Volcano number:312260
Country:United States
Geodetic measurements?Yes
Deformation observation?Yes
Measurement method(s):InSAR
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
Location:-153.672, 58.77

Photo of Fourpeaked. Source: B. Shavelson, U.S. Geological Survey AVO website