Event Name : Aniakchak 2009/2
|Start:||February 27, 2009 ||Observed|
|Stop:||June 3, 2009 ||Observed|
|Seismicity with no confirmed eruption: ||
|Eruption Type:||Not an eruption.|
From McGimsey and others (2014): "Following several episodes of anomalous seismicity in 2008 (Neal and others, 2011), deep, low-frequency seismic events continued to be recorded at Aniakchak Volcano through the first half of 2009 while the seismic network was still operating. On February 27 and 28, 12 low-frequency events were recorded that had magnitudes of ML 1.0-2.1 and hypocentral depths of about 15-28 km (9.3-17.4 mi), and another sequence of events occurred on March 4 with one locatable low frequency event about 7 km (4.4 mi) depth (Scott Stihler, U.S. Geological Survey, written commun., 2011). Another burst of low-frequency events occurred at Aniakchak on June 3, 2009.
"By September 2009, chronic station outages and data interruption prompted AVO to include Aniakchak in the list of four volcanoes considered for downgrading to UNASSIGNED. On November 17, AVO issued a Volcanic Activity Notice and an Information Statement formally declaring that Aniakchak and three other volcanoes: Veniaminof, Fourpeaked, and Korovin were no longer seismically monitored due to seismic station outages, and thus were changed from volcano alert level NORMAL and Aviation Color Code GREEN to UNASSIGNED. Two seismic stations at Aniakchak became operational by December 8, 209, but would again go out in early 2010. The network would eventually become operational again during the summer of 2010."