Temporal magnetotellurics reveals mechanics of the 2012 Mount Tongariro, NZ eruption

Geophysical Research Letters
By: , and 

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Abstract

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.

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Publication type Article
Publication Subtype Journal Article
Title Temporal magnetotellurics reveals mechanics of the 2012 Mount Tongariro, NZ eruption
Series title Geophysical Research Letters
DOI 10.1029/2019GL086429
Volume 47
Issue 8
Year Published 2020
Language English
Publisher American Geophysical Union
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description e2019GL086429, 9 p.
Country New Zealand
Other Geospatial Mount Tongariro
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