Introducing inter-site phase tensors to suppress galvanic distortion in the telluric method


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Date

2015-09-30

Publication Type

Journal Article

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yes

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Abstract

A common problem when interpreting magnetotelluric (MT) data is that they often are distorted by shallow unresolvable local structures, an effect known as galvanic distortion. We present two transfer functions that are (almost) resistant to galvanic distortion. First, we introduce the electric phase tensor, which is derived from the electric tensor, where the electric tensor relates the horizontal electric fields at a field and base site. The electric phase tensor is only affected by galvanic distortion, if present, at the base site. Second, we introduce the quasi-electric phase tensor, which is derived from the quasi-electric tensor, where the quasi-electric tensor relates the electric field at a field site with the magnetic field at a base site. The quasi-electric tensor is not affected by galvanic distortion. Using a synthetic data-set, we show that the sensitivity of the MT phase tensor, the quasi-electric phase tensor, and the electric phase tensor is comparable for our model under consideration. Furthermore, we demonstrate that stable (quasi-) electric phase tensors can be recovered from a real data-set with the use of existing processing software. In addition, we provide a formalism to propagate the uncertainties from the estimated (quasi-) electric and impedance tensors to their respective phase tensors. The uncertainties of the (quasi-) electric phase tensors are of the same order of magnitude as the uncertainties of the MT phase tensor. From our study, we conclude that the (quasi-) electric phase tensors are an attractive complement to the standard MT responses.

Publication status

published

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Volume

67 (1)

Pages / Article No.

160

Publisher

SpringerOpen

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Edition / version

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Subject

Magnetotellurics; Inter-site response functions; (quasi-) electric phase tensors

Organisational unit

09494 - Saar, Martin O. / Saar, Martin O. check_circle
03734 - Jackson, Andrew / Jackson, Andrew check_circle

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