|Duration of observation:||2003 - 2010|
|Inferred cause of deformation:||Magmatic|
|Characteristics of deformation:|
Deformation observed at Fourpeaked covers both the Douglas and Fourpeaked areas. InSAR measurements show broad inflation of this region between 2003–2010, with deformation mostly vertical. This deformation is modelled by a Mogi source of poorly constrained depth (5 – 10 km). Fixing the depth to that of local seismicity (7 km) yields an average rate of volume change of ~0.004 km³/year. Deformation is attributed to magmatic intrusion (possibly episodic), or isostatic rebound as the ice cap thins and recedes.
|Reference:||Lu, Z., and Dzurisin, D., 2014, InSAR imaging of Aleutian volcanoes: Chichester, UK, Springer-Praxis, 390 p.|
|Reference:||U.S. Geological Survey Alaska Volcano Observatory (AVO) website|
Photo of Fourpeaked. Source: B. Shavelson, U.S. Geological Survey AVO website