local stations have been brought online to locate volcanic earthquakes and detect any potential activity above background at the volcano. As a result, the Aviation Color Code and Volcano Alert Level are being changed to GREEN/NORMAL.
Aniakchak volcano, located in the central portion of the Alaska Peninsula, consists of a stratovolcano edifice with a 6 mile (10 km) diameter summit caldera. The caldera-forming eruption occurred around 3,500 years ago. Post-caldera 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 16 miles (26 km) southeast of the nearest community, Port Heiden, and 416 miles (670 km) southwest of Anchorage, Alaska. It is located in Aniakchak National Monument and Preserve.
Matt Haney, Scientist-in-Charge, USGS, mhaney@usgs.gov, (907) 786-7497
Tarsilo Girona, Acting Coordinating Scientist, UAFGI, tarsilo.girona@alaska.edu, (907) 378-5460
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.