Aniakchak reported activity

Event Name : Aniakchak 2008/3

Start:	March 8, 2008	Observed
Stop:	March 14, 2008 ± 2 Days	Observed

Seismicity with no confirmed eruption:

Description: Seismometers at Aniakchak Volcano appeared to record anomalous seismicty at Aniakchak during the spring of 2008. Further analysis revealed that the signals were a product of icing on the seismometers, and not of volcanic origin.

From Neal and others (2011): "AVO seismic analysts noted a swarm of seismic events at Aniakchak during routine seismic checks of Alaskan volcanoes on March 8. The activity continued intermittently over the next week with events occurring as frequently as 5-10 per hour. Interpreting the significance of the signals was hampered by the fact that only a single station in the Aniakchak network, ANNW, was operating at the time. AVO increased seismic watch frequency for Aniakchak in response and contemplated organizing a winter-time field visit to restore more of the seismic network.

"Subsequently, an evaluation of historical seismicity at Aniakchak during times of more complete network operation suggested that the anomalous signals were likely weather-related (Katrina Jacobs, AVO/UAFGI, written commun., 2008). Similar swarms had occurred on a number of occasions between 2005 and 2008, but none were typical multi-station volcanic events and all showed a strong correlation with time of day. Years of maintenance efforts at the Aniakchak network documented a strong vulnerability of sites to heavy icing that could have been responsible for the intermittent seismic signals. Based on this, an AVO field response was canceled."