Description: From McGimsey and others (2011): Akutan is one of several Alaska volcanoes at which seismicity was triggered by the M8.2 earthquake generated in the Kurile Islands on January 13, 2007, 0423 UTC. Four of the seven largest triggered Akutan events, ranging in magnitude from 0.0 to 0.5 and depths from 0.86 to -2.17 km, were located (see fig. 36 in original text; John Power, AVO/USGS, written commun., 2010). The earthquake locations fall along the trend of intense seismicity and ground breakage that occurred in March 1996 at Akutan (Neal and others, 1997; Waythomas and others, 1998, fig. 10; Lu and others, 2005). The AVO Akutan seismic network was installed in the summer of 1996, and this was the first instance of observed triggered seismicity at Akutan; however, it was short-lived and did not result in any detectable surface disturbance.
"In early October 2007, AVO remote sensors using GPS time series for Akutan detected signs of renewed inflation over the previous month of the west flank, the same area that inflated during the 1996 seismic crisis. A few days later, on October 8, the manager of the Trident seafood processing plant called to alert AVO of 'strong steaming' from a 'new' area in the Hot Springs Bay valley [see fig. 37 in original text]. Long-known thermal springs occur along the lower course of the stream draining the valley, and the photograph of figure 37 shows a steam column apparently rising from further up-valley of the springs area. This also is the area of maximum deflation following the 1996 seismic swarms. No unusual seismic activity was noted for the period of west-flank inflation or this steaming episode. This location for a steam plume was considered 'new' by local observers because the lower-valley thermal springs rarely emit a concentrated, vertically rising plume of steam and most reports of steaming arise from the prominent fumarole field located at the 1,500-ft-level of the eastern flank at the headwaters of Hot Springs Bay valley [see fig. 38 in original text]."