Ischia

Volcano number:	211030
Region:	Mediterranean and Western Asia
Country:	Italy
Geodetic measurements?	Yes
Deformation observation?	Yes
Measurement method(s):	Levelling
Duration of observation:	Unknown
Inferred cause of deformation:	Surface deposits, Faulting/tectonics
Characteristics of deformation:	Sepe et al. (2007) present levelling surveys carried out between 1990 and 2003 on the Mt Epomeo resurgent block (Ischia Island). They record negative dislocations on its northern and southern flanks with a maximum subsidence rate of 1.27 cm yr⁻¹. The authors show that deformation is not associated with the cooling, crystallization or lateral drainage of magma and cannot be explained by a pressure point or prolate ellipsoid source. The results show that the subsidence is due to crack closure processes along two main ENE–WSW and E–W preexisting faults, which represent the preferred pathway of CO₂ degassing from the hydrothermal system located beneath Mt Epomeo.
References:	'Sepe, V., Atzori, S., & Ventura, G. (2007). Subsidence due to crack closure and depressurization of hydrothermal systems: a case study from Mt Epomeo (Ischia Island, Italy). Terra Nova, 19(2), 127-132.', 'Smithsonian Institution Global Volcanism Program \nhttp://www.volcano.si.edu/volcano.cfm?vn=211030'
Location:	13.897, 40.73