| Volcano number: | 312090 |
|---|---|
| Region: | Alaska |
| Country: | United States |
| Geodetic measurements? | Yes |
| Deformation observation? | Yes |
| Measurement method(s): | InSAR |
| Duration of observation: | 1992 - 2010 |
| Inferred cause of deformation: | Hydrothermal, Magmatic |
| Characteristics of deformation: |
InSAR measurements show that the caldera floor of Aniakchak volcano has subsided. The rate of subsidence decreased from ~12 mm/yr during 1992 – 2000 to ~8 mm/yr during 2000 – 2005 and ~6 mm/yr during 2005 – 2010. The deformation is modelled by a point source at shallow depth (2 – 4 km). Evidence from melt inclusions show that this is equal to preeruptive magma storage depths at the volcano. Subsidence may therefore be due to crystallisation or fluid loss from a shallow magma body. Another possible cause is a decrease in pore fluid pressure due to cooling or fluid loss from the hydrothermal system. |
| References: | 'Kwoun, Oh-Ig, Lu, Zhong, Neal, Christina, and Wicks, Charles Jr., 2006, Quiescent deformation of the Aniakchak Caldera, Alaska, mapped by InSAR: Geology, v. 34, n. 1, p. 5-8.', '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 \nhttp://www.avo.alaska.edu/volcanoes/volcinfo.php?volcname=Aniakchak' |
| Location: | -158.17, 56.88 |
