Observations of Deformation

Volcano number:311350
Country:United States
Geodetic measurements?Yes
Deformation observation?Yes
Measurement method(s):InSAR, GPS - campaign
Duration of observation:1992 - 2000, 2003 - 2010
Inferred cause(s) of deformation:Hydrothermal, Magmatic, Uncertain
Characteristics of deformation:

GPS and InSAR measurements show that Fisher caldera has subsided at ~15 mm/yr between 1992 – 2010. Subsidence is modelled equally well by point, sill, and spheroid sources at depths of 4.5 – 7.5 km. The best fitting sill is 7 – 11 km long, 0.7 – 2.0 km wide and strikes N35° – 55º. Subsidence is attributed to cooling and crystallisation of magma intruded prior to the first deformation measurements. An alternative source would be a reduction of pore fluid pressure due to cooling of the hydrothermal system.

Reference(s):Mann, Dorte, and Freymueller, J., 2003, Volcanic and tectonic deformation on Unimak Island in the Aleutian Arc, Alaska: Journal of Geophysical Research, v. 108, n. 2, p. 1-12.
Lu, Z., and Dzurisin, D., 2014, InSAR imaging of Aleutian volcanoes: Chichester, UK, Springer-Praxis, 390 p.
U.S. Geological Survey Alaska Volcano Observatory (AVO) website
Location:54.65, -164.43
REST API endpoint (JSON):

Latest Sentinel-1 Data

Filename: fisher_124A_03521_060410.jpg
Size: 501px x 660px (151.65 KB)
Filename: fisher_044D_03605_070807.jpg
Size: 501px x 669px (160.35 KB)
Filename: fisher_044D_03600_070805.jpg
Size: 501px x 668px (161.51 KB)