2007 Volcanic activity in Alaska, Kamchatka, and the Kurile Islands: Summary of events and response of the Alaska Volcano Observatory

Abstract

The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, and volcanic unrest at or near nine separate volcanic centers in Alaska during 2007. The year was highlighted by the eruption of Pavlof, one of Alaska's most frequently active volcanoes. Glaciated Fourpeaked Mountain, a volcano thought to have been inactive in the Holocene, produced a phreatic eruption in the autumn of 2006 and continued to emit copious amounts of steam and volcanic gas into 2007. Redoubt Volcano showed the first signs of the unrest that would unfold in 2008-09. AVO staff also participated in hazard communication and monitoring of multiple eruptions at seven volcanoes in Russia as part of its collaborative role in the Kamchatka and Sakhalin Volcanic Eruption Response Teams.

Crustal structure along the Aleutian island arc: New insights from receiver functions constrained by active‐source data

“…Akutan volcano is one of the more active volcanoes within the Aleutians, with 31 eruptions since 1790 most recently in 1992, as well as subsequent seismicity, inflation, and steaming [ McGimsey et al ., ]. A seismic swarm in March 1996, inferred to have been at least in part caused by a magma intrusion, had epicenters between near‐sea level to about 8 km in depth [ Lu et al ., ].…”

Regional controls on volcano seismicity along the Aleutian arc

“…Of the 142 known Quaternary volcanic centers, 94 have been active in the Holocene [ Cameron , ]. Eruption style varies greatly along the arc and in the past 10 years alone has included (for example) 24 h of violently explosive activity at Kasatochi Volcano in 2008 [ Waythomas et al ., ], 31 days of strombolian activity at Pavlof Volcano in 2007 [ McGimsey et al ., ], 5 weeks of sustained phreatomagmatic activity at Okmok Caldera in 2008 [ McGimsey et al ., ], and more than 2 months of both ash explosions and lava effusion at Augustine Volcano in 2006 [ Power et al ., ].…”

Modeling Magma System Evolution During 2006–2007 Volcanic Unrest of Atka Volcanic Center, Alaska

“…The dilatant fault may serve as a sink (on the order of 10 5 m 3 ) for the groundwater at Atka, similar to the process proposed at Kilauea (Hurwitz & Johnston, 2003) and Mayon (Albano et al., 2001) volcanoes. Considering that there is an active hydrothermal system ∼2–3 km beneath Atka revealed by a previous InSAR study (Lu & Dzurisin, 2014) and the geological records (McGimsey et al., 2007, 2011; Neal et al., 2008), the hydrothermal system at Korovin may connect to the Atka fault system through this shallow “hydrofluid zone” (Lu & Dzurisin, 2014). The water table at Korovin may drop due to water discharge (Figure 10d), which is consistent with the lake drainage event occurring between September and October 2006 (Neal et al., 2008).…”

“…The red circles and diamonds are the surface deformation calculated by the numerical models (i.e., Model II) with data assimilation. The unrest events, including steam plumes, tremors, and lake drainage are labeled as gray triangles, orange stars, and green boxes (McGimsey et al, 2007(McGimsey et al, , 2011Neal et al, 2008). (b) The numbers of VT earthquakes per day are shown as orange bars.…”