Premium
Depressurization of a hydrothermal system following the August and November 2012 Te Maari eruptions of Tongariro, New Zealand
Author(s) -
Hamling I. J.,
Williams C. A.,
Hreinsdóttir S.
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl067264
Subject(s) - geology , subsidence , cabin pressurization , volcano , phreatic , hydrothermal circulation , phreatic eruption , fumarole , lahar , geochemistry , magma , seismology , geomorphology , pyroclastic rock , groundwater , aquifer , geotechnical engineering , structural basin , aerospace engineering , engineering
In 2012, two phreatic eruptions occurred at New Zealand's Tongariro volcano for the first time in over a century. Interferometric Synthetic Aperture Radar data collected by the Italian Space Agency's COSMO‐SkyMed satellite constellation, indicates up to 20 mm/yr of post eruptive subsidence focused across a 4 km 2 region in the vicinity of the eruption site. Modeling of the deformation data indicates a shallow source at ∼500 m depth (1100 m asl) consistent with the depth of the hydrothermal system. We estimate an annual volume loss of 35,000 m 3 , leading to a pressure loss of ∼0.09 MPa/yr. We suggest that fracturing associated with the eruptions has enabled the continued depressurization of the shallow hydrothermal system and that subsidence will continue until the fractures become resealed.