Temporal Magnetotellurics Reveals Mechanics of the 2012 Mount Tongariro, NZ, Eruption

0525107 - GFÚ 2021 RIV US eng J - Journal Article
Hill, Graham J. - Bibby, H. M. - Peacock, J. - Wallin, E. L. - Ogawa, Y. - Caricchi, L. - Keys, H. - Bennie, S. L. - Avram, Y.
Temporal Magnetotellurics Reveals Mechanics of the 2012 Mount Tongariro, NZ, Eruption.
Geophysical Research Letters. Roč. 47, č. 8 (2020), č. článku e2019GL086429. ISSN 0094-8276. E-ISSN 1944-8007
Grant - others:AV ČR(CZ) LQ100121901
Program: Prémie Lumina quaeruntur
Institutional support: RVO:67985530
Keywords : magnetotellurics * Taupo Volcanic Zone * eruption dynamics * Tongariro
OECD category: Geology
Impact factor: 4.720, year: 2020
Method of publishing: Open access
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL086429

Monitoring dynamics of volcanic eruptions with geophysics is challenging. In August and November 2012, two small eruptions from Mount Tongariro provided a unique opportunity to image subsurface changes caused by the eruptions. A detailed magnetotelluric survey of the Tongariro volcanic complex completed prior to the eruption (2008-2010) provides the preeruption structure of the magmatic system. A subset of the initial measurement locations was reoccupied in June 2013. Significant changes were observed in phase tensor data at sites close to the eruptive center. Although subsurface electrical resistivity changed, the geometry of the preeruptive reservoir did not. These subsurface resistivity variations are interpreted as being predominantly caused by interaction of partial melt and the overlying brine layer causing volume reduction of the brine layer through phreatic eruption. The ability to detect significant changes associated with the magma reservoir suggests that magnetotellurics can be a valuable volcano monitoring tool.
Permanent Link: http://hdl.handle.net/11104/0309318