Robust error on magnetotelluric impedance estimates

Pierre Wawrzyniak (1) , Pascal Sailhac (2) , Guy Marquis (3)

1 IPGS - Institut de physique du globe de Strasbourg
2 IPGS-GE - Géophysique expérimentale (IPGS)
3 Shell Houston

We propose here a new, robust, methodology to estimate the errors on a magnetotelluric (MT) impedance tensor. This method is developed with the bounded influence remote-reference processing (BIRRP) code in a single site configuration. The error is estimated by reinjecting an electric field residual obtained after the calculation of an impedance tensor into a tensor function calculation procedure. We show using synthetic examples that the error tensor calculated with our method yields a more reliable error estimate than the one calculated from Jackknife statistics. The modulus of realistic error estimates can be used as a quality control and an accurate inversion constraint of MT surveys. Moreover, reliable error estimates are necessary for new applications of MT to dynamic subsurface processes such as reservoir monitoring.

Mots clés: Electromagnetics; Passive methods; Monitoring; Data processing; Signal processing

Domaines: Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]; Milieux et Changements globaux

Pierre Wawrzyniak, Pascal Sailhac, Guy Marquis. Robust error on magnetotelluric impedance estimates. Geophysical Prospecting, 2013, 61, pp.533-546. ⟨10.1111/j.1365-2478.2012.01094.x⟩. ⟨hal-00930099⟩