Ez-response as a monitor of a Baikal rift fault electrical resistivity: 3D modelling studies

Autor: I. L. Trofimov, V. S. Shneyer, D. B. Avdeev, A. V. Kuvshinov, O. V. Pankratov
Jazyk: angličtina
Rok vydání: 2004
Předmět:
Zdroj: Annals of Geophysics, Vol 47, Iss 1 (2004)
Druh dokumentu: article
ISSN: 1593-5213
2037-416X
DOI: 10.4401/ag-3267
Popis: 3D numerical studies have shown that the vertical voltage above the Baikal deep-water fault is detectable and that respective transfer functions, Ez-responses, are sensitive to the electrical resistivity changes of the fault, i.e. these functions appear actually informative with respect to the resistivity «breath» of the fault. It means that if the fault resistivity changed, conventional electromagnetic instruments would be able to detect this fact by measurement of the vertical electric field, Ez, or the vertical electric voltage just above the fault as well as horizontal magnetic field on the shore. Other electromagnetic field components (Ex, Ey, Hz) do not seem to be sensitive to the resistivity changes in such a thin fault (as wide as 500 m). On the other hand, such changes are thought to be able to indicate a change of a stress state in the earthquake preparation zone. Besides, the vertical profile at the bottom of Lake Baikal is suitable for electromagnetic monitoring of the fault electrical resistivity changes. Altogether, the vertical voltage above the deep-water fault might be one of earthquake precursors.
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