Description: From Dixon and others (2015): "In July and August [2013], AVO duty personnel responded to observations from a USFWS crew conducting ornithology work on Gareloi Island. The initial reports were of 'tremors of a magnitude that were noticeable to crews working outside, moving around.' A check of the seismicity showed no unusual activity. The background activity at Gareloi, since seismic station installation in 2003, has been constant low-level seismicity consisting of low-frequency earthquakes at a rate of one per minute. In light of the 2008 evacuation of a USFWS crew at Kasatochi and the subsequent eruption of Kasatochi (Waythomas and others, 2010), AVO closely monitored seismicity at Gareloi during the late summer. Despite close scrutiny, no changes were noted in the seismicity, nor were there further observations of felt events. Although the cause of the felt earthquakes was not determined, the felt reports were forwarded to AVO offices a week after a July 7 ML=5.5 earthquake and aftershock sequence south of Gareloi. The felt reports did not include event timing, and the most plausible explanation is that the USFW crew felt regional earthquakes and not volcano-related seismicity.
"The USFW crew also noted 'steam coming from the extensive fumarole area on the west peak' on July 30. Although this was a single observation, the field crew additionally commented that the weather on July 30 was unusually clear and allowed for the observation of steaming (fig. 47 in original text). Steaming at fumaroles on Gareloi is routinely seen, with observations of steaming in 2003 and 2005 (Michelle Coombs, USGS/AVO, written commun., 2005)."