Observations of Deformation
Volcano number: | 311350 |
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Region: | Alaska |
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 http://www.avo.alaska.edu/volcanoes/volcinfo.php?volcname=Fisher | |
Location: | 54.65, -164.43 |
REST API endpoint (JSON): | https://comet.nerc.ac.uk/wp-json/volcanodb/v1/volcano/889 |